Plus:5th West Coast Computer Faire, an on-the -spot report

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US S2.00/F F8.80/L I RE 1700/DM 3.80/F L 4.00/BF 55 S Fr 3.50/Pts 135 DKr 10.75/SKr 7.65/NKr 8.25/A Sch 28
*11111 i]

World MAY 1980 50p
Coi;telk'AUe-T3FAI

BUTTONING -UP THE INFORMATION AGE
Plus:5th West Coast Computer Faire, an on -the -spot report

The best computers PLUS the best service

At MicroCentre, we're concentrating our resources on what we genuinely believe
are the very best computers available
today. . . . Cromemco computers, naturally. This way we can offer you the best deal
possible.

What we don't do
What we don't do is spread our
expertise thinly amongst umpteen different systems, or try to stock every S100 product
on the market. We don't claim to offer
"impartial" advice on the best buy. And we don't sell from price lists or catalogues.

The MicroCentre approach
Some micro -computer suppliers work like that, but we don't. Because we realise that when you're buying a computer you want more than the "brochures and boxes" approach. You want to see computers
running: to try them out with different
software products; to study the documentation; above all, you want expert answers to your most searching questions.
Cromemco specialists
That's why we've specialised in Cromemco systems. Not simply because we think Cromemco systems are the best serious computers available at the price.

Cromemco Model Z -2H hard disc computer. 10 megabyte hard disc, 2 floppy discs, Z-80 computer and 64K memory. MicroCentre price £5,326.

But because by doing so we can dedicate our time. energy and resources to giving you the highest standard of Cromemco support possible.

demonstration; expect the full range of Cromemco peripherals; single -user and multi-user systems: and interactive
graphics.

Demonstrations
So when you visit MicroCentre expect to
find Cromemco systems on permanent

Software
Expect a choice of operating systems and compilers to evaluate; expect complete documentation; and expect the largest collection of Cromemco systems software in the UK.

Expertise
Expect to find in-depth professional expertise at MicroCentre, the kind that is only acquired by installing Cromemco systems all over Britain. Expect a thorough appreciation of how Cromemco systems can be applied . . . in business, scientific research. industrial engineering, medicine and education.

Support
Expect to get frank, accurate answers to your questions at MicroCentre. Above all. once you've bought a Cromemco system from us, expect to get a very high standard
of technical support with your hardware enhancements and continuing software
needs.

MicroCentre's Cromemco demonstration room, with the full range of Cromemco computers, peripherals, operating systems and software products on permanent exhibition. Why not pay us a visit? We're only an hour's Shuttle flight from Heathrow!

At MicroCentre, simply expect the best.

For Cromemco... call the experts

MicroCentre NOW IN SPACIOUS
NEW SHOWROOMS

Tel. 031-556 7354

Complete Micro Systems Ltd., 30 Dundas Street, Edinburgh EH3 6JN

CONTENTS
Volume 3 No 5. May 1980

3&NEWSPRINT: Guy UKewney with, this
month, an additional Stateside supplement.
45COTMIOMN:UTNhIeClAett-ers
this month. 40 BEI%1CHTEST 1:
4141David Tebbutt
covers the Texas TI 99/4 Home Computer.
52 BENCHTEST 2: Sue Eisenbach reports on the Altos ACS 8000-2.
5e BENCHMARK
ROUND -UP: The timings for all machines tested since our September 1979 issue (plus a few more besides).
57 BENCHTEST 3: Guy Kewney casts an eye over Hewlett Packard's HP85.

7.7 HARD COPY/
SOFT PRICE: A DIY teleprinter conversion feature - by YCW contributor, Tim Steele.
COMPUTER GAMES: More complex evaluation functions - David Levy continues his series.
86 CALCULATOR CORNER EXTRA: Calc AI. . . Peter Brooks puts some thought into programmables.
88WAOVNEA-MNAASKCIONMG1:
Don Finlay describes a synthesis program - for acoustics or making music.
91PET PRINTER PEP -UP: J. C. Moore tells how he over-
came the problems he found with the CBM 3022 printer.

117 DIRECT ACCESS: Featuring IN STORE, TRANSACTION FILE, DIARY DATA and FAX
132 PROGRAMS As well as those in YCW, this month we offer a superb backgammon program that features excellent graphics.
13e LEISURE
JUNES: J. J.
Clessa talks turkey and includes the most disgraceful "Quickie" yet seen.
135 BLUNDERS: More "nasties" come creeping out of the woodwork.

60 POWERING -UP THE POST: PO or no PO, electronic mail is coming. David Hebditch evaluates some of the available modems.

92PASCAL: Sue Eisenbach and Chris Sadler explain some advanced programming
techniques.

63VIEWDATA: Part two of Adrian
Stokes' introduction to the Information Age.
67 COMPUTER ANSWERS: Sheridan Williams and friends handle another batch of reader problems.
71FAIRE PLAY: A special report, direct from the 5th West Coast Computer Faire. 74SYSTEMS: This month Mike Knight looks at Information Retrieval and Databases.
76CHECKOUT: John
Moore examines the Microdata UV8 EPROM Eraser.

96BOSOo KwhFaAt iRf iEt w: orks!

Cover illustration Tony McSweeney

Malcolm Peltu on writing

with elegance.

Founder

Angelo Zgorelec

101 RANDOM WRIT- Editor INGS RESUMED: Bruce Sawford

What to do with random numbers. Michael James picks up the threads of a previous article.

Technical Editor David Tebbutt Editorial Office: 01-637 7991/2/3

Consultants

John Coll, Mike Dennis,

106CACLOCRUNLEART: AOR

Michael James, David Hebditch, Sheridan Williams,

TI59 accountancy appli- Dr. Adrian Stokes, Dr.

cation. . . where a calc Stephen Castell.

provides a cost effective Advertisement Manager

alternative to the micro.

Stephen England (01-631 1786)

110 INTERRUPT: Watch out for monkey business! Also a warning to companies on accumulating micros.

Sales Executive Liz Banks (01-631 1786) Micromart Jacquie Hancock (01-631 1682)

11102 YOUNG COM-

Group Advertising Director Richard Howell (01-631

*NP PUTER WORLD: 3187)

Taken over from this

Production Manager

month by Derrick Daines. Dick Pountain

Art Director Paul Carpenter Art Assistants Jimmy Egerton, Julia Davies Typesetter Jane Hamnell Published by Sportscene Publishers (PCW) Ltd., 14 Rathbone Place, London W1P 1DE, England. rat: 01-637 7991/2/3. Telex: 8954139 A/B 'Bunch' G. London. Copyright notice Personal Computer World is published by Sportscene Publishers (PCW) Ltd. © 1980 Felden Prod-uctions. No material may be reproduced in whole or part without written consent from the copyright holders. Printed by Riverside Press, Whitstable. Distributed by Seymour Press Ltd., 334 Brixton Road, London SW9 7AG. PCW welcomes all unsolicited material (written, photographic and illustrative) and although no guarantee can be given as to its safe return, reasonable care and attention will be exercised.
Guidelines for contributors PCW welcomes articles of interest. Don't be put off if your style of writing is `under developed'. . . true worth lies in the content, and shaping features comes naturally to us! Manuscripts should not exceed 3,000 words and authors as asked to use triple-spaced lines with a wide left-hand margin; diagrams, listings and/or photographs should be included wherever possible. Please enclose a stamped, selfaddressed envelope if you would like your article returned.
Because of the foregoing, it is necessary to add that the views expressed in articles we publish are not necessarily those of Personal Computer World. Overall, however, the magazine will try to represent a balanced viewpoint.
Finally, before submitting an article, please check it through thoroughly for legibility and accuracy.
Subscription rates: Britain £8.00 for 12 issues, USA $2Q for 12 issues (surface ma g), Continent and elsewhere £9.80 for 12 issues. All prices include postage and packing. Supplies to specialist shops can be arranged by negotiation direct with the publishers.

PCW 1

PET 2001
from
mimm147.5
110 Cr commodore
authorised dealers
TRS 80 dmitm,,.. from
1118 1365
6;1Ifr
From Radio Shack Corp.
APPLE H from IWO

"pock & ITT 2020
authorised dealers
SORCEROR from 1740
7777,r

authorised dealers

COMPUCOLOR

from

only
1999

27-"*

for computer min colour monitor, keyboard end intesrat disk drive Second disk drive £316 .00

MICROCOMPUTERS ETC For Hardware, Software, Peripherals, Consultancy and Competitive Prices.

PET 3016 (16K RAM and large
keyboardl PET 3032 (32K RAM and large
keyboardr

BASIC SYSTEMS

PET 2001,8 (PET with 8K memory

£675.00 + integral cassette

£475.00

PET 3008 (8K) with large keyboard £475.00

£795.00 PET C2N External Cassette Deck

£53.00

ACCESSORIES

IEEE/RS232 Serial Interface 'A' Output only

IEEE-4413/Centronics type parallel £106.00 Interface

£45.00

IEEE/RS232 Serial Interface 'B'

IEEE to Pet Cable

£19.00

Input/Output

086.00 IEEE to IEEE cable

C24.00

Programmers Toolkit - 10 powerful new co rnm.nd. PETSET 1 16 Channel AD Convertor

for your Pet - plug in ROM chip 8K and 16/ 32K resp

c.w. all interfacing requirements £166.00

TRS 80, 4K Level I consisting of

BASIC SYSTEMS TRS 80, 16K Level II (as above with

Keyboard with 4K memory, Video

16K memory)

Unit, Cassette Drive and 240v

TRS 80, Expansion Interface with

power supply unit

£365.00 16K RAM

TRS 80, 4K Level II las above with

TRS 80, Expansion Interface with

Level II Basic)

£425.00 32K RAM

ACCESSORIES

TVJ 232C serial Interface

0500 Radio Shack Phone Modem

Centronics Parallel Printer Interface

UHF Modulators (encased with

(direct to keyboard)

£40.00 leads for 625 lines)

TRS 80. Voice Synthesizer

f345.00 RAM upgrade I4 -16K, 16-32K,

TRS Voxbox - speech recognition

32-4801 supplied and fitted at our

system

£135.00 premises (Kit (80.00)

TRS 80, Numeric Key Pad supplied

S100 interface for TRS 8016 slots)

and fitted

E49.00 TRS80 CPU 3 speed mod.

£499.00 £275.00 £360.00 £160.00 £20.00
C8500 1375.00 £26.00

BASIC SYSTEM Apple II Plus computer - APPLESOFT extended basic in ROM- (16K RAM) - video output £695

ACCESSORIES

Apple black and white modulator

Real time clock/calendar card -

for domestic TV

C20.00 1/1000 sec to 388 days with

Eurocolor card - provides colour on

interrupt, software controllable £128.00.

domestic N

£79.00 Speechlab - provides voice control

Parallel Printer Interface Card

C110.00 for the Apple

£127.00

High Speed Serial IRS232C) Inter-

Supertalker - adds human speech

face Card Communications Card

E113.00 output! E130.00 ALF Music Synthesizer Card

£205.00 E180.00

Centronics Card

£130.00 A1-02 Data Acquisition Card

Integer Basic Firmware Card

£116.00 Graphics Tablet

££41;0000

PASCAL language system - includes

AC Line Controller

language card to provide user with PASCAL PALSOFT &

RAM Upgrade (16-32K. 32-48K) Hobby Prototype Card

1E.62709,00 £20.00

INTEGER BASIC

E299.00 Romplus - u, l/c, mixed text/graphics £105.00

Sorceror 16K RAM inc UHF Modulator)
Exidy Video Monitor (High Resolution)
Exidy Video Disk Unit

BASIC SYSTEMS Sorceror 32K RAM line UHF
0740.00 Modulator)
ACCESSORIES Exidy S100 Bus with Interface
£240.00 motherboard PSU £1,800.00 CP/M for Sorceror on Disk

(840.00
1200.00 £14500

ADVANCED SYSTEMS Altair, Equinox, Billings, Heath, Rair, Horizon. Installations include hard disk and multi tasking. Prices on Application

CORVUS 11rne Hard Disk for TRS 80 & Apple. Complete
with interface & D.O.S. £3500.00

TANDY Model ft now

available for demon.

season at our Camberley

Office (by appo(nt men

onivi

O.A

sPEchu
OFF
dunned demi)

PET BUSINESS SYSTEM.

For only 61999.043

Comprising CBM 3032 Microcomputer. CBM 3040 Dual Disk Dnve.

CBM 3022 Tractor Feed Pnnter and all cables - Total cost if items purchased

separately

E2158.00

(Comprehensive bueness software available including; Sales. Purchase,

Nominal Accounts: Stock Control: Word Processing etc)

DISKS

PET

CEIM 3040 (dual drive) 343K User storage. £795.00

Computhink (dual drive1400K
storage Cornputhink (dual drive1800K storage

189600 11145 00

119.880

Shugart drive

£315.00

Micropolis drive

1315.00

Percom FD200 drive 110v

1299 00

Micropolis Dual Drive 13940 storage/ Corvus Hard Disk II /me)

1995 00 13500 00

APPLE

Apple Drive - 116K storage 1st drive Apple Drive -116K storage 2nd drive

£349.00 £299.00

Corvus Hard Disk 111mal

f 3500 00

SORCEROR

Evidy - 1430 storage

£496.00

Exidy Dual drive (630K storagel Corvus Hard Disk I I Imp)
PRINTERS

1119500 13500 00

PET

CBM 3022180 col with PET graphics tractor feedl
TRS90

1525.00

TRS 80 Screen Printer I text

graphicS) I 1 10v1 New Radio Shack Micro Printer GENERAL

1445 00 1245 00

Teletype 43 KSR Serial (pin or pinch

feed. 132 cols/

1825.00

Teletype 33 KSR Serial 1110 Baudl

Reconditioned
OKI - parallel/serial /pin or pinch feed, 40, 80. 132 cols selectable)
Centronics 779 parallel (tractor

£450.00 1499.00

feed, t32 cols)

1825 00

Anadex DP 8000 serial/parallel (112 cps bidirectional

tractor feed, 40, 80 cols selectable)

1560.00

Centronics Micro Punter 120.40.

80 cols selectable/

[39500

Heath WH 14 serial 180.96. 132 cols

selectable)
QUME daisy wheel printers TCM100/MICROHUSH Thermal

£475.00 P 0 A

Printer (40 cols) inc interface

for PET/APPLE, TRS80
ETC.

1266 00

Diskettes 5' ." (blank/ boxed (min

order 10/ each

from £3

C12 Cassettes (min order 101 each

CO .35p

Ansaback'phonemate' telephone answering machine.

voice operated twin cassette

[190.00

Pace EZ-PHONE - Cordless Telephone

1225.00

Computalker Speech Synthesis for S,00 E350 00 BOOKS - Large range of microcomputer related

books and magazines

TERMINALS

Pentland V1. BO char /24 lines 2

Page memory

1580 00

PROGRAMMABLE CALCULATORS. TEXAS

INSTRUMENTS, Business Programmable

Calculators - complete range. Send for list +

cotes. (We are authorised TI dealers).

IF YOU DON'T SEE IT -ASK IF WE HAVE IT

SOFTWARE
PET

PETSOFT authorised dealers - over 160 programmes on cassette and disk Send 1m

catalogue.

STAGE ONE -COMPUTERS S/W dealers- PETAID. Stock Control. etc. Send for list.

74 Common BASIC Programs on one rape

E15.00

PETACT Business Software- Sales and Purchase Ledger

P.O.A.

CBM DISK -WED BUSINESS SOFIWASS -

Commodore Word Processor powerful word processor package

£75.00

CSTOCK - STOCK CONTROL - gives complete stock report

£150.00

CB1S - BUSINESS INFORMATION SYSTEM - Storage & Retrieval of all types

of company records

E150.00

COM ACCOUNTS - Full Financial Business Accounting System incl:

Sales, Purchase. Nominal Ledgers (integrates with C Stock and C INV) £810.00

PAYROLL - Handles hourly, weekly or monthly paid employees IMO.) £50.00

Me are authorised CBM Business Software Dealer., Send for List.

GD 1001 - Assembler Development System

£50.00

GD 010 - Lisp Interpretive Language (Artificial intelligence)

£75.00

JOYSTICK PACKAGE - complete was connector software

E25.00

CAR INSURANCE QUOTATIONS - computerised car insurance quotation

suitable for insurance brokers ITVJ SAN/

£25.00

MORTGAGE QUOTATIONS - suitable for agents/mortgage brokers (TVJ SNYI E25.00

TRS SO COMAC III SUITE computerised accounting for TRS 80171/3 SOFTWARE I STOCK CONTROL - complete inventory control - recorder level- P/O's etc CP/M
CBASIC

£75.00 £116.00
£95.00 £75.00

FORTRAN includes compiler. relocatable assembler text editor and linking loader
PASCAL -tomorrow's programrnmg language todeV ELECTRIC PENCIL - powerful word processor allows full cursor movement,

£95.00 £195.00

insert/delete. strong search block movement. adjustable line length. Justification on cassette ELECTRIC PENCIL as above - disk version LOWER CASE MOD KIT for Electric Pencil DATA MANAGEMENT/REPORT GENERATOR - easily formats disk files. allows entry, edit. delete and list of records and retrieves data for display or calculation on screen or printer

£B5,00 E115.00
£28.00
£20050

RSM2() DISK MONITOR - powerful system manipulates disk data, has 2.80 break routine

£25.00

(SAM - INDEX SEQUENTIAL ACCESS METHOD - sub routines to facilitate control of random data files

E45.00

STBOD communications software NEWDOS - TRSDOS with corrections and enhancements NEWDOS -es above but with further facilities.-
KBFIX, Renum. Screen to printer in one step. DOS commends from

E60.00 £25.00 E45.00

BASIC, Level I in II, Supereap, Disassemble. load and save faster, list variables LIBRARY 100 - an assortment of 100 programs SARGON CHESS - 16K Level II -the 1979 Champ Version I SARGON CHESS - 16K Level II - the 1979 Champ Version It

E49.00 £39.00 E14.00 E24.00

APPLE

A2FP FUNCTION PLOTTER - Comprehensive graph plotting

£113.00

U'DRAW II- High Resolution graphics editor. Create a figure then intake. expand,

contract etc and store on disk

27.00

LISP- programming language suitable for research in artificial intelligence

£30.00

3 -MILE ISLAND- Complex disk based game simulating nuclear reactor

627.50

VISICALC - Instant Visual Calculation - provides a powerful planning and forecasting

tool

E95.00

APPLE WORD PROCESSOR - Complete text editing. storage and retrieval of text

(disk based)

£42.00

LITTLE GENIUS- Comprehensive disk based Apple Soft Tutorial

535.00

MUSE authorise! dealers. Many programs on cassette and disk. Send for list.

SORCEROR many programs awasoie- send for list.

5% DISCOUNT ALLOWED FOR EDUCATIONAL ESTABLISHMENTS

T

Member of the TV Johnson Group of Companies

Hours of business
LTD Mon -Fri. 9.30-5.30
Sat. 9.30 -1.00

Camberley (Head Office) 165 London Road, Camberley Surrey, GU153JS.
Telephone (0276162506

Oxford
148 Cowley Road. Oxford 004 1J.1
Telephone 108651721461

Bristol
48 Gloucester Road, Bristol 857 EIBH
Telephone (02721422061

Ansaback eves end w/ends.
Telex 858893

(VIM EXCLUDE VAT, FREIGHTS. HANDLING SSNISOP
'PHONE FOR PRICE LIST, BROCHURES lull pro...cora. et time of tompilsttont

Gorectors

Or S V Stag BA. MITE S G Johnson, BSc IHons I Is Johnson. /kaiak NEWS F BSC. WONT a S Barton AGIT 0111(1W Cclow1F

Brandt. al
Birmingham. Br Wok Edinburgh. Leeds. London. Louth Newmarket. ffomnghand Oxford. flytlexl..dxlng5xxl

Advanced interfacing for micro -mainframe connection, control instrumentation and communications for the microcomputer user.

We have interfacing experience with
Mainframes
IBM, ICL, Univac, Honeywell, DEC, Harris, Etc.

Peripherals Punches, Readers, Discs,
Tapes, Plotters, Bar Codes,
Etc.

Instrumentation
Strain Gauges, Gas Chromatographs, Chart Recorders, Auto Analysers,
Digital Oscilloscopes, Thermocouples, Accelerometers, Etc.

For further information please contact Graham Knott or Jeff Orr on 051-933 5511
Stack Computer Services 290/298 Derby Road, Bootle, Liverpool 20.

PCW 3

ANOTHER gggp THROUGH
//000/////'"

5 FIGURE COMPUTING POWER AT A 4 FIGURE PRICE!

COMPLETE SYSTEMS FROM
£1999
(Plus V.A.T.) Delivery 30-60 Days
* Built-in 1/2 Megabyte 8" Floppy Disk
* 32 or 64k Random Access Memory
* 12" High Resolution Video Monitor
* 24 Lines of 80 or 40 (wide) characters
* Upper/Lower Case * Two RS -232C Serial Interface
Ports * "Power -Up" Self Testing * One Centronics Parallel Interface
Port * Two Programmable Special
Function Keys * Direct Memory Access * Vector Driven Interrupts * Full 4 Megahertz operating speed * Provisions for plug-in Expansion
Boards
*These prices are inclusive of V.A.T.

We've added a bigger, more powerful "brother" to the TRS-80 family. It's TRS-80 Model I I - a completely new microcomputer whose capabilities begin where TRS-80 Model I approaches upper limits. Model I I operates at twice Model I's speed, but it's not intended to replace - or compete with - the original TRS-80. It is designed specifically for the user who needs more data storage and versatility. Model I I uses the enhanced Level III version of TRS-80's Level I I BASIC and 27k Disk Operating System automatically loaded. into memory. System software is on diskette so future languages will permit maximum use of available memory. Operation is easy and requires no special training when our applications software is used. And like its little brother, Model I I is completely modular, allowing easy -plug-in expansion. Listed above are some of Model II's sensational capabilities. See your nearest Tandy store or Computer Center for details. Discover how 5 -figure computing -at a 4 -figure price - can benefit you!
32k, 1 -Disk TRS-80 Model II. 26-4001
£2298.85*
64k, 1 -Disk TRS-80 Model II. 26-4002
£2586.35*
32k Memory Board. 26-4102
£343.85*

4 PCW

THE EXPANDABLE TRS-80 MODEL I I
SYSTEM
Like TRS-80 Model I, Model I I systems are
expandable to meet changing - or growing needs. Three expansion connectors (one parallel and two serial) allow you to connect printers, plotters, digitizers, telephone communications and many other external devices. Internal plug-in card slots allow for more expansion and enhancement options in the future... several are in the planning stages now. Model I I comes with a disk containing our expanded Level III BASIC programming language and our all -new command compatible 'TRSDOS' operating system. This "system software" will be upgraded periodically with new features, and we plan to offer additional programming languages for Model I I in the future. Complete Model I I packages can include up to 2 Megabyte Disk storage, advanced line printer for hard copy, system disk and more... 11/2 Megabyte System illustrated includes 26-4002, 26-4161, 26-4301, 26-1156
£5.433.60*

THE BIG NAME CENTRES FOR LITTLE COMPUTERS
Tandy are opening specialist TRS-80 microcomputer centers the length and breadth of Britain - many are already open and new ones will be appearingall the time. So you'll be able to drop in and experiment with the TRS-80 range, discuss your needs with a TRS-80 expert and buy one over-the-counter. Each store will be backed by a service engineer to iron out any problems you may encounter when commissioning your system.

SHORT TEACHING COURSES
Every TRS-80 Computer Center has its own classroom where inexpensive practical short courses in TRS-80 use and programming take place regularly. Anybody can use a TRS-80 the courses are designed to prove it - fast.
Level 1 Basic Course - 1 day Level 2 Basic Course - 2 days Level 3 (TRS-Disc operating system) - 2 days

OVER 180 STORES AND DEALERSHIPS NATIONWIDE.
KNOWN AS RADIO SHACK IN U.S.A. MAKERS OF THE WORLD'S BIGGEST SELLING MICROCOMPUTER TRS-80.

TRS-80 COMPUTER CENTRES NOW OPEN AT: -
BIRMINGHAM, Edgbaston Shopping Precinct, Hagley Road, BRADFORD, 2/4 Forster Square, BRISTOL, Colston Centre, Colston Avenue, MANCHESTER, 30 Market Place, Deansgate, SOUTHAMPTON, East Street Centre.
NEW COMPUTER CENTRE/ AUDIO SUPERSTORES NOW OPEN AT:
DOWNEND, 5 Badminton Road, Downend, Bristol, HENDON, 21 Sentinel Square, Brent St., London NW4, LEEDS, 72 Merrion Centre, IVERPOOL, 168 Market Way, St. John's Centre, LONDON, 1-2 Seacoal Lane, Ludgate Hill, London EC4, WEDNESBURY, Bilston Road, WIMBLEDON, 124-126 The Broadway, London SW19.

THE WORLD'S BIGGEST SELLING
MICROCOMPUTER
TRS-80 MODEL 1 FOR BUSINESS, LEARNING &
ENTERTAINMENT

4K LEVEL I
085.25 26-1001

16K LEVEL II
£559 .95
26-1006 (with green screen monitor)

Two years ago Tandy introduced the TRS-80, the wired, tested and ready -to -run computer that more people have bought

/ /%

than any other single computer. It has proven ideal for uses in

school, business, lab and home, where a large computer is

impractical.

Now available with new improved video monitor!

r._,..,_._.
-......,, /4////////./.61/

7

r4

,4`

Most items also available at Tandy Dealers. Look for this sign in your area. Prices may vary at individual stores.

Offers subject to availability. Instant credit available in most cases.

THE BIGGEST NAME IN LITTLE COMPUTERS
Access, Barclaycard and Trustcard welcome. VISA Check your telephone directory for your nearest store.
PCW 5

Sintrom Microshop
The S100 computer centre
Sintrom Periflex microcomputer with both
5" and 8" floppy disc drives Vector Graphic microcomputers Micropolis 5" floppy disc drives (now in stock) Micropolis 8" Winchester/ S100 systems Telema computer systems

Come to Sintrom for professional microcomputer systems backed -up by the long established Sintrom Group, with years of experience in mini and micro computer systems and peripherals.

Sintrom Electronics

SINTROM GROUP

14 Arkwright Road, Reading, Berks RG2 OLS Tel: Reading (0734) 85464 TELEX: 847395
Sintrom Microshop is a division of the Sintrom Group of Companies

6 PCW

146 OXFORD STREET, LONDON W.1.

To Order simply photostat this page & circle items required and send with your remittance. ALL
PRICES INCLUDE 15% VAT where applicable.

PLEASE SEND THE FOLLOWING PROGRAMS FOR MY MICROCOMPUTER: -

APPLE (I = Integer A = Applesoft) APPLETALKER (I) APPLE LIS'NER (I) CITY MANAGER (A)
STARWARS + SPACEMAZE APPLE 21 (I) MICROCHESS TAPE MICROCHESS DISC BRIDGE CHALLENGER (I) DOS 3.2 TUTOR (A) MAIL LIST/LABEL (A) STOCK CONTROL (A) VISICALC
AIMS DATA BASE (A) DATA BASE UTILITY (A) FORTH
LISP L. GENIUS APPLESOFT L. ADVANCED APPLESOFT KNOW YOURSELF SPACE GAMES SPORTS GAMES STRATEGY GAMES CAI PROGRAMS SPACE INVADERS APPLE INVADERS CONTRIBUTED V3/5 REFERENCE MANUAL HIRES CHAR. GENERATOR SHAPE BUILDER MASTER CATALOGUE STATISTICS DATESTONES OF RYN TEMPLES OF APSHAI WIZARDS MOUNTAIN RELOCATED INTEGER (A)

£15.00 £15.00
9.00 9.00
9.00 £12.00 £16.50 £12.00 £34.50 £57.50 £80.50 £109.00 £140.00 £50.00 £40.00 £34.50 £46.00 £46.00
£ 6.00
6.00
£ 6.00 £ 6.00
6.00 £12.00 £13.80 £69.00 £11.00
£19.00 £19.50 116.00 £23.00 £15.00 £26.00
9.00 £14.00

FOR APPLE/TRS 80 and SORCERER ADVENTURE!!!

ADVENTURELAND

£10.00

PIRATE ADVENTURE

£10.00

MISSION IMPOSSIBLE

£10.00

VOODOO CASTLE

£10.00

THE COUNT

£10.00

STRANGE ODYSSEY

£10.00

MYSTERY FUN HOUSE

£10.00

PYRAMID OF DOOM

£10.00

FOR APPLE OR TRS80 * SORCERERS CASTLE * KING TUT'S TOMB * HOUSE OF 7 GABLES * JOURNEY/CENTRE OF EARTH
(ALL 4 above on disk for) ENCHANTED ISLE ATLANTIS

£ 8.50 £ 8.50
8.50
£ 8.50
£28.00
£ 8.50 £ 8.50

T RS80 ANDROID NIM BEE WARY! LIFETWO SNAKE EGGS THE GREAT RACE LYING CHIMPS OWLTREE TRS80 OPERA NEWDOS + MTREK

£ 9.00
9.00
9.00
9.00
£ 5.00 £ 5.00
5.00
£ 5.00 £49.50 £ 8.00

PET
ENLARGE (DISPLAY) TIME TREK DUCKSHOOT

£ 6.00
£12.00 £ 5.00

This is just a selection from our software range - we have the widest range of software and
are adding new items daily. Send for our FREE catalogue. NEW - APPLE UTI LITIES DISC - single disc copy, patch zap etc. £19.50. BUSINESS APPLICATIONS CONSULTANCY: we can offer help & advice - we specialise in the
APPLE/ITT and offer tailored programs, complete systems and advice. Send for details of our unique PROGRAMMERS COURSE & WORKSHOP (APPLE). We also distribute the 80 -US JOURNAL - a SUPERB magazine for the TRS80 £14.00 p.a.
Programs are in development for the SHARP and most popular micros. If you don't see what you require - please ask - we regularly import the
latest programs from most sources.

NAME ADDRESS

MICROCOMPUTER TOTAL FOR PROGRAMS £ (orders under £15.00 p&p 50p)

Cheque/P. Order/Cash enclosed
For 80 -US subscription tick here Items over £20.00 in value are sent by recorded delivery. We welcome outside programs - our standard royalty is 15%.

The Softwarehouse is next door to OXFORD WALK (between Oxford Circus and Tottenham Court Road) and is open Monday to Friday 9.30 am to 5.30 pm

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Z -Plus Microcomputer System

Over One Megabyte Disk Storage 4 MHz Z-80 Processor Two Serial and Two Parallel I/O Ports 64k Memory An alphanumeric keyboard
Including System Desk

63950 Price

plus VAT

THE Z PLUS SYSTEM IS MARKETED

THROUGHOUT THE UK & EUROPE

AND IS AVAILABLE THROUGH A

NUMBER OF SELECTED DEALERS

;SF

115-117 WANDSWORTH HIGH STREET, LONDON SW18 4HY

Telephone: 01-874 1172

Telex: 8813089 INTPRM G

S PCW

I Scottish Office: 8 ROYAL CRESCENT, GLASGOW Telephone: 041 332 7642

easy solution!
are to
at rod
A 48K Disk based computer system for only

16K byte Apple Computer
Disk System
Total with 32K free extra memory

Nett

VAT Total

£695.00 £104.25 £799.25

£349.00 £52.35 £401.35

£1044.00 £156.00 £1200.60

11111111ieri.ornillaftiliet
OFFICAL ORDERS
We Welcome official orders from bona -fide commercial and government organisations. We require payment 14 days after invoice date.

Latest Apple I
with foadngointic and auto-start
ROM -

ABpupylea

16K with

Disk drive

and get 32K

of memory

Free.

Extras Second Disk Drive

£299.00 £44.85 £343.85

Pascal Language System
Graphics Tablet Appletel System

£299.00 £44.85 £343.85 £462.00 £69.30 £531.30 £595.00 £89.25 £684.25

Black & White Modulator
Eurocolour Card Joystick

£14.00 £2.10 £16.10 £7900 £11.85 £90.85 £25.00 £3.75 £28.75

All Prices include courier delivery within U.K.

Apple Business Systems -ring Graham Jones 051227 2535

Software Packages Stock Control General Ledger Purchase Ledger Sales Ledger

£
£225.00 £295.00 £295.00 £295.00

Word Processor/Letter £

Writer

£130.00

Book keeper Package £295.00

Credit Control

Package

£150.00

Payroll

£385.00

+ VAT at 15%

Ilikplatonvuticir
an0 Serena
ME EMI III MI IMO Ell MINI IMO
IPlease send systems as above at £1200.60 in addition please send:

Total Remittance

Name

Address

MICRODIGITAI

25 Brunswick Street, Liverpool L2 OBI Mail orders to. MICRODIGITAL LIMITED,

Tel: 051-2360707 (24 hour Mail Order)

FREEPOST (No Stamp Required)

051-227 2535 (All other Depts.)

Liverpool L2 2AB.

Access and Barclaycard welcome. =rill

=NE I. .11

N. viol

PCW 9

ENTERPRISES

Room PCW 8 Cambridge House, Cambridge Road, Barking, Essex IG11 8NT, England.
Telephone: 01-591 6511

BY OSBORNE

Introduction to Microcomputers Series

Vo 0: Beginners Book
Vo 1: BASIC Concepts Vo 2: Some Real Microprocessors (without binder) Vo 2: Some Real Microprocessors (with binder) Vo 2: Updating supplement set Nos. 1-6 Vo 3: Some Real Support Devices (without binder) Vo 3: Some Real Support Devices (with binder) Vo 3: Updating supplement set Nos. 1-6 1 binder (Specify for Vol 2 or 3) 1 Updating supplement (Specify for Vol 2 or 3)
See Subscriptions!

£ 5.95
£ 6.30 £ 18.95 £ 24.70 £ 17.00 £ 11.95 £ 17.70 £ 17.00
£ 5.75
£ 4.00

6800 Programming for Logic Design

8080 Programming for Logic Design

Z80 Programming for Logic Design

Z80 Assembly Language Programming

6502 Assembly Language Programming

8080A/8085 Assembly Language Programming

6800 Assembly Language Programming

Wang Basic

Accounts Payable and Accounts Receivable £ 12.75

Payroll with Cost Accounting

£ 12.95

General Ledger

£ 11.95

£ 6.30 £ 6.30
£ 6.30 £ 8.15
£ 8.25 £ 7.95
£ 7.95
C Basic
£ 13.15 £ 13.50 £ 12.25

Some Common BASIC Programs

£ 7.95

GENERAL

See Magazines and Subscriptions!

See Osborne Books!

Microprocessors from Chips to System
Microprocessor Interfacing Techniques
Cheap Video Cookbook CMOS Cookbook IC OP -AMP Cookbook RTL Cookbook TTL Cookbook Ciarcias Circuit Cellar First Book of Kim Buyers Guide to Microsoftware Calculating with BASIC Computer Programs that Work (In BASIC) BASIC Software Library: (Listings)
Vo 1: Business and Games Programs Vo 2: Maths, Engineering and Statistical Programs
Vo 3: Advanced Business Programs
Vo 4: General Purpose Programs Vo 5: Experimenters Programs Vo 6: Miniature Business System Vo 7: Chess/Medbil/Wdproc Programs
Vo 8: Homeowners Programs Bar Code Loader for 6800, 8080, Z80 and 6502 Best of BYTE Scelbi BYTE Primer Best of Creative Computing, Vol 1 Best of Creative Computing, Vol 2 Program Design Programming Techniques: Simulation PIMS -A Database Management System Numbers in Theory and Practise

£ 7.00 £ 8.75 £ 4.30 £ 7.50 £ 8.95 £ 4.25 £ 7.50 £ 5.50 £ 7.00 £ 2.40 £ 4.95 £ 2.95
£ 17.50 £ 17.50 £ 26.95 £ 7.95
£ 7.95
£ 32.50 £ 26.95 £ 14.95
£ 1.75 £ 8.95 £ 8.95 £ 6.95 £ 6.95 £ 4.25 £ 4.25 £ 5.95 £ 5.95

FOR THE Z80
See Osborne books!
Programming the Z80 (Zacs) Z80 Instruction Handbook (Wadsworth) Z80 Microcomputer Handbook (Barden) Z80 Software Gourmet Guide and Cookbook

£ 9.95 £ 2.95 £ 7.50 £ 7.95

FOR THE 6800

See Magazines and Subscriptions!

See Osborne Books!

6800 Software Gourmet Guide & Cookbook 6800 Tracer - An aid to 6800 Program Debugging
Tiny Assembler
RA 6800 ML - An M600 Relocatable Macro Assembler Link 68 - An M6800 Linking Loader MONDEB - An Advanced M6800 Monitor Debugger

£ 6.95 £ 3.95 £ 5.75 £ 15.95 £ 5.50 £ 3.50

CONCERNING LANGUAGE
SCE LBAL - High Level Language Supplements Instant BASIC Basic BASIC Advanced BASIC My Computer likes me ... when I speak in BASIC Users Guide to North Star BASIC A Practical Introduction to PASCAL Microsoft BASIC

£ 15.00 £ 6.95
£ 6.50
£ 6.00 £ 2.75 £ 10.00 £ 3.95 £ 5.50

FOR THE 6502
See Magazines and Subscriptions!
Best of Micro, Vol 1 Best of Micro, Vol 2 Programming the 6502 (Zacs) Programming the 6502 (Foster) 6502 Applications 6502 Software Gourmet Guide and Cookbook

See Osborne Books!
£ 5.50 £ 5.50 £ 7.95 £ 6.75 £ 7.95 £ 6.95

FOR THE 8080
See Osborne Books!
8080 Programmers Pocket Guide 8080 Hex Code Card 8080 Octal Code Card 8080 Software Gourmet Guide & Cookbook 8080/8085 Software Design 8080 Standard Monitor 8080 Standard Assembler 8080 Standard Editor 8080 Special Package: Monitor, Editor, Assembler BASE X: A Simple Language and Compiler for the 8080

1.95
1.95 1.95 6.95 6.75 9.95
9.95 9.95 20.00
5.50

FOR FUN
SARGON -A Chess Game (for the Z80) BASIC Computer Games More BASIC Computer Games What to do After you Hit Return 8080 Galaxy Game SUPER-WUMPUS -A game in 6800 Assembler Code
& BASIC Computer Music Book Computer Range (A board game) Artist and Computer Games, Tricks and Puzzles for a Hand Calculator Introduction to TRS-80 Graphics Take My Computer Please ... (Fiction) Introduction to Low Resolution Graphis

9.50 5.00 5.50 8.95 6.95
4.25 6.75 6.95 3.95 2.49 5.75 3.25 5.50

FOR THE NOVICE

See Magazines and Subscriptions!

See Osborne Books!

Your Home Computer
Introduction to Personal and Business Computing Getting involved with Your Own Computer How to Profit from Your Personal Computer Microcomputer Potpourri Hobby Computers are Here New Hobby Computers
Understanding Microcomputers and Small Computer Systems
Understanding Microcomputers and Small Computer Systems and Audio Cassette Getting Down to Business With Your Microcomputer

5.95 4.95 4.75 5.50 2.40 3.95 3.95
£ 6.75
£ 8.75 £ 5.50

MAGAZINE BACK ISSUES
Micro 6502 Journal Personal Computing Interface Age ROM Dr. Dobbs Journal Computer Music Journal Peoples Computers (now called Recreational Computing) BYTE Creative Computing Calculators and Computers Kilobaud Compute - for the 6502 68' Micro Magazine Storage Box (Holds 12) 80' Microcomputing

£ 1.50 £ 1.95 £ 2.95 £ 1.95 £ 1.95 £ 3.75 £ 1.95 £ 2.95 £ 1.95
£ 1.95 p.o.a. £ 1.95
£ 1.95 £ 1.25 £ 2.25

MAGAZINE SUBSCRIPTIONS (all processed within 3 weeks)
Micro Journal (12 issues) 68 Micro (12 issues) Personal Computing (12 issues) Interface Age (12 issues) Dr. Dobbs Journal (10 issues) Computer Music Journal (4 issues) Recreational Computing (6 issues) BYTE (12 issues) Creative Computing (12 issues) Kilobaud Microcomputing (12 issues) Compute for the 6502 (6 issues) 80' Microcomputing (12 issues)

12.50 17.50 17.00 25.00 13.50
11.00 8.50 24.50 16.50 21.00 10.50 17.50

I() PCW

NTERPRISES

Room PCW 8 Cambridge House, Cambridge Road, Barking, Essex IG11 8NT, England.
Telephone: 01-591 6511

BYROM SOFTWARE
BSTAM - Utility to link one microcomputer to another also using BSTAM

Software Manual & Manual only
£ 70.00/ 5

COMPUTERS PLUS
FMS -80 (File Management System) Demo Pack (includes manual & disc) Complete System

£ 35.00 £395.00/25

COMPUTER SERVICES
Bidirectional driver for Diablo Hytype printers for use on CPM & CDOS systems

£ 65.00/10

CP/M USER LIBRARY
33 Volumes on 8" disc 33 Volumes on 5" disc

£ 4.00 £ 8.00

CREATIVE COMPUTING
For CP/M CS -9001 BASIC Computer Games disc 1 CS -9002 BASIC Computer Games disc 2 CS -9000 Both discs purchased together

£ 12.00 £ 12.00 £ 20.00

Multi -FORTH

CREATIVE SOLUTIONS

£ 65.00/20

DIGITAL RESEARCH (Most formats now available)

MPM 1.1 CP/M 1.4 CP/M 2.2 SID ZSID MAC TEX DESPOO L
PL/1

£175.00/18
£ 65.00/18 £ 90.00/18
£ 45.00/12 £ 55.00/12 £ 55.00/15 £ 45.00/12 £ 30.00/ 5
TBA

INFORMATION UNLIMITED
WHATSIT (Database Management System) on North Star on CP/M on APPLE 2:48k (requires int Basic) on APPLE 2:32k (requires int Basic on ITT 2020 (see Apple)

£ 59.00 £ 75.00
£ 72.00 £ 59.00

GUNN Utilities for Cromemco CDOS

£ 65.00/10

KLH SYSTEMS
Spooler for CPM systems
L.P. ENTERPRISES
Diablo driver runs 110 to 9600 baud with autoload for CP/M or CDOS OMNIX - UNIX like multiuser, multitasking operating system for Z80 i.e. IMS, Cromemco, Horizon Yearly maintenance on OMNIX

£ 65.00/ 5
£ 30.00/ 5 £150.00/30 £ 50.00

MICAH INC
CP/M for CDOS Users: Program to Expand CP/M system to be compatable with Cromemco CDOS software
ORDER INFORMATION:

£ 59.00/ 5

Software prices reflect distribution on 8" single density discs. If a format is requested which requires additional discs a surcharge of £4.00
per additional disc will be added.

Please add VAT and 1.50 for first class postage, packing and insurance.
If required, DATAPOST D service is available for an extra charge of £6.00.

All software on this Advertisement is available from stock and a 24 -hour return service is thereby offered on all prepaid orders.

When ordering CP/M software please specify the format you require otherwise software will be dispatched on a 8" single density disc.

BONUS DISCOUNTS
a) For the purchase of 3 or more books and paying by cheque, P.O. or cash with the order, give yourself a 10% DISCOUNT.
b) For the purchase of 3 or more magazine back issues and paying by cheque, P.O. or cash with the order, give yourself a 10% DISCOUNT.

Software Manual & Manual only

Disc Utilities:
Pack one for CDOS users includes: Fast disc copy, Track test, Disc test, Compare files and others Pack two for CP/M users includes same as pack one Pack three for Cromemco users includes same as pack one and spool & print

£ 30.00/ 5 £ 30.00/ 5 £ 65.00/ 5

BASIC -80 BASIC Compiler FORTRAN -80 COBOL -80 EDIT -80 MACRO -80

MICROSOFT INC

£175.00/17 £195.00/17 £220.00/17 £355.00/17 £ 45.00/17 £ 80.00/11

MICHAEL SHRAYER INC
Electric Pencil Word Processor SSI I for tty etc. DSI I for Diablo TRS-80 Cassette/disc

£100.00
£105.00 £ 50.00

MICROFOCUS LTD
CIS COBOL version 4.2 FORMS 2

£425.00/25 £100.00/10

MICROPRO INC

WORD -MASTER 1.7

TEX-WRITER

2.6

WORD -STAR

1.00

SUPER -SORT: version 1

version 2 version 3

£ 70.00/20 £ 35.00/15 £240.00/25
£120.00/20 £100.00/20 £ 75.00/20

NORTHSHARE Multi-user system for Horizon Users

£ 24.00/ 5

SOFTWARE SYSTEMS (Compiler systems)

CBASIC v2.05

£ 65.00/15

SOFTWARE WORKS
Northstar Format Only Inventory -1 (Stock Control) Inventory -2 with order entry, invoicing Mailroom Housekeeper (Utilities, sorts) Preventative Maintenance
Housekeeper -2 (Coming soon)

£ 50.00/10 £130.00/15 £ 50.00/15 £ 35.00/10 £ 75.00/15
TBA

STRUCTURED SYSTEMS All converted to UK standard

Sales Ledger
Purchase Ledger Nominal Ledger Stock Control Letteright Analyst (File management Reporting System) NAD (Name & Address selection system) OSORT

£275.00/15
£275.00/15 £325.00/15 £275.00/15 £ 95.00/10 £115.00/10 £ 50.00/10 £ 50.00/10

TINY -C ASSOCIATES Tiny -C language for 8080, 8085, Z80 systems

£ 50.00/35

c) For the purchase of 2 or more software packages and paying by cheque, P.O. or cash, with theorder, give yourself a 10% DISCOUNT.

For more information on any of these items, please phone, write or visit. (We are open during office hours).

All publications are published in the U.S.A. and are stocked in Britain by L.P. Enterprises. Prepaid orders are despatched by return of post, or advice concerning.
HOW TO ORDER:
Send cash, postal order, cheque card number to L.P. Enterprises, Room 8, Cambridge House, Cambridge Road, Barking, Essex IG11 8NT. All payment must be in Sterling and drawn against a U.K. bank. Please note: If you wish to pay by Diners Club credit card, we must have your signature. For any payment by credit card, we need the expiry date of the card and the address that the credit card company knows (although we can send the goods to an alternative address).

For the purchase of software, please add VAT and £1 .50 for First Class postage, packing and insurance.

Due to fluctuations of the dollar, prices are subject to change without

not ice.

TRADE ENQUIRIES WELCOME

PCW 11

. .. 11

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small systeMs
. presents

JJJ
PET COMPATIBLE -er,

DAISY WHEEL

PRINTER

;

S.S.E. RICOH R.P 40

:

: .
.

. ".Printing Speed - 40 C.P.S.

Character -set - 96 characters, metal faced printwhee

. Choice of typefaces

,

Line width - 136 characters (10 characters per inch)

Line width - 163 characters (12 characters per inch)

Form width - 16"
. Integral PET IEEE -488 Addressable Interface

(Disc compatible)

240v 50Hz

Micro -Processor controlled

Reputation for high reliability

6.

Options:- ..

Pin Feed Platen

Acoustic cover

"

Form Tractor

RS232 C Interface, Centronics Interface

Complete word processing systems - Commodore PET,

:

Software and RP40 Printer also available.

M Small a..
Systems .
rA Engineering

. HIGH QUALITY PRINTING AT LOW COST £1590.00 inc. PET INTERFAC .

+: .
.

. .

Limited

62 New Cavendish Street London. W1M 7LD Telephone: 01 637 0777 Telex: 8813085 (Abacus

Thinking Computers?
'fan; A T-Tir.r.TAr i I

Then come to the number one
micro -computer centre

If you're wondering if a micro -computer can help you, we are here to advise you.
At Lion House -London's leading centre for micro -computers - you'll find:
* Experts who'll explain( the equipment
in a way you can easily understand,
showing how and where it applies to your work.
* Demonstration areas where you can get
immediate experience of using microcomputers yourself.
* Probably the biggest range of soft-
ware in the UK.
* Programmes can be tailored for your particular commercial needs by our In House Analysts and Programmers.
* Total service -including the availability of full maintenance after you've bought an installation.
* Leasing and H.P. facilities immediately available.
* A computer book section with publications that give you new insight into the world of micro -computers.

How will micro -computers help your in thousands of ways -only a few can be mentioned here...
MICRO -COMPUTERS FOR BUSINESS
For business and professional, the
versatility of compact micro -computers means that all the benefits of big computers are made available to all at low cost. The businessman can now computerise his accountancy, his stock control, his records and much more -cutting his overheads and improving his efficiency. For the home, micro -computers have innumerable uses and considerable value too - sometimes in unexpected ways.

MICRO-COMPUTERS FOR THE HOME

Budgeting . . . investments . . . controlling heating or security ... storing information on things like recipes . . . designing complex and fascinating games ... education ...
Come and see. We invite you to visit us and investigate the possibilities and the potential. If you're too far away, phone or write and we'll send you more information.
You need a micro -computer. We can
supply it.

UON

-

HOUSE

Tzi

LION MICRO -COMPUTERS
SMALL COMPUTERS -TO MAKE YOUR BUSINESS BIGGER

Lion Computer Shops Ltd, Lion House, 227 Tottenham Court Road,

IN

i\

London WI (First Floor). Telephone: 01-637 1601. Telex:28394 MLioonnt.

9 to 6, Monday to Saturday (Thursday to 7). 10 =

Tottenham Court Road

PCW 13

Britain's first corn!

A complete personal computer

for a third of the price of a

...

bare board.

\C-cciztlmo,

niik,VOMAV

AttittthUAOr

Also available ready assembled for £9995
The Sinclair ZX80.

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Until now, building your own computer could easily cost around £300 -and still leave you with only a bare board for your trouble.
The Sinclair ZX80 changes all that. For just £79.95 you get everything you need to build a personal computer at home...PCB, with IC sockets for all ICs; case; leads for direct connection to your own cassette recorder and
black and white or colour television; everything! And yet the ZX80 really is a complete,
powerful, full -facility computer, matching or surpassing other personal computers on the market at several times the price. The ZX80 is programmed in BASIC, and you could use it to do quite literally anything from playing chess to running a power station.
The ZX80 is pleasantly straightforward to assemble, using a fine -tipped soldering iron. Once assembled, it immediately proves what a good job you've done. Connect it to your TV set...link it to an appropriate power source*... and you're ready to go.
Your ZX80 kit contains...
Printed circuit board, with IC sockets for all ICs.
Complete components set, including all ICs -all manufactured by selected world leading suppliers.
New rugged Sinclair keyboard, touch sensitive, wipe -clean.
Ready -moulded case. Leads and plugs for connection to domestic
TV and cassette recorder. (Programs can be SAVEd and LOADed on to any portable cassette recorder.) FREE course in BASIC programming and user manual.
Optional extras Mains adaptor of 600 mA at 9 V DC
nominal unregulated (available separately - see coupon). Additional memory expansion boards allowing up to 16K bytes RAM. (Extra RAM chips also available -see coupon.)
'Use a 600 mA at 9 V DC nominal unregulated mains adaptor. Available from Sinclair if desired (see coupon).

Two unique and valuable components of the Sinclair ZX80.
The Sinclair 'GM() is not just another personal computer. Quite apart from its exceptionally low price, the ZX80 has two uniquely advanced components: the Sinclair BASIC interpreter; and the Sinclair teach -yourself BASIC manual.
The unique Sinclair BASIC interpreter... offers remarkable programming advantages: Unique 'one -touch' key word entry: the ZX80
eliminates a great deal of tiresome typing. Key words (RUN, PRINT, LIST, etc.) have their own single -key entry.
Unique syntax check. Only lines with correct syntax are accepted into programs. A cursor identifies errors immediately. This prevents entry of long and complicated programs with faults only discovered when you try to run them
Excellent string -handling capability - takes up to 26 string variables of any length. All strings can undergo all relational tests (e.g. comparison). The ZX80 also has string input to request a line of text when necessary. Strings do not need to he dimensioned.
Up to 26 single dimension arrays.
FOR/NEXT loops nested up 26. Variable names of any length.
BASIC language also handles full Boolean arithmetic, conditional expressions, etc.
Exceptionally powerful edit facilities, allows modification of existing program lines.
Randomise function, useful for games and secret codes, as well as more serious applications.
Timer under program control.
PEEK and POKE enable entry of machine code instructions, USR causes jump to a user's machine language sub -routine.

High -resolution graphics with 22 standard graphic symbols.

All characters printable in reverse under program control.
Lines of unlimited length.

...and the Sinclair teach -yourself

BASIC manual.

If the features of the Sinclair interpreter

listed alongside mean little to you -don't worry.

They're all explained in the specially -written

128 -page book free with every kit! The book

makes learning easy, exciting and enjoyable, and

represents a complete course in BASIC pro-

gramming -from first principles to complex

programs. (Available separately -purchase

price refunded if you buy a ZX80 later.)

A hardware manual is also included with every kit or

built machine.
Z80A microprocessor- new,

UHF TV modulator.

faster version of the famous Z-80 microprocessor chip, widely recognised as the best ever made.

Sockets for TV, cassette recorder, power supply.

RAM chips.

Rugged,
flush, Sinclair keyboard

14 PCW

ate

ter kit.

Including VAT Including post and
packing. Including all leads and components.

ewer chips, ompact design, olume production lore power per pound!
ie ZX80 owes its remarkable
w price to its remarkable sign: the whole system is packed on to ver, newer, more powerful and advanced LSI ,ips. A single SUPER ROM, for instance, contains e BASIC interpreter, the character set, operating stem, and monitor. And the ZX80's 1K byte RAM roughly equivalent to 4K bytes in a conventional ,mputer-typically storing 1001ines of BASIC. (Key
.ards occupy only a single byte.) The display shows 32 characters by 24 lines. And Benchmark tests show that the ZX80 is faster
an all other personal computers. No other personal computer offers this unique
,mbination of high capability and low price.
'he Sinclair ZX80. Kit: £79.95. kssembled: £99.95. Complete!
he ZX80 kit costs a mere £79.95. Can't wait to ave a ZX80 up and running? No problem! 's also available, ready assembled, for only
99.95. Demand for the ZX80 is very high: use the aupon to order today for the earliest possible elivery. All orders will be despatched in strict nation. We'll acknowledge each order by !turn, and tell you exactly when your ZX80 will e delivered. If you choose not to wait, you can ancel your order immediately, and your money ill be refunded at once. Again, of course, you ave a refund option for 14 days after your amputer is despatched. We want you to be ttisfied beyond all doubt -and we have no aubt that you will be.
=(B.11Dr1=IMirm
>cience of Cambridge Ltd
Kings Parade, Cambridge, Cambs., CB2 1SN. el: 0223 311488.

,00111111111111111111161

.... ,,,,,,,

...
............

r --Order Form
To: Science of Cambridge Ltd, 6 Kings Parade, Cambridge, Cambs., CB21SN. Remember: all prices shown include VAT, postage and packing. No hidden extras.

Please send me:

Quantity Item
Sinclair ZX80 Personal Computer kit(s). Price includes ZX80 BASIC manual, excludes mains adaptor. Ready -assembled Sinclair ZX80 Personal Computer(s). Price includes ZX80 BASIC manual, excludes mains adaptor. Mains Adaptor(s) (600 mA at 9 V DC nominal unregulated). Memory Expansion Board(s) (each one takes up to 3K bytes). RAM Memory chips - standard 1K bytes capacity. Sinclair ZX80 Manual(s) (manual free with every ZX80 kit or ready-made computer).
NB. Your Sinclair ZX80 may qualify as a business expense.

Item price £
79.95
99.95 8.95
12.00 16.00
5.00 TOTAL

Tots
L.
L

I enclose a cheque/postal order payable to Science of Cambridge Ltd for £ Please print Name: Mr/Mrs/Miss
Address

PON 15

Computer
timmunicatio

STACK COMPUTERS

ANNOUNCE

Eff

KEYPAK© £45p.s.

REMOTE PROGRAMMING AID

FOR PET COMPUTERS

SEMiCES

Stack Computers have developed packages for the old ROM and NEW ROM PETS to enable them to be programmed from external devices.
Once KEYPAK is running Paper Tape Reader:- a listing of a PET basic program can be read in by a reader directly into program area and run without any user contact with the PET.
Transfer Programmes:- a PET or any other microcomputer
outputing a PET acceptable basic

structure can send its programme
to the PET running KEYPAK.
Send Programmes by 'phone using an accoustic coupler or
modem a PET running KEYPAK
can receive programmes via the GPO Telephone System.
Telephone Communication and Editing. Ring your collegue
and under KEYPAK have him
edit your program on your PET screen or show you the correct lines.

KEYPAK is a PET compatible programme supplied on cassette * Remote stop key operation is
implemented * Remote clear screen is
implemented * Handles quotes mode
KEYPAK does not handle
cursor or screen controls in quotes mode during programme run.
Suitable interfaces and accoustic couplers are available from stock.

STACK COMPUTER SERVICES

290/298 Derby Road, Bootle, Liverpool 20.
051-933 5511

PCW

Now available from UK stocks

The microcomputer which outsells all others in Scandinavia.

Write: Dator Ltd. / Fox Oak / Seven Hills Road / Walton -on -Thames / Surrey kt 124 dg

0
Apple or PET? West London's specialists are also in the West End:

aPpla®
APPLE II EUROPLUS 16K DISC DRIVE WITH CONTROI.1 FR DISC DRIVE WITHOUT CONTROLLER 16K ADD ON MEMORY
HITACHI 9" BLACK & WHITE MONITOR
EUROCOLOUR CARD PASCAL LANGUAGE CARD
_ALF MUSIC SYNTHESISER CARD
TCM 100 SJI.FNT 40 COLUMN PRINTER PAPER TIGER PRINTER TCM INTERFACE FOR PET OR APPLE

£695.00
£349.00 £299.00 £ 69.00 £127.00 £ 69.00
£296.00 £215.00
£243.00
£585.00 £ 49.00

PET®

PET 8K WITH INTEGRAL CASSEI 1 L.

£475.00

NEW PET 8K WITH LARGE KEYBOARD £495.00

PET 3016 16K COMPUTER

£675.00

PET 3032 32K COMPUTER

£795.00

PET 3040 DUAL DRIVE FLOPPY DISK

£795.00

PET 3022 TRACTOR PRINTER

£525.00

PET 2023 FRICTION PRINTER

£475.00

PET C2N TAPE DECK

£55.00

24K EXPANSION MEMORY

£320.00

COMPUTHINK 800K DISK DRIVE

£1145.00

TELETYPE 43 PRINTER

FROM £860.00

QUME SPRINT DAISYWHEEL

FROM £1800.00

adila adila FROM

FROM

Adda Computers, 17-19 The Broadway (between W. H. Smith and Burtons), Ealing, London W. 5. Tel. 01-579 5845 *New West End address: Abbott House, 1-2 Hanover Street, London W1R 9WB. Tel: 01-408 1611

PCW 17

MICROTAN 65
The Microcomputer that thinks it's a Mini

18 PCW

The MICROTAN kit has won widespread acclaim for it's super presentation.

High quality, plated thru' hole printed circuit board,

solder resist and component legends.

Full set of I.C.

sockets. 64 way D.I.N. edge connector. 6502 microprocessor.

1K monitor TANBUG.

1K RAM for user programme, stack and

display memory.

VDU alphanumeric display.

Intelligent

keyboard socket. A4 MICROTAN 65 system file binder. 136

page, bound, A4 size users hardware/software manual with

constructional details and sample programmes.

Logic and

discrete components to fully expand MICROTAN 65.

TANEX

from £43.00 plus VAT

Fully expanded TANEX offers; 7K RAM, 6K ROM, BK MICROSOFT BASIC, 32 parallel I/O lines, two TTL serial I/O ports, a third serial I/O port with RS232 20mA, full modem control and 16 programmable baud rates, four 16 bit counter timers, cassette interface, data bus buffering and memory mapping.
Ready built the mini-mother board has two 64 way female connectors, a 4 way power supply connector and a reset switch on board. It is used to connect MICROTAN to TANEX, and will fit inside the mini system rack. £8.64 plus VAT.

Full System Rack

from £49.00 Plus VAT

For the man that has everything! 19 inch wide system rack which accepts MICROTAN 65, TANEX, TANRAM, SEVEN FURTHER EXPANSION BOARDS, TANDOS AND THE SYSTEM POWER SUPPLY. Available in many formats e.g. Individual module front panels, full width hinged front panel, back panel with or without connectors, etc.

We have produced a mini-rack which accepts MICROTAN 65

and TANEX, it has an integral power supply, just plug it

into the mains and away you go! Finished in Black/Tangerine/

Brushed aluminium, it gives your mini-system the professional

finish.

£34.75 plus VAT

Full ASCII keyboard

£49.00 plus VAT

The ASCII keyboard includes a numeric keypad and ribbon cable connector. Available only as fully built and tested.
Cabinet available at £21.21 plus VAT.

ULAMTNEWN COMPUTER SYSTEMS LIMITED

Extract from Mini
Review in ET I

April 1980

An excellent kit
The concept of TANBUG is excellent Rock steady VDU The extremely reasonable cost has not been achieved by skimping on design A gem of a product An excellent introduction to 6502 based systems

A 6502 based microcomputer.

Superb 1K monitor TANBUG.

Lxpansion boards to make a full system.

Fully socketed

1K RAM for user programme, stack and display memory

136 page software/hardware users manual, with example programmes and A4 size!

Intelligent keyboard socket, accepts 20 key keypad or full ASCII keyboard

Full alphanumeric video display on an un-modified domestic TV - makes
programming much easier

Optional lower case pack

£9.48 + vat

Optional chunky graphics pack £6.52 + vat

We welcome Access

BROCHURE AVAILABLE ON REQUEST, 12p stamp

TANGERINE COMPUTER SYSTEMS LTD., FOREHILL, ELY, CAMBS. Tel: (0353) 3633

,; , .

powaialiammi9

(157=7-(1 ev. fuelmagiiimp swirawror

r7

Climilkomma

11.40111.111P

NAME ADDRESS

Come and see us on stand No: 36
at the Mersey Micro Show
PCW 19

JP

0Y1

TRS-80 SOFTWARE

FROM THE PROFESSIONALS

EDITOR/ASSEMBLER PLUS
Now get every feature of Tandy's Editor Assembler and T -Bug all in one package. PLUS - many "big computer" features to simplify your programming, editing and debugging. Its no longer necessary to waste time creating both source and object tapes - Assembler Plus assembles directly into memory. Macros are supported, simply define a Macro and any frequently used sequencies are automatically assembled. Assembler Plus also supports Conditional Assembly with 2 new pseudo ops, which enable assembly if a condition is true. There are 7 new expressions available, together with an automatic ORG, improved symbol print out and a Quash command to give you more storage space for general text editing. And that is all just on the Assembly side: The Editor is improved with extra commands like Substitute, Move, Copy and Extend for moving entire blocks and repeating them anywhere in the file, and for searching and substituting occurrences in old text for new text. A Range command is available for both Edit and Find enabling you to operate on a single line or a range of lines. Included in the package is a debugger called Z -Bug which includes all of the features of Tandy's T -Bug and features single step execution, direct execution in command mode and symbolic references, plus up to 8 breakpoints, rather than the single one in T -Bug. Editor/Assembler Plus is written by the original author and comes with an 80 page Manual - best of all it costs the same as Tandy's Editor/Assembler alone

Editor/Assembler Plus for 16K Level II. Cassette based

£21.70 + VAT = £24.95 50p P & P

ADVENTURE

The original Adventure was written for a main frame computer and was called Adventureland.Since then there have been

many derivatives. The best are written in machine code like the Scott Adams series (for which label we happen to be the sole importers 1) but good as they are, they have had to be shortened to fit into 16K. This Microsoft Adventure is the original uncut main frame version, for the first time available for a microcomputer. Once you enter the Colossal Cave,

your journey takes you through a labyrinth of caves containing active volcanoes, green snakes, sulfur lakes,killer dwarves,

trolls, five foot oysters and many many more surprises before you can collect the 25 Treasures and be a Grand Master All the while directing your journey with commands and questions to the computer in English. Over 400 messages and descriptions are combined in an endless number of ways in the program vocabulary. Almost literally mind blowing

Adventure. 32K single drive minimum. Disk based

£19.50 + VAT = £22.43 50p P & P

ASSEMBLY LANGUAGE PACKAGE

A Complete Assembly Language package for the user who requires the ultimate in programming aids. This package consists of a Macro Assembler, a Linking Loader, a Text Editor and a Cross Reference Facility. The Macro Assembler accepts Z-80 opcodes and supports a complete Intel standard macro facility including IRP, IRPC, Repeat, local variables and

ExitM. The code is assembled in relocatable modules which offer the advantages of easier coding, faster testing, debugging and modifying. An expanded set of conditional pseudo ops allows testing of assembly pass, symbol definition and parameters to macros. Other assembler features include comment blocks, octal or hex listings, titles and subtitles, variable input radix (base 2 to 16) and a complete set of listing controls. The Linking Loader provides a number of loader capa-

bilities executed by means of easy command lines and switches. Any number of programs may be loaded in user specified locations. Internal and external references between modules are resolved automatically. The Loader also performs library
searches for system subroutines and generates a load map of memory showing the locations. The Text Editor is a random
access line orientated text editor similar to those used on the IBM 360 and PDP-10 computers. The Editor's speed and simplicity make it easy to insert, replace, print or delete lines ;edit individual lines; renumber lines in a file and to find or substitute specified text. The Cross Reference Facility provides a convenient alphabetical list of all program variable names, together with the line numbers where they are referenced and defined.

Assembly Language Package. 32K single drive minimum
FORTRAN

£65.00 + VAT = £74.75 50p P & P

The best Fortran Language Compiler available for the TRS-80 - a standard ANSI Fortran from Microsoft. The package includes the Compiler, a Linking Loader, a Text Editor and a Fortran Runtime Library. The Compiler has a number of
enhancements to the ANSI standard: LOGICAL variables which can be used as integer quantities, +127 to -128;LOGICAL DO loops for tighter, faster execution of small valued integer loops; mixed mode arithmetic; hexadecimal contants ; Literals and Holleriths allowed in expressions ; logical operations on integer data AND..OR..NOT..XOR can be used for
8 or 16 bit Boolean operations; READ/WRITE End of File or Error Condition transfer, that is, control may be transferred to a specified statement on end of file or error encounter; Encode/Decode for Format operations to memory. The standard library supplied includes 49 subroutines, together with routines for 32 bit and 64 bit floating point functions. Users may write non-standard I/O drivers for each Logical Unit Number - making the task of interfacing non standard devices to Fortran, a straightforward one.

Fortran Package. 32K single drive minimum

£65.00 + VAT = £74.75 50p P & P Access

Send large SAE (27p) for our current Catalogue of TRS-80 Software. Add £1.45 for a binder.
A.J.HARDING CMOLIMERX3
28 COLLINGTON AVENUE,BEXHILL-ON-SEA, E.SUSSEX. TEL: (0424) 220391
TELEX 86736 SOTEX G FOR A. J. HARDING

BARCLAYCARD
MVEISAM

20 PCW

MICRO MARKET
ALL YOUR FAVOURITE SYSTEMS AT PRICES YOU CAN AFFORD

WE OFFER A WIDE RANGE OF PERSONAL, PROFESSIONAL AND BUSINESS SYSTEMS, AND PERIPHERALS AT DISCOUNT WAREHOUSE PRICES, BUT WITH A SUPPORT SERVICE MORE COMPREHENSIVE AND EFFICIENT THAN FULL PRICE STORES. ALL MACHINES CARRY OUR EXTENDED NO QUIBBLE WARRENTY, AND 'MICRO MAINTENANCE' OFFERS YOU COMPETATIVE MAINTENANCE AGREEMENTS OR REPAIR SERVICES ON ALL EQUIPMENT AFTER THE WARRENTY PERIOD. OUR IN-HOUSE SOFTWARE DIVISION IS ALWAYS AVAILABLE TO OFFER ADVICE AND SOLUTIONS TO YOUR SOFTWARE PROBLEMS, AS ARE THE STAFF OF `MICRO MAINTENANCE' TO HELP WITH YOUR HARDWARE AND PERIPHERAL
ATTACHMENT DIFFICULTIES.

EXTRACTS FROM OUR PRICE LIST

COMPUTERS

COMPUCOLOR II 16K RAM with internal

Floppy Disc, Extended Basic, Assembler,

Text Editor Sampler Disc, Formatter, and

10 part basic tutorial

From E1095.00

EXIDY SORCEROR 32K ROM Basic, dual
cassette interface, RS232, fully expandable From £699.00

ALTOS 4MHz Z80 32K RAM, I megabyte 8 inch dual density Floppy Discs, RS232 x 2, Parallel Port. Full software range available
including CP/M, Cobol, Business Basic, Fortran, Pascal, Microsoft Extended Basic
From £2750.00

VDU'S

CIFER 2600 series - high quality displays with detachable 62 or 102 key keyboard
From £650.00

PENTLAND VDU terminals - excellent

value for money

From £430.00

PRINTERS

PAPER TIGER 132 char. RS233/parallel

switchable interface, up to 275 lines/

minute, tractor feed

From £525.00

ANADEX DP 8000 serial/parallel switchable

interface, 120 CP's bi-directional, tractor

feed

From £499.00

SUPPLIES
Full range of top quality discs, cassettes, paper etc. always available

SPA 8000
WE ARE NOW DISTRIBUTORS FOR THE SJL 8000 BUSINESS MANAGEMENT SYSTEM. SJL HAS BROUGHT TO THE MICRO COMPUTER INDUSTRY INVALUABLE EXPERIENCE GAINED FROM DESIGNING AND IMPLEMENTING SYSTEMS ON LARGE MAINFRAME COMPUTERS.

THE SJL SYSTEM IS PRICE FROM £8500.00 AND INCLUDES:-
* HARDWARE AND SOFTWARE COMPLETE IN SYSTEM DESK
FULL SUPPORT BEFORE, DURING AND AFTER INSTALLATION
SYSTEM TAILORED TO YOUR UNIQUE REQUIREMENTS
DATA BASE CONCEPT ENSURES TOTAL INTEGRATION OF APPLICATIONS

* DESIGN CONCEPT ELIMINATES OPERATING SYSTEM, FILES, AND USER PROGRAMS, ENSURING EASE OF USE BY EXISTING STAFF. CALL IN FOR DEMONSTRATION

PHONE, CALL OR WRITE FOR COMPLETE PRICE LIST AND DEMONSTRATIONS TEL: 01-751 6695 TWX: 8954428 138 CHALMERS WAY, NORTH FELTHAM TRADING
ESTATE, FELTHAM, MIDDX.

MICRO MAINTENANCE
NOW THE MAINTENANCE AND REPAIR SERVICE YOU HAVE BEEN WAITING FOR. WE HAVE EXPANDED OUR EXISTING LARGE MAINFRAME ENGINEERING OPERATION TO INCLUDE MOST MAJOR MAKES OF PERSONAL, PROFESSIONAL AND BUSINESS COMPUTER SYSTEMS. THIS MEANS YOU CAN NOW OBTAIN THE SPEEDY AND EFFICIENT SERVICE DEMANDED THROUGHOUT DATA PROCESSING BY LARGE INDUSTRIAL MAINFRAME
USERS! MAINTENANCE CONTRACTS ARE AVAILABLE ON INDIVIDUAL ITEMS OR ON COMPLETE SYSTEMS. BECAUSE OF OUR LARGE RESOURCES BOTH IN TEST EQUIPMENT AND MICRO ENGINEERING SKILLS, THOSE NOT REQUIRING A MAINTENANCE CONTRACT WILL FIND THEIR REPAIRS ARE CARRIED OUT WITH MINIMUM DELAY AND EXPENSE. BOTH REPAIR AND MAINTENANCE SERVICES ARE OFFERED ON SITE OR DELIVERED TO ENGINEERING
CENTRE BASIS. TRADE ENQUIRIES WELCOME.

PHONE, CALL OR WRITE FOR COMPLETE PRICE LIST AND DEMONSTRATIONS TEL: 01-751 6695 TWX: 8954428 138 CHALMERS WAY, NORTH FELTHAM TRADING
ESTATE, FELTHAM, MIDDX.
"MICRO MARKET AND MICRO MAINTENANCE ARE PART OF SUN COMPUTING SERVICES LTD"

PCW 21

apple/
ITT USERS
8" DISK DRIES I MEGABYTE On LIME
Available either as:
I .COMPLETE SYSTEM E1800 +UM
2.1'2 MEGABYTE SYSTEM E1200 AJAX
3.COMTROLLER ONLY E283 +MAI

FARMPLAN /SVA Netherton
Ross -on -Wye
Herefordshire
22 PCW

Tel: 0989 4321

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Micro -computers for research, laboratory work, word processing, business systems, Schools, Colleges, Universities and Industry. At Almarc, when you buy Vector Graphic Micro -computers, you get Almarc's experience of over 200 systems installed throughout the U.K. and their back-up of full service facilities carried out by experienced staff. Plus an ever growing list of compatible software
including: Pascal, Fortran, Cobol, APL, Algol, C Basic Compiler, etc.

Vector MZ Spec
* 56K Bank Selectable Ram. * 3 Serial Ports, 2 Parallel Ports. * Twin Disc Drives, 630K Capacity. * 280 CPU, with Fast 4MHZ Clock. * Prom Programmer (2708). * Interrupt Handling on 1/0 Board. * 18 slot Motherboard

Vector System B
* Vector Mindless Terminal. * Flashwriter II Video Board (24 x 80). * MDOS + CP/M2 Operating System. Plus Microsoft Version, 5 basic options. Plus many S100 Bus add-ons, such as Extra Memory, A/D-D/A Boards, High Resolution Graphic, etc.

We will be pleased to demonstrate any of the Vector Graphic Systems, please contact:

906 Woodborough Road, Nottingham. Telephone: (0602) 625035
Specialists in Vector Graphic Equipment.

PCW 23

which computer? tapple

24 PC \

VN.!ch a ffibmiere

Fully Integrated Ledger System

£855

Gives management information i.e. aged

accounts on individual clients, sales analysis.

Trial balance. Profit and loss and Balance

sheet included.

Payroll ll

£375

Accepts all tax codes. Gives departmental

analysis. It's user configurable and tax rates

are user changeable. Operator can change

names of items on payslips.

Invoicing

£140

Either stand-alone - or can form part of our

General Ledger System.

Cash Flow/Bank Forecast

£80

Automatically updates all data following each

alteration of an item. Gives Column and line

totals. Saves a lot of boring work when a

Company operates with more than one bank

account.

New Word Processing/Data Base

£120

Screen-based editor, powerful global search

editing facilities, formatting facilities, address

data base facilities and possibility to join

sections of text, old and new, for the final

printout. FAST AND EASY TO USE.

The above programs work either on Apple II floppy system or a version for 10Mb Corvus hard disc drive is available.

Complete computer system with above,
under £5,000
including installation, training and 1 year warranty.

Financial Analysis with VisiCalc £95.00 VisiCalc combines the convenience and familiarity of a pocket calculator with the powerful memory and electronic screen capabilities of the computer and can do calculations of sales projections, income taxes, financial ratios, your personal budget, engineering calculationii, cost estimates, in fact, anything normally done with a calculator, pencil and paper. Recalculation makes VisiCalc a powerful planning and forecasting tool. Not only can you effortlessly correct mistakes and omissions, you can also examine various alternatives, and above all it does not require any previous knowledge of computers and programming.

TRADE ENQUIRIES WELCOMED

Stationery Support
Listing paper and labels Please phone for details or send for comprehensive catalogue.
let/LASAK

Binders Special sizes to fit those non-standard computer listing paper sizes.
BASF Diskettes Best quality at reasonable prices.
Bespoke Stationery Ring for advice on customised stationery or consult our catalogue - no quantity too
small.

Service is our business We are as near as your telephone, an extensive range of standard items always in stock.

BARCLAYCARD
VISA

eAi

Vlasak Electronics Ltd., Thames Building, Dedmere Road, Marlow, Bucks. Tel: Marlow 74789

. . . THERE MUST BE ONE HERE FOR YOU

Tne Exidy family is a sophisticated range of products designed to meet the ever increasing variety of computing needs, including home and business uses, educational and laboratory applications, industrial process control etc. The Exidy range has been designed with built-in growth capacity to take the risk factor out of computer investment. The Sorcerer Computer now has a memory expansion capability from 8K up to 48K within its own cabinet, enabling the system to grow with your needs plus the ability to add many additional plug-in facilities such as disk drives and
pre-programmed ROM PAC's. The standard configuration includes a 63 key typewriter -style keyboard and a 16 key numeric pad. Remote control for dual cassettes. Serial RS232 and parallel interfaces, Z80 processor, 4K resident operating system, 8K Microsoft BASIC in separate plug-in ROM PAC cartridge, 64 character x 30 line display, 128 upper/lower case ASCII character set and 128 user defined graphic symbols, operators manual, introduction to basic programing, connecting leads. All Exidy equipment is backed up by a 12 month warranty covering both parts and labour. The Word Processing ROM PAC features auto wraparound, dynamic curser control, variable line length, global search and replace, holding buffer for re -arrangement of text, right justification, line width and line to line spacing, underlining or boldfacing, text merging and a macro -facility permitting tasks such as formletter typing, multiple column printing of automatic forms entry.

Now contact your nearest dealer:
The NORTH T.W. COMPUTERS, 293 London Road, Hazelgrove, Stockport. 061 4568187 BASIC COMPUTING, Oakville. Oakworth Road, Keighley. W. Yorkshire. 0535 65094 E. S. MICROCOMPUTERS, 7 Berkeley Precinct, Eccleshall Road, Sheffield Si 1 8PN. 0742 668767 GLYSTHYDON LTD., Nook Farm, Rake Lane, Warton, Preston, Lancs. 0772 633138 MICRODIGITAL, 25 Brunswick Street, Liverpool L2 OBJ: 051 227 2535 MICROPUTE, 7 Westbourne Grove, Manchester M20 8JA. 061 445 8588 MAGNUM CONSULTANTS. 57 Fairburn Drive, Garforth, Leeds. 0532 867892
MIDLANDS M & R SYSTEMS, 20 Norwich Road, Wisbech, Cambs. 0945 5900 MIDLAND MICROCOMPUTERS, 1 Cherry Wood Dove, Aspley, Nottingham. 0602 298 281 GRIFFIN & GEORGE Birmingham, Manchester, London, Eastkilbride 01-997 3344
LONDON and the SOUTH EAST C.C.S. MICROSA L ES, 7 The Arcade, Letchworth, Herts. 046 26 73301 MICROBITS, 34b London Road, Ellackwater, Camberley. Surrey 0276 34044 SLOUGH MICROSHOP, 120 High Street, Slough, Berks. 0753 22855 HOME & BUSINESS COMPUTERS, 445 High Street, Manor Park, London E12. 01-472 5107 E. M. G.. 30 Heathfield Road, Croydon, Surrey CRO 1 E4 01 688 0088 G. P. W. ELECTRONICS. 146a London Road. North End. Portsmouth. Hants. P02 90..I 0705 693341 INFORME X LTD., 8-12 Lee High Road London SE13. 01-3184213 N.I.C., 61 Broad Lane, Tottenham N15. 01-808 0377 TVJ MICROCOMPUTERS, 165 London Road. Camberley, Surrey CU15 3JS 0276 62506
WALES and the WEST ELECTROPRINT, 5 Kinosdown Parade. Bristol BS6 5UD D272 292375 TRYFAN COMPUTERS, 3 Swifts Buildings, High Street, Bangor, Gwynedd LL57 1 UW. 0248 52042 TVJ MICROCOMPUTERS, 48 Gloucester Road., Bristol 0272 422061

Or send coupon for further information to: SOLE DISTRIBUTORS
Geoff Wilkinson LIVEPORT DATA PRODUCTS The Ivory Works, St. Ives, Cornwall 0736-798157
PLEASE SEND DETAILS OF THE EXIDY RANGE
I NAME
I ADDRESS
I I I I

PCW 25

GREAT

NORTHERN

SOLVE

THE

SOFTWARE

If you are puzzled by the lack of good software for micro computers - then puzzle no longer! Great Northern Computer Services are distributing first class packages for CP/M based and Apple micro computers.

PUZZLE

There are complete packages for: Stock Control for retailers for Apple or CP/M Systems. Integrated Accounting System - Sales, Purchase and Nominal Ledger for CP/M systems. Professional Client Billing - complete invoice and sales ledger system for a professional practice.
Statistics for Apple. Data Base Management for Apple or CP/M systems. If you want to write your own then use MAGSAM multi -index routines within your Basic Programmes. Whatever your needs, stop puzzling - contact your dealer or

GREATNORTHERN Computer Services Limited

116, Low Lane, Horsforth, Leeds, LS18 5PX. Telephone: [0532]589980. Telex: 556276 FOR GT. NORTHERN.

RICOH RP -1600.

£1250

Richo high-speed daisy wheel, heavy duty commercial

printer gives a high -quality printout, coupled with

low noise level necessary for office environment. Nation-

wide service by UDS. Service under 90 day warranty

is provided at your premises.

124 char: upper/lower case. - 60 chars:/sec print

speed - 10/12 chars: per inch giving 136 or 163 columns.

- 15 inch wide friction platen. - forward/reverse

paper feed for graphics. - Top of the form and host of

other features. - Centronics type parallel interface

as standard. Options: serial interface £60 - PET interface £75 APPLE interface £75 -
TRS-80 interface £45.

OKI MICROLIN 80
lopTHE QUIETEST DOT MATRIX PRINTER AVAILABLE. VERY HIGH PRINT QUALITY. TAKES ALL THREE, LETTER HEADS (SINGLE SHEETS), OR FANFOLD PAPER OR PAPER ROLLS. 40, 80 OR 132 CHARACTERS PER LINE SOFTWARE SELECTABLE. 100% DUTY CYCLE, YOU CAN USE DAY IN AND DAY OUT. VERY COMPACT. NO MAINTENANCE NECESSARY. CENTRONICS PARELLEL INTERFACE STANDARD. INTERFACES FOR RICOH, ANADEX AND OKI PET NON. ADDRESSABLE £40.00, ADDRESSABLE £75.00, APPLE £75.00, SERIAL (RS232) £75.00.
Prices quoted above do not include VAT.

ummommiammiS

SUPERBRAIN £1875

COMPLETE COMPUTER TWIN Z 80-A 4MHZ. -2 DOUBLE DENSIT.Y DISC DRIVES. -64K RAM.- HIGH RESOLUTION 12 INCH CRT. 80 x 24 LINES. - UPPER/LOWER CASE. 111 2 RS232 PRINTER PORTS. - CPM OPERATING
SYSTEM. - WORD PROCESSING & ACCOUNTS PACKAGES AVAILABLE.

EPSON TX -80

£395

DOT-MATRIX PR INTER WITH PET GRAPHICS

PRINTS 80 COLUMNS ON PLAIN PAPER AT 90

CHARACTERS/SECOND. ADJUSTABLE TRACTOR. -

UPPER/LOWER CASE. - DOUBLE WIDTH PRINTING. -

MICRO CONTROLLED. -SELF TEST. - HEAVY DUTY

PRINT HEAD USING JEWELL BEARINGS FOR LONG LIFE.

- CENTRONICS PARALLEL INTERFACE. - MADE BY

SHINSHU SEIKI AN AFFILIATE OF SEIKO WATCH CO OF JAPAN. OPTIONS. PET INTERFACE WITH CABLE £50.

APPLE INTERFACE WITH CABLE E80.

EPSON
Phone or call for further details or demonstrations.

LONDON COMPUTER STORE 43 GRAFTON WAY, OFF TOTTENHAM COURT ROAD, LONDON W. I
TEL: 01-388 5721 OPENING HRS: 11-7 MON-FRI, 12-4 SATS.

26 PCW

DATRON of S EFFIELD 110/C0111 skisrEnn
001300

IMP PRINTER
£325 +VAT

SYSTEM 80 Case & Card Frame
£85 + VAT

INTEGER PASCAL FROM DATRON

Nascom 2 (Kit) £225 + VAT

I.N/..1IP1,0V1I1N11P11IP111,01111011011.100 '1614 ARVIN rila MVO SI a
2, A AINNMEMINII

Memory Boards
16 K £110 32K £165 48K £ 225

+ Z 80 Books

+VAT

Z80 Programming For Logic Design

Osborne

Practical Micro. Programming with 280 Weller

Z80 Microcomputer Handbook

W. Barden

Z80 Microprocessor Programming &

Nichols &

Interfacing Vol. 1

Rony

Z80 Programming & Interfacing

Nichols &

Vol. 2.

Bony

Z80 Assembly Language Programming Osborne

Z80 Instant Programs

J. Hepton

Z80 Instant Programs - Cassette of above

Mostek Z80 Microcomputer Software

Programming Guide

Z80 Assembly language Programming Leventhal

£6.30 f19.55
£6.95 f7.75
£6.50
£6.95 £7.50 £10.00 £6.00
f6.95

+ Basic Books

The Basic Handbook The little Book of Basic Style Basic/Basic Basic/Basic Advanced Basic Outline Programming with Basic Problem Solving & Structured
Programming in Basic Illustrating Basic Some Common Basic Programs Some Common Basic Programs
(Pet Cassette) 32 Basic Programs for the Pet Basic Primer A Guide to Basic Programming A Guide to RIM Programming

David k lien
Nevison Donald M. Munro J. Coen J. Coen Gottfried Koffman & Friedman

£11.50 f5.25 £2.00 £6.50 £6.00 £3.70 f8.95

Donald Alcock Osborne

£2.50 f6.45 £7.95

Rugg & Feldman Waite & Pardee
Spencer McCracken

£9.75 £6.95 £8.85 £7.95

+ Basic Course PROGRAMMING IN BASIC
An intensive week -end course 28 -29 June 1980 Hallam Tower Hotel, Sheffield. 19-20 July 1980 £125 inclusive

T2/B-BUG/T4/NASSYS Compatible.
For this 12K Compiler we recommend a 32K ram Machine. The compiler produces Z80 machine code and supports.
Procedures and Functions, BEGIN -END, IF -THEN -ELSE, CASE -OF -ELSE -END, WHILE -DO, REPEAT -UNTIL-, FOR-TO/DOWNTODO-, CALL- (Call assembler routine), READ/WRITE (Character, hexadecimal and decimal integer I/O is allowed WRITE also allows string output). MEM(-) (An array allowing access to memory, the equivalent of PEEK/POKE), Arrays allowed, Programme fully recursive, Integers ± 32767.
Each statement fully documented, and a complete set of syntax diagrams provided. Also a sample programme is provided.
Cassette Et Documentation £35 Plus V.AT. Documentation alone £2.50.

+ Pascal Books

Introduction to Pascal Structured Programming & Problem
Solving with Pascal Primer on Pascal Programming in Pascal Pascal An Introduction to Methodical
Programming Micro Problem Solving - PASCAL

Welsh & Eder Richard IGeburtz
Conway et al Grogono Fndlay & Watt
Bowles

£6.95 £8.40
£7.10 £6.75 £4.95

CROMEMCO, SHARP, APPLE, ITT, PET, ITHACA

IMMO

1=I

IMEN

Please supply: -

I NASCOM I Imp at ; System 80 Case

TICK
£325
£ 85 0

TICK Pascal Tape £35 D
for monitor -T2

I Nascom 2

Z225

T4 111

1 16 K Memory Board £110 E

B Bug D

32K

£165 0

Nas Sys

48K

£225 Documentation £2.50 0

ME - 12 Amp Power Supply £ 29.50 0 Basic Course Details 0

MI= MINI Mill MINE IMO

MIIM

Books

I

I enclose :- £

I

Cheque/Postal Order No.

I

Barclaycard/Access No.

I

Name

Address

DATRON MICRO CENTRE, Latham House, 243 London Rd

Sheffield S2 4 N
mom

Tel:0742 585490 Telex: 547151 Nom

PCW 27

aLi:01

ALECI.5

SOFTWARE DEVELOPMENT SERVICES LTD
Micros and Micro Software
11 ST CROSS ROAD WINCHESTER HAMPSHIRE TEL: (0962) 68956/7

We are a software house, specialising in commercial applications for Microcomputers. We provide a
complete service from the initial survey through to the turnkey system designed for YOUR business
needs. The machine we recommend for ease of use and reliability is the ALTOS 8000.
For further information contact:
Monitor (Data Processing) Ltd Prospect Chambers, 4 Prospect Crescent,
Harrogate, North Yorkshire HG1 1RH
MONITOR (DATA PROCESSING) LTD.

Profac Computer Services Ltd.
100 Park Street, Camberley, Surrey. GU15 3NY Tel: Camberley (0276) 25247
"Altos hardware, software, and complete systems."

Peter Naelfaa9koff (gialmodata
Suppliers of Systems in the East of Scotland
PETER MACNAUGHTON & ASSOCIATES ANNFIELD, GLENALMOND, PERTHSHIRE
Tel: (073 888) 267

Dealer Guide Dealer Guide Dealer Guide Dealer Guide Realer Guide Dealer Guide Dealer Guide Dealer Guide Dealer Guide Dealer
28 PCW

INTERFACE SOFTWARE LTD.
100 Park Street, Camberley, Surrey, England GU15 3NY
"Altos software packages including Sales ledger, Purchase ledger, Nominal ledger, Payroll, Inventory, and Mailing Address."

Production Control Systems:
Work -in -progress Control Workshop Scheduling (to finite capacity)
Factory Load Reports Inventory Control, Parts Explosion
Requirements Planning Job Costing
Kewill Systems Limited 500 Chesham House 150 Regent Street London W1R 5FA Tel: 01-734 5351

5

eu

:14lizeA

Cd

N. LONDON AND HOME COUNTIES

NOW HERE !

01- 950 0303

Serving Yorkshire & North Midlands

BOYD MICROSYSTEMS
59 HIGH ROAD, BUSHEY HEATH,
HERTS.

SHEFFIELD

COMPUTER CENTRE

Computer Centre (Sheffield) Ltd. 225 Abbeydale Rd., Sheffield S71 FJ. Telephone 0742 53519.

MICROCOMPUTERS MKROPROCESSORS
S°FTWAREsERviaNG
SALES& CONSULTANCY

I
Dealer Guide Dealer Guide Dealer Guide Dealer Guide Realer Guide Dealer Guide Dealer Guide Dealer Guide Dealer Guide Dealer
PCW 29

For Altos equipment and associated systems contact:
METRODATA

Derwent Electronics Ltd Mirlees House Holgate Road
CITY of YORK. Tel: (0904) 53990

Metrodata Sutcliffe House 49 Barrack Road,
LEEDS 7 Tel: (0532) 623788

SILICON CHIP, (Ian Laurie) 302 High Street, Slough,
Berks.
0753 70639
Bespoke software available Packages available for stock control
(up to 10,000 stock lines.) Payroll up to 3,000 employees, mail shots/ word processing (up to 10,000 customers.)
Ledgers available soon.

Sseis Clunputar

Urns Id

Mini/Micro Computer System Consultants
Commercial Software Services
Midlands Dealer for ALTOS SERIES 8000 Micro -Computer Systems
Telephone : 021-643 2021.

OFFICE EQUIPMENT UNIT 14, ANDERSTON CROSS CENTRE
ARGYLE STREET GLASGOW G2 7PH
SPECIALISTS IN MICROCOMPUTER SYSTEMS. FOR APPLICATIONS IN THE
WEST OF SCOTLAND CONTACT JOHN THOMPSON ON (041) 221 5401/2.

Dealer Guide Dealer Guide Dealer Guide Dealer Guide dealer Guide Dealer Guide Dealer Guide Dealer Guide Dealer Guide Dealer
30 PCW

EiEti3 [Computers] Limited
The Coneutterite for the forth West

For ALTOS systems in the West Midlands Region contact:
CLE. COM Ltd., 8 Stanley Road, Kings Heath BIRMINGHAM 14.
(TEL. 021-444 3618 or 021-472 8233) Specialists in the provision of COMPLETE
systems: Technical Advice, Hardware, Software Development, Installation and Training.

hat other system offers you so much for

a capital investment of £3000.
Wendmore offer brokers an easy to operate and

inexpensive micro -computer system called Offload.

Offload produces the
following: Storage of client
information. Financial and statistical analyses. Debtor controls and profit accounts for easy insurers reconciliation.

Production of renewal
notices.
Ability to select particular categories for direct mailing. The facility for automatic letter writing. What other system offers you so much for a capital
investment of £3000.

FOR ALTOS 800 SYSTEMS IN THE SOUTH-WEST CONTACT BOB CHEDD AT VALIDATA
IMILIDATA

- the system designed to grow with you.

- WENDMORE the company that
MANAGEMENT SERVICES LIMITED brought you MOQUOTE.

For further information Jeremy Berated.

Sariebury Buildings. Tel: Locks Heath

about the 'offload'

The Sates Director. 180 Bridge Road.

system please write to: Wendmore

Sariebury Green.

(04895)6318M/0 Telex. 47146

Management Services Hampshire. SO3 7EH

Limited.

FOR ALTOS 800 SYSTEMS IN THE SOUTH-WEST
CONTACT BOB CHEDD AT VALIDATA
26 HIGH STREET, ME LKSHAM, WILTSHIRE (0225) 705 957

Dealer Guide Dealer Guide Dealer Guide Dealer Guide Healer Guide Dealer Guide Dealer Guide Dealer Guide Dealer Guide Deaici

40
TIAE:Nentor4 GIOMF'UrrEIR BEFcVIGIES.(MAIL

41 PRICE LIST APRIL 1980 *********************

ALL PRICES EXCLUSIVE OF DELIVERY & V.A.T. 41

I . . . 720120 WITH COLOUR CARD AND PALSOFT IN ROM.

16K k. 71:3'-9.00 32K £ 7 9-9. C:0 48K Ea

(.)

41

I.T.T. 5.25 INCH DISK DRIVES :-

CONTROLLER CARD £49.00 DISK DRIVE £299.00

PRINTER CARD (PARALLEL) £79.00

40

MEMORY UPGRADE (16K) FOR I.T.T.2020 £60.00

ANAEIELX EIF-E3000
40 ALSO NEW ANADEX APPLESIDER AND DP -9500.

11.5 BY 8.5 PAPER 4000 SHEETS £18.00 5.25 INCH MINI FLOPPIES (BOX OF TEN) £19.50
ALL CONSUMABLES AVAILABLE !!!

40

TRAINING GIVEN.COURSES FROM IDIOT LEVEL UPWARDS !

BAULFLTWEARNEI4Q.U1FI:FRI I1E-1S1ERWIELOCR DAVMAIELABLE EX -STOCK

41

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40 * WE RECOMMEND THE E-cF: I "I" I SI-I MADIE ITT 2020 MICROCOMPUTER

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*

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*

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11 FULL SUPPORT WITH ALL SERVICING AND "HANDS ON" COURSES AVAILABLE
SIEJF-TWAFRE ABBISTAMIC !!!
BEFORE PURCHASE.LET US SHOW YOU HOW TO WRITE YOUR OWN PROGRAMS....

ALL MAJOR CREDIT CARDS ACCEPTED.

DON'T DELAY,PHONE TODAY.

WE APPRECIATE THAT NOT EVERYONE SPEEKS COMPUTERESE AND WE TRY TO

GIVE NEWCOMERS TO THE MICRO -CHIP ERA EVERY ASSISTANCE POSSIBLE.

40

FOR ADVICE AND DETAILS OF OUR COURSES AND SUPPLIEStJUST LIFT THE

TELEPHONE AND DIAL :-

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-71-4 v no !NI SO I B ( ESSEX )

:2 1.

ONLY FIVE MINUTES FROM THE LONDON UNDERGROUND (CENTRAL LINE)

WARNING FFRIOM -FFIEVIDDIN COMPUTER SERVICES.

40 DEALING WITH OTHER COMPANIES CAN DAMAGE YOUR PURSE

41

32 PCW

"Micro mania hits London staggering success-the sort of frenzy usually seen at January sales." Datalink (16/7/79)

Tr2 big One

See you atTheWembley Conference Centre
22-24 July,1980

Last year's Show broke all records and made headline news in many newspapers. The 1980 Show with it's

exhibition, international conference and one -day seminars, adds up to the most significant microcomputer

event ever held.

Join the top names in the business and reserve your space now-and remember exhibitors who have also booked for the Mersey Micro Show are entitled to a 10% discount on both events!

//

Seminars held on the first two days will inform the business man of the many ways micros can be used as a commercial aid, both in the office and the home. The seminar on the third day will be devoted to education applications.

e
/ //roc.14 .k

In addition, a two-day international conference will examine the state of the art in

/ co('

microelectronics with distinguished speakers from the UK and overseas.

Return this coupon or call Jane McBarnet at Online Conferences Ltd.,

Argyle House, Northwood Hills HA6 1TS.

Telephone: Northwood (09274) 28211

//

/ 4' \

/ e6

cc,

v e

e,`" 4!)

cps -

0-4c,;c"

O

0,:7>

/// Oq

c).

/z/

PCW 33

Consumer
Division
Texas Instruments' consumer products incorporate the latest micro -electronics technology for which our name has become
a by -word.
Pioneers in electronic calculators, digital watches and learning aids, Texas Instruments' position as market leader was established with winners such as the TI -30 student calculator and 59 programmable calculators. This leadership is maintained by the continuous introduction of innovative ideas. Consumer products such as Speak and Spell, the speaking Language Translator; Starbust
- the world's first analogue display LCD watch; and now
the Home Computer.

Home
Computer Marketing

c £7000 + car

Texas Instruments are developing a new concept in personal computing and are building a dynamic, consumer -oriented marketing team in Bedford.
An opportunity now exists for a technical contributor to this team. He or she must be familiar with technical aspects of personal computing hardware, but should already be thinking about the applications of this new technology to self -tuition, entertainment and home management.
The job includes aspects of market research, promotions, product evaluation and marketing planning. This assignment
offers a unique opportunity for a self -
motivated individual who wants to join one of industry's most innovative organisations and give micros to the world.
The ideal candidate will probably be under 30, with HNC or above and knowledge of

microprocessor technology. Above all, he or shewill be ableto demonstrate a creative flair which can be harnessed to this exciting new market place.
The position is based at our UK Headquarters in Bedford, easily accessible, with reasonably priced housing in an attractive part of England. Comprehensive relocation assistance will be given where appropriate.
Starting salary is negotiable c £7000 p.a., depending on age and experience plus car, profit-sharing, free medical and life assurance schemes, contributory pension plan and extensive sports/social facilities.
In the first instance, please write with full details to: Ann Stevens, Texas Instruments Limited, Manton Lane, Bedford, or telephone her for an application form on Bedford (0234) 67466.

TEXAS INSTRUMENTS Fifty Years
Innovoaftion

LIMITED

where people and technology meet

IF you want the best service you need professional advice years of experience impress you you are trying to find the best computer equipment
as well as the finest software
is the Company to contact
MICROSOLVE COMPUTER SERVICES LTD 3rd Floor (rear),
MIDDLESEX HOUSE, 29-45 High Street, EDGWARE, Middlesex.
(exit 4 M1/20 mins. West End). (prices ex. VAT)
01-951 0218/9/0

We cover a full range of equipment including the APPLE II (from £695/16K); the
MICROSTAR multi-user system (from £4,950) and the powerful ALPHA MICRO which will
run 1 to 22 terminals - the most cost effective system available today.
WE OFFER A COMPLETE SERVICE which encompasses advice, systems design, sale
and installation of computer and peripherals, as well as tailor-made software, where necessary. There are fully documented ACCOUNTING and WORD PROCESSING PACKAGES etc., for
Accountants, Solicitors, Manufacturers, Retailers, Medical Practitioners in fact all
business applications.
ALSO in stock are PRINTERS, VDUs, CONTINUOUS STATIONERY, DISKETTES,
DISK BOXES, all from the best names in the computer world - TEXAS, LEAR SEIGLER, TALLY, QUME, PAPER TIGER etc.
So if you either wish to buy a computer to program yourself or take advantage of our service TELEPHONE NOW FOR AN APPOINTMENT.

1111CROSOLVIIIIICROSOLVE
34 PCW

OUR SYSTEMS
CAN GROW

When you buy one of our

The prices include an

low price microcomputer

operating system and

development systems you

language,in this case

not only get a fully

CP/M and C-BASIC,to

burnt -in and tested system designed and

give a typical system cost. But with slight cost

manufactured to industrial standards.You also get adjustment the software options are:

access to an ever-increasing range of software tools.And if you require a VDU or printer now or later,there is a selection of these and other peripherals from which to choose. So your system

Operating Systems
CP/M PASCAL CAP MICROCOBOL BOS
Multi -User, Multi -Tasking Operating Systems

can grow and grow.

Languages

Our systems start to grow on you at £1450.This C -BASIC COMPILER M -BASIC FORTRAN -80

buys you a 32KB system with dual 5+ inch double

COBOL -80 PASCAL CIS -COBOL

density floppy drives.At £1675 you can have a 48KB system or for £2495 one with the extra memory storage provided by dual 8 inch double

There is also a word and text processing system available that is ideal for report writing.

density floppy drives.All the systems are based on

You simply take your pick from the software

the powerful Z80 microprocessor and S100 bus

options.Or visit our London showroom and see the

structure and can provide memory management. systems demonstrated.

Cartridge disc drives are available providing up to 40MB of storage.

SYSTEMS 32KB + Dual £

1675 WITH CP/M AND 51 inch Floppies: C -BASIC. 48KB + Dual

51 inch Floppies:

48KB + Dual £
8 inch floppies:

Prices exclude VAT. Nationwide maintenance facilities available.

EQUINOX
COMPUTER SYSTEMS LTD.
Kleeman House,16 Arming Street, New Inn Yard, London EC2A 3HB Tel:01-739 2387/9 & 01-729 4460

PCW 35

In addition to his normal run through the general news, this month Guy Kewney presents a special Stateside Supplement.

The ups and the downs

Many firms have gone bust in the micro business both in the UK and in America including famous ones such as Byte Shop and less famous ones such as Sphere. The question of why they went under is important. To Clive Sinclair, the answer is clearly "competition". He is very nervous about the market lead he has established with his ZX80 £100 computer, and will not say anything about how the inside works.
To people with less at stake, the reason that companies like Processor Technology (American maker of the Sol computer) died is simple: bad management, and an apparently mindless determination to destroy themselves. As far as I have been able to find out, nobody with microprocessors to sell has been unable to sell them. More, even those without microprocessors to sell, have been able to get money in advance, with which to design them.
Where most of the companies that have gone wrong, went wrong, was in trying to move "up market" and in trying to supply "business machines". The new micro men have all arrived in the computer business by mistake, and it isn't surprising that they should be tempted by the "up market" argument. They weren't around for the Small Business Crash of six or so years ago.
At that time, the advances of technology which made the minicomputer possible, had led to the VRC - the visible record computer. Its strong point was that it was cheap, and that it was a very basic do-nothing machine. That was in about 1968; and around then, the idea that these things were "really" computers began to tease the minds of their makers.
If the machine is "really" a computer, reasoned the buyers, they could do all the things on the machine that big computer owners could do on their machines. It took a while for this attitude to feed back to the

computer makers ... to
Phillips, Olivetti, Kienzle, Triumph Adler, and similar office computer makers. But when it did, the result was: disaster.
In theory, a machine which does accounts under control of software can, indeed, do anything else. In practice, the cost of getting it to do something else is prohibitive. Very roughly, the cost of an item of software, to a commercial enterprise producing it by paying clerks, is £10,000. The cost of marketing it, and supporting it, is estimated as between another £10,000 and three to four times that figure.
The office minicomputer companies found that their salesmen were promising to supply programs to do anything from stock control to planning of salesman's rounds, for an additional fee of around £3000 "or more". The "or more" naturally turned out to be anything up to £20,000 - on a computer costing under £10,000.
Is all this starting to sound familiar?
The simple fact is that unless a man writes his own software in his own time, software costs that sort of money. To sell a £30,000 package for £300, you have to sell 100 identical packages. Moving "up market" immediately tells your customers that you are in fact going to do a little better, and that you can tailor the software to their requirements; this usually costs much more than either side expects.
The logic usually advanced to justify a move "up market" is: "We've saturated the hobbyist market, and have to cater to the small business, which is more profitable anyway; so we've packaged the system and put the price up."
What has actually happened is often a lot simpler. The product has gone out of date. If the market for hobbyists has indeed become saturated, why is Clive Sinclair selling at a rate of well over 1000 systems a month? Because he has gone up market? At £100

including tax? I doubt it. All this is about as long an
introduction as even I can be expected to write, to front the news that Nascom has packaged its Nascom 2. From the tone of the introduction, readers will gather that the packaging and "moving upmarket" doesn't impress me. The only thing about the new -look Nascom that does impress me is the new memory board with 48 Kbytes of memory chippery - and a paging system.
Look at Nascom from historical experience: when the first machine was announced, the choice was between the Motorola D2, the Kim 1, American systems retailing at a couple of thousand pounds, or the first rumours of the PET (to sell at £1000 at today's prices). The Nascom was the first cheap system that you could build with a real typewriter keyboard, a real video output, and a whole 2 Kbytes of memory. By contrast, the competition had 16 grotty keys, had to be programmed in hex, and could output only hex numbers on six calculator -type display characters, from a mere 256 bytes of store.
Technology has not got stuck since then, and if Nascom truly wants to sell the way it did in the early days, a £500 system (using a central processor that looked reasonable when it

was originally announced but won't be available till nearly a year later) is not going to steal any thunder from Clive Sinclair. Well if Nascom did it once, why not again? The answer, if you want my opinion, is that Nascom isn't in the business of stealing thunder, but of cushioning our ears. It doesn't want to upstage the Nascom 1 too much.
There is the subsidiary problem; that the money which should have been transforming the Nascom 2 into the Nascom 3 (the way the Apple I was transformed, utterly, into the Apple II) has been kept off stage in the wings. Nascom boss John Marshall has arranged about £1 million worth of finance, jointly from the NRDC and the City (Grove wood Securities, in North London geographically but in the City nonetheless) . he's not used a penny of it. Grovewood tells me that he has until June to make up his mind about whether he wants it. John Marshall himself tells me he has plans and hints that they involve other sources of finance, and asks for secrecy while he wheels and deals. He won't want my advice, but here it is: he is almost a genius at buying semiconductor parts, and producing products that are much cheaper than anyone else could arrange. He should stick to his genius.

4%, PFfiliEsi.YOT iriflUSEC

pe

The ultimate comeback to a computer -printed income tax demand or overdue and overestimated gas bill is, of course, to get your own computer to add its own comments, and return it. While waiting for the price of printers that can do this to come down to your budget level, a mere $11.00 will get you these stamps - plus a red stamp pad and a small carrying bag. Get them from New York firm Martha Herman, 5 East 17th Street, NY, NY 100003; send enough for postage/ packing ... maybe $2. It'll be chocolate with byte -sized prices next; we computeers are becoming a truly consumer market.

36 PCW

NEWSPRINT

hurry, or people with

machines able to com-

differing tastes.

municate," he added, "so it

Acorn will announce firm won't be a standard Prestel

prices at the official launch, modem with slow transmit

which may not come until and different (fast) receive,

June.

which can't talk to itself."

The diskette drive will

Z80 on the line
By the end of this year, the Sinclair ZX80 will have a Prestel circuit and a diskette both at prices "in keeping with the price of the machine", as Uncle Clive put it. This means that the machine will be able to talk to other ZX8Os down

happen this year, but only "if we can get the price down to a comparable level with the machine." That means well under £200 he agreed, but wouldn't say if it also meant well under £150. Tantalisingly, he also refused to confirm that it would be a five -inch minifloppy.

the phone line.

Paging The alterations that will
make the ZX80 a Prestel

Three different sizes of computer print-out can be filed in the Cavadex binder. For those who think printouts are only for the big computer rooms that can afford line printers turning out words at 300 lines a minute, here is a little thought. Call round to one of these places, and get as much used, scrap paper as they have left after teachers, children and other paper hoarders have had their cut - and use the back. Cave is in Northampton on 0604 48125.

machine are slight, points out Sinclair. It offers 32 characters on a TV screen now: it only has to offer eight more to be Prestel compatible. The changes will involve a completely new read-only memory chip, since that

Nascom
About the cleverest idea to emerge from the Nascom stable so far this year is a deeply buried technical specification in a paragraph dealing with details of the new 48 Kbyte memory

Acorn's mighty Atom
At last a new computer! A genuinely new personal machine is to be launched by the Cambridge firm Acorn, in May, at about £125 kit or £150 built. It's called the Atom.
The machine incorporates that fundamental necessity
for a cheap system ... it's on
a single board. It includes a BASIC which Acorn people say is three to five times faster than Apple Integer BASIC, and has the unique feature of including an assembler in the interpreter.
Normally, a BASIC interpreter is the program that a computer runs all the time; even when it appears to be running your own program it's actually doing nothing of the sort. The interpreter program is handling your BASIC instruction list data. The output from the data is what the BASIC expected, but the BASIC is not what does it.
In the case of Atom BASIC data supplied includes standard 6502 mnemonics. When the interpreter finds and recognises this data, it actually runs it, rather than calculating output from it.
Acorn directors, Herman Hauser and Chris Curry explain the ingenious nature of this BASIC by pointing at the writer, Roger Wilson. He happens to have a 6502 assembler in his head, and

running this routine. Nobody else has found a routine quick enough to run in this way: Acorn's diskette operating system therefore runs at least three times faster than anyone else's.
At the back of the Atom, there will be a 64 -way connector that is exactly the same as the one on the bottom of today's £70 Acorn two -card system. There will also be outputs to cassette tape, TV colour, and to other Atoms.
The "other Atom connection" is a daring innovation, and looks very like an idea first proposed by Chris Moller, an engineer at Modular Technology (the minimodem makers) two years ago. Each Atom can have a receiver/transmitter (not wireless, wired) with its own station code; this is done with what's known as a universal asynchronous receiver transmitter . .. or UART. Any Atom can transmit the station code of any other Atom in the circle of connected computers, and the UARTs of all remaining machines in the circle immediately set themselves to a "do not transmit" position until the other two have finished talking. The conversation runs at 9600 baud. The Acorn people see this as a classroom technique first; the teacher can take over any of the pupils' machines and see what's going on - and they can print messages on the screen.

contains the BASIC interpreter, the operating system, and the video character generator. The ROM was going to be changed anyway: a new, enhanced (floating point arithmetic) BASIC with all the trigonometric and logarithmic functions currently omitted, will be with us some time soon.
The Prestel attachment is still in fact in Uncle Clive's eye. However, he has had this twinkle undimmed since he first conceived the machine. "I would have mentioned it at the launch, only nobody asked me about it," he told me.
The modem that talks to the central Prestel computers, he hopes will work by acoustic coupling. The idea is that a plug-in socket for the normal sort of Prestel modem would cost too much compared to the cost of his coupler. "Definitely the main objective is to get the

board. It's the fact that "four of these boards can be plugged into a system simultaneously."
Normally, plugging four 48 Kbyte boards into a system using the Zilog/ Mostek Z80 chip would be a waste of three of them. The machine has 16 wires with which to address memory, and the maximum memory that can give is 64 Kbytes (65,536 memory locations, in strictly accurate point of fact, that number being the possible permutations of 16 dots and -lashes, or 2 to the power 16). Nascom has done its trick by "paging". An output instruction addressed to port FF of the Zilog cpu chip sets any one of the boards to read, and any of the boards to write. They can be the same board, but they don't have to be.
According to technical director David Wadham: "I use the paging system to keep a protected copy of my software in memory when doing development work.

can at any stage in the pro-

The machine looks, to me,

gram, apparently recall what like a slightly more polished

is in the various registers,

version of what Clive Sinclair

stack pointers, and status

has produced in the ZX80; it

flags; he can do amazing short has a proper typewriter key-

cuts.

board, and as things stand

As an example, the

right now, the video offers

diskette operating system is a a few extras in sophistication. A neat solution to some of the problems involved in expanding

routine that is run by the

The price is proportionately a micro that monitors a factory is this one from Burr -Brown:

machine every time data

higher, but still in an

each input/output card has its own memory on the board. The

comes in from the diskette. acceptable bracket to make it IOS 2000 10z also keeps the software needed to run the I/O

The data interrupts the

credible as a higher priced cards on them, so that the system is always the right size for

machine, which responds by alternative for buyers in a the number of lines being controlled. 0923 33837.

VCIEV 37

"Ifyou wantwhat's best
foryourPET, choose

Commodore

software': KitSpencer General Manager of Commodore Systems 360 Euston Road London NWI 3BL

The Commodore PET is Britain's best selling micro-

you may need can be obtained from

computer, with over 18,000 already installed in a wide
range of fields, including Education, Business, Science and Industry.
This has led to a tremendous demand for high quality software.
And Commodore has met this demand by producing a first class range of programs, now available from the nation-

BUSINESS SOFTWARE PROGRAMS ON DISK
Commodore's Floppy Disk Unit and high-speed Printer, combine with PET to form a complete system (ideal for running a business) for under £2,500.
Commodore also produce a range of business software application packages on disk. They were created by leading experts specifically for the PET business system. Here is our current range:-
NE W/COMACCOUNTS fl' PROGRAM -£650 +VAT This puts complete financial control at your
fingertips, with immediate access to current and trial balances. It is an integrated accounting system with up to 650 Sales Accounts, 650

Commodore Dealers. On the other hand, for rapid train-
ing on a basic or advanced level, you will certainly be interested in Commodore's intensive 2- and 3 -day residential courses. We also run one day general appreciation seminars.
PET USERS' NEWSLETTER This is Commodore's official
method of sharing new information and ideas between the many thousands of PET users. The newsletter is published regularly and for an annual

wide network of Commodore Dealers.
Commodore's support also includes training courses,
a Users' Newsletter and Official Approval for compatible products of other manufacturers who reach

Purchase Accounts and 400 Nominal Accounts.

subscription of £10 you can start

NE jyJ comiputeriseddiary

receiving copies now.

FV-COMPIANNER £50 +VAT

APi:*ot- Look out for this sign.

Business Information -COMBIS £150 +VAT Stock Control-COMSTOCK £150 +VAT

Nwt It tells you that compatible

WordProcessor -COMWORDPRO

< products of other manu-

11 +111 £75 +VAT & £150 +VAT Payroll -£150 +VAT

-,1' moodik' facturers have met with our

standards of approval.

PET

agreed standards.

COMMODORE PETPACKS

.....,0010.111 Over 50 Petpacks

of programs are available (mainly on cassette) from

HA, V/ A" ANA f A WA. WM, /ASV' WAWA,

Commodore Dealers. These cover such pop-

iiminimumionimmour (Tick the appropriate

ular titles as Strathclyde To: ComModore Information Centre, 360 Euston Road, London NWI 3BL 01-388 5.711

Tutorial, Statistics pack 1, Assembler

I am a PET owner Please put me in touch with my nearest dealer D

Development System, Stock Market

Please send me details of: Commodore PET Software D

Trends and the Treasure Trove

Training Comses & Seminars D I would like to receive the Users'

Collection of game packs. Plus the

Newsletterand enclose £10 annual subscription

new Arcade Supergame Series including "INVADERS"- quick to learn but difficult to master and

Name Address

already a No 1 favourite. Prices range from £5-£50.
TRAINING COURSES AND
SEMINARS PET systems are simple to use
and any normal advice or assistance

TeL No.
Cr commodore I'C5s
L We made small computers big busines_

38 PCW

NEWSPRINT

You make the copy by executing the copy instruction, LDIR (check that) from each byte to itself. But you set one board to read, and a different one to write, so you end up with one board copied to the other. Then you set the original board to write protect, and you can't corrupt it."
Paging systems are as simple as that - plus the associated simple chip on each memory board which decides what page that board actually is. But the snag with paging is that without modification, programs written for one system of paging will not run on another. The modification may look trivial at code level ... but compilers and assemblers don't work at code level. They have to decide at the time they write code whether it will fit on the page, or whether it's time to turn over - and loading programs have to make the same decision.
The result is that any paging system tends to stay around for ever, providing it catches on in the first place. As Nascom's ex marketing man Kerr Borland said, this one offers almost the same capacity as a floppy disc, at about the same price. It could well catch on.
Ingersoll
dangles carrot
Prices for the Atari 400 and 800 video computers have been set by Ingersoll provisionally. The 400, with 16 Kbytes of memory, is expected to cost £395 (including tax) and the 800, 2695.
My immediate reaction is

that Apple dealer Microsense has already arrived at a price level where these machines pose little threat to the Apple. Ingersoll, the importer of Atari (remember that picture of two video games players dressed in basket ball gear) seems to think so too. The company has decided to recruit its existing users as salesmen.
The deal is: if you are a member of the Atari Owners Club and introduce a new member (subject to a dealer's proof of purchase) you get a free set of Atari keyboard controllers, worth £19. The controllers, which look like pocket calculators on leads, are used for certain Atari games. But that's the video computer, not the 800. To make one take the 800 more seriously, Ingersoll has announced a price of £500 for the Atari printer, and £525 for the disc drive. Don't get too excited before July, however, because nothing will be available generally before then. More details from Ingersoll on 01-226 1200.

Pet collection
A free catalogue of ACT Petsoft PET goodies: that is how Julian Allason describes the Pet Collection. There are 16 pages, covering programs from Personal Software, Programma International, Understanding (Petplan business simulator),

Typing at a video is a great way to enter errors into a computer, especially if the output is appearing line by line on a printer somewhere else. This is an idea from Data Dynamics; the video on this Zip KDP terminal slides from side to side, above the printer/keyboard, and can be swivelled about to cut out reflections, or accommodate people who type with their heads on one side ( a lot do). I'd tell you the cost, only DD is, as usual, unaccountably coy about mentioning money . try 01-848 9781.

Hipposoft and, of course,

other likeminded sceptics, at than as a visual stimulus.

Petsoft. All are said to be

a seminar costing £28 on

And if you didn't know

available through the 220 PET Thursday June 17. It's a

about it, you've just missed

dealers. Copies from 021-455 "practical seminar" organized the chance to see Telidon at

8585.

by the London Chamber of the Viewdata 80 exhibition

Commerce and Industry

which ran from March 26-28

Yes or no?
Should you be using a computer? Ask yourself this question, together with a few

(members get a £6 discount) from 2.15 pm to 5.15 at the LCCI premises in 69 Cannon Street EC4N 5AB. Queries on 01-248 4444 and talk to Ann Measures.

at Wembley Conference Centre. I'd have told you sooner, but the Canadian High Commission (bless their Maple leaf socks) didn't announce it until

Feb 21, and a fat lot of

Original is not

good that is to us monthly journals.

The most daunting thing about the majority of domestic systems is their insistence that the user know exactly what the computer thinks is going on. Turn the power on, and the system says "?" without any clue given as to what on earth you are expected to do. My favourite way of solving the problem involves a set of different firmware programs; the user sets a switch on the panel to "expert" through "quite bright" down to "idiot" ( and ending with "journalist") and the machine treats him accordingly. This switch will give you ten such options: your monitor/program can read it and see what decimal number (coded in binary) appears across its four contacts - and act accordingly (when set to Journalist, it can phone up the Thought Police, for instance). Impectron, the maker, is on 0403 50111.

the greatest
Where the Americans today pay the penalty for their cleverness in being first to use colour television - theirs is crude, sensitive to transmission troubles, and most unlifelike even down cable TV lines - we are likely to find the boot on the other foot when it comes to Prestel.
So say the Canadian viewdata people who offer a system called Telidon. It's hard to disagree: Telidon generates images using basic geometric shapes which can be positioned all over the screen. By contrast, Prestel (and the French system, Antiope) think the screen is really a sheet of paper, and type blobs starting from the top left corner, line by line. Putting a convincing picture on Prestel is an art more satisfying as a pure intellectual challenge

Gassing on oil
The application of process control computers in oil and gas industries will be discussed by the British Computer Society specialist group on process control on April 23 and 24 at the Waldorf Hotel, London. Speakers are from Ferranti, Kent, Honeywell and Shell, as well as British Gas and British National Oil. Details from Deborah Hart 01-637 1471. Prices from £60 for BCS students to £115 for non BSC members.
Translator transformation
The translation machine I got so excited about a couple of issues back - the Lexicon - is now officially the Nixdorf. It has the Filing System module that is supposed to

PCW 39

The New DDP Video
Monitor . . .

,,,,
....
40 ithieofv*e*----//

. . . to save

operational

error

.

.

,
.

i #1/0/1i/f4t,

At last, from DDP, here's the video monitor that eyes and ears all over Britain have been waiting for. Eyes, because as alternatives to black and white tubes, green and revolutionary new orange tubes are optionally available. Ears, because now you're going to enjoy the sound of silence - from your service engineer. But to take first things first, we mention a few colourful facts. After Scandinavian scientists had proved how close -range human vision could benefit from working with orange light, orange tubes quickly replaced green as standard for most Scandinavian videos. A few years behind, we in Britain still belong to the Green Screen Club - but as indifferent members when it comes to monitors. With DDP's new monitor, however, you can experience Scandinavian sophistication. And all the difference it makes to operating profits when allowance is made for operator fatigue.

. . and, therefore, your time . . . . . and money.

Inside our monitor you'll discover its second big advantage. More easily overlooked, but just as important to long-term operating profitability is the unique modular circuitry. The resin -block circuits will outperform conventional systems and delight engineers when, aeons into the future, servicing is eventually required. And the cost? Bearing in mind the big 12 inch screen, you'll be amazed at our recommended retail price of £140 (ex. VAT). Generous DDP volume discounts are equally astonishing, but most surprising of all is how quickly we can deliver. To find this out, though, you'll need to make a phone call ...
DDP Video Monitor Orderline: (0268) 727563

Distributed Data Processing Ltd.

40 PCW

Essex House, Cherrydown, Basildon, Essex SS16 5AQ

NEWSPRINT

turn it into a genuine personal computer system, and the price is £85 on 30 days delivery, according to PhoneAids, a distributor. The company will sell through two offices: one at Brackley, Northants in premises quite noticeably similar to those of Portable Microsystems, and with the aid of one Heather Ayres, of the same surname as Mike at Portable - ah, probably coincidence. Also at Southampton. Phone 0280 704761 for Heather, or 0703 771400 for Andy White.
LSI go business
Four micro -based systems under £10,000 have been launched by LSI Computers aimed at the businessman. Smallest is the M -One Model I at £6000 with twin floppies, screen and printer: biggest is the £10,000 Model V with faster printer, two terminals, faster processor and bigger floppies. Software announced includes a bill of materials processor, an inventory management package, and a modular account packate - Bomp, Imp and Map. Details: 0344 54471.
8080 lives
A reminder that the Intel 8080 is far from dead: a microtutor called Micro tutor, made by Northwich company Limrose, has been bought by the Post Office and the Navy. Actually the Navy ordered 48 and the PO 36 - in two lots of 18. The Microtutor has been around a while: it was one of the machines on show ready built at the very first Build Your Own Computer Show (run by Online four years ago) where such things as the RML 380Z were nests of wire -wrap, and the Bear software was all kapok stuffing. Limrose is on 0606 41696, and all the other people who make things called Microtutor needn't bother ringing me up unless theirs pre -dates the RCA Cosmac microtutor.
On the button
This week's prize in the "at the touch of a button" award goes to one of our own consultants, Stephen Castell. He used the phrase in the announcement that BBCData was getting involved in the Prestel International market trial.
You needn't feel guilty at never having heard of BBC Data - because it's new. It's the trade name under which the BBC is sending "a unique and integrated database covering World Business and Trade Personalities and Events, to Prestel's international service".
As a man who has used

Prestel, and occasionally

even discovered that the

information he could not

find was definitely not in

the system- rather than

merely disguised under some

other heading - I feel that

the Rest of The World should

be disabused of the notion

that the information, (which

"a typical overseas business-

man will be able to see on

his TV screen,") is avail-

able at the touch of a

button.

It was I who, when

Computing Consultant of

New Scientist -a mantle

which passed, after I was

fired, to our own Malcolm Peltu (Shame! Ed.) - sat down one evening and touched buttons until the

Cut-price Hazeltine video terminals: Electronic Brokers offers "as new" standard models at £425, and editing versions at £695. Details on 01-837 7781.

system eventually asked me to "Enter Password". It was

summary of his superb book "The computer revolution in

"real" and what is an empirical definition of "life"?

I who, wondering what it

philosophy" it could be said (with acknowledgements to

did if you entered the

that Sloman has found a

The Hitch Hiker's Guide to

wrong password, touched a few buttons at random. It

real use for both philosophy and artificial intelligence by

was, therefore, I, who at the touch of a button, rendered the entire New Scientist database inaccessible to New Scientist staff by creating a password which not even I knew. That is the only thing I've ever done on Prestel at the "touch of a button" ... all else took blood and tears and sweat and persistence.

observing how well they solve the limitations of each. In particular, he accuses philosophy of building theories without the barest models of Mind to test them on. By testing concepts of Mind in artificial intelligence one can quickly find out if it is possible to create a set of rules that express the concepts: and from that, whether the rules (simulated

the Galaxy). And Lisp is now available from Microsoft, together with another product written by the Soft Warehouse, for micros. The package is called muLisp (microlisp) and costs $200, to run under CP/M. The other package is a maths package, muMath at $250.
The muLisp package "offers all of Lisp's unique programming features," says Microsoft: "including 83 Lisp functions, flexible

on a computer) actually

program control structures,

Lisp for the big produce "behaviour" that

and infinite precision integer

parallels observable intelligent arithmetic in any desired

behaviour.

radix from base 2 (binary) to

questions

All this is by way of saying that the language

base 36." Dealers, contact Microsoft on (206) 455 8080

The words "Artificial Intel- Lisp, used by artificial

in the USA.

ligence" are equated in too intelligence researchers, is

many minds with some vague eventually going to be the

picture of a lunatic

sort of tool that enables

Business guide

scientist trying to create a Computer That Lives.
A man called Aaron

someone to define "sense of humour" accurately, and freeing philosophers from

update

Sloman describes the actual protesting that, sure,

A guide to some 900

benefits of artificial

they're concerned with the

different computer systems

intelligence much more

problems of real life - like, is available for £24 from ECC

accurately. In a grotesque what do we mean by

Publications: it's the Guide to

Small Business Systems, and

it covers machines from £100

£1000 up. Last year's edition

had 250 systems fewer and

sold well, according to Cathy

Lane at ECC. It's designed

"primarily for the business-

man with little or no com-

puting knowledge." Details

from Cathy on 01-359 7481.

File it

The Intelligent Filing System

advances further into our

midst: Compsoft has

enhanced DMS, its

information storage and

retrieval system, to run

on a 32 Kbyte PET. It will

organise up to 5,000 items

One of these test devices would be a comforting thin$ to see in the back room of the place you buy your system. It is a Millenium microsystem analyser - now revealed to be the machine which National Semiconductor refers to (internally) as an ICAT . .. that is, in -circuit automatic testing. It combines the "signature analysis" test system developed by Hew-

on one diskette and manipulate them for even the least sophisticated user, says Compsoft: for details please phone Guildford (0483) 39665.

lett Packard as a very good fault pinpointing aid for systems

Courses that are nearly working correctly, with the in -circuit emulation
(ICE) system that exercises components on a board that is

definitely not working. It's available through Microsystem

A wide range of four -day

Services, and anyone bright enough to use one is bright enough courses on micros has been

to sort out your system in minutes. With luck. 0494 41661. announced by ICS Publishing.

PCW 41

Your Commodore PET System

The Commodore PET is Britain's best selling microcomputer

d the most popular choice in every field:-

A SELFCONTAINED MICROCOMPUTER FROM £550.

* In Education for teaching Computer Science and as a teaching aid for other subjects. * In Science and Engineering for solving problems and for monitoring laboratory
equipment.
* In Business the PET system
can be put to a wide range of functions including Payroll, Accounting, Statistical
Analysis, Stock Control and Word Processing.

Not least of its attractions is the price of a PI - from 2550 for a self contained unit, to under 22,500 for the complete system including Floppy Disk Unit and high-speed Printet Ask your nearest
Commodore dealer below for details about Commodore hardware, software and training courses.

Our Dealer* Network

LONDON
Capital Computer Systems. Wl. 637 5551
ACE (by Top TV Ltd). SW1. 730 1795 Micro Computer Centre, SW14. 876 6609 Logic Box Ltd. SW1. 2221122 Sumlock Bondain Ltd, EC1. 250 0505 Da Vinci Computers Ltd. NW4.202 9630 L 6 J Computers, NW9.204 7525 Adds Computers, W1 408 1611 CAS Business Equipment Ltd, Ea. 254 9293 Advanced Management, EC2. 638 9319 Metyclean Ltd, SW1.828 2511 Microcomputation, Southgate. 882 5104 T.L.C. World Trading Ltd, WC2. 839 3894
HOME COUNTIES
Orchard Electronics Ltd, OXON, 049135529
D. L. Chittenden Ltd. CHESHAM, 4441 J. R. Ward Computers Ltd,
MILTON KEYNES, 562850 Dataview Ltd, COLCHESTER, 78811 South East Computers Ltd.
HASTINGS, 426844 Symtec Systems Ltd,
SOUTHAMPTON, 38868 Alphascan Ltd, BANBURY, 75606 Super -vision, SOUTHAMPTON, 774023 Millhouse Designs Ltd.
ALTON.(0421050374 Micro Facilities Ltd, MIDDX, 979 4546 DDIA, BRENTWOOD, 230480 Stuart R. Dean Ltd, SOUTHEND, 62707 Alpha Business Systems.
HERTFORD, 57423 HSV Microcomputers,
BASINGSTOKE. 62444 HSV Microcomputers,
SOUTHAMPTON, 22131
RUF Computers (UK),
BURGESS HILL. 45211 Wego Computers Ltd,
CATERHAM. 49235

T.& V. Johnson, CAMBERLEY. 62506 T & V. Johnson, OXFORD, 721461

Business & Leisure Microcomputers, KENILWORTH, 512127

Tripont Associated Systems, SUNDERLAND, 73310

LIVERPOOL

Petalect Electronic Services Ltd,

Caddis Computer Systems Ltd.

Newcastle Computer Services,

Microdigital, LIVERPOOL, 227 2535

WOKING, 23637/21776

HINCKLEY 613544

NEWCASTLE UPON TYNE,

Rockliff Brothers Ltd,

Business Electronics.

Allen Computers, GRIMSBY, 40568

(0632) 615325

LIVERPOOL, 521 5830

SOUTHAMPTON, 738248 Amplicon Micro Systems Ltd,

CPS (Data Systems) Ltd, BIRMINGHAM, 707 3866

SOUTH WALES &

MANCHESTER

BRIGHTON, 562163 Bromwall Data Services Ltd,

Camden Electronics. BIRMINGHAM. 773 8240

WEST COUNTRY

Cytek (UK) Ltd, MANCHESTER. 832 7604

HATFIELD, 60980/64840

Cliffstock (Computer Systems) Ltd,

Executive Reprographic Ltd.

MMS Computer Systems,

WOLVERHAMPTON, 24221

BROADSTONE, 0202 697341

MANCHESTER, 228 1637

BEDFORD, 40601 Isher-Woods, LUTON, 416202

YORKSHIRE &

A. C. Systems. EXETER, 71718 Computer Supplies (Swansea),

Sumlock Manchester Ltd, DEANSGATE, (0618) 834 4233

Sumlock Bondain, NORWICH, 26259 CSE (Computers). READING, 61492

NTH. HUMBERSIDE

SWANSEA, 290047 Sigma Systems Ltd. CARDIFF, 21515

Computer Workshop, MANCHESTER, 832 2269

Oxford Computer Systems, WOODSTOCK, 811976

Microprocessor Services, HULL, 0482 23146

Devon Computers, PAIGNTON, 526303 Bristol Computer Centre.

Professional Computer Services Ltd, OLDHAM 061-624 4065

MIDLANDS &

Microware Computers, HULL, 562107 Computer Workshop, LEEDS, 788466

BRISTOL, 23430 J. A. D. Integrated Services.

D. Kipping Ltd, SALFORD, 834 6367 Catlands Computers Ltd,

STH. HUMBERSIDE

Hallam Computer Systems Ltd, SHEFFIELD, 663125

PLYMOUTH, 62616 Sumlock Tabdown Ltd, BRISTOL, 26685

WILMSLOW 527166
SCOTLAND

Taylor Wilson Systems Ltd.

Ackroyd Typewriters Ltd.

Radan Computational Ltd,

M icrocentre, EDINBURGH. 225 2022

KNOWLE, 6192 Betos (Systems) Ltd,
NOTTINGHAM, 48106
Holbrook Business Systems, DERBY. 368088
Lowe Electronics Limited. MATLOCK, 2817
Davidson -Richards Ltd, DERBY, 366803/4

BRADFORD, 31835 Datron Micro Centre, SHEFFIELD, 585490 Yorkshire Electronics Service Ltd. MORLEY, 522181 Sheffield Computer Centre. SHEFFIELD. 53519
NORTH EAST

BATH, 318483 T & V. Johnson Ltd, BRISTOL, 422061
NORTH WEST & NORTH WALES
B.6 B. Computers Ltd, BOLTON, 26644 Megapalm Ltd, CARNFORTH, 3801 Tharstern Ltd, BURNLEY 38481

Thistle Computers, KIRKWALL, 3140 McAllister Business Equipment,
EDINBURGH, 336 2402
IRELAND
Softech Ltd. DUBLIN, 784739 Medical and Scientific,
LISBURN, 77533

Arden Data Processing,

Dyson Instruments, DURHAM,66937

Fylde Business Machines Ltd,

r commodore LEICESTER.22255
Tekdata Ltd. STOKE-ON-TRENT, 813631 C.S.M. Computer Systems,
BIRMINGHAM, 360 6264

Currie & Maughan, GATESHEAD, 774540
Wards Office Supplies, GATESHEAD, 605915

PRESTON, 731901 Preston Computer Centre.
PRESTON, 57684 RPL Microsystems. DOUGLAS, 4247 /8

*This is a list of dealers participating in associated advertising and not a full list.

We made small computers big business.
Commodore Information Centre, 360 Euston Road, NW1 3BL. 01-388 5702

42 PCW

NEWSPRINT

WO Oak

17A

The important object in this picture is the background: it's a non -slip mat. The idea is that one hand holds the soldering iron, the second holds the component and the solder, and instead of the tiny board immediately tobogganing off the bench, it stays put. Impressively the "coefficient of friction" quoted by the maker, Cobonic, is close to 12; by comparison, the quoted figure for steel to rubber is 1/2. It will work on the wall, they say. Details on 01-767 6780.

Subjects range from Hands-on micro trouble -shooting to Voice input and output for computers, and the program starts from April 4, with seminars in London and Amsterdam. Details from ICS UK at Leatherhead (03723) 79211.
Ongoing
I quite like Prime -a minicomputer -making company that will obviously go far. The company's reputation is not being enhanced, however by its persistence in sending information to PCW care of a man who stopped being its editor last August, to an address which we haven't use used for even longer. Other dozies, please copy.
Centronics News from
A £555 printer from Centronics is to marketed by Rair, aimed at the micro user. It's the Model 730 mini printer. Details on 01-836 4663 for anybody who can't get the X -Data Oki 80.
Who's who
One of the most visible men in the UK computing world is the director of the National Computing Centre -a job that can steal as much limelight as that of the secretary of the Computing Services Association. When the CSA lost Alan Benjamin, it did take care (by employing Doug Eyeions) to ensure that everybody knew there was a new man in the job. The NCC, by replacing David Firnberg with David Fair bairn, has been rather less

careful - especially as Fair bairn, like Firnberg, is ex-ICL. Now all together: who is NCC Director? No, not Benjamin Fairberg, try
again...
Database Primer -free
A free primer on database, attempting to explain it both to users and prospective users, has been launched by the Lafayette producer of micro database systems, MDBS, mentioned in our last issue. The primer runs to 54 pages, and is free as long as stocks last from MDBS Inc, PO Box 248, Lafayette, Indiana 47902.
Curry sauce
The arrival of the washing machine chain, Curry's, into computers is planned for April 8th. Derek Moon has announced that they will carry PET and ITT 2020 for the business he calls "traffic" with the Sord and National Panasonic computers supplying the business end. Stores will be opening in Birmingham, Nottingham, Bristol, and New Malden in South London.
As you were
In the March edition of "Newsprint" I referred to "a lawsuit" which supposedly existed between Nascom and Mine of Information. In fact, although "sabres were rattled" towards the end of last year, up to this moment no direct legal moves have been made. I will of course keep you informed of any future developments.

The source of
the trouble
In theory at least, the Post Office's Prestel system of publishing information on TV screens could have a chance in America as its biggest competitor is now widely tipped to go under. The competitor is The Source, a network of information providers that's connected to home users via two existing networks - called Tymnet and Telenet.
Normally, these two networks are used by people who need to retrieve information from very large scientific databases. .. chemical, legal, all the way through to current affairs. And normally, these people are company librarians, who have considerable skill in chasing down the information they want, and who have practised the virtuoso performance of entering passwords and signing on, many many times.
The idea of using Tymnet and Telenet to carry the information was a good one, in that they already existed and were in good working order. By comparison, when the Post Office set up Prestel, the salesman who sold them the first GEC 4000 computer ended up earning more (in commission on that and subsequent sales) than his corporate boss, Sir Arnold Weinstock; you get some idea of the money that was needed to set it up.
What the idea had going for it there was countered, technically, by the fact that first, you can't call up Tymnet and Telenet on your television, and second, there is a lot more to it than just pressing a button and finding a page index.
It's quite true that the Prestel page number system can be infuriatingly slow and tedious for the sophisticated user who longs for short cuts in the search for the elusive bit of information. And it's also true that in the UK, the television sets are in short supply, and the information available is still not all that comprehensive (although I did find out, in flying over here, that Pan Am puts its standby ticket status on a Prestel page. It said: "NIL", but never mind).
However on The Source, the routine of signing on is a bit like casting a magic spell. One full stop wrong, and the genie escapes out of the bottle and eats the terminal
Computer store owners have to sell subscriptions to The Source, and they describe it as a hard sell. They say they get a once -off payment of $100 for every subscriber signed up, that they have to keep stocks of the sign-up kit, and that confused subscribers keep coming back to try to work out what they are doing wrong. Perhaps, all

this might matter less if the company had not run into financial trouble.
No official word has been released yet from Telecomputing Corporation of America, which runs The Source; but it has written a pleading letter to its creditors, asking for time to pay its debts. The theme of the letter is disturbing to its recipients. It doesn't say, jauntily: "We may be short of cash, but we're signing up a thousand users a day, and while this costs us a thousand times a hundred dollars, now, revenues of at least $5 per month and $15 per hour connect..." and so on. Instead it says that, of course, if they really want to insist, then creditors can get some money by forcing TCA into bankruptcy under Chapter 11... after which assets will be frozen until the company is wound up, and then they'll only get a level of repayment to be decided by the authorities; gloom and doom is the name of the game.
Dealers tell me to interpret this as meaning The Source will be closed down in three months or less. They also speak highly of the deal offered by competing service Micronet, which promises dealers 25% of all revenues generated by any of their subscribers, for ever.
Whatever happens (and the situation has not been helped by the fact that, since former TCA boss William von Meister left the company, a great many more debts have been discovered) it would be a tragedy if the idea failed. What The Source offered (that Prestel is still dreaming of) is instant communication with any other user, plus actual data processing power to boost the micro user's system.
Apple change of heart
The heart of the Apple II computer has been transplanted - an astonishing bit of surgery that has drastically changed its character. The standard Apple II computer uses the 6502 micro and therefore cannot run any of the software available to users of systems with Z80 or 8080 micros (which have the standard CP/M operating system). This gap in the Apple's abilities has prompted one of the two best-known suppliers of computer control software Microsoft - to produce a card which gives the Apple II a Z80 processor.
This unexpected grafting allows the Apple II to run the piece of software produced by the other bestknown systems software company - Digital Research - that is, the CP/M operating system. The cost of the new processor board and two diskettes (with the CP/M

PCW 43

NEWSPRINT

software) is $349. Microsoft executives at
the West Coast Faire promise that the package will be available by May... good news from their point of view as the card will be a way to sell more copies of disc BASIC. Microsoft BASIC, included in the package price, "has all the features not found in Apple soft, plus exclusive new features added to take advantage of the Apple II's special capabilities".
And adding the Z80 soft card doesn't stop the Apple being an Apple. "It allows you to use either the 6502 or the Z80 processor whichever is needed to run a particular program", says Microsoft: "and switching between the two processors is as easy as typing in a particular command. All the features that you love about your Apple stay intact".
The only caveat is that programs and data generated on the Apple in CP/M are not transferable to the normal Apple. It's either one, or the other... never both.
Pearls for the swine
The newcomer to computing quickly finds that he can either buy programs or write them - and that writing programs is exactly the sort of

job (tedious, repetitive nitpicking and long) that he thought the computer was going to save him from.
The obvious step of getting the computer to write the programs for you has now been achieved by many. Not all are successful, not all are cheap, but usually it's easier for the complete beginner to write in high level languages and get the computer to write the machine code.
The concept is moving further: an example was released at the Faire in the form of PEARL levels 1 and 2 which actually write the high level language instructions.
Where Pearl (Producing Error -free Automatic Rapid Logic) differs from other systems is in its $90 listing.
The level 1 cannot cope with difficult subtleties of computing such as multiplication and division, but it can, and does (according to Computer Pathways Unlimited) write useable personal programs.
It can do data validation - something human programmers often neglect - operator messages, and data editing. It can generate reports, and control input and output.
Level 2 is for business applications; it has an indexing function which it can build into your programs. And when levels 3 and 4

arrive, they will be capable of generating saleable programs, according to Pearl's creator, Dan Miles: they will also be more costly. Currently Pearl runs under CP/M, but Computer Pathways hopes to have versions for the PET within a year.
No UK agent was booked at press time: hopefuls should contact CPU on (503) 363 8929.
Disc deals
Users of the Apple II who think they need to store 10 million characters inside the machine can buy the wellknown Corvus hard disc from Tim Keen. Keen has the import exclusive on the device - which uses a mechanism made by disc company IMI in America.
However, Keen doesn't have the exclusive on the IMI drive; that has been sold to, not Corvus, but Lobo of Goleta California. At the Faire, I saw an Englishman setting up a deal to import the Lobo product.
The differences between the two devices, technically, is not large. Where the Corvus drive is electronically disguised as 20 floppy discs, the Lobo drive is configured (that means disguised) as one drive, which the Apple II operating system will think is a normal

floppy disc, 11 million characters long.
The differences between the two in price could be something else. Trade price of the Corvus drive here is around $3500 whereas the Lobo sells for $500 less. The Englishman (he has requested anonymity until the deal is clinched) hopes to reflect the buying price in his UK selling price.
Tandy to Tandy
Any Tandy computer in America can talk to any other TRS-80 via a $250 telephone modem that plugs into the processor... and the company that makes it is hoping to sell the modem in the
UK.
That company is the Micro Peripheral Corp. of Mercer Island, Washington 98040, and the story they tell is that the device will need very little adaptation to be used on UK phone lines.
What is needed, however, is for somebody to get the specification approved by the Post Office for connection to Buzby's knitting. That somebody should contact Don Stoner about the device called The Connection - on (206) 454 3303. Guy Kewney is Technology Editor of Computing.

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4a (

COMMUNICATION

PCW welcomes correspondence from its readers. Be as brief and concise as possible and please add "not for publication" if your comments/questions are to be kept private.
Address letters to: "Communications", Personal Computer World, 14 Rathbone Place, London W 1P 1DE.

Software

tines. (Developed from the disturbed by use of the paper "Microcomputer Soft- routine.

Section 10 gives any I/O interfaces and peripherals

datasheets
Nothing makes me so wild as to hear computer hobbyists being told that any program that more or less works is a good one.
Bad programming, whether perpetrated by professionals or amateurs, is an abomination that pollutes the mental processes of anyone, including those who actually wrote it, who might later want to use and modify it.
Hobbyists do not have to use machine code programming of anything but the highest quality.
Any software takes time

ware Design" by Thomas P. Hughes, Dwight H. Sawin III and David R. Hadden Jr. of the U. S. Army Electronics Command.)
RULES 1. Registers not being used to convey data into or out of the routine will, if used by the routine, be saved on entry to and restored before exit from the routine. 2. It is assumed that the general routines library will always be in memory (possibly ROM) so that routines may call other general routines. 3. RAM addresses, outside the general routines' library,

Section 7 gives the maximum number of bytes that could be added to the stack, including growth from the routine calling other routines.
Section 8 gives the memory size of the routine. Section 9 lists any monitor or general purpose routines on which the routine depends.

needed. Section 11 states whether or not the object code is 8080 compatible. 3. The third part is a complete listing of the routine, with assembler mnemonics, comments and object code.
Alan Tootill, Enfield, Middlesex.

; = DL1S - One second delay at 2MHz

;/ "DL1S" -1,evel 0

;/ To use 2000000 time states, inclusive of call, without other effect.

;/ ACTION: ( SP

L

( SP -1 H

H +- ( S +1 )

L 4- ( SP )

repeated 42,551 times

to develop and test into something the originator can

will never be explicitly speci- ;/ INPUT: None fied in routines. References ;/ OUTPUT: None

use. Just a little extra time could turn it into something that could be shared and
improved by others, so that

to RAM may be made through the contents of registers, which the caller supplies

;/ REGs USED: None ;I STACK USE: 6 ;/ LENGTH: 19 ;/ SUBr DEPENDENCIES: None

as pointers or as address

;/ INTERFACES: None

everyone finishes up with a parameters immediately fol- ;/ 8080 COMPATIBLE?: No

set of first class software pro- lowing the call in the main DL1S

ducts.
I would like, through PCW, to get a group of people writing Z80 general purpose

routine.
4. Registers HL, DE, IX and IY will be used as pointers
to RAM.

PUSH AF ;save flags

PUSH BC ; & registers

LD BC 42551 ; set loop counter

PUSH HL ; main

POP HL

; delay

F5 C5 01 37 A6 E5
El

subroutines, to define standards, for criticism and improvement by others. Those submitting the original

5. Registers B and BC will be used to pass single and double byte counts. 6. To avoid having areas of

DEC BC LD A,C OR B JR NZ, -5 PUSH HL

; decrement counter

OB

; set zero flag only if both 79

; bytes of BC are zero BO

; jump if not zero to loop 20 F9

; make up

E5

routines could choose
whether their offerings were anonymous or signed.
Final, improved, versions

RAM that need to be defined by the user, the stack may be used for local RAM.
7. Data may be supplied to a

POP HL NOP NOP POP BC POP AF

; delay to ;1,999,983 ; time states ;restore registers ; and flags

El
00 00 Cl
Fl

of the most useful routines subroutine as parameters

RET

;return

C9

would then form a collection immediately following the

of Software Datasheets.

call in the main routine.

Magazine, book and EPROM 8. The alternate register set

publishing rights of the Soft- will not be used by routines,

ware Datasheets would belong to the magazine but

to leave it available for processing interrupts.

the right to use and list them, 9. Routines that call no other

as part of applications soft- routines are classed as level

ware, would belong to

0 and all others as level 1.

anyone. I would edit and check
that contributions worked and conformed to standard and even supply routines, if necessary, for the first few months, to get the project off the ground.
To illustrate the standards I have in mind, I list Rules and Documentation standards for the routines, together with an example. I would try to improve on the presentation of these, perhaps PCW
readers could help with this.
The ideas of the Z80 routines could, of course, be worked in 6502, 6800 and other machine codes as well.
A useful set of BASIC general purpose routines might also
be worth developing.

DOCUMENTATION 1. The first part of the documentation, marked ";=", contains a brief textual description of the routine. 2. The second part, marked ";/", contains a technical description developed after a format used by Nicoud:Line 1 gives the name and level of the routine.
Line 2 gives a one -line description. Section 3 gives the main actions carried out by the routine.
Section 4 specifies flags, registers, parameters, stack or other areas assumed to have meaningful values when the
routine is called. Section 5 specifies flags, registers and other areas contain-

A very interesting letter. I agree with Alan's sentiments and would like to help him move this idea forward. The magazine welcomes all ideas, proposals and modifications from interested readers; some we'll publish and all will be passed to Alan. Please
Suffering systems
For the past three months I have read the software reviews by Mike Rose with increasing frustration and annoyance. These really are the worst sort of review to publish in an influential magazine such as yours and are guaranteed to confuse and even mislead any potential purchaser.
Here are my specific complaints: 1. By reviewing only a small proportion of the available packages it leaves the potential buyer no better off as

write stating your area of interest and likely involvement, marking your envelope "standards". If you do not wish your letter to be printed please write "not to be published" on it. I look forward to hearing from you Ed.
Can you imagine Which only reviewing 6 brands of washing machine and leaving the rest to the imagination? No way.
By not being reviewed there is a stigma attached to other software, which is unfortunate since in all cases the best available software has not been reviewed. 2. The reviews themselves are not sufficiently thorough. Many of the important aspects of the packages are completely ignored whilst trivial information is provided. As an example, the one on stock recording packages ignored the important subject of response times to

Rules and Documentation ing results when the routine he does not know if there is an enquiry. There is a world

for Software Datasheets for returns.

a better system available

of difference between

Z80 general purpose subrou- Section 6 gives the registers which was not reviewed.

the best (about 3 seconds

PCW 45

ackaged nformation recessing ystems
We offer a variety of turnkey systems based on APPLE II and MICRO STAR. It is our endeavour to give a complete service from problem determination through to the supply of computer based solutions. We will solve the problem either with a tailor made suit of programs, or a ready written package from another famous software house.
We can also supply three excellent DEVELOPMENT SYSTEMS, namely NASCOM, ACORN and NORTH STAR HORIZON
Agappie computer Sales and Service
Phone for further details or...
Come along and see all of the above equipment, plus a wide range of peripherals, which are now on display in our new offices and showroom. AT 15 Sandhill, Quayside, Newcastle Upon Tyne Tel: 0632 614939

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46 PCW

COMMUNICATION

with 1500 items) and the worst (30 seconds or more). In this same review the author listed as a desirable point a facility to link assemblies to components a facility that has nothing to do with the majority of stock recording applications and is most difficult to achieve within the restraints of a microprocessor system. 3. Such items as system capacity do not seem to be consistent. Some systems are quoted on a per diskette
basis, while others are for a maximum configuration of
four discs.
All in all, a poor series, especially as Mike Rose adver-
tises himself in your magazine as an expert in the field. The general impression given is one of a quick half hour read of the manuals rather than a thorough try -out of the work-
ing systems. Perhaps you should try again with a somewhat larger budget!
Mike Collier, West Yorkshire
Thank you for your interesting letter. You have actually highlighted the need for us to restate our objectives from time to time -if not every month. I see you have only been reading this feature for three months; you will therefore not realise that our intention is purely to examine documentation made available to us by software package suppliers and to report on the various claims made. Bearing this in mind I shall now take your points one by one.
1. The Stock Control feature was the first review in the series, following the introduction in the previous issue. We underestimated the time it would take for suppliers to respond to our questionnaires and requests for documentation. We were also surprised by the generally low response. We are about to repeat the sequence, starting with Stock Control, so this will give those companies that missed us first time around another chance (dealers,please contact us for inclusion). We cannot hope to review every package on the market because a) we haven't the time and b) even if we did, we wouldn't have
enough space in the maga-
zine.
2. At no time did we ever intend to set up dummy systems and test the programs themselves; our intention is simply to save the reader a bit of "leg work" by getting hold of the information that would be made available to him anyway, analysing it and producing a comparative

report. The series has the

parties should write to me or

added benefit of outlining the telephone during the

sort of things a buyer might evenings on Hornchurch

need to consider when

(STD 04024) 42905. Affili-

purchasing a package.

ation of the Group to other

Any in-depth reviews will User Groups will be conside-

be occasional and based on a red at a later stage, depending

real -life user's experience of on the response from

his chosen package. (Users members.

please note -if you are soon Do you know if Sharp

to implement a standard

Corporation have any plans

package and don't mind being for establishing a Software

put "under the microscope", Bank along the same lines

then why not contact us and used by the American produ-

we shall be pleased to

cers? If not, this may be a

consider you as a case study.) profitable venture for your

As far as the comment

magazine!

regarding sub -assemblies etc Joe Seet, 16 Elmhurst Drive,

was concerned, I think Mike Homchurch, Essex, RM11

said something along the lines 1PE.

of "If we do manufacture then we probably want details of the relationships
between parts, sub -assemblies and assemblies". Note: "If we
do manufacture... "; in fact, none of the packages considered this requirement and, provided that you are not a manufacturer looking for these facilities, then there is no problem.
I suppose that we could have quoted response times as claimed by the brochures but these do rather depend on the chosen test circum-

Sharp have looked at this problem and have appointed HB Computers to manage this task. HB Computers have confirmed that the marketing exercise is well under way with 25 programs
already available and more
arriving daily. Catalogues are available on request. HB Com-
puters welcome high quality software for inclusion in the catalogue. Royalty terms are negotiable. All enquiries to Johnnie Johnson 0536-83922 /520910 - Ed.

stances, which in a selling

brochure are likely to be "loaded" at the very least.

School games

3. This information is based At our school, we are forming

on that provided by the

a program library for all the

supplier.

computer users. We need to

I trust that these replies find a source of cheap pro-

have helped clarify the situa- grams. It was suggested that I

tion regarding "Systems"-Ed. write to you for help. If

you would please write a list

Praise indeed

of programs you have included in earlier issues, with the

Under no circumstances must you do anything which would
alter "Bookfare"! Malcolm Peltu is the only technical book reveiwer (that I know of) who does not treat his
readers as a bunch of mindless jerks waiting for the Sirius Cybernetics Corporation to emply them.

issue number and the length of the program in Kilobytes, I would be very grateful. We have only a PET microcompu-
ter. When you send us this list, we will be able to send off for some of the back issues of the programs. Thank
you very much. R. J. Lewis, Winchester

Clive Jackson, Tewkesbury, Gloucester

Sorry, we can't help with the sizes but you'll find that the

programs have been listed in

Look Sharp

our Back Issues advertisements - Ed.

I have recently acquired a
Sharp MZ-80K Personal Computer with 22K User RAM after a close evaluation of its competitors (the PET Apple, Sorcerer, etc.) on performance and price. I can only say that I am entirely satisfied with the capabilities of the machine. I would be grateful if you could publish my intention to form a London and South East Sharp MZ-80K User Group
in your magazine to enable all
members to exchange ideas, software, etc. Interested

Program power
It has been apparent for some time that there has been a lack of software available for
Nascom 1 & 2. We are certain that a substantial number of near -professional standard
programs have been written, but knowledge of these probably remains with the author or his local Nascom club. Not least amongst the reasons will be the variety of monitors which have been available at one time or

another. To remedy this situation,
"Program Power" has been set up to act as a form of program exchange. We will undertake to make programs available nationally to owners of Nascoms, at a price which will enable us to pay reasonable royalties to the authors. We hope this will generate the enthusiasm to finish off those brilliant ideas which are almost saleable programs and perhaps generate a few more original thoughts. We shall be concentrating on 8K BASIC and machine code programs.
In this respect if there are any authors out there, of BASIC programs written for TRS 80,PET or other micros who could provide listings for conversion to Nascom,we would love to hear from them.
Nascom have produced some terrific hardware and we would like to see an equally terrific and complementary software base established. R. G. Simpson, "Program Power", 5 Wensley Rd, Leeds LS7 2LX
Right and wrong
Congratulations on publishing Macronoia, the best example of program documentation I have met in any magazine, British or American. May it soon become the accepted standard, for any and every non -trivial program or short routine, to: - Explain the model and give a flowchart of it. - Explain how to "play" or use the program. - List the equations (algorithms). - List and identify all variables. - Identify the computer on which the program was developed. - Generalise the BASIC, to work on most machines. - Modularise the program, with adequate REMarks. - Show a program flowchart.
A good piece of work like this whets the appetite for more and if you want to do even better may I suggest reproducing results of a typical run?
You probably know about the errors. I hope you will be able to publish the corrections promptly before too many readers lose interest in the original. Peter Reynolds, Tunbridge Wells, Kent
Thanks for the comments, Peter, we certainly endorse them. The errors were corrected in Blunders last month and this month -Ed.

PCW 47

BENCH
TI 99/4
HOME COMPUTER The long awaited launch of the T199/4 marks the beginning of a "new wave" of personal computers aimed at the home. Like most
electronic consumer goods, it's well made, well packaged and would hardly look out of place in the living room alongside the
family hi-fi. by David Tebbutt

Introduction
The 99/4 had been designed for domestic use and it makes absolutely no pretence of being a business computer. I suspect, however, that a businessman would find it useful provided that he can set sensible limits on his expectations.
The machine comprises a single unit which can be connected to the domestic television (more on this in a moment) and a normal audio cassette player. It even has a lead for connecting
to the hi-fi system for those with a yearning for computer music in full
stereo. Unfortunately, there is one drawback to this approach - you need a television which can accept American NTSC colour signals. (In the UK we use the PAL system, which is quite incom-
patible). This is not the end of the
story, however, because you can buy dual standard televisions which accept both types of signal. In view of this difficulty, Texas are packaging their home computer with a variety of televisions at prices ranging from £750 for the 99/4 plus black and white monitor (or a modification to a suitable existing set), to £1300 for the 99/4 and a really swish dual standard, colour set with remote controls and viewdata
options. Should you prefer your viewing and
computing to be kept separate then you
would need to buy some sort of television anyway, so the point may
become somewhat irrelevant. Therefore, enough said, except perhaps to add that, although TI engineers are working on
the problem it will be some time yet
before the machine itself comes suitably modified.
The 9914 has a slot which accepts
"Solid State Software Command Modules" i.e. preprogrammed ROMs. A
wide variety were supplied with the
review machine, the favourites being the

games and Beginning Grammar. As well as running programs from the
command modules, it's possible, too, to write your own in TI BASIC and to save them on cassette.
There's one other feature - a rather curious one which I have never seen implemented elsewhere. It's called an equation calculator and it does just that. The user keys in details of a calculation just as he would write it algebraically, assigning letters or names to all the variables. (The equation is shown on the screen while each variable is given a value.) Once they've all been entered, a press of a button and the equation is evaluated. In this way the exercise can be repeated with different values, but without any need to rekey the equation. It's halfway between employing the BASIC in direct mode and actually running a program . . . and much simpler to use than a program-
mable calculator. All in all, the 99/4 is elegant looking,
well made, easy to set up and simple to use. The major drawback, in my view, remains its inability to plug straight into a PAL television.
Hardware
In this section I shall consider each of the hardware elements separately, starting with the CPU and working outwards to the keyboard, screen, sound unit, and cassette.
As the name would suggest, the 99/4 is built around Texas' 16 bit processor
- the 9900. Thus it has far greater
inherent mathematical precison than the more common 8 bit micros. In fact its
display shows an apparent 10 digit
decimal precision whereas the internal precision is between 13 and 14 digits, depending on the value. One would expect the machine to perform well on benchmark programs, but partly because of the extra effort needed to

maintain this level of precision and partly because of the speed of the interpreter, the test results were nothing to write home about. Exactly 26K of ROM looks after the BASIC and the
operating system, while 16K of RAM is available to the user. "Only 16K eh?", I hear you say. Yes, despite the 9900 being a 16 bit machine and therefore capable of addressing much more
memory, TI are offering 16K - no more, no less. My feeling is that later
they may just decide to provide some add on memory, but I shouldn't let this form part of your decision to buy - just in case I'm proved wrong.
I only managed to make the system go wrong once and that was as a result of a poor cassette recording (probably caused by the overwriting of something else). The effect was to make the system
ignore the end of file record, thus
loading rubbish at the end of a program. The fun began when I tried to list or run the program - it would get to this bit and then dive off in a loop, throwing up spurious patterns all over the screen. I must stress that this only happened
once and I mention the fault not because it was terribly important but rather it was something out of the ordinary. With this one exception the system was completely idiot proof.
The keyboard (comprising 40 slightly dished keys) has a very nice feel to it;
it's small and laid out in the normal qwerty format. Having allocated letters and numbers the remaining 4 keys are used for space, shift, enter and full stop. There is also a space bar but everything else has to be found using
the shift key. This can be very irritating,
especially with common things like mathematical symbols and punctuation

48 PCW

The TI 99/4 connected to a Shan tic dual standard television. The TI power supply is to the right.

marks. The keyboard is provided with a useful overlay which indicates the use of various keys when in EDIT mode. Other overlays are supplied with some
of the command modules to show which functions are assigned to which
keys.
The screen comprises 24 lines of 32 characters each of which can have a foreground colour and a background colour. The screen itself may be any one of 16 different colours as may be the character foreground squares, it's simply a case of defining the same foreground and background colours for a character.
By now you may have realised that high resolution graphics are not provided on this machine, although it is possible to redefine the pattern of each of the 128 characters. In this way it would be feasible to improve the resolution - although that's something you'll have to work out for yourself.
Each character comprises an 8 x 8
matrix which may be redefined by using a 16 character hexadecimal string. For character graphics this is a great
approach because it means you'll be able to produce just about any shape
you're ever likely to need.
The TI manuals suggest that you ignore the first and last two characters of every line on the grounds that, on a poorly adjusted television, they could get lost. This was no problem on the machine I had but it's nice to note that
Texas have taken their own advice, with all their displays fitting in positions 3 to
30.
The only other point worth making is that the connecting lead between computer and screen is mighty short. I

found continued proximity to the
screen a bit too dazzling and would
strongly recommend getting an extension or persuading TI to provide something longer.
The 99/4 has a built in loudspeaker which drives you round the bend after a while (although I'll admit the kids didn't seem to mind it at all. In fact one of the games got played for hours, simply because they loved the jingles
that went with it - we seem to lose something in the process of growing up). The machine can play three part music plus one part noise and it's
possible to vary duration, frequency and volume, thus giving a very wide range of effects. The top end of the frequency range is reputedly 44733Hz (great for
sending the dog up the wall) but my machine could only get up to 14911Hz. This may have been limitations in the internal amplifier and speaker, but I'm not sure; I didn't fancy connecting the system to my hi-fi to find out. Braver men than me (at TI) have tried and said there are no problems - I believe them.
Another useful thing about the internal speaker is that you can hear the cassette loading and, because you have a manual volume control, it doesn't shatter your eardrums. The system and command module software is also designed to make the machine "peep"
at you when it requires an action, or when it doesn't like something you've done. If you are a particularly selfless individual there's an earphone socket at the front of the machine that will enable you to compute in complete
privacy. The cassette connection, comprises a

9 pin plug at one end and five jackplugs at the other, enabling you to connect two cassette recorders - one for reading and writing and the other for writing only. Occasionally, as on my Panasonic machine, the motor control jack polarity is the wrong way round. This is easy enough to solve although I didn't bother . . . I just kept switching the
recorder on and off. You may have some difficulty setting the playback
volume correctly but once cracked you will have no further problems.
TI recommend that any recorder
used with this machine should have the following features: volume control; tone control; microphone jack; remote jack; earphone or external speaker jack and a digital tape counter to help you find your recorded programs or data. TI are currently evaluating all the cassette recorders commonly available in the
UK to see which ones perform best with the 99/4. No doubt in due course
they will make their conclusions known to their dealers.
Just one or two more hardware
related comments to go. First, I haven't
yet mentioned sprites, yes - sprites.
These are used in the command modules but cannot be employed by the BASIC programmer. They are the images that move around the screen . . . things like targets and gunsights. The clever bit is that the 99/4 will detect a coincidence, thus increasing the realism of certain types of game. It's a shame that the BASIC doesn't allow access to these as it's probably one of the most useful features in games programs.
Another thing I noticed was a
vibration on the metal part of the
computer whenever the television was plugged in. This was presumably a fault with the television although I couldn't locate the problem (TI are now getting it fixed). And there are a couple of sockets that I haven't yet mentioned one is for the attachment of joysticks and the other for a speech synthesis unit, an RS232 interface (for two devices), a disc controller and a print controller. None of these extras are available at present but they are on the way (see Expansion). Each of these plug in modules carries the 41 way edge connector so they can be piggy backed on to each other.
The only other thing is that the
manuals are full of dire warnings about touching the machine and causing static problems. In fact, they advise you to always touch something metallic before using the 99/4. Those with children will know there is no chance of enforcing this rule. I didn't remember and nor did the man from TI. I suspect it's a case of excessive caution, although I think that you should steer well clear of edge connectors and suchlike, just to be on the safe side.
System software
Invisible - that was my first thought
when I came to write this section of the benchtest. Of course, it's not invisible at all, the system software is there to help
you key in, test and run programs. Apart from that I suppose you could
say it's invisible. When keying a program
you are first of all struck by the fact that the syntax checking is pretty strict. You must flank reserved words with

PCW 49

spaces or operators, for example. My own view is that this is a jolly good discipline, making your program much more intelligible than, say, some of the
PET programs I have seen. The editing is a joy - key EDIT followed by the first line to be edited and from then on any
adjacent lines to be edited will be presented when you hit the cursor down or up keys. Insertion and deletion as well as cursor right and left are all provided making it very quick and straightforward to use.
Before a program actually runs, the code is checked through and the system reports any errors it might find. This always happens when you type RUN. Should you encounter persistent problems then there are two facilities to make your debugging easier. The first is the BREAK function which allows the program to stop running at the lines at which you have set breakpoints. Provided you do not amend any variable values, the CONTINUE command will resume the running of the program. Secondly, you have the TRACE facility which lists the line numbers being executed in a program. This is particularly helpful when your program
is looping and you can't see why.
Indeed it was when tracing one of my
programs that I felt the need for a printer; easier to browse through a listing than trying to debug from a
moving display. I'd like it if TI were to offer a printer option on this particular facility.
The final points on system

software relate to the user friendliness

aspects of the machine. It's very helpful

in that it always gives full instructions

to the operator, issuing messages like

"REWIND CASSETTE CS1 THEN

PRESS ENTER"; it will then issue

another message telling you what to

- do next - all jolly good stuff. Another

nice touch

although to the

experienced user quite superfluous - is

that when a program terminates, the

message **DONE** appears, followed

by the usual operator prompt. It's

superfluous because a) we have the

prompt and b) the screen has a natty

way of changing colour according to

whether or not a program is running -

light green when running and cyan

when not. Finally, you will notice that

after about ten minutes of non use the

screen goes blank. Don't be alarmed;

this is quite intentional and hitting any

key will bring the display back again.

ROM Software
"Solid State Software" is supplied in a brightly coloured card box containing the Command Module itself, an instruction booklet and, when appropriate, a keyboard overlay. The command module comprises a single pcb carrying from one to five ROM chips (depending on the complexity of the package) all contained in a black plastic cartridge about the size of an 8 channel cassette which slides into the front of the 99/4. Once inserted you have the option of any of the packages

contained on the module, as well as TI

BASIC and the equation calculator. The

children loved them, for a while at

least, especially the moving colour

graphics and the Stylophone-like tunes.

Some of the packages were very

good, in particular the games and

grammar

packs.

The

pre

school learning package seems a bit

confusing - it uses lower case letters

(quite rightly) but the keyboard is

exclusively upper case. It may be that

there should have been a suitable key-

board overlay supplied, in which case

this is an unfair criticism. Another

package insisted that I press the key

marked BKWD when the overlay had

BACK written on it. Attention must be

paid to this sort of detail when dealing

with the home consumer; however

obvious to the experienced DP person,

it can be very confusing to the beginner.

Another package offered was the

previously mentioned Keep Fit, in

which little graphic people show you

how to do an exercise; the machine

plans a sequence and talks you through.

I'm sure that this sort of thing goes

down a treat in the USA but I wonder if

it will catch on over here?

Our very own David Levy has written
a chess program for the TI 99/4,

although it will be a while yet before

the ROMs are produced. I suspect that

this is going to be quite something, and

I'm not saying that just because he

writes for us!

Finally the sprites again. They are

used in several of the games and their

size can be from one to four characters

in each direction; they move around the

screen quite freely, without any sign of

jerkiness. It's possible to move them

vertically, horizontally or diagonally

using (refer to a keyboard) the

WERSDZXC keys. I'm sure this is done

just to make you covet joysticks!

TI BASIC
The BASIC seemed fairly normal
although Texas prefer to use some of their own command names rather than the more familiar ones. Extra instruction sets are included to handle colour, graphics and sound as well as a fairly comprehensive set of file handling instructions. GCHAR is the equivalent of the more familiar PEEK except that it only works on the screen memory you can't ferret around inside the other parts of memory. KEY is a touch more than the equivalent of a GET instruction, in that it returns the value 1 if a new key is pressed, -1 if the same key is pressed again and 0 if no key is
pressed. The BASIC can handle string
constants up to 112 characters long, although these can be concatenated to the string limit of 255 characters.
Variable names can be up to 15 characters in length and every character counts, giving an enormous number of possibilities. Numeric variables may carry the same name as string variables,
the difference being that the string variable name is terminated with the conventional $. A number of string functions are offered, most of them
familiar to BASIC aficionados but one or two are unusual. The functions are: ASC, CHRA LEN, POS, SEGA STRA and VAL. POS will find the position within a string of any specified sub -

50 PCW

Basic
ABS BYE CALL GCHAR CALL SCREEN CLOSE(DELETE ) DEF EDIT
FOR. .TO. .STEP INPUT (REC) LIST NUMBER OPEN OPTION BASE READ RETURN SEG$ STOP TRACE

ASC CALL CHAR CALL HCHAR CALL SOUND CONTINUE DELETE END GOSUB INT LOG OLD POS REM RND SGN STR$ UNBREAK

ATN CALL CLEAR CALL JOYST CALL VCHAR COS DIM EOF GOTO LEN NEW ON. .GOSUB
PRINT(REC) RESEQUENCE RUN SIN TAB UNTRACE

BREAK CALL COLOR CALL KEY CHR$ DATA DISPLAY EXP IF. .THEN. .ELSE LET NEXT ON..GOTO
RANDOMIZE RESTORE SAVE SQR TAN VAL

string and SEGS is our old friend MIDS in disguise.
Alphabetic or numeric arrays are available,each up to 3 dimensions. You
also have the option of defining the base
of the array as 0 or 1, thus avoiding
great confusion. Several graphics commands are
available enabling you to colour the screen, the individual characters and their own backgrounds. You could, for example, have a cyan screen with a black letter on a red background while the letter next door could be green on a
yellow background (ugh!). Two
instructions exist to enable you to
repeat a character horizontally or vertically. Two nested loops containing these instructions would produce a rectangle of the chosen character.
The characters from 96 to 159 are undefined . . .g you may create whatever characters you like using these codes. You may also redefine characters in the range 32 to 95, replacing the conventional character with one of your own choosing. If you were to redefine 32 (space) for example and then issue a CALL CLEAR instruction, the screen will be covered in your chosen
character instead of spaces. TI BASIC has commands to handle
files on cassette and disc. They comprise OPEN, CLOSE, INPUT, PRINT, RESTORE and EOF. Files can be held sequentially or randomly on disc, with fixed or variable length (sequential only) records. The information may be stored in internal or display format, that is to say packed or ASCII. Files can be opened in input, output, update or append modes - thus minimising the risk of data corruption. EOF reports the logical or physical end of file when reading from disc while RESTORE puts the record pointer back to the beginning of the file.
All in all a pretty comprehensive BASIC although the graphics potential is restricted through the lack of plotting
facilities.
Documentation
A lot of thought has gone into the
documentation for this machine. Three books are provided - Read This First
(quick steps to get you set up and
started now), the Beginners BASIC manual and the Users Reference Guide; each is ideal for its respective audience. A BASIC reference card is also supplied which is simply a memory jogger containing the syntax for each of the BASIC commands, together with lists

of things like frequencies associated with the C Major scale and a hex to
decimal conversion table. Each cartridge comes with its own explanatory booklet. There's not much one can say
when presented with documentation
such as this except that it is very good.

Potential use
By now,- the aim should be quite clear
. . . the TI 99/4 is intended for the home where it can be used to educate,
play games or handle tasks like household accounts. I've no doubt that some people working from home will
slip in the odd business application, but this will not be the prime reason for purchase. The fact that you can learn to program in BASIC on this machine means that the possibilities for use are, as always, only limited by the users'
imagination.
Expansion
Lots of things are planned although none of them are available as yet. In the order that they are likely to appear,
the add ons are speech synthesis, RS232, joysticks, printer and discs. The printer will be 32 columns, thermal and
therefore almost silent. Up to 3 disc
drives may be attached each being single sided, single density, 5" and 90K Byte capacity. The speech synthesis will be user programmable (if you're clever) and contain vast numbers of words and phrases already programmed in; according to TI it will be "much better than our Speak 'n Spell". All I can say to that is "Thank goodness"!
The RS232 interface means that all sorts of non TI devices may be hooked

TECHNICAL DATA

CPU: Memory: Keyboard: Screen: Cassette: Bus: Ports: Language:

9900, 16 bit, 3.58MHz 16K user RAM, 26K ROM 40 keys 32 x 24, NTSC Audio Unknown TI's own, RS232 on the way TI BASIC

Benchmark Timings (in seconds)

BM1

2.9

BM2

8.8

BM3 22.8

BM4 24.5

BM5 26.1

BM6 61.6

BM7 84.4

BM8 38.2

up, not forgetting the acoustic modems which are to become increasingly important in this game (just ask David Hebditch). Prestel is being considered although there are no firm plans for it to be introduced. The problem here
centres around the fact that Prestel
demands 24 lines of 40 characters and a 240 x 240 resolution graphic capability - the 99/4 has 24 lines of 32 characters and no high resolution graphics facility
as such. Don't write it off though,
because internally the 99/4 can work in compressed character mode which (surprise, surprise) offers 40 characters per line.

Conclusion
This machine, very smartly packaged in silver and black, will look good in your
home and will undoubtedly provide hours of pleasure. It has a good BASIC and high precision mathematics. Its drawbacks are that it needs a special, pr modified, television and, surprising for a "gamey" type of machine, lacks high resolution graphics facilities. The add ons will undoubtedly make this a very attractive machine, especially with a speech synthesis that's likely to be ahead of anything seen so far. It comes rather expensive to my mind, at £655 plus the cost of the special TV or modification, but on the other hand, it
certainly has a lot to offer. The question
is, are people in the UK yet ready to spend this sort of money on a home
computer?

Prices

TI -99/4 with B/W monitor

£750

TI -99/4 with modification to

existing set

£750

TI -99/4 with 14" dual standard

colour TV

under £1000

TI -99/4 with 20 or 26" colour

set, remote controls etc £1300

Command Modules

£14.95-£44.95

Speech module (due April) under £90

RS232 interface " " under £150

Joysticks (due May)

under £30

Printer (due May)

under £270

Discs (due July)

n/a

At a glance

FIRST IMPRESSIONS Looks Setting up Ease of use

SOFTWARE AND LANGUAGES

BASIC

****

System software Home and education packages

* ** **

PERFORMANCE

Processor CasSette Interface

** ***

EXPANDABILITY Memory Cassettes Discs Speech synthesis Printer

n/a
** coming coming
coming

COMPATIBILITY

Hardware Software

n*/a*

DOCUMENTATION

VALUE FOR MONEY

**

excellent v. good good fair poor

PCW 51

BENCH TEST
ALTOS AeS8000-2

As designers develop methods for putting more and more circuits onto a single chip so the computer designers develop complete systems with fewer and fewer components.
The American manufacturer ALTOS has taken advantage of the situation to produce a range of single board computers with the power of bus based systems. The British company Logitek have put
together a turnkey business system, based on the ALTOS range of computers, complete with accountancy
packages and a word processor. Sue Eisenbach reports.. .

Hardware

In addition to the configuration I user's files while SAVE no longer alters had, the literature reports that a the memory image and STAT and PIP

The Altos ACS 8000-2 computer is a Z80 -DMA controller and an AM9511 have been extended. STAT VAL gives a

Z80 disc based computer that comes in Arithmetic Processor (for floating point summary of the available status com-

a box 7" high by 18" deep by 17" trigonometric and other mathematical mands, STST DSK produces a drive

wide. The box normally sits in a special- functions) are available as options. An characteristics table for all currently

ly designed desk, but because I live in a EPROM programmer is listed in the active drives and STAT USR produces a

flat (and not a computer showroom - table of contents of the Altos system list of user numbers which have files on

which may come as a surprise to some manual although the manual itself the currently addressed disc.

of my closer friends!), Logitek thought- reveals that this feature has yet to Any file can be made Read Only

fully supplied the review machine with- become available.

(R/O) or a system file - e.g. PIP - and

out its "office" housing. The lid comes The review machine came with an system files won't feature in a DIR list-

off the box by the removal of six Adds Regent 25 VDU and a Texas 810 ing, but will appear under STAT. PIP

screws, revealing the single board com- printer. The VDU keys, which have an has three new functions: Gn for setting

puter on the right side and one of the extremely firm feel, require a lighter a file from user n's area, W for writing

disc drives and its related circuitry on touch than I am used to. There are 76 over 11/0 files and R for reading system

the left. By unscrewing the single board of them and that includes a separate files. ED now standardly verifies lines

computer the second disc drive numeric/cursor pad. The layout is good and to disable this a "-V" command is

plus circuitry becomes accessible. and includes both shift and case keys so needed. There's a new utility, XSUB,

The CPU is a Z80A running at 4 MHz that upper case typing does not require which allows the SUBMIT facility to

and the 64K of RAM is dynamic. A shifting to get to the numbers. There's include line input to programs as well

1K ROM containing CP/M bootstrap no repeat key but the "repeat" function as to the CCP.

and monitor with the usual set of com- occurs when a key is held down longer CP/M 2.0 is upwardly compatible

mands is also on the board.

than usual. The printer (with single with 1.4 but only downwardly compat-

The ACS 8000 range of computers printhead which produces a nine by ible if none of the new features are

uses a Z80-SIO and two times Z80-PIO seven dot matrix) is bidirectional at the used.

for communications. Each of these rate of 150 characters per second. The Most of the Altos utilities supplied

controls two ports. The first serial port one I had for review had options for with the review machine (and these

is used by the console while on the compressed print (so that 132 columns come supplied with any Altos 8000

review machine the second was linked can fit on an A4 piece of paper) and computer regardless of the choice of

to a printer (it can be used for a modem compressed lines (8 to the inch rather CP/M version) dealt with the density of

instead). One PIO is used to control disc than 6). Both peripherals seemed robust. the discs. The Altos utilities are:

operations while the other is connected to an external parallel connector and may be used for a printer, EPROM programmer or any other parallel device.
The disc drives are controlled by a 1771-1 floppy disc formatter/controller which is able to cope with both single and double density discs. For double density the formatting is as follows:

Track Density Sectors Per Bytes Per

Track

Track

0-1 Single

26

3328

2-76 Double

48

6144

So, when formatted, each disc holds 450K. The disc drives are Shugart's SA800 and are mounted horizontally, but with their controlling circuitry on top. In other words, the discs are posi-

System software

SINGLE X - sets drive X to single
density.

The review machine came with both CP/M 1.4 and CP/M 2.0. The major enhancement which CP/M 2.0 has over 1.4 is the ability to deal with up to six-
teen logical drives each containing up to
eight megabytes - its directories can
hold 512 names. Random access facilities have been improved over previous versions: CONTROL H
now backspaces properly and Delete or Rubout can be altered to send ^H There are four differences between 1.4 and 2.0 at CCP level. DIR lists four elements per line (in MBASIC format) while a USER command allows the maintenance of up to 16 different logical areas in a direc-

DOUBLE X - sets drive X to double
density.
REFORM - allows the formatting of discs in IBM or ISIS single density or
Altos double density.
SETUP - for changing the bootstrap loader with reference to disc density
and printer baud rate. COPY - for copying a single density
disc. DCOPY - for copying a double density
disc.
PROMMR - not available yet, but for programming 2708's and 2716's. DTEST - tests disc drives. MTS - tests memory.

tioned with their front facing down. tory. ERA now only deletes the current Like most CP/M software, the Altos

52 PCW

utilities are supplied in single density format; the user requiring double density operation must transfer into Altos double density. This is a sensible arrangment since it allows the user to purchase any CP/M software and also to transfer to and from non -Altos CP/M systems. Unfortunately, I was unable to succeed in producing double density discs under single density CP/M 2.0 (although I had no difficulty using the same utilities under CP/M 1.4). Using two discs of different densities was not quite as straightforward as I would have liked. When the system is bootstrapped it takes on the density of the disc from which the bootstrap occurs. If the second drive is to be of the other density then a SINGLE B (or
DOUBLE B) will allow access. However, there's no command which enables the user to find out the density of a particu-
lar disc. I feel that the system should take care of changes in disc density automatically, or there should at least be some command that will allow a human check to be made. All I could
think of doing was using STAT and counting the Kbytes, or taking a chance on
which density it was - thereby risking a disc read error (BDOS error) and hav-
ing to re -boot the system.

Languages
The Microsoft BASIC is release 5.1 and has a few features not found in release 5.0 - in particular:
RANDOMIZE now prompts with
"Random Number Seed (-32768 to
32767)" INKEY$ returns either a one character
string (from the terminal) or a null
string if nothing has been typed in. No characters are echoed. (similar to PET's GET$). VAL now strips leading blanks, tabs and linefeeds. VARPTR(4<file number>) for random access files returns the address FIELD buffer instead of the disc I/O buffer.
The other languages provided were CBASIC, Fortran 80 and Cobol 80.
Applications software
The Logitek Business System comes
with a full range of application software; Wordstar is provided for word-
processing. The rest of the business
packages come from Interface Software Ltd (which is half owned by Logitek). They have anglicized (and improved) the Peachtree business packages which hailed originally from Retail Sciences of Atlanta, Georgia.
I had never seen Wordstar before and I must say that I was impressed. It's easy to use (menus at the top of the screen eliminate the need to turn to a manual) and extremely powerful; it was fun watching lines justify themselves before my eyes. By following the menus it's a simple matter to insert and delete individual words, re -arrange
lines, re -format whole pages, insert external files into the middle of the text
and of course output the file on the printer. In theory editing and printing can occur at the same time (using dif-
ferent files). . . in practice, without the DMA chip, keyboard input must be so

The processor/disc unit with its lid removed showing the single board computer to the right and one of the drives visible on the left.

slow (to avoid losing the odd character or command input during a disc swap) as to make it worth letting the printer have the processor to itself. My other criticism, as a touch typist, is that all cursor controls involve the CONTROL
key and one of the left-hand keys,
which must be depressed simultaneously.
In the interests of balanced action, it would be more comfortable if the righthand keys were used in conjunction

file rather than the terminal. When I ran the packages manually there was obvious confirmation that data input was being vetted; anything unacceptable
caused a "beep" and a request for
another input. During disc transfers the user is asked to wait. If a user has the full set of accounting packages, during month end processing, ledger information can be transferred to the Nominal Ledger Transaction File for an integrated

with the CONTROL key. The Interface Software packages that
were provided with the review machine included Inventory Management, Mailing
Address System, Nominal Ledger, Sales

ledger system.
To give some idea of the level of
sophistication of the packages in general, the following is the list of programs in the Sales Ledger package:

Ledger and Purchase Ledger. The payroll package was not available at the
time of the review. All the software was written in Microsoft BASIC 5 and although the version that I had was in interpreted BASIC, there are plans for
the next release to be compiled. The programs are all menu driven and well laid out on the screen (they don't scroll up but rather come down from the top
of the screen). Interface Software Ltd. provided an

Set today's date; Customer file maintenance; Enter transaction; Delete transaction; Open credit reconciliation; Invoice report generation; Statement report generation; Aging report; Transaction report; Customer account report; End of period processing; Query customer activity; Verify file structure; System initialisation; Create demonstration data files.
The one criticism I have of the packages

automatic demonstration of the ledger is that disc maintenance must be done packages which took its input from a through the operating system. From the

PCW 53

Expansion
The minimum system comes with 32K but this can be upgraded to 64K with the plugging in of a few chips. (The review machine arrived as a 48K version but was expanded to 64K in a matter of minutes). Also, as previously mentioned, the machine's desk has room for extra drives - adding them should be straight. forward. There are sockets on the board for the DMA controller and the arithmetic chip.
To expand the system from a single to a multiuser, the one board computer must be replaced with another (double size) board. According to the literature, the largest system (ACS 8000-6, with DMA as standard) can handle up to four users and two printers. This can run under either M/PM or AMEX, Altos' own operating system which can still run CP/M programs. A fully expanded four user system can have 208K RAM on board - AMEX takes 16K and each user gets 48K.

Logitek business

systems

All Logitek Business Systems come com-

plete with an Adds Regent 25 VDU,

Texas 810 Matrix printer and all the

point of view of the beginner, it would have been easier if a disc maintenance

is varied. The ACS 8000 Operating Man-
ual is reasonably accessible - the text

business and software listed above - as well as CP/M and BASIC.

option had been included, thus allow- within it is coherent and there's a de-

Prices ing formatting and disc copying without tailed table of contents (but no index).

the need to be aware of CP/M.

The pages are numbered, although the

numbers don't appear in the table of Logitek sells a wide range of computers

Potential

contents; a full set of circuit diagrams is and business systems based on the

included.

Altos range of computers. Below is a

The Altos ACS 8000-2 has been put together to appeal to the businessman. Logitek say that their desk consists of a leather -topped table, plus separate cabinet fitting neatly underneath (which can be used to house additional floppy or Winchester drives).
Although potential business users are

But there's no User's Guide for CP/M 2.0. Instead, the operator is expected to make himself familiar with the main features of CP/M 1.4 via the corresponding User's Manual, and then "transfer" by means of the "CP/M 2.0 User's Guide for CP/M 1.4 Owners". This is extremely inconvenient for new users and not as

representative sample of their range.

Altos CPU with single floppy capacity

'/2 Mbyte

32K

£2398

48K

£2569

64K

£2713

Altos CPU with twin floppies capacity

at liberty to build up their own suites helpful as it sounds for ex 1.4 users, 1 Mbyte

from the available range of CP/M system since two manuals have to be accessed 32K and applications programs, they are un- and cross referenced in order to under- 48K

£3083 £3240

likely to do so since the Interface Soft- stand the system. I hope that Digital 64K

£3398

ware packages, together with Word star, form as complete and comprehensive a collection as most could require. Interface Software discs 'can be set up to boot directly into the package - thus avoiding the more complicated "manual" initiation via the system soft-

Research are planning a CP/M 2.0 User's Guide.
The manual for BASIC 80 version 5.1 has not shown any signs of improvement over the 5.0 manual - in fact if anything it's got worse as there are now two pages of 5.1 additions at the front

Additional Disc and Tape Drives

Single capacity 1/2 Mbyte

£1028

Twin capacity 1 Mbyte

£1370

Winchester 14.5 Mbyte

£2450

Winchester 29 Mbyte

£3250

Tape backup 17.5 Mbyte

£240C

ware.

of a 5.0 manual.

Peripherals

Looking at the machine from an edu- However, I was impressed with Inter- Texas 810 with options

£1650

cational vantage point, there are advan- face Software Ltd.'s manuals for appli- NEC Spinwriter tages and disadvantages. It feels solid cation software. These don't ask the Adds Regent 25

£2195
£ 675

and having CP/M for its operating system allows the widest range of system software. Also the optional floating point processor must make it a good bet for a micro number cruncher. However, the lack of graphics cannot be inexpensively overcome - there's no bus into which to slot a graphics board and a full graphics terminal would be necessary to provide such a facility. Also the lack of a bus structure would prevent some educationists from custo-

user to become familiarised with system
manuals as they contain step by step details for using any necessary system
utilities. As well as eliminating the need to go about finding information from other manuals, the application software
manuals contain descriptions of the systems, equipment requirements and
capacities, detailed instructions for
using the programs and sample runs using test data supplied with the software. The tables of contents are pagin-

System Software CP/M + Altos Utilities AMEX (Altos Multiuser executive) BASIC 80 Interpreter BASIC 80 Compiler
CBASIC
Fortran 80 Cobol 80 UCSD Pascal
Z80 Macro Assembler

£ 85
£150 £215 £215
£ 85
£245 £375 £125
£ 85

mising their hardware, although the lat- ated and detailed.

Business Software

est Altos glossy does describe a proto- I have to admit that I found it easier Nominal Ledger

£295

type board.

to use Wordstar's menus than to go Purchase Ledger

£295

by their comprehensive manual. For Sales Ledger

£245

Documention
Since the hardware and software come from several sources, the documentation

most practical purposes the information contained in these menus is sufficiently
detailed for the user to achieve any
required effect.

Mailing List Stock Control Payroll (forthcoming)
Word Processor

£295 £395 £295 £255

54 PCW

Single User Systems

F1 -48K Altos CPU with

1 Mbyte floppies

£ 8900

F2 - as above but 64K

£ 9060

Hi - System F2 + 14.5 Mbyte

hard disc

£12,135

H2 - As H1 but 29 Mbyte

hard disc

£12,960

Multi User Systems

MU2-112K with 1 Mbyte floppies

and 14.5 Mbyte hard disc plus

another terminal

£13,795

MU2A - as MU2 but 29 Mbyte

hard disc

£14,615

MU4 - 208K with 1 Mbyte floppies

and 14.5 Mbyte hard disc plus

three more terminals

£16,065

MU4A-As MU4 but 29 Mbyte

hard discs

£16,885

The Logitek Business System prices include installation and hence are more expensive than the component parts.

Conclusion
As well as examining the software provided and running the disc and benchmarks, the review machine underwent extensive use as a word processor. Both this article and Chapter 9 of The Complete Pascal were typed (and subsequent-
ly revised) using Wordstar. I soon came to trust the reliability of the system.
Since the Altos range of computers are single board systems, any potential user is locked into Altos hardware. Fortunately, the Altos single user system runs CP/M while the multiuser systems run operating systems that are upward compatible with CP/M. And even though potential users are not tied into one supplier for software, Logitek have made every effort to hold customers by selling at reasonable prices a range of business software tailored to the Altos range of hardware.

BENCHMARKS

TECHNICAL DATA

BM1 BM2 BM3 BM4 BM5 BM6 BM7 BM8
DISC TESTS: D1 D2 D3 D4 D5

1.4 secs. 4.3 " 11.3 " 11.3 " 12.0 " 21.2 " 34.9 " 2.7 "
0.9 secs. 6.3 "
33.5"
6.3 " 31.9

CPU

Z80A 4MHz

Memory 32K to 64K dynamic RAM

Keyboard

Adds Regent 25

Screen

Cassette

N/A

Disc Drives

2 drives, 8" double

density single sided

Printer

Texas 810

Bus

N/A

Ports

2 serial, 2 parallel

System Software

CP/M and Altos

utilities, UCSD Pascal

Languages BASIC 80 CBASIC,

UCSD Pascal, Fortran 80

Cobol 80, 8080 Assembler

AT A GLANCE 'FIRST IMPRESSIONS Looks Setting Up Ease of Use
HIGH LEVEL LANGUAGES BASIC Cobol Fortran Pascal System Software
PACKAGES Business Education Home
PERFORMANCE Processor Cassette Disc Peripherals
EXPANSION Memory Cassettes Discs Bus
COMPATIBILITY Hardware Software
DOCUMENTATION
VALUE FOR MONEY ***** excellent
**** very good *** good ** fair * poor

*** **** ****
**** **
*** **
***
**** **
***
**** N/A *** ***
*** N/A **** N/A
** ****
***
***

BENCHMARKS ROUND -UP
Here follows all the timings for all the machines tested since the September 1979 issue. For the sake of completeness, others have been
included that date back to the days of "the old regime". Timings from this month's Benchtests do NOT appear in the list.

Machine
ABC 80 ACT 800 Apple II Challenger C2 4P Challenger C3 S1
CP/M 65D Compucolor II Cromemco System Three Short reals long reals Heath WH89 EBHB MBASIC Micromation Z Plus
Interpreter Compiler Panasonic JD 700
PET Sharp MZ-80K Sinclair ZX80 Sorcerer TRS 80 Level I TRS 80 Level II Video Genie

BM1 BM2

BM3 BM4

BM5

BM6

BM7

1.1

2.3

11.1

12.1

12.6

17.7

23.9

.9

4.6

8.5

9.4 10.1 14.9 23.4

1.3

8.5

16.0

17.8

19.1

28.6

44.8

1.4

7.8

15.0

16.5

17.8

27.0

39.5

2.3

7.9

21.0

21.0

22.5

37.5

59.6

1.7

13.1

21.6 23.7 29.2

39.6

58.3

2.0

10.9

22.4

23.9

25.7

38.7

55.2

1.7

4.6

14.9

17.8

19.4

30.2

41.9

1.9

5.7

16.4

19.7

21.3

32.4

44.1

4.1

17.0

35.0

38.8 44.0

75.8 113.0

2.5

9.2 25.8 26.0 27.0 46.6 73.2

1.4

4.4

11.2

11.3

11.5

21.2

34.9

.6

.5

3.6

1.8

1.8

4.7

13.5

2.8

9.1

24.6 24.7

26.2

43.9

69.7

1.7

9.9

18.4 20.4

21.0

32.5

50.9

1.4

9.4

16.3

22.5

25.4

36.8

51.1

1.5

4.7

9.2

8.9

12.7

25.9

39.2

1.8

10.0

20.7 22.2 24.3

37.6

53.7

2.5

18.0

34.5 39.0 45.0

67.0 109.0

2.7

11.6

28.0 28.5

31.3

51.9

81.0

2.7

11.6

28.0 28.5

31.3

51.9

81.0

BM8 13.6
5.6 10.7
7.5
9.9 17.6 10.2
22.9 22.9
11.0 13.0
3.9 4.9 11.8 12.3
-10.2 -9.6
11.7 11.7
PCW 55

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56 PCW

11 HP -85

Hewlett Packard are much renowned for their high quality electronic equipment, with a range that stretches from television waveform monitors through
pocket calculators to computers. The HP 85 (or Capricorn) is their long awaited entry into the small computer market and has many "plus" features -
and some surprising omissions. Has it been worth the wait?
by Guy Kewney

Hardware
As is to be expected from HP, the
machine is superbly engineered and similar in design concept to the PET. The processor, power supply, keyboard, screen, loudspeaker, tape drive and printer are contained in a unit about the same size as an Apple; although reasonably light in weight HP's excellent carrying case would be a worthwhile investment.
The CRT screen is a minuscule 5" with a paltry 32 characters per line and 20 lines to the screen. The CRT uses its own dedicated memory and can store up to four screenfulls that "roll -away" out of sight at the top of the screen but can easily "roll -back" at the touch of a key. However, the limit of 32 characters is rather low and this must give rise to serious misgivings as to the machine's business potential. In addition to these four screens, there's an additional graphics screen that is comparable to the
Apple Hi -Res graphics. Actually it's 255
horizontal dots by 191 vertical dots
thus giving the same apparent resolution
in both axes. Several commands are available to
manipulate the dots, such as DRAW 40,30 which draws a line from where ever the "spot" happens to be to point 40 on the X-axis and point 30 on the Y-axis. These points are referenced to the edges of the screen and if your chosen points are off the screen then tough luck as it will attempt to draw a line there anyway. The absolute movement of the DRAW instruction is affected by the dimensions set by the SCALE statement that effectively tells the computer what scale you are using on the screen, be it 40 points in each direction or 40,000. DRAW 40,30 will have more effect with a coarse SCALE such as 40 by 40 than with a finer scale of 40,000. A similar command is IDRAW but this draws relative to the last plotted point on the screen. For example, 130,-40 will add 30 to the last plotted point's X co-ordinate and subtract 40 from the Y co-ordinate. It then draws a line from where the last point is to these newly calculated coordinates. MOVE and IMOVE are identical to DRAW and IDRAW except that the "pen" moves to the new specified location but without drawing a line
behind it. BPLOT enables you to draw pictures
but the actual operation, like the Apple SHAPE table, is a bit awkward and cumbersome. Care has to be exercised when BPLOTTING lest the BPLOT data "interferes" with existing screen data to produce a meaningless
scribble. Mixed text and graphics is possible with the LABEL command. The snag is that, while you can put messages onto the graphics screen by

saying LABEL "WHAT KIND OF
PARAMETER IS THAT?" getting them
off again requires care. If you know exactly where the PEN was when the
LABEL started, you can go there again, reverse the PEN and reLABEL and it will vanish. If you know approximately where the LABEL was and it was near the bottom of the screen, you can specify a detailed GCLEAR from a certain Y level down and clear only that much of the screen. GCLEAR, by itself, will clear the graphics screen but I couldn't
find an easy way to clear the text
screens under program control. A nice feature is the ability to dump the entire contents of the screen - both text and graphics - to the 32 character thermal printer under the action of the COPY key. LDIR is a beautiful command that defines in what direction the label will be printed and also re -orientates the attitude of the letters - straight up will
print cci .
Co-tmC parison with the Apple graphics is inevitable and both have their good
and bad points. The HP 85 has total lack of direct cursor control under pro-
gram command. With the Apple you can
type a list of prompts down the lefthand side of the screen - move the text window to the middle of the screen and
clear the remaining half ready to accept data from the keyboard. Not so with
HP85 - it will take blood, sweat and
possibly even tears to program it to reach a similar result. Most graphic routines that I have seen get round this
problem by re -writing the screen every time - just like a VDU on the end of a bit of wire - which in a 32K BASIC is a bit of a drop-off.
Eventually, the HP85 will come with
a disc based operating system but currently there is a very good tape operating system driving the 3M mini cartridge. This features fast and slow tape movement under program control and a sliding tab that prevents accidental erasure. It's much more efficient
than the humble cassette in locating and loading data and makes the PET tape system look even more pathetic. Data
files are either sequential or random in access and to avoid unnecessary tape movement, the last 22 items from the
catalogue are kept in RAM for immediate
access - which is good. The loading routine will look for the first available
space on the tape big enough to take the program. . . a very economical system. The 98 series of HP machines uses an identical drive but the two tape formats are different. However, a man from HP
said that "a binary program is available to convert between the two". Another strong point of the tape system is its security checking. For example, it's possible to protect a program to the level that an unauthorised user cannot

load it, or even see it in the catalogue! The weak point of the tape system is in
the error protection - it's too good. One example that one would love to ignore is the tape flaw detection. This involves a light which shines onto the tape. If a piece of brown oxide flakes off, the tape becomes transparent and
the computer thinks that it has reached
the end of the tape - and stops the
drive. I wrote fifteen programs, but in the process of amendment, damaged, number two. Thereafter, all thirteen programs that followed were lost for ever. It was small consolation to hear the HP man explain that a bit of black ink on the backing would solve the
problem! The keyboard is excellent and suppli-
es the full ASCII set and also a comprehensive numeric pad. There are other
single function keys such as RUN,
PAUSE, LOAD, COPY, TEST, STORE, CLEAR and GRAPH although the idiot that put the SCRATCH key where it is needs burying in a deep hole... it's very easy to accidentally SCRATCH instead of ENDLINE (Carriage Return to you) and hence erase that program that you
spent two hours typing in. Another
part of the keyboard that deserves special mention is the idea of programmable or user -defined keys. Under the screen are keys that can be made to control the user's program without the necessity to hit return everytime. At the bottom of the screen, the program can display the labels, like "THINKS" bubbles, that it has assigned to each
key - such as STOP, YES, NO etc.
This simplifies operation for the unsophisticated user no end. In conjunction with the editing keys, the cursor forms a very powerful on -screen editor that features both character and line editing; however, there's the drawback that the cursor deletes any underscoring of letters as it progresses along the line.
The HP85 is built around Hewlett Packard's own custom built chip set and includes an 8 bit CPU, dynamic RAM and I/O controller. As a consequence, the chip count on the CPU board is reduced considerably to only 16 ICs! The disadvantage with this is that no-one outside HP knows the instruction set and no programming is available in either machine code or assembler - which is a potential disaster particularly if you want to write some very tightly controlled timing
loops for some outside peripheral.
True, there is a real time clock with a resolution in mSecs but in practical terms, the unknown and variable time delays introduced by the other BASIC program statements tend to make this clock perhaps not quite as useful as it otherwise might be. I feel this lack of any machine code programming to be a serious oversight on the part of HP.

PCW 57

BASIC INSTRUCTIONS Statements: ASSIGN, BEEP, CHAIN, CLEAR COM, CRT IS, CREATE, DATA, DEFAULT OFF/ON, DEF FN, DEG, DIM, DISP, DISP USING, END, FN END, FOR..TO..STEP, .NEXT, GOSUB, GOTO, GRAD, IF. THEN.. ELSE IMAGE, INPUT, INTEGER, KEY LABEL, LET, LOAD BIN, NORMAL, OFF/ON ERROR... GOTO, or GOSUB, OFF KEY/ON KEY, ON TIMER.. .GOTO or GOSUB OPTION BASE PAUSE, PRINT, PRINT USING, PRINTER IS, PURGE, RAD, RANDOMIZE, READ,
R RENAME, RESSTEOTRTEI,MRE,WAITTURN, SHORT, STOP, STORE BIN, TRACE, E TRACREAL, ALL, TRACEVAR,

GRAPHICS STATEMENTS ALPHA, BPLOT, DRAW, GCLEAR, GRAPH, IDRAW, IMOVE, LABEL, LDIR, MOVE, PEN, PEI4UP, PLOT, SCALE, XAXIS, YAXIS.

BASIC FUNCTIONS ABS(X), ACS(X), ASN(X), ATN(X), ATN2(Y,X), CEIL(X), CHR$(X), COT(X), COT(X), CSC(X) DATE, DTR(X), EPS, ERRL, EARN, EXP(X), FLOOR(X), FP(X), INF, INT?X) IP(X), LEN(S$) (note that it is S$), LGT(X), LOG(X), MAX(k,Y), MIN X,Y)), NUM (S$), P1, POS(Sl$,S2$), RMD(X,Y), RND, RTD(X), SEC(X), SGN(X), SQR(X), SIN(X), TAB(N), TAN(X), TIME, UPC$(S$), VAL(S$), VALS(X).

HP85 SYSTEM COMMANDS

Non programmable: AUTO, CONT, DELETE, INIT, LOAD, REN, RUN, SCRATCH, STORE, UNSECURE. All except REN and UNSECURE are single key commands.

Programmable: CAT, COPY, CTAPE, ERASETAPE, FLIP, LIST, PLIST, PRINT ALL, REWIND, SECURE. Only COPY, LIST/PLIST and REWIND are single keystrokes.

to understand about 95% of the HP 85's

Software
The BASIC comes in a 32K ROM with floating point, 12 digit precision and is claimed to "meet and exceed the ANSI

BASIC repertoire. Notice however, the surprising omission of PEEK, POKE USR and CALL - all confirmation of the lack of machine code support. As can be seen from the Benchmarks, the

Pass the magnifying glass - the 5" `micro" screen plus user defined keys.

standard". Let's get one thing straight, HP85 is respectably fast if not the

the ANSI standard is not a competition fastest.

but an attempt to standardise on avail- Firmware support is achieved by able BASIC commands and thus save making the bottom 8K of the BASIC

you and me a lot of time laboriously ROM "transparent" and user firmware

rewriting programs from one machine packages up to 8K in size can be acces-

to another. So any claim to "exceed" sed at this location instead - the idea

the standard is so much hot air. Never- being, I guess, for HP to issue a stream

theless, as can be seen from the list of of plug-in packages.

statements, the BASIC is very compre- Another aspect of HP BASIC is that
hensive and has many features not it's very friendly while the program is

normally found in personal computers. being entered and the comparison with

All the software is upwardly compati- other micro's in terms of writing and ble in that HP say, providing state editing programs is astonishing. If, for

ments are limited to one per line, then example, you try to enter a faulty

the more advanced 98 series will be able BASIC statement, the old statement

TECHNICAL DATA

with the same number is not deleted thereby giving you the chance to cor-

CPU:

Hewlett Packard custom - rect your mistakes or leave the old line

designed chip, in NMOS alone.

Memory: Keboard:

16K bytes standard; addon 16 Kbyte modules planned. IBM typewriter standard, plus programmable function keys, plus numeric calculator pad, plus system

Comprehensive error checking and reporting is another good feature although one annoying error was overflow. Try loading a long program (there's one supplied with the HP85 called COMPZR which plays tunes,

1NPuT

Screen: Tape:

function keys. Five -inch, with 32 characters per line, 20 lines per screen Cassette -width, cartridge drive integral, 195 Kbytes per cartridge, 29 -second rewind, 650 bytes/second

using the BEEP instruction. It will load a data file called MUSIC and thereafter, if not carefully handled, will play over 600 notes from Rossini's William Tell overture with heartrending accuracy and total lack of sensitivity). Unfortunately, the William Tell notes seem to take up

115:2;i0V`.1 50/60 Hz
sow
HEWLETT PACNAI

transfer rate, 60inches/ all available memory because, when I

second search, error -

attempted to change a section of the

correcting

Printer: Integral thermal printer,

identical character set as

screen, same size - per-

mits totally accurate

screen copies of print and

graphics. Speed: two lines

per second.

Bus:

Will support the HP-IB

eventually.

Peripherals: To be announced; will

attach to HB-1B or other

interfaces.

System Tape operating system

software: with high security options

to prevent accidental or

deliberate access to impor-

tant data.

Language: Only BASIC, with sophis-

ticated graphics exten-

sions, no Peek or Poke.

Power

UK standard, safe, Mac -

supply:

cessible, integral.

Cooling: Convection

tune, I got the OVF message - overflow of memory. Once the machine signals OVF the only thing that can be done to start the program again is RESET. However, you can't clear the OVF problem by pressing RESET! The program will run until you try to delete the overflowing data when the OVF will be signalled again. Presumably the system software looks down the data block for an "end
of block" code which doesn't exist because it was never entered, or so it seems. The same thing happens again if you try to write a new block of data over the old block. I hardly need to
point out that this problem could easily be solved by a simple POKE instruction but. . . you have to SCRATCH, LOAD the program and LOAD the data and hope that this time the problem solves itself. It can be a time consuming procedure.

Documentation
The biggest thing going for the HP85 is the manual. The quality will come as no surprise to anybody who has ever bought an HP calculator before. Any reference to keys is accompanied by a clear diagram of the key to assist recognition and when any output is derived, then that output as produced by the machine is printed; there are no discrepancies, or at least very few. The manual is also the best "Teach Yourself BASIC" book that I have ever met although it needs the machine to make it work.
Expansion
Theoretically, it should be possible to design one's own interface boards but in practice this will be difficult with

58 PCW

Have case will travel - HP's neat extra that makes carrying that little bit easier.

. its market is so completely different.
It has been designed specifically for one
area - the scientific - and in that par-
ticular sphere it excels. Nonetheless, there are annoying gaps in the
manufacturer's understanding of the market, perhaps reflecting the fact that the HP85 comes from the calculator side of HP. The most irritating of these gaps is the absence of any access to machine code instructions and the most puzzling, the omission o: the Hewlett Packard Interface Bus. If more attention had been paid to this and perhaps the needs of the business user - say a larger screen and an RS232 socket at the rear for a printer - then the HP85 could be described as an
excellent all-rounder. In the final analysis, the machine is overpriced for the hardware content but almost redeems itself by producing superb documentation that is virtually 100% error free.

PCW acknowledges the assistance given by Mike Dennis in producing the final draft of this Bench test.

PRICES (excluding VAT) Basic System Additional 16K RAM Applications packages

£1950 £ 237
57

HP85 Benchmarks (in seconds)

1

1.8

2

3.8

3 16.3

4 16.5

5 17.7

6 30.0

7 44.8

8 12.7

HP's no-nonsense back panel - showing the four expansion sockets.

the HP85 as little information regarding
the exact nature of the hardware is
available. This means relying just about
exclusively on HP for any add-on
boards, of which there are four promised for June. They are an IEEE -488 or HP-IB, ASCII parallel, RS232 serial and BCD board and all will come presumably with appropriate software in ROM. It just seems a bit crazy that HP didn't include the HP-IB as a standard fitting from the outset - after all, they invented it! All of these boards plug into four expansion sockets at the rear of the machine.
The standard machine comes, perhaps surprisingly, with only 16K of
RAM of which 14.5K is available to the user. This RAM can be expanded by plugging a further 16K in to one of the
rear sockets. The big question mark, how-

ever, is the lack of hardware information - would you send your car back to the factory to have the oil changed because the bonnet was welded shut?
Potential
HP sees the 85 as being aimed at "the scientific, technical and professional user" who is prepared to pay a price premium for good mathematical and graphic features; clearly the HP85 meets these objectives, albeit at an excessively high price. The business user would do better looking elsewhere at a machine that had been designed with him in
mind - that screen really is tiny.
Conclusion
The HP85 cannot be compared sensibly with most classes of personal computer

At a glance

FIRST IMPRESSIONS Looks Setting up Ease of use
HIGH LEVEL LANGUAGES BASIC Graphics BASIC System software

*** **** *****

PACKAGES Games Mathematics Business

**** ****
**

PERFORMANCE Processor Tape Diskette Printer Video
EXPANDABILITY Memory Diskette HB-IB Printer Other interfaces

to come to come to come possibly to come to come

COMPATIBILITY

Hardware

*

Software

**

DOCUMENTATION System Processor Software
VALUE FOR MONEY

*****
*
******( **

excellent v. good good fair poor

PCW 59

POWERING -UP
THE POST

With the concept of electronic mail rapidly approaching popular fruition it's timely that
David Hebditch should have turned momentarily from his endless discussions with the Post Office to produce this two part costing evaluation on "the state of the art".

PART 1: ECONOMICS AND EMBRYONICS
For many companies wishing to transmit
messages between their own various locations, the use of the dial -up telephone system could yield big savings over both the Post and Telex. For example, a 3000 character inter -office memo could be sent long-distance over the telephone for as little as 6p compared with 12p by first-class post and 5'7p by telex. Both the speed and the accuracy of transmission are also significantly improved, especially when compared
with the mail. In performing these calculations,
these are the assumptions made:
1. A message of 3000 characters (or about 600 words). This is probably
longer than the average but does tend to
favour the postal service where the charge is fixed (up to a certain number of characters - which cannot easily be calculated because it depends upon the
weight of the paper you use)! 2. That the call made would be a longdistance one. Again, this biases the
study in favour of the post (which is distance -independent) and against the telephone and telex networks (which
have distance -structured tariffs). 3. I've made two calculations for telex. The first assumes that the message be entered directly on the keyboard by the
operator at a sustained rate of 3 ch/s.
In the second case, I assume the message
to be prepunched into paper tape and then transmitted at the full line rate of
6.6 ch/s. 4. The calculations for transmission be-
tween microcomputers on the public

telephone network were performed

three times, once for each tariff time -

band:

- Peak

0900 - 1300

- Standard

0800 - 0900

- off Peak

1300 - 1800 1800 - 0800

The results of the study are summari-

zed in the table below. Clearly, the use

of the public telephone network is

much cheaper than telex. Also, trans-

mission on the speech network after

6.00pm is much cheaper than first class

mail. The scale of the difference becomes

even more marked if one assumes that

only a local call is required for the trans-

mission; in this case, the message costs one half of a penny compared with 12p

for the first class post!

The major reason for the telephone

being cheaper than telex is the difference

in speed; 30 ch/s compared with 6.6

ch/s respectively. Also, Telex doesn't

have a low off-peak rate.

But what are the other costs involved?

A telex machine with paper tape facilities currently rents from the Post Office for £592 p.a. (£632 p.a. for a console
model). Telex machines have no secondary applications (except as ugly paper weights). If you already own a microcomputer (for data and/or word processing) the cost of enhancing it for communication purposes may well be minuscule. Many machines (e.g. the Rair Black Box, the Cromemco range and the North Star Horizon) all come equipped with spare V -Series (RS -232) ports as standard. On other machines, the cost of a serial communications adaptor
might range from between £50 and
£200. A modem is then required to convert
between digital and analogue signalling. These range in price from £75 p.a. to £250 outright purchase. Clearly, the use of the public telephone network for outside business hours message transmission is only going to take -off if calls can be originated and received automatically.

Comparison of Transmission Costs

Transmit Time (secs)

First Class

-

Post

Telex @ 3 ch/s

1,000

Rate Cost per
- -message

2.5p

125p

per 20s

Telex @

455

6.6 ch/s

2.5p

57p

Micro @

100

3.5p

35p

Peak

per lOs

Micro @

100

Standard

3.5p

24p

per 15s

Micro @

100

Off-peak

3.5p

6p

per 60s

Transmit Time (mins) 12 hrs (?) 17 mins
8 mins 2 mins 2 mins 2 mins

Cost per message 12p 125p
57p 35p 24p
6p

POST TELEX
MICROS VIA PUBLIC TELEPHONE NETWORK

60 Pew.

PART 2:

become standard.

who can meet this requirement. . - the

4. The Post Office has chosen (until Post Office and Modular Technology.

WHICH MODEM?

recently) to exercise its monopoly For many years the Post Office only privilege over the provision of units offered 300 bit/s working on the public

Modems must be the most boring pieces of equipment in the marketplace (unless you are another modem, I suppose). We
use the telephone network for data
transmission because it's there; we have no choice about it. But digital signals
are not suitable for transmission on telephone lines and have to be converted to an analogue form within the speech frequency band carried by the
Post Office. Obviously, at the receiving end, the signals need to be converted back to digital form. All this is the job of the modem (short for modulator demodulator).
The functionality of modems is very limited; they work one bit at a time in each direction and know
nothing about things called "characters". This review of available modems is purposely restricted to those devices which
are most applicable to the home and small business environments. In other
words, they are cheap and simple to use. I've also limited the list to those modems with which either I or my associates
have had some practical experience. Having said that, if I'm doing any company an injustice by not including them in the list, if they'd care to write in I'll give them a mention in the upcoming "Network Notes" column.
First of all, what does one look for in a modem? The following notes correspond to the columns in the comparison
table. 1. Modems can be directly connected to the telephone line (via a junction -box or
jack plug) or, alternatively, they can transmit and receive signals via a tele-
phone handset.
2. The UK Post Office will not "assume" transmission on the public telephone network at speeds greater
than 200 bit/s. In spite of that, 300 bit/s seems to have worked reliably enough for some years. You can get 1200 bit/s modems but they are more expensive (as you would expect). Acoustically coupled modems which work at 1200 bit/s have also been around for a while, but the reliability of these is question. able. I would certainly have to use one

that will automatically dial calls on the public telephone network. The Post Office device for dialling calls under computer control is called a "DEC 1". It's bigger than a PET and is reputed to have valves and cogs inside. There's no reason at all why auto -dial cannot be built into every modem (just as it is in the Prestel 1200/75 modem). 5. Auto -answer is usually incorporated in modems but these have to be hardwired, thus restricting the choice. 6. On the hard -wired modems, it's sometimes possible to get simple loop
test facilities. I've found these to be invaluable in development work, but
they are also recommended for operational working for times when you need to isolate a fault.
Most of the modems in the comparison table are, unfortunately, acoustic couplers. The majority do a fine job but the coupler is an expedient solution to the requirement to transmit on the public network. Originally, couplers were designed for use in situations where the terminal was itinerant. I would suggest
that today, only a small minority of
couplers are employed in such applications. They are popular now because they provide a handy way of getting started in data communications - one that doesn't involve the Post Office.
Over the past ten years or so, I've regularly used a variety of acoustic couplers. Mostly I've stayed with the
Anderson -Jacobson ADC212 in its fine
polished wooden case and the less -
elegant but more compact Minimodem 3001C. The latter is made by Modular Technology and resembles a tank landing craft in Post Office red (if you can imagine that).
If you have a reasonably quiet office you should be all right. But I've found that in acoustically and electrically noisy environments (especially exhibitions) such couplers can become totally unusable. That, however, is the exception; under normal circumstances there should be no problems. Unquestionably
though, you should use a hardwired modem whenever possible. At the present time there are only two suppliers

network with its Modem No. 2. You cannot purchase these - they rent for £130 per annum. A more recent alternative is the Modem 13; it's provided as
an integral unit and forms the base of a regular telephone set. Costing £75 per annum, it's powered from the telephone
line itself but will only transmit on
Channel 1 - which is an obvious limita-
tion. I've used both these modems extensively and have had no trouble from the point of view of reliability.
I've also used Modular Technology's Minimodem 3C and 3A (the C standing for a call modem and the A for the answer model). These cost £225 and £250 respectively but that's a one time purchase price. Again the equipment is very reliable. . . indeed I cannot remember ever having a fault on Modular Technology equipment.
One advantage of using the Mini modem unit is that each device includes a display of the various interface lead
levels. This is a very encouraging facility
because it enables you to see exactly when the device is transmitting and receiving or has lost carrier - or whatever the problem might be. The modems also include local and remote test facilities which enable you to carry out various simple routines for locating possible faults in your link up. The 3C and 3A modems also include a Quality Indicator lamp which is a useful facility when working on the variable public network. The Post Office modems do
not include such facilities.
The major disadvantage with the Minimodems is that, at present, there is no facility to switch one model between call and answer functions; by the time you are reading this, how-
ever, Modular Technology should have announced a completely new range of acoustic couplers and hard wired modems. These are as yet un-named (as
you will see from the entries in the
comparison chart) but they carry a very impressive specification. For example, they are both switchable between call and answer operation and in addition to the usual standard V -Series interface,

for a sustained period before being con-

vinced of their practicability.
3. Most of the modems and couplers

included in the list are designed for use

at 300 bit/s (CCITT V21 Specification).

This is a full duplex arrangment (simul-

taneous both way transmission). Trans-

mission takes place on different carrier frequencies for each direction a

"calling modem" sends on Channel 1

and receives on Channel 2. Clearly, the

connected modem cannot do the same

- it must receive on Channel 1 and

transmit on Channel 2. Three techniques

are employed to achieve this:

a) The modem is constructed to receive

on Channel 1 only.

b) The modem can be switched (man-

ually) to transmit or receive on Channel

1.

c) The modem normally transmits on

Channel 1 but will switch to Channel 2

if it hears a carrier frequency on Chan-

nel 1 (the Post Office Modem does this).

For home and business applications,

there seems to be a clear need for the ability to switch between channels to

"It's not very encouraging I'm afraid Mr Nisbett I fed your symptoms into the computer and it died"

PCW 61

they also offer a 20 MA interface and din type connectors for the attachment of cassette tape units. The hardwired
modem includes an auto -answer
facility (as does the present 3A) and
an optional auto -dial capability.
In view of what I said earlier, the auto dial arrangment can only be used
on inhouse PABX networks or in countries where the telecommunications

authority is a little less paranoid than ours about such attachments. For an estimated price of around £300 it would seem to be an excellent modem for domestic and small business purposes. Modular Technology will continue to
sell their low cost (£160) calling coupler. The other suppliers on the list, name-
ly Peripheral Hardware Ltd., K&N Electronics and Transdata Ltd., all supply

high quality and reliable modems
although my personal experience of these is not as extensive as it has been with the other units mentioned above.
I certainly look forward to an opportunity of trying out a Peripheral Hardware Sendata 1080 acoustic coupler which works at 1200 bit/s. If I manage to get my hands on it I'll report the results in Network Notes.

Supplier/Product

Hardwired (HW)
Acoustic (AC)

Anderson -Jacobson

ADC 211

AC

ADC 212

AC

K & N Electronics Ltd

AC 3500M

AC

Modular Technology

Minimodem Range

3001C

AC

3001A

AC

3C

HW

3A

HW

New Range (1)

AC

(2)

HW

Peripheral Hardware Ltd

Sendata 1080

AC

Speed (Bit/s)
300 300 300 300 300 300 300 300 300 1200 (+ 75 return channels)

Call Answer

V

1

x x

I

x

./ x x1
./ x

x

V,

V,

V,

V

,./

V
,./

C/A Auto Switch Dial

x

x

x

x

x

x

x

x

x

x

x

x

x 1,
V

/x
x

x

x

Post Office Modem 13 Modem 2 Transdata Ltd Acoustic Modem 307

HW

300

HW

300

AC

300

V

x

I

V

V

x

x

x

1

V
(extra)

x

x

Auto Test Price Notes Answer

x

x £193 Includes

x

x £255 complete

enclosure

x

x £212 for handset

x

x £160

x

x £160 Includes

x
/
x

/V
V

£225 V -Series £250 20 mA 8c c.£220 -Cassette

V V c.£300- Interfaces

x

x £345 Includes

complete

enclosure

for

handset

x x £75pa -Rental
7 x £130pa-only

x

x £185

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R2 PCW

VIEWDATA
AND THE INFORMATION AGE

PART 2: -THEORY INTO PRACTICE
by Dr. Adrian Stokes

Last month I described the background to viewdata and Teletext and included instruction on the basic mechanics of how to use them. Here, in part two, I'll be considering tasks to which they can be put with particular reference to the use of microcomputers as videotex receivers (and vice versa). I'll be
looking too at possible future uses for such systems.

Although I've described how to find your way around the viewdatabase, the mechanical ability to meander around a fairly large database doesn't imply any ability for finding useful information.
The basic structure of the viewdata base is a tree and can only be searched with a simple search strategy, compared to the complex strategies allowed in most information retrieval systems. For example, to find an Italian restaurant
in North London in a conventional information retrieval system would re-
quire a search of the type: FIND (RESTAURANT) AND
(ITALIAN) AND (NORTH LONDON)
whereas, in a viewdata system, no connectives are allowed and the user has to choose the search path carefully. In the above case, a reasonable choice
is:
Entertainment = > Eating Out = >
Italian Restaurant = > North London.
It might, however, have been just as reasonable to start the search by geography, looking for entertainment in North London, and then deciding what type of entertainment was required. Therefore, the Information Provider should ideally include multiple routes to the same data.
Given that this has been done (and it leads to significant problems if cross linkages are required to other IP's data), to what tasks can viewdata be put?
The different usages can be divided
into four major areas - residential,
public, business and specialised. Viewdata was always intended to be aimed at the general public rather than at business users and the Post Office are predicting that, within three years, the ratio of domestic to business receivers will be about five to one (with a projected total, in 1983, of three million sets). In this market, one major role of viewdata will be as a first line of reference. Even though the viewdatabases are
reasonably large, there is no way in which they can be extended to hold
even a small fraction of the information which might be required. For example,
a user who wanted to find out about
microcomputers would probably be
able to get a list of (most of) the micros available at present and might even be able to get some details of
configurations available; but he'd almost
certainly not be able to get hold of

machine code listings, purely because of the amount of data involved.
This is one type of data likely to be available. A second is transient information, again provided that the volume of data is not too high. For example, railway timetables are noticeably subject to change at frequent intervals and printed timetables can easily be made incorrect; these could be stored on viewdata and updated as regularly as needed.
If data changes even more rapidly -
take share prices for example -
viewdata is perhaps not the ideal medium. This is where Teletext is more attractive since not only can its data be changed within seconds, but also the revised version is automatically disseminated to customers whereas, with viewdata, the updated frames have to be called for.
The fact that viewdata can be used as the first line of reference implies that the user might want access to the full reference; so one obvious place to have a viewdata terminal would be in a library or other public place. And there
is likely to be a growing market for
"coin -in -the -slot" viewdata terminals;
already there has been a six-month experiment with half a dozen such facilities (made by Cherry Leisure).
The third area for viewdata is in business applications. In the case of large companies, there's likely to be relatively small use of viewdata since they'll quite probably have their own dedicated
systems - although they might use
viewdata for communicating with either the general public (advertising), with distributors or with other companies. However, in the case of small businesses, viewdata might provide the ideal solution for maintaining information since the investment is very much lower than
for a dedicated system and can be increased in small steps. Also, the
information can be accessed from remote locations if required.
Finally, there are specialised uses of the system. Teletext was originally proposed as a means of sub -titling television programmes for deaf people but there are now many other ways in which viewdata and Teletext can be used to help the disabled. Indeed for the deaf, viewdata has been adapted so that they may communicate via the telephone using the system's interactive capabil-

ities. The screen is divided in two, half being dedicated to each customer with the centre line being used for system messages. Also, a nice touch, each user's typing comes out in a different colour. Of course, there would be no need to go through viewdata at all, except for the fact that the send and receive channels
of the modems operate at different
speeds. Obviously ordinary keypads
cannot be used - one needs the full
alphanumeric range (as used by the IPs for editing frames).
Viewdata can also be very helpful to physically disabled people. One simple use is to be able to order (and pay for) goods without leaving home. But another, perhaps more important use, is the provision of generally helpful information and there is an experiment in progress at the moment to provide a Prestel database on the problems of disability.
There are in fact lots of other specialised uses, many of which are
only just beginning to be realised as a result of the research that's going on now in this area.
Telesoftware
A viewdata adaptor consists of, among other things, a processor and memory
- so does a computer! In fact, if the
processor wasn't too restricted in what it can do and if there were more memory, then the viewdata adaptor would make for quite a respectable microcomputer with, of course, its own (usually colour) display. In addition, it has communications capabilities.
This is the basis of telesoftware, the idea that the hardware at the user's end can be enhanced, thus providing him
with a micro as well as a viewdata
receiver. From there, an obvious step is
to keep most of the software on the viewdatabase (since there is no reason
why the data on the viewdatabase need be textual) and retrieve it when needed.
Similarly, programs can be kept on
Teletext and loaded as required. Of course, there are problems. First,
what language should be used? There are a number of common languages around and although one obvious solution might be to use machine code, there are enough different processors about to make this impractical, parti-

PCW 63

cularly for Teletext where storage is limited. Perhaps the best idea is to use a
standard language such as ANSI Minimal BASIC which, though not particularly efficient, should work on most
machines. In addition, what programs should be
retained? On Teletext, due to the limited storage (although the problem is not quite as bad as I have implied in this case), it's likely that the programs to be stored would be standard ones, e.g. a calculator simulator, a mortgage calculation etc. On the other hand, not only could viewdata hold a large library of programs (possibly in different machine codes), it could, because of its
interactive nature, allow the user to
write his own programs. One problem that arises with
proprietary software is the question of cost. The most that can be charged for a frame on Prestel is 50p and, for his money, the user can keep a copy of the program forever. In order to overcome this, some work has been done in the field of self-destructive programs so that you can rent a program, only for it to become inaccessible either after a fixed period of time or a certain number of
uses.
In this section, I have implied that Telesoftware is not on the market yet and, to some extent, this is so in that it's not generally available. However, the IBA has been conducting regular experiments in this area and one soft-
ware company, CAP Microsoft, has been carrying out texts with the implementation of MicroCOBOL via Telesoftware.
Of course, to make significant use of Telesoftware, the receiver ought to be enhanced by means of a printer - and backing store, such as cassette tape or discs. Once these are available, not only will the receiver run Telesoftware, its use as a viewdata set will be greatly enhanced.
Intelligent
terminals
The first "enhanced viewdata receivers" were, in fact, micros which interfaced between the receiver and the line. There
are now quite a few of these on the
market and, forgetting those which can be used as stand-alone viewdata systems (such as GEC's), the prices vary from about £1500 up to nearly £10,000. In the lower price range are such machines as the Telemachus TM -1, the TECS (Technalogics Expandable Computer
System) and the Jasmin Electronics
machine. At these prices, the storage is obviously limited and consists of RAM with no backing storage (although this can be added). At the upper end of the market, the Telemachus TM -3 is based on a PDP-11/03 with twin 8" floppy discs - obviously an extremely powerful system.
Although these machines can be used as stand-alone micros, their intended use (and what the customer is paying for) is as an intelligent viewdata terminal, enabling pages to be obtained from a view database and stored locally (or created
locally), edited as required (with far more facilities than the minimal ones provided by the Post Office on Prestel) and then transmitted to the viewdata base. The number of frames which can be held locally vary from about three up
to 200 per disc for the TM -3.

Home computers as
viewdata terminals
What of the user who already has a micro and wants to use it as an intel-
ligent viewdata terminal? Already, coming onto the market there are packages that enable micros to be modified for this purpose. For example, "Appletel" was recently announced in PCW (Feb 80). This is a package which converts an Apple II into an intelligent editing terminal, allowing storage of up to 60 frames per disc. At present, the display is only monochrome and a separate Post Office Datel 600 modem is required; future developments, however, include an integral modem with autodialler and a colour display.
Further packages for other machines are coming onto the market, especially for S-100 bus machines and there will be regular updates to this article on this topic. In fact, if any reader has experience of any such packages, I'd be pleased to hear from them.
The future
It's obvious that there is a significant future for viewdata and Teletext, even if perhaps not quite what was envisaged ten years ago. Such ideas as transmitting daily newspapers via these systems are technically feasible but impractical at present when one considers the volume of data involved. However, use of viewdata for "electronic mail" has far-
reaching implications including the
whole question of the Post Office
monopoly. The PO has already relaxed its mono-
poly significantly because of Prestel (for

example, by allowing television sets with integral modems to be connected to the telephone system) and further changes are inevitable. Also, there are problems over the Post Office's role as a common carrier. Already, for reasons of demand, it has had to suspend this role - it hasn't been able to give Prestel facilities to everyone who has asked.
A further problem which has raised considerable interest recently is that of frame content on Prestel. The ones in question described various pornography shops in Soho (and were called, most appropriately, "Rupert Streetwalker"). They were removed after complaints from an MP (and replaced by frames telling you how to complain if you were offended by material on Prestel). The Post Office has no more responsibility (nor control) over content than it does over the content of mail but this could lead to some interesting situations.
The introduction of "new" technology raises many new questions. For example, there was much discussion last year over the VAT rate for the information content of frames. When the Finance Act 1972 excluded books etc. from VAT, viewdata was not considered and hence not mentioned; eventually Customs and Excise agreed that the information content should be zero rated.
Viewdata is an area where there is bound to be considerable growth over the foreseeable future, particularly when coupled with home micros and, although it may not so far have lived up to all its expectations, during the next five years or so we should increasingly be able to witness the impact of this
Information Age.

64 PCW

ACORN ATOV

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Every kit is sent with assembly instructions and a beginners guide to Atom BASIC, ASSEMBLER and operating system.
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COMPUTER Cambridge, CB2 3NJ Tel. (0223) 312772

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See page 76 for complete list of approved dealers.

Each month Sheridan Williams and his panel of consultants answer readers questions. Topics may be hardware - from kits to mainframes, or software - from differential equations and statistics to file handling or sorting; the choice is yours. Send your questions direct to Sheridan Williams at 35 St Julians Road,
St. Albans Herts.

Growing pains
I am considering buying discs for my Commodore PET. I have been told that there are alternatives to the PET discs ... are they worth considering and if so, why? B. Abbott, Nottingham
It's very unusual to find someone asking this sort of question; in my experience most people would just go out and buy PET discs for their system. Why on earth people are prepared to spend hundreds of pounds without seeking advice I don't know.
One of the important considerations in choosing a suitable disc system is its ease of use, by that I mean its operating system. I find the PET disc system a pain to operate and simple everyday tasks like a disc directory are far more difficult to obtain than they should be. I think the main reason for the difficulty is that the PET disc thinks it is a "printer".
One of the best alternatives to the PET disc is the Computhink disc; it comes with its own operating system which supports a very comprehensive set of commands. These commands allow direct access files which although possible on the PET discs, are incredibly tedious to implement. The Computhink discs are available in two forms: 200K per disc (single sided)1 and 400K per disc (double sided) . thus with the two drives you can have 800K on line!
Many people consider that double siders tend to be unreliable, mainly because of the heads banging together as they access the disc; the Computhink discs have the heads slightly offset and seem no less reliable than single sided disc drives. The PET disc drives are available only in a 170K version - which is single sided. Prices compare quite favourably too; around £810 for PET discs and cable; and £895 for single density Computhink discs; remember though that you get 15% greater capacity on the Computhink for an extra cost of only 10%. The double sided 400K Computhink discs will cost around £1150. Neither disc system uses any of the main store on a 32K

PET so there are no worries LPRINT CHR$(14); 'Large%

there.

CHR$(15); 'Chars'

The only advantage that I

can see for the PET discs is Printing ASCII code 12 will

that they are "intelligent", activate a form -feed.

which is to say they have

The ANADEX is compact,

their own processor on board. fast, robust, versatile, and

In plain English this means cheap, and I can certainly

that the PET discs can be recommend it.

getting on with one job while S. W.

the PET itself is tackling

another. The next point

Call for CAL worth considering when
buying discs is the availability

of software. It seems that my Can you give me any

approval of the Computhink information on existing CAL

discs is backed up by

packages, including where

Petsoft who can supply

they may be obtained. Ideally

most of their software on I'd like to know what is avail-

both systems. Before anyone able and what machines they

asks, I have used both

run on.

systems and am totally un- J.H. Ruston, Wimbledon

connected with Computhink;

I'm just making recommenda- As a computer is a general

tions based on my personal purpose tool, we need to

experience. The Computhink tailor it to suit individual

disc operating system is not requirements. If the

perfect by any means, but it's computer is to assist learning

far easier to use than the PET in a particular subject area

system.

there should be good, well

S. W.

tested packages available.

This whole subject comes

Printing to a

under the term "Computer Assisted Learning" (CAL).
At present it's difficult to

price

provide a single CAL package for any topic because there is

Can you recommend a goods too large a variety of hard-

cheap printer for our school ;s ware and systems software on

Research Machines 380Z. Our which to run it (different

budget won't extend much versions of BASIC for

past £500 so this makes a

example). There are dozens

Teletype 33 out of the

of micros and mainframes,

question.

each one with its own sub

D. Thomas, Bath

varieties. A package designed

to run on the old 8K PET

The Teletype 33 does have a might not run on a larger PET

keyboard, paper tape reader that makes frequent u of*

and punch - all very useful PEEK and POKE. If we try

for preparing programs and and use a standard subset of

data off-line. They can be

BASIC we are up against the

obtained in a refurbished

problem that we cannot use

condition, but as you say,

graphics, files and machine

they are still outside your

code routines - all of which

budget.

make the package more

One of the best value -for - impressive and useful. For

money printers on the market this reason, and the fact that

must be the Anadex; it's a

there is not much profit to be

fairly fast (110 c.p.s.), bi-

made, the availability of CAL

directional matrix printer and material is severely limited.

can be used on the 380Z with I suggest that you keep in

only a single modification

touch with material available

(you have to connect the

by reading PCW, "Computer

busy signal from the printer Education" (from North

to the 380Z ... a very simple Staffordshire Polytechnic,

thing to do). The Anadex has Blackheath Lane, Stafford,

both serial and parallel inputs ST18 OAD), "Educational

and can be used very easily Computing" (30-31 Islington

and with little trouble on

Green, London N1 8BJ) and

virtually any micro. It

by joining MUSE (Oundle

supports 110-9600 baud

School Oundle, Peterborough,

input, together with others PE8 4AQ).

that control double sized

Find out if your local

characters and form feed.

education area has a policy

Amazingly enough, I've seen towards computers in

many people using the

schools and colleges. If it has

Anadex who have not yet

then it should have developed

found out that it can print some CAL material of its

double sized characters. You own; in the Hertfordshire

need to send the ASCII

area for example there is the

character 14 to switch on the Advisory Unit for Computer

double sized facility, and

Based Education. There

ASCII character 15 to switch ought to be equivalent

it off. Example on the 380Z: organisations in all areas -

but there aren't, which is an absolute disgrace.
Material currently available can be obtained from Edward Arnold Ltd, Woodlands Park Avenue, Woodlands Park, Maidenhead, Berks SL6 5BS; information about what they supply can be obtained from the Educational Computing Section, Chelsea College, Pulton Place, London SW6 5PR. These two work in collaboration and can supply BASIC programs on paper tape or, in some cases, cassette for the 380Z, in the subject areas of Biology, Physics, Economics, Chemistry, and Geography.
Other bodies that may be able to help are Council for Educational Technology, 3 Devonshire Street, London W1N 2BA. Petsoft have one or two educational programs for the PET. Qwertysoft 20 Worcester Road, Newton Hall, Durham, have several programs written by teachers for the PET and TRS 80. There is the Central Program Exchange at Wolverhampton Polytechnic which has BASIC programs available and MUSE have a fairly good library for the SWTP and 380Z micros. For those using the 380Z there are programs available from F. Donovan 35 St Julians Road, St Albans, Herts AL1 2AZ (an address that may not be too unfamiliar with some of you).
Finally, I am always interested to hear of any material available from any source and in any language; I'll keep you posted of anything good that comes my way.
S. W.
PET to printer problems
Some time ago my school purchased a PET, and through the good offices of a local company we acquired two printers. The first was an 8B CREED, the second a terminal printer with keyboard, tape reader and punch facilities. Our problem is to know how to connect these printers to our machine. A. Mawdsley, Manchester Your terminal printer probably has an RS232 or "current loop" interface. These use a seven bit ASCII code, sent serially along a pair of wires, sandwiched between parity, start and stop bits. In an RS232 interface each bit is expressed by a positive or a negative voltage; in a current loop interface, by a current or no current.

PCW 67

COMPUTER ANSWERS

The PET IEEE 488 port is an eight bit parallel one, so the data must be converted to a serial format, and to the voltage or current level that is compatible with the terminal. Most interfaces use a UART (Universal Asynchronous Receiver Transmitter) chip and they are readily available from most Commodore dealers at around £89 for a uni-directional and £149 for a bi-directional interface.
With a paper tape reader/ punch and keyboard a bidirectional one would be useful. The CREED teleprinter is a bit more tricky. This uses a 5 -bit Murray code which again is serial, although not an ASCII code. The data from the PET must be converted to the right format, either by hardware (expensive) or by software in the computer (fiddly). Don't forget either that the teleprinter will have to be switched between letter and figure modes. If you browse through copies of PCW you will find a number of companies who specialise in producing interfaces for the PET. They may be able to supply one to suit your needs.
If any readers have made an interface for the CREED and can let me know, I will gladly pass on the information. M. Wratten (Mr Mawdsley may well find it interesting to read "Hard copy at a soft price" p.77 this month - Ed.).
The forgotton interface
I am the owner of a Compukit UK101 (6502 cpu) and a TI 58 calculator. Please could you inform me if it would be possible to interface the two, allowing extensive number -crunching on the computer with intrinsic functions of the calculator and if so, how? M. Buckley, Norwich. I found your question particularly interesting, not least because it brings to the fore the idea of the "Systems Approach". This is one of the main foundations of professional computing, yet so far it has rarely been mentioned in personal computer magazines. As you may know, professional computer staff tend to work within one of three groups of activity: operators, programmers or systems analysts. The task of the latter is to consider each problem in its entirety, and decide the best approach to take . .. which may not involve computers at all!
Just as many recent articles have (rightly I think) exhorted us "not to rush into coding" when writing a program, so the "Systems Approach" would advise us "not to rush to use a

computer" when first considering how to tackle a problem. Perhaps it's because systems analysts are not so directly computing orientated that this topic has received little attention in personal computing circles. More likely, however, it's that having to combine the tasks of programming and operating and in our leisure hours at that - is quite enough, and there isn't time to consider the Systems Approach. (Not to be confused with "operating systems"!)
Supposing we take the Systems Approach to the problem of interfacing your UK101 & TI -58? We may well be surprised to find that this quickly yields an easy, cheap and reliable solution. There is a near perfect interface available and at no cost whatsoever .. . yourself! Write your program so that when "number -crunching" is needed the screen displays "NOW CRUNCH THIS" (or some similar message) the nature of the operation, and the numbers in question. This should be followed by an INPUT statement so that the answer can be entered back to the computer via the keyboard. Key the numbers and operation into the TI -58; key the answer back into the UK101 . . . and proceed!
Now, I know this is not the answer you had in mind - or were hoping for - but I do think that the Systems approach should more often be borne in mind.
In fact electrically interfacing the UK101 to the TI 58 is far from easy, for the calculator is not designed to accept an electrical input. Therefore you would either have to build an electromechanical device to enable the computer to literally press the keys of the calculator, or else remove the keyboard of your TI -58 to make an electrical connection to the Texas chip. Neither approach is beyond the hobbyist who is really skilled in electronic construction and measurement.
If you would like to know more about the possibility of connecting your UK101 directly to the calculator chip, then you will find the article "Sinclairly Yours" in the February 1979 issue of PCW very helpful. This describes interfacing a Sinclair Cambridge Programmable calculator to an MPU, and as well as discussing techniques, it also explains how to overcome some of the other problems that are likely to arise - such as incompatability between the supply voltages for the computer and the calculator. I don't know of anyone who has taken the other approach of constructing an electro-mechanical "key -presser", but I'd be delighted to hear from any reader who has tried to build something of the sort.

(Then of course you still

don't occur in yours. How

have the problem of reading the calculator display! -

can I get an English made printer to print the before

Ed).

mentioned characters. And last, if I succeed in putting

Holding on

another floppy than the Pertec on my ABC -80, can I use software from other

On the ITT 2020 a single

firms than Luxor?

character can be fetched from Eivind Trana, Bergen,

the keyboard as soon as a key is depressed - either by

Norway

means of the. GET statement, or by PEEKing the keyboard buffer. The character so obtained remains in the keyboard buffer until another key is depressed. Is there any way of detecting the lifting of the finger from a key? This

I'm afraid that your queries are difficult to answer specifically. Why don't you want to use the Luxor disc drives (which according to Sue Eisenbach's review are BASF not Pertec)? My advice is to stick to the Luxor drive

would have applications in unless you are prepared for

interactive programs such as one for an electronic organ.

an awful lot of extra work at ALL levels of hardware and

D. C. Leedham, Enfield,

software. As far as the printer

Middlesex.

is concerned I would suggest

I'm afraid not. Most keyboards generate a strobe pulse once when any key is pressed and it is the edge of the strobe pulse that is used by any following circuitry. The ITT 2020 is no exception.

that you approach some printer manufacturers directly in Norway. Alternatively, maybe an IBM Selectric could be fitted with the appropriate golfball. M. Dennis

Students What you require is a
constant output while the key is pressed and that is only

choice feasible with a custom built
keyboard.

M. Dennis

Because I'm a student I'll

have to buy a kit micro-

Cursor

computer very soon. Which one shall I buy? Shall it be an

S-100 bus system with a little

damage? bit from this and a little part

I am considering the purchase of a NASCOM1 and wonder

from that or should I stick to kits like the Nascom. Also can I upgrade a Nascom 1 to

whether the VDU's cursor

a Nascom 2?

would damage a television

Reidar Otto Johnsen,

screen.

Tromsdalen, Norway

G.M. Taylor, Leeds

S-100 is fine for really -to -

It's undoubtedly true that run business systems and a lot

the high intensity of the

of computer shops plug them

characters on a VDU screen hard - purely and simply

can cause deterioration of the because they are complete

phosphor on a cathode ray and well made. However,

tube, as witnessed by the

they are expensive for the

screens of industrial terminals enthusiast and a single -board

which have seen heavy use. computer would be much

However, for domestic pur- cheaper than an equivalent

poses where you will be using S-100 system.

the computer on and off and

Which single -board

not continuously there should computer? Well, if you want

be little problem. It's advis- to program with equal ease in

able you keep the contrast machine code and BASIC

and brightness to the mini- then without a shadow of a

mum visible display, and blank doubt buy a Nascom 2. If

the screen when not in use. you only want to program in

Other than that I wouldn't BASIC then the other two

worry.

may be suitable. You should

M. Wratten

be aware that the Nascom 2

does have a few more BASIC

Adding to the

commands available but only you can decide whether they

ABC -80
I really have problems. My ABC -80 is working so well that I would like to put on floppies, printer etc. What should I do if I don't want the Pertec floppy which Luxor sell, or the Centronics

are worth the extra cost or not.
Don't forget that you have to add the cost of a power supply for the Nascom (approx. £30) and you can't upgrade a Nascom 1 to a Nascom 2. M. Dennis

printer either? You see I

don't understand about

interfaces. How is the IEEE 488 and RS232 bus? Can I

Brain -racking

just buy a Shugart or Macro I am fully aware of the vast

and put it on?

selection of personal

Also the last three letters computers available. I am

of the Norwegian alphabet now in a position to purchase

68 PCW

COMPUTER ANSWERS

one for myself and can probably afford as much as the top end of the range of PETs or the new Sharp MZ80K. I have been racking my brain about the right choice; to add to the confusion, having read a lot about Superboards as well I find it difficult to see the advantage of, say, a PET over a Superboard - providing you own a TV as I do. Will it be wise to pay £750 when £250 will buy something as good and probably more expandable? S.W. Hepburn, Bisley, Surrey Your question is difficult to answer as you don't state exactly what you expect of your computer. If by expandability you mean a large range of ready-made "addons" that are currently avalable, then none of the computers that you mention fall into this category. You should look instead at either the Apple or ITT 2020 which are about the same price as the top -end PET.
The single board computers such as the Ohio, Compukit UK101 and the Nascoms are, at the moment, limited in their upward growth. There is simply no well-defined path to follow. The long promised additions seldom seem to materialise. As you can afford £750 then I suggest that you take a closer look at the

Apple/ITT2020; buy one with only 16K and get the extra memory as and when you require it - it simply plugs in. Try, too, to treat yourself to a floppy disc as soon as possible. I don't think that you will regret the decision. Remember, make 1980 the year of the Apple!! M. Dennis
380Z Basic access
How do I access the keyboard directly in BASIC on a Research Machines 380Z? What I require is a function similar to the Commodore PET's GET command where the keyboard is scanned and the character returned (or a zero if no key is depressed). The INPUT statement is no good to me because I require truly interactive routines such as reaction times. Anon. This is a common question so I'm answering it here for the benefit of all 380Z users. As most users will know, the 380Z is available in two machine types - the C4100 and the C100. It doesn't matter which version of BASIC you are using and neither does it matter how much store is available. The subroutine below will store

in CH the ASCII code of the key pressed and CH will be zero if no key is pressed.
1000 CH=PEEK(K9)AND127 1010 IF CH=0 THEN 1040 1020 POKE P9,195 1030 IF CH=26 THEN STOP (CHR$(26) is CONTROL Z)
This subroutine could be used as follows:
10 K9=4092: P9=16403: REM C4100

20 K9=64508: P9=65301: REM C100
(Delete 20 or 30 as appropriate) 30 PRINT "PRESS ANY KEY" 40 GOSUB 1000: IF CH=0 THEN 40 50 PRINT "YOU HAVE PRESSED"; CHR$ (CH) 60 GOTO 30
I have many programs available that use this technique, and those interested are welcome to write directly to me.
S.W.

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San Francisco boasts many attractions - Golden Gate bridge, Fisherman's Wharf, Chinatown and the cable cars to name but a few. Last weekend, however, the biggest attraction for 20,000 computer
buffs was the Fifth West Coast Computer Faire. David Tebbutt reports from the show.

San Francisco, that delightful
Conference city at the top end of "Silicapers con Gulch" was chosen as the

music. This turned into the "2001" theme and then, reaching the climax of the

to the writers of the Visicalc program. He noted that
the latter award was in recog-

location for the Fifth West

first crescendo, Don Perry nition of "the beauty of

Coast Computer Faire. It's an

Dunlap squeezed the remote design and timeliness of the

event that has the reputation I managed to attend a few of control of the carousel

product". There's nothing

of being something of an

the sessions and of those the projector. A blinding rec-

wrong with what Adam says,

enthusiast's show, packed to best was undoubtedly that the gills with computer freaks given by Hal Chamberlin of

tangle of white light appeared except maybe his tendency to on the screen! He pressed it repeat the same old jokes;

and full of pioneering spirit. MTU; he was describing the It has the distinction of being various ways of producing the place where many very computer music. He's an un-

again - another white rec- what jars is the way he says

tangle. The music continued. it.

Don Perry Dunlap pressed,

So what, I hear you ask, is

successful products and com- assuming young man with

and pressed, and pressed but a white elephant award? Well,

panies achieve their first

shoulder length hair, the sort

public showing; it's also high- you might meet in any pro-

ly likely that it's the place gramming department. But

all to no avail. The slides had, it's a North Star board conpresumably, been mounted taining a suitably inscribed on the "wrong" side of the brass plate plus a chip

where quite a few of them unlike such programmers,

projector . . . The music died mounted for each recipient;

appear in public for the last time!

Hal is something of a world authority on the digital

and so, slowly, did Don Perry each chip is, in turn, surDunlap. More in hope than mounted by a microscopic

The show is staged by Jim representation of music. He expectation he continued to white elephant. Before leaving

Warren, an ex -roller skating gave a fascinating lecture instructor. To be fair to Jim, with demonstrations which

squeeze the remote control the presentation I asked a until, finally, he realised the pretty young delegate why

he's also very knowledgeable convinced me that we are

game was up - modern tech- she had attended the session.

about computers; he was once only at the very beginning

nology had pulled the rug She replied: "I didn't under-

editor of Dr Dobb's Journal of the development of the

from under him. The lights stand a word of what he said

and currently he's working on computer's potential as a

came on and everyone waited but, wow, that voice!"

a sort of Ceefax/Oracle of

music machine. Hal's own

expectantly, wondering how (Rumour has it that the

the radio waves, a project

very successful company,

he would continue. Up to young lady in question was

that's due to be announced which he runs with David

then he had had our sym- subsequently invited to go

later this year. He was to be Cox, produces the hardware pathy, but not for long. He yachting by the man himself).

seen frequently (and fleeting- and software necessary to

proceeded to read his speech And, while on the subject

ly) buzzing in and out of the make the finest music ever - jokes and all - from a copy of sailing with Adam Osborne,

stands on his skates.

heard on a micro - more

of the conference proceed- I simply have to tell you the

Over 200 companies filled about their products later in ings. Being near the door I misfortune that struck our

the two halls and, in addition, the report.

sneaked out.

very own Guy Kewney just a

there was a full, three stream Another memorable talk was The whole world seemed day or two before the show.

conference programme.

given by Don Perry Dunlap, to turn up to see Adam

Seeking the pleasures of the

People who should know told who chose as his topic "Is

Osborne present his white sea, the two of them (having

me that this year's effort

Electronic Technology Mak- elephant awards (despite the decided that it would be a

placed less emphasis on hard- ing Mankind An Endangered name these are a genuine good idea to use the engine

ware and far more on end

Species?". With a title like

attempt to grant recognition for pottering around San

user products -a trend which that, you'd perhaps expect to significant achievements). Francisco Bay) carefully

is happening all over the

the hall to be full - but then Unfortunately, I find Mr. stowed the sails, upped anchor

place as the hobbyists find maybe people knew what was Osborne 's style irritating; and motored off. After a while

themselves diluted by busi- coming.

there is something very dicta- it became apparent that the

ness, education and home

The hall was plunged into torial in his manner, but

yacht wasn't making too much

users. Around 20,000 people darkness .. . a carousel pro- then he usually has some- progress - in fact it was pro-

attended and the overall

jector was checked ... the

thing sensible to say. He gave ceeding at approximately

impression I gained was that cassette player was checked one award jointly to Zilog walking pace even on full

it was lively, interesting and

. and the show began. At and Intel for their 8002 and throttle. Guy held on to the

worthwhile.

first there was just spooky

8089 products and the other rudder while Adam went

PCW 71

Stories from

possible to have up to 65 Apple computers working

the Show

together in a network. All machines have access to cen-

Ipex International Inc. pre- tral storage - up to 33

sented the answer to every editor's prayer - an attach-

Mbytes of it - thus enabling each machine to work by

ment which can convert the itself or with others, sharing

below to investigate and, not knowing quite where to go, our "newshound" steered into the middle of the bay.

common -or -garden Selectric
typewriter into a computer printer. It doesn't alter the appearance of the typewriter because it fits neatly inside,

the same files and communicating. A system was run-
ning at the show on which one screen displayed a list of names for whom messages were

Eventually Adam re-emerged with the news that the gears (or something) had stripped and that they would have to unstow the carefully stowed sails; the job done, Guy was
again given the tiller while Adam went below to fix a drink. This time Guv headed in the general direction of the harbour entrance and just
as he was starting to feel apprehensive about getting
back again, Adam reappeared

into existing screw holes. It comprises a solenoid assembly (which pulls the appropriate bail bars depending on the letter required), a control unit which can contain the power supply as well as being able to decode the computer's ASCII into the ball select code and, for the S100 user, a card which fits directly into your computer. If you choose the S100 option then the
control unit comes minus the

held in the central system.
Anyone seeing their name on the list could walk up to another terminal on the Clusterbus, type in their name (as spelt on the list) and have one or more memos displayed to them. Guy Kewney and Imade frequent and good use of this system. Contact Nestar Systems Inc.,
430, Sherman Avenue, Palo Alto, CA 94306 for further information. (Any buyers .

Another exciting product was
the Minimover-5.. . a five jointed, computer controlled arm. It can handle weights up to 8 ounces (even when fully extended), operates within a sphere of 17.5" radius and travels at between 2 and 6 inches per second, depending on the weight being carried. The jaws open to a maximum of 3 inches with a squeezing pressure of between 0 and

to take over the helm. A few power supply. By the way, yes, please contact me for a

31bas. I saw the arm being

deft course adjustments later it does work on the UK power possible future PCW case

they were stranded on a mud - supply. In the USA this

study).

bank! And technology wasn't ESCON SELECTRIC Interface

finished yet!

System costs from $495. Those I talked to a college professor

Adam, attempting to catch interested should contact

from Canada about Computer

the harbourmaster's ear via 16140, Valerio Street, Van Aided Instruction and he told

the radio waves, managed to Nuys, CA 91405, USA.

me a true story about his

disintegrate an important

own experience in Vancouver.

button on the radio; thus the Another very interesting pro- The day came when some of

driven by a TRS-80, for which a package exists. It will cost around $1700 plus freight; $30 for the software and $19 for a reference and application manual. Contact: Microbot, 1259 El Camino
Real, Suite 200, Menlo Park, CA 94025.

two of them were reduced to duct was one made by Nes- his colleagues decided to

tation in the business. They

frantic waving at passing

tar .. . called the Cluster -

evaluate these new-fangled specialise in 6502 products -

boats. It's all true... it must shared microcomputer system. computer things as teaching things like AIM, KIM and

be, Guy told me.

Using this system it's

aids. Well, what do you think SYM floppy disc controllers,

the demonstration packages visible memory for the PET

were designed to teach? Wait (with light pen facility) and

for it . . . the use of slide

the excellent four voice sound

rules and logarithms! It's so system mentioned earlier.

awful it's hardly even funny. One day this firm will pro-

duce a music compiler to save Gary Kildall, the man who all the tedious coding of brought us CP/M and MP/M, waveform tables and the like. is launching PL/1 worldwide All you'll need to do is feed on April 15th. I took a pic- in the music, dictate the inure of him so that you'd all strument definition and away know what he looks like - it will go to compile your unfortunately the gremlins got music for you. IJJ in Marlat it and it didn't come out; borough are their UK agents. sorry Gary.

Infoworld is a great bi-weekly

newspaper for the micro -

computing community. Pub-

lished in the heart of Silicon

Valley, its writers are really in

touch with things as they

happen. The cost is $35 per

year ($18 per half year) air-

The inhabitants of Menlo Park have the good fortune to count Ramon Zamora and Bob Albrecht among their neighbours. Ramon and Bob, with help from their friends, have set up a project called "Computertown USA!". It's an attempt to introduce the community, mainly the kids, to the joys of computing. The picture shown here was taken in the Menlo Park library
where a number of PETs and a TRS-80 have been installed, at no charge. Children spend an hour or so being taught how to
use the machines and once they can prove themselves able they are given a badge apt proclaims "my computer likes me". This gives them the authority to attend the library at any time and also qualifies them to help other children less able than themselves. They are not allowed to ask the librarians for help, only the organisers of Computertown USA! - or other children.

mail. Write to Infoworld, 530 Lytton Avenue, Palo Alto, CA 94301. (By the way, it used to be called the Intelligent Machines Journal). The publisher is John Craig - the same John Craig that used to edit Creative Computing. If there are any dealers out there who'd be interested in selling this or any other maga-
zine from the USA I suggest they contact me at PCW for pointing in the right direction.

Eric Bakalinsky dreamt up the well-known phrase or saying "Dr. Dobb's Journal of Computer Calisthenics and
Orthodontia". He describes himself as an "Interior designer and willing co-pilot for
flights of fancy". He also

Although all of the programs used are games, they are educational ones and they give the children a grasp of fairly advanced Back to Hal Chamberlin

pressed us to publish his phone number, (415)

mathematics - for example, the complex problems involved and MTU. Professionally

DAFODIL, where he awaits

when manoeuvring in deep space. More about this enterprising thorough and a company to calls from "beautiful women

idea in a future issue of PCW - probably via an Interrupt from Ameria.

watch, they are reputed to who'd like to join him for produce the best documen- chocolate moussee".

72 PCW

making the language really

powerful. He hawked his

ideas around the show and

ended up with a company

accepting his ideas and giving

him a new machine to enable

him to develop them still

further. That could have been

one of us. I'm sure software

is the one area where we can

really show the world that

Britain is a good match for

anyone. Another example is

the man who computerised

the Luscher colour test. He

was running one of the most

popular stands at the show,

giving personality evaluations

based on colour preferences.

Sharp has produced a hand-held computer which can be
programmed in BASIC and here's a picture to prove it. The machine fits into a cradle which in turn connects to a miniature cassette recorder. In America it retails for around $300 for the 400 byte version or around $450 for the 1424 byte version. Amazing! What's more, Sharp UK are actively considering marketing it in Britain.

Another man I bumped into has already proved how good
we are. His company, Micro -
focus, has set up an office
in Santa Clara to sell its products in the USA. Their CIS Cobol is the only microcomputer Cobol to have been

The stringy floppy was as

terists. It lists articles, book certified by the US govern-

much in evidence as it was at reviews, letters and editorials ment. Among the big deals

the Las Vegas show. Next

by subject from all the popu- they have pulled off are one

month we'll be bringing you a lar computer, radio and elec- from Intel and another from

user's report... in the mean- tronics magazines - including Texas Instruments. The

time those interested could PCW, of course. The 1979

company is Microfocus of

write to Exatron, 3555,

issue will cost $5.95 surface 58, Acacia Rd., St. John's

Ryder Street, Santa Clara,

($7.15 air) while 1976, 77

Wood, London, NW8 6AG.

CA 95051. For those who don't know, a stringy floppy

and 78 cost $5.00 surface ($6.00 air). Write to E Berg

Three cheers for them - if you've got something on the

is a cassette drive which

Publications, 622 East Third. boil that you'd like to show

powers a continuous loop cas- Kimbell, NE 69145 for

at the next Computer Faire,

sette (of tape length between further information.

it will be held on the 3rd -

5 and 75 feet). The tape is pulled from the centre of a capstain which revolves as
the tape is unwound; at the same time the other end of the tape is rewound on to the outside of the same reel. It's used as a mass storage device and far outstrips the

John Craig and Hal Chamberlin both reckon that PCW has got a head start over other foreign computer publications in that it's written in a language that they can understand. Such taste and
discrimination!

5th April 1981. Address all enquiries to Computer Faire, 333 Swett Road, Woodside, CA 94062. Don't try to go there, as I did, because all you'll find is one of those
American letter boxes on a stick. The building is being constructed. If you want to

performance of a normal cassette drive both, in terms of speed and also because it's
possible to access data randomly, without any need to
rewind the tape. Maximum tape capacity is 2.88 million a flux change is one bit - you work it out from there, but don't forget the control bits). It's fast, cutting program loading time down from minutes to seconds (e.g. 4K in 6 secs).

The Atari graphics are super but the word is we may have to wait until the end of the year before the international version is ready - and that means us folks.
Another lovely lady was manning the Syntauri music exhibit. She had a piano type keyboard interfaced to the Apple - through which she was playing some pretty good music. She was able to fiddle

phone them the number is (415) 851 7075.
Here's a very quick round of the various magazines that caught my eye. (Remember, dealers, if you want to sell them, liaise with me and I may be able to help). Compute magazine specialises in the 6502 - uses, products, packages etc. PET,

around with various parame-

Ken Cohn collects Apple

ters at the Apple keyboard

programs the way some

thus varying the nature of the

people collect matchbox

notes produced. The sound

labels. He's got over 3600, was nowhere near as good as

some of which he's never

Hal's but that keyboard inter-

tried. Is this a record? He

face was so tempting. For

belongs to ADAMII (standing further information contact

for Arizona Desert Apple

Ellen Lapham, Vaille Associ-

Menagerie) - what else can I ates, 3506, Waverley Street,

say?

Palo Alto, CA 94306.

Atari, Apple and single boards all catered for. $22.50 in US funds drawn on a US bank to Compute, PO Box 5119, Greensboro, NC 27403. 104 pages - good and glossy.
Interested in robots? Robotics Age, issued 4 times yearly, is aimed at professional, student and hobbyist. Send $15 or $16(air) per annum to Robotics Publishing Corporation, 3410 Marquart, Suite 203, Houston, Texas 77027.
There's a non profit program exchange and they publish 9 times per annum. Get your Apple group to contact them at A.P.P.L.E, 517 11th Avenue E., Seattle, WA 98102. In the USA the one time Apple -cation (ugh!) fee is $25 and the 1980 sub is $15.
Dr. "Lux" Luxenberg is the man who runs SYMPhysis, the SYM 1 user's group bi-monthly publication. It looks good to me, full of hard information to the equivalent of 20 pages of single spaced typing. As "Lux" says in his introduction "...that's a lot of software and documentation for the money". They are quite independent of Synertek. Send a cheque for $12.50, payable in US Dollars to SYM Users' Group, PO Box 315, Chico, CA 95927.
Finally, my favourite quote from the show. A company mentioned earlier (and who shall remain nameless) tell me that they are being extremely cautious - they want to hold their growth down to 400% this year!

I have to report that Suzanne Rodriguez - editor of Dr Dobbs Journal - is lovely. I took some pictures of her, too, but they didn't come out either - sorry fellas!
Something no enthusiast should be without -A Periodical Guide for Compu-

One thing is pretty clear to
me and that is that there's as much opportunity in software for us here in the UK as for anyone else. The Cana-
dian chap I talked about ear-
lier had unravelled the innards of the SYM and had been able to define a lot of new BASIC instructions -

How about this for a bit of plotting? The machine that did it can handle paper 81/2" wide by up to 11" long and plot in an area of 8" by 10". In America it costs from $755 (for Apple II) plus the cost of the software package at $60. It can be hooked up to a TRS-80 or an S100 system and packs of 4 pens cost $7.50. Contact Strobe Inc., 897.5A Independence
Avenue, Mountain View, CA 94043.

PCW 73

SYSTEMS

INFORMATION RETRIEVAL

AND DATABASES

Mike Knight of Mike Rose Micros sifts through all available documentation to present this month's selected report.

If you were to ask the "man in the
street" what his impressions of a

Evaluations

computer were, his response would ANALYST

probably be prejudiced by the films he This package, written by Structured

had seen or the TV programs which he Systems Group Inc, of California, USA,

watched regularly. How many times has is marketed in this country by Terodec

Dr Who been saved by K9? Could Blake (Microsystems) Ltd of Yateley, Hants

really triumph over the Federation with- (0252 874790). The package is designed

out ORAC or ZEN? Even Wonder to run on any Z80 or 8080 using CP/M

Woman uses the services of a computer with 48K, one disc, printer (80 column

which can instantly tap into any other. min) and a VDU, amounting in all to

Almost daily on our screens, instant approximately £3000. Costing £180 it

responses are given to large numbers of consists of four program segments link-

world savers by friendly computers who ed by a menu, written in CBASIC. The

can call upon enormous banks of data. manual supplied is reasonably compre-

Of course, a businessman with a micro- hensive but little thought seems to have

computer is not normally expected to been given to the small number of

save the world. He may, however, wish examples presented.

to run his company more efficiently and The major illustration is of an

to do this he certainly needs to be able attorney at law which, even if the

to tap the information available within American wordage is understood, is not

it.

likely (apart from the legal profession)

Over the past few months I have to fill most small business users with

reviewed a large number of packages confidence. However, even if the

covering most of the functions normally illustrations are comprehended, I have

found in any business i.e. Stock some doubts whether the jargon, used

Control, Sales Ledger, Purchase Ledger, extensively throughout, would be. If

Payroll and Word Processing. In some this communication problem could be

cases, particularly in accounting, link- overcome I'm sure that the package

ages are provided between the packages. would be useful to many small busi-

But almost without exception these nesses. Bought together with the minim-

linkages simply mean that a user of the um hardware, an installation service is

system can move from one business provided for £150; training is provided

function to another without resubmit- at £75 per day and maintenance support

ting the basic data entered into the first. costs 14% of the retail cost per annum.

In this months "Systems" I am, there-, The functions available in this

fore, going to look at packages which package are: define a data file, create

may enable the businessman to use his or modify a data file, define a report,

computer, not just as a workhorse with- print a report. Data may be selected by

in the various functions of his company, use of up to ten range or match condi-

but as a databank of information which tions.

he may call upon as needed.

AUTO INDEX

Objectives

Written by CAP-CPP of London (01404 0911), Auto Index is available from

The major objective of any Databank is to be able to easily store information
on, and retrieve information from it with a minimum of "system" control data and no duplication of "live" data -

their dealers throughout the country. The package is written in MicroCobol and consists of twelve programs linked by menu. It was introduced in the spring of 1979 and there are so far

while fully meeting the needs of the approximately 50 users. The list price application currently being processed. from CAP is £500 but there may be
In my opinion none of the packages

reviewed this month fully meet this objective; almost all, however, would
provide the business or professional user

COSTS Package

Software

with a very useful tool with which to Analyst

£180

save large amounts of time and effort in the creation and access of their files of information.

Auto Index Cromemco Data Base Management

£500(+) £59

Tasks and volumes
I am not going to compare each of the packages this month since there are no common objectives. I'll give instead some indication of the facilities available within each package, in the evalua-
tion section.

Data Base Management DMS Locate Petaid Pagemate Protext

£32.50 £170 varies £45-300 £325 £38.50

some variation in amounts charged by various dealers. The minimum hardware required is a 64K disc system with a 132 ch printer costing between £5000 and £6000.
A user manual is supplied but it's
not for the beginner. Firstly,
jargon is used throughout, with no
accompanying definitions; secondly, al-
though many examples are used the language is, to say the least, unusual. This is a great pity because, if the manual were rewritten in English with the first time business user in mind, it would enhance what I am sure is a fine product. In fact, the sales literature
supplied is very good and will undoubtedly attract many small businessmen.
Back up for the package varies according to the dealer who supplies it, but all of them are supported by CAP. The package allows for the following functions; defining the database, build-
ing and updating the database, enquiries, maintaining the database and loading/
unloading the database. Records are defined as key, attribute or text data and selection from the database can be made from all of the key and attribute
portions of the record.
CROMEMCO DATA BASE MANAGEMENT This package was written by Cromemco Inc. of California, USA and is available from Computerland in Manchester (061 236 4737) or any of the Cromemco dealers around the country. The package costs £59 and the minim-
um hardware required is a 64K dual
drive Cromemco System 2 costing
£2095. First introduced in 1978, the package is written in 16K extended BASIC and consists of approximately
12 programs which are linked, invisible to the user, by a menu.
A user manual is supplied which has obviously been written with the first time user in mind. All jargon where used is explained in laymans terms and each operation is illustrated with examples.

MM Hardware £3000 £5000(+) £2095
£500 £1800 £3000 £605-1495 £1495 £1200

Total £3180 £5500(+) £2154
£532.50 £1970
£650-1795 £1820 £1238.50

74 PCW

SYSTEMS

Support during and after installation with any enhancements made to the with an existing format, insert amend

varies from dealer to dealer but in most package. The system is split into three delete and display records, search and

cases if the package was supplied to- main sections, namely creation of file display selected records, and search and

gether with the hardware, it would be description, creation and update of print selected records. Selection is done

installed and maintained on the same individual records and selection and by matching a field or part of a field us-

basis, ie. three months warranty and reporting of stored information. Selec- ing any logical function.

12% of the total purchase price per tion is done by matching to preset

annum thereafter. Training on the pack- constants or by any logical comparison PAGEMATE

age would normally be provided free in of fields or partial fields.

A product written by Computhink,

the dealer's showroom.

California, USA and available from ACT

The operations available in this pack- LOCATE

Petsoft ,Ltd., Newbury, Berks (0635

age are as follows: create a new data- This system was written by Loveden 201131) and Birmingham (021 455

base, examine a system layout, enter Computer Services Ltd of Grantham, 8686) or from any of their Computhink

new data, create sort files, display Lines (0476 72000) and is available dealers (approximately 150) throughout

change and delete records, enquiry, directly from them. The package is the country.

modify the master, change master file written in BASIC and costs vary since The package consists of six programs

and drive assignment and print mailing it all depends on the amount of person- linked by menu and it costs £325. A

lists. Selection is done by simple match- alisation required. It's designed to run :nanual is supplied which explains the

ing criteria.

on a minimum 24K plus disc configura- organisation and access to the database;

tion although 32K is preferred; the cost it doesn't, however, give the first time

DATABASE MANAGEMENT
This product was written by Hubert S Howe and is available from A J Harding
(Molimerx) Bexhill -on -Sea, Sussex (0424 220391) or any of their country-

of the minimum hardware is approximately £3000. Part of the customisa-
tion service is the provision of personalised operating instructions and if necessary that would include telephone

user enough help in creating anything other than the simplest of databases. Petsoft seem to have recognised this since they organise regular courses on the use of the package. With training I

wide dealers. It's designed to run on a backup and training. The facilities avail- believe most businessmen would find

16K TRS 80 with cassette, costing able within the package are access, dis- it very useful.

approximately £500. A disc version is play, change, create and print.

The options available are editing,

also available for a 48K TRS-80. The

sorting, copying, statistics, listing and

package costs £32.50 and if necessary PETAID

diskcopy. Selection criteria are by

can be customised. A user manual is Stage One Computers of Bournemouth matching field(s) using any normal

supplied which gives a simple overview (0202 23570) wrote this package and logical function.

both of the system and of databases in it's available direct from them or from

general. A full telephone backup service any one of their countrywide dealers. PROTEXT

is provided during installation although It can be supplied in five different Nigel Dibben wrote this one and it's

no actual training is available.

versions, namely sequential tape, available from A J Harding (Molimerx),

Maintenance arrangements depend sequential disc, random disc, sequential/ Bexhill -on -Sea, Sussex (0424 220391)

on the dealer concerned but if necessary random disc and indexed sequential disc or any of their countrywide dealers. It's

the program listing could be supplied. - costing £45, £130, £180, £220, £300 written in BASIC and costs £38.50.

The commands available in the package and £250 respectively - together with The minimum hardware is a 32K TRS

are as follows: add records to the file, an associated utility Extract & Sort 80 with disc backing store costing

change records, delete records, find an costing £75.

approximately £1200. It comes supplied

item, justified or format printing, list The prime use of the package is as a with a manual which is definitely not

the file on the VDU, print the file, sort formatted access file management for the faint hearted. To be fair, A J

the file, total the items in any numeric system which will allow the user to Harding does warn that the package is

field and write the file to cassette or create, maintain, examine, and print not intended for the beginner. A great

disc. Selection is done by single field random access files on PET floppy discs. pity this because the facilities available

matching.

The package is supplied with a user look just what a small businessman

manual which tends to concentrate on might need and I'm sure that eventually

DMS
Written by Compsoft Ltd. of Guildford, Surrey (0483 39665) DMS is available direct from them or from any of their dealers throughout the south of England. The package consists of two programs written in Microsoft BASIC which are never co -resident but are complementary. The package was intro-
duced in July 1979 and to date has
about 46 users. The minimum configuration is a 32K
PET with dual disc drives, costing
£1800; the package itself costs £170 for

system operation although it does illustrate the instructions with simple examples. The system is designed for the user with no programming experience, yet no attempt has been made to introduce the package in simple English. Computer jargon is used extensively throughout the introduction and while my experience leads me to believe the package would be beneficial to many business users, I have some doubts as to whether they would appreciate it from the description given. However, since there are 300 users of the system, pre-

both the software and the manual will be modified for "normal" humans. In the meantime perhaps business users right consider this package when they
are fully acquainted with both the
machine and programming - until then, be warned.
An installation backup service is provided and maintenance support thereafter depends on the dealer concerned. The facilities available in this package are creation/amendment of datafile structure, creation/amendment of data file, display, print and include,

the full version or £95 for each of two sumably they either went straight to the smaller versions which are available. The operating sections relying on a previous

print and exclude. The selection is done by field, partial field or floating field

documentation supplied is excellent, a demonstration for an overview, or were matching using any normal logical

first time user would not only under- already knowledgeable about computers. criteria.

stand but would enjoy reading the first The minimum hardware required for
Post script section. If he's daring he might go past the package is an 8K PET with two tape
the warning issued when the technical drives costing £605 for the tape version

section is entered and even there he could and £1495 for the 16K minimum dual One other package which I have not had

probably get well stuck in before realis- disc configuration. Training is offered at a chance to review is Visicalc, available

ing his mistake. As my secretary said on £75 per day and maintenance, including from Microsense Computers Ltd. Hemel

reading it: "Thank goodness some updates, costs £100 per annum for Hempstead (0442 41191). This runs on

microcomputer people are real humans!" written answers to queries submitted on a 32K Apple armed with at least one

(You may not have realised that I have special report forms.

Disc II drive. Among the functions avail-

three heads and am coloured green.) The facilities available within the able are sum values in list, minimum

As regards support, any bugs found package are as follows: create a new value in list, maximum value in list and

are corrected free of charge together screen format or file, create a new file average value in list.

PCW 75

by John Moore

MICRODATA UV8 EPROM ERASER

Microdata Computers Ltd is a recently formed company based in Hayes, Middlesex, and the UV8 eraser is their first product on the market. Already a good seller I decided to take a look at it to see
what you get for your money.

The UV8 sells for £97 plus VAT, can erase up to 14 EPROMS at a time, and does so in the surprisingly short time of 8 minutes. The secret lies in driving the UV tube from a high frequency (16 kHz) inverter instead of directly from the 50 Hz mains. This keeps the tube, an 111/4 inch Sylvania germicidal type, continuously ignited instead of letting it flicker at 100 Hz because of the re ignition every time the mains voltage passes through zero. The result is a much higher intensity than you would normally expect. Microdata tell me they have consulted the tube manufacturers and they confirm there will be no reduction in tube life running it like this. In fact, as the heater is not used, the tube could well last longer than when conventionally driven.
My own home built eraser uses a tube of twice the wattage and takes typically at least 10 minutes to erase a 2708. The UV8 is claimed to take 4 to 7 minutes, and my first tests on a Motorola 2708 showed that complete erasure of all 1024 locations could be
achieved in 2 minutes 35 seconds when positioned at the centre of the tube, or 4 minutes 20 seconds at one end. These

times are undoubtedly fast by any standards. They also confirm my find-
ings with my own eraser that the output of UV tubes varies considerably along the length. When four National Semi-
conductor ICs were tried they took
rather longer, between 31/2 and 9 minutes. However these were quite old
ICs that may have become "sticky": incidentally did you know that some PROMs can go like this if they have been cycled many times? I once had a 2708 that even after two or three dozen
consecutive programming runs (with no erasure in between) still had about 3 bits stuck high. I tried the standard cure of baking in an oven for 40 minutes at 400 deg F (the same as for bread!) and this worked wonders. It may be possible
that ageing can lengthen the erasure time as well. If a situation like this should arise it's catered for by a switch on the eraser that doubles the exposure
time to 16 minutes.
Although the erasure time of the UV8 is internally preset to a nominal
8 minutes, the model under test actually
ran for anything from 9 minutes 44 seconds when cold to 8 minutes 34
seconds when hot:This variation arises

because the timing is derived by division from an RC oscillator that uses ordinary standard temperature sensitive components; however the variation is not usually critical. In any event there is a 100k pot in the circuit which could no doubt be adjusted if necessary to bring the time down a bit.
The case and lid of the eraser are made of good thick aluminium and are very nicely finished. The whole device occupies a bench space of only 7 by 14
inches. There's 41/2 feet of 3 core mains lead which is fused at 1 amp and properly earthed inside the case. Surprisingly
the exposed live line inside the box passes within only 3/16 inch of the chassis at one point. This is not good practice, but everything seems secure
in this area so it doesn't appear dangerous.
When power is applied the circuit automatically resets to prevent the UV light coming on. The PROMs are insert-
Cont. on Page 128

am*

IN ESSENCE THE BEST IN

INTEGRATED CIRCUIT TECHNOLOGY

Approved Dealers

SCOTLAND
Aethotrol Consultancy Services, Unit 4, Clyde Workshops, Fullerton Road, Tollcross, GLASGOW. G32 8Y L. Tel: 041.641-7758/9. Robox Ltd., Scottish Calculator and Computer Centre, Unit 14, Audenston Centre, GLASGOW. Tel: 041-221-5401.
Peter MacNaughton and Associates, Annfield, GLENALMOND, Perthshire. Tel: 073-888267.
NORTH EAST AND YORKSHIRE
Shermac Computers Ltd., Victoria Industrial Estate, HEBBURN, Tyne and Wear. Tel: 0632-837405.
Monitor (Data Processing) Ltd., Prospect Chambers, 4, Prospect Crescent, HARROGATE, N. Yorks. Tel: 0423-60670.
Metrodata Sutcliffe House, 49, Barrack Road, LEEDS 7. Tel: 0532-623788.
Derwent Electronics Ltd., 120, Holgate Road, CITY OF YORK. Tel: 0904-53990.
Sheffield Computer Centre, 225, Abbeydale Road, SHEFFIELD, S7 1 FJ. Tel: 074253519.
NORTH WEST
Computer Business Systems, 36, Clifton Street, LYTHAM, Lancs. Tel: 0253-730033.
Min icom Business Machines, Brook Mill, Wrea Green, KIRKHAM, Preston, Lancs. Tel: Kirkham 686617.
B. & B.Computers Ltd 24, Newport Street, BOLTON, Greater Manchester. Tel: Bolton 26644.

MIDLANDS
East Midlands Computer Services, 12, Astle Court, Plains Estate, Arnold, NOTTINGHAM, NG5 6R U. Tel: 0602-267079. Evans Jackson, 92, Monks Road, LINCOLN, LN2 5PG. Tel: 0522-30371. M icrospecific, 91 , Braunston Road, OAKHAM, Rutland, Leicester, LE15 6LE. Tel: 0572-2528.
Saba Computer Systems Ltd., Scala House, Holloway Circus, Queensway, BIRMINGHAM B1 1EQ. Tel: 021-643-2021.
CLE-COM, 8, Stanley Road, King's Heath, BIRMINGHAM. Tel: 021-444-3618 or 021472-8233.
SOUTH WEST
Validate Services, 26, High Street, MELKSHAM, Wilts. Tel: 0225-705957.
Opco Ltd., Coln House, Mawley Road, Quenington, CIRENCESTER, Glos. Tel: 0285-75225.
BEDFORD
Starwest Computer Services, 7 Thurlestone Close, Devon Park, BEDFORD. Tel: 023457135.
SOUTH EAST INCL. LONDON Boyd Microsystems Ltd., 4, Ivinghoe Road, BUSHEY HEATH, Herts. Tel: 01-950-0303.
Computer Systems Analysis, Ravenscroft, Bulstrode Way, GERRARDS CROSS, Bucks. Tel: 02813-85389.

Silicon Chip, 302, High Street, SLOUGH, Berks. Tel: 0753-70639.
Micro -Market, 138, Chalmers Way, North Feltham Trading Estate, FELTHAM, Middlesex. Tel: 01-979-9824. Systematika, 36, Montpelier Grove, LONDON NW5. Tel: 01485-3634. Logic Box Ltd., 31, Palmer Street, LONDON SW1. Tel: 01-222-1122. Profac Computer Services Ltd., 100, Park Street, CAMBER LEY, Surrey. Tel: 027625247.
Kewill Systems Ltd., 4, Drynham Park, Oatlands Chase, VVEYBR I DGE, Surrey. Tel: 09322-22448.
EAST ANGLIA
Proloc Computer Services Ltd., Fair Close, B ECCLES, Suffolk. Tel: 0502-714038.
SOUTH Software Development Services, 11, St. Cross Road, WINCHESTER, Hants. Tel: 096268956. Wendmore Management Services Ltd., 180, Bridge Road, Sarisbury Green, SOUTHAMPTON, Hants. Tel: 04895-6318.
CHANNEL ISLANDS
Jersey European Airways, States Airport, JERSEY, Channel Islands. Tel: 0534-44171.

Portland Street, Chorley, Lancs. Tel: Chorley 66803 also at. 30 Kelvin Avenue, Hillington Industrial Estate, Glasgow G52 4LH The exclusive distributors of Altos Computer Products.
See colour advertisement on Page 66

76 PCW

HARD COPY
ATA SOFT PRICE

One of the most trying tasks in this world is programming a micro -computer while having no facilities for hard copy. Apart from the problem of not being able to print computer art (?), listings or program
output cannot be produced and you have no record at all of what was done during the day. In this article, Tim Steele shows the practicalities of "making" a cheap output printer from a "common
or garden" teleprinter.

If you know the "right" shops the trans-
formation could cost you as little as £10; a more realistic figure, however, would be £20 - £50. This compares
extremely favourably with the socalled "quick" or "screen" printers
available and, to my mind, produces better output. As an added bonus, certain machines provide the facility to punch input (programs, etc.) into paper tape off-line while your computer is thinking about something else, and then to run the corrected and (you hope) error -free paper tape into the micro.
Teleprinters come in all shapes and sizes, and you can buy anything from a machine that would sink the Titanic to a small, lightweight, civilised machine not much larger than an electric typewriter. Beware of scrap machines: if you see any rust, blackening or corrosion, steer well clear! If you're thinking of buying one second-hand, try and get it plugged in - at least see if the motor runs - or failing that, turn the governor (the black drum with white stripes on it)
in the direction of the white arrow only.
If there is any binding or jamming, don't buy it. If you turn the governor the other way, you will lock the thing solid, and possibly break it. Be careful when transporting the machine, it may be heavy, but it's also delicate! Fig. 1 shows some of the more common models available and their prices; they
are all made by Creed.
You can also buy a paper tape
reader, the Creed 6S6 or 6S6/M for £5
- £10. The suffix /M means that a
solenoid is fitted for remote control of tape start and stop. The reader is electrically identical to the keyboard contacts. (See later.)
Most machines are coded with the standard teleprinter code, but some use a special computer code because they were used as computer terminals. It doesn't matter greatly which type of machine you use; the computer -coded variety are easier to write software drivers for, but the teleprinter -coded machines are to be preferred for their compatibility with standard 5 -track punched tapes and the Amateur Radio teleprinter transmissions (if that's a field that interests you).
Once bought, commissioning the teleprinter will of course take a little

Machine Tape Reader Tape Punch Price

7B

7E

54

75

X

444

XX

X

£5 - £.25

X

£5 - £30

X

£5 - £30

X

£30 - ,£100

XX £50 - £150

X = Available Option XX = Installed always

Meaning of Suffixes

/RP - Includes tape punch /R0 - No Key Board

Fig. I

time, and it pays to plan everything
before you start. If you want to be really thorough, buy the Teleprinter
Handbook (from the Radio Society of Great Britain, 35 Doughty Street, London) and clean and adjust the machine in accordance with the instructions. This is not essential, and if you fully understand the technical gobbledygook they use you are well on the way to becoming a teleprinter repairman
anyway.
The teleprinter works by using the movements of a solenoid (known as the

mark

Fig. 2
-
space
Fig. 3

mark wiper space

magnet) to set up five two -state latches these determine which character is to be printed. The magnet has two positions
- "mark" and "space". To move the solenoid lever from side to side, a
current is passed through it one way for "mark" and the other way for "space". To ensure the magnet mcves quickly enough, a high voltage (80V) is used and resistors are placed in series to limit the current to 20 mA. The keyboard is an SPDT switch which produces the character when a key is pressed. A typical character is shown in Fig. 4.
It can be seen from this that the character consists of a start pulse, five character elements that are mark or space, and a stop pulse 11/2 units long. The extra length is to give the mechanism time to come to rest. After this, the next character can begin. Since the maximum number of characters is 32, a shift key has to

MACHINE Magnet Keyboard "J" Bell Comments

m w m wiper s

7B

5367

8 4 Earth Prints one character

behind

I

7E

7912

3 31 32

1

54

7912

3 10 11

75

J G Obtain wiring K L Keyboard wiring complex

diagram from

Creed,

444

9 32

2 3 27 31 Tape reader M -1 wiper - 12

Fig. 4

"Start"
Pulse

5 -Unit character

"Stop"
Pulse

PCW 77

CODE
MMSSS MSSMM SMMMS MSSMS MSSSS MSMMS SMSMM SSMSM SMMSS

Letters
A B C D E F G H

Fig. 5 Figures
WRU?
3 %* @*
£*
8

MMSMS

J

MMMS

K

BELL*

SMSSM SSMMM SSMMS SSSMM SMMSM MMMSM SMSMS MSMSS SSSSM MMMSS SMMMM MMSSMM MSMMM MSMSM MSSSM SSSMS MMSMM MMMMM SMSSS
SSMSS SSSSS

L M N
P Q
R
S
T U
X
Y
z
CAR RET FIGS LTRS LINE FEED SPACE ALL SPACE

9 0
1
4
5 7
2
6
CAR RET FIGS LTRS LINE FEED SPACE ALL SPACE

be used to determine whether "letter" or "figures" shift is selected. Once having sent "letters" or "figures", the machine stays in that shift until another shift character is sent - a little practice will make this clear. The complete code is reproduced in Fig. 5.
So, assuming that you have the machine in your workshop and you have checked it turns over freely, connect the mains to the motor. If the teleprinter makes a noise like a machine-gun, find the solenoid arm (RHS of machine at front)
and push it to its other position. The sound is perfectly normal and does not indicate any damage being done. If it
makes loud screaming noises, or goes off
bang, blame whoever you bought it from! Now try waggling the solenoid lever from side to side - the machine should print gibberish (assuming you have put paper in). If this test does not work, refer to the Teleprinter Hand-
book or your scrap merchant. Now press

a key (if the machine has a "HERE IS" key, press that instead) and check that the machine makes buzzing noises.
Having done this, you will probably want to see if it types properly. To do this, hook up the circuit of Fig. 5. If
you wish to adjust the speed of the machine, find the black drum on the end of the motor (if the machine has one) and adjust the screw on the rim (first switch the machine off and on
again afterwards) until a piece of white paper or tape stuck across a diameter of the disc appears stationary in neon light. Then turn the screw 71/2 turns in the "-" direction. This sets the teleprinter up for 45.45 Baud.
All that is left now is to interface the machine to your micro. To type into the micro from the keyboard, the circuit shown in Fig. 7 will suffice. This will send the input high for "mark" and low for "space". Fig. 8 is a flow diagram of a suitable keyboard input routine.
Outputting to the printer is slightly
harder; I suggest using the circuit of Fig. 9 for this - although other circuits will do as well. Fig. 10 provides a flow diagram of a suitable output routine.
Having wired up your teleprinter,
Fig. 7
05.

IMARK

Keyboard ----

contact. /

s

!

% .../

'SPACE

100K i' /64050

To standard, general purpose input port

o.

Fig 8a Subroutine INCH

(START)

N.B. 0 = SPACE 1 = MARK LSF = Letter shift flag
1 = Figures 0 = Letters

A

CALL BITCHECK1
NO
CALL BITCHECK 5 TIMES -STORE RESULTANT BYTE

LOOK UP CHARACTER IN LETTERS TABLE
NO

LOOK UP CHARACTER IN FIGURES TABLE NO 4

SET LSF = 0

(RETURN CHARACTER

SET LSF=1

78 PCW

Fig. 8b Subroutine BITCHECK

N.B.
K0 depends on your micro's speed

(START)

ZERO COUNTERS

RETURN SPACE

SPACE>MARK

NO

NO

RETURN MARK

SPACE=SPACE+1

MARK=MARK+1

Fig. 9

3K3
3W
OR BF457
IN4004

A 3K3 3W IN4004

o +80V
IN4004 1K

Magnet
MJE 3400111k

4K7

OR

BF457 -.110F IN4004

BC108
Oh%
nir

4K7

o +12V 4K7

i\AA,

To standard,

47K

general purpose

output port

1/64050

IN4004E

BC108

you are ready to start writing programs. The first thing you may want to do is produce listings on the printer. You can
do this using the same LIST routine as your monitor software by shifting
the routine somewhere else in memory, correcting the branches and substituting the OUTCH routine for its own.
When you use INCH to input from the keyboard, try to bear these points
in mind:1 Don't leave it longer than 30 milli-
seconds before calling INCH again or you may lose characters.
2 Don't forget to call OUTCH after
inputting a character so that the character is echoed back to the printer.
Also, you might like to write your input routine so that on pressing "CAR RET" the user gets "CAR RET", "LINE FEED",")" - (as a prompt).

Fig. 10a Subroutine OUTCH

(START)
LOOK CHARACTER UP IN LETTERS
TABLE

YES
NO CALL PRCH
WITH A LETTERS SHIFT

YES

IS IT

THERE

9

w NO

LOOK CHARACTER UP IN FIGURES TABLE

IS IT THERE
9
YES
LSF=0
?
YES

NO
RETURN
NO CALL PRCH WITH A
FIGURES SHIFT

CALL PRCH WITH
CHARACTER

Fig. 10b Subroutine PRCH
(START)
SET OUTPUT
=0
WAIT Ki MILLISECONDS
t4
[REPEAT 5 TIMES] SET OUTPUT =RIGHT BIT
WAIT K2 MILLISECONDS
tV
SET OUTPUT=1
V
WAIT K3 MILLISECONDS
(RETURN)

(RETURN)

PCW 79

COMPUTER
MES

MORECOMPLEX EVALUATION FUNCTIONS
Those readers who have followed the previous articles should now have a good understanding of the principles of tree searching. The concept of the evaluation function has already been
introduced (sometimes called the scoring function), but up to now only simple functions have been considered. In this article David Levy will look at those for more complex games and the
reader will also be shown how to devise his own. David considers, too, some simple methods of learning, and illustrates a method that allows the program to improve
its own evaluation function.

How good is good?
Show a chess master a position from a game of chess and he will most likely make some comment about which side has the advantage. He might say: "White is slightly better," or "Black has a clear advantage", or "White is winning". Press him further and he will tell you why it is that White is slightly better: perhaps the reason will be simple, such as White has an extra knight ... or maybe it will be more subtle, such as Black having the inferior pawn structure (or, even more specifically, a pair of "doubled pawns").
In the language of chess players all of the master's comments will mean something. But when we write a chess program we have to put some numerical value on advantages such as an extra knight or a superior pawn structure, and the accuracy with which we can do this is one of the principal factors in determining the strength of our program. The result of our efforts to quantify various forms of advantage is a device called an evalu-
ation function, and for all interesting games the evaluation function is part of
the key to successful programming.
In an earlier article I suggested a simple evaluation function for noughts and crosses, the justification for which lies in the fact that only rows, columns or diagonals with moves by one player only (and not his opponent) are of any real interest. Once a row has one move
by each player, that row is of no further use to either of them. I did not get this

evaluation function from a World Champion noughts and crosses player, I made it up by taking a brief look at the underlying structure of the game. Alas, chess, checkers, backgammon, etc., etc., are all far too complex for such a simple approach to be possible. We must therefore rely, for our evaluation function, on the advice of experts, either spoken or in books.
There are three stages in building a useful evaluation function for a complex game, and I shall illustrate these stages by using chess as my example.
Identifying the important features
In order to be able to tell a good position from a bad one, it is first necessary to know what features to look for. If you know nothing about chess, and you and I both look at the same position, I will be able to make a fairly accurate assessment of which side has the advantage and by how much simply because I know what to look tor. You will be looking at the same thing but will not understand what you see. But suppose I were to tell you that the most important thing in chess is material - how many pieces each player has on the board, and that the player with the most pieces usually wins. Then you can count the pieces, and if White has 16 pieces but Black has only 8 you will hazard a guess that White is doing quite well, and in general you will be correct. I could

further advise you that the pieces have different values: that a queen is worth 9 pawns, a rook 5, a bishop .or knight 3, and that the king was beyond normal values. Then you could look at a position and fairly easily tell which side, if any, was ahead on material. You may know nothing else about chess but at least you can make a meaningful, first order estimate of which side is ahead and by how much.
If it were possible for a chess program to search a tree 200 -ply deep, an evaluation function with material as its only feature would almost certainly be sufficient to enable the program to play better than Bobby Fischer. But such is the nature of the game that a 20 -ply search is not yet realistic, let alone 200 -ply, so our evaluation function must have more features.
In order to discover which features of the game are important, you may do one or both of two things. You may read some books on the subject, in the search for general advice (heuristics), and you may ask someone who is expert in the game. In answer to your question "What else is important in chess, apart from material?", you may well receive the reply "Control of the central squares". On investigating further you discover that pieces in the centre can move to, or attack, more squares than pieces on an edge or in a corner. And pieces that attack central squares may eventually be able to move to a central square, so attacking central squares is a useful thing to do.

80 PCW

Further questioning, and/or reading, control, mobility, etc., when playing the second most important feature in

will reveal that if your pieces are getting games against each other, there exists chess, and if you plot (White's mobility

in each other's way they will not be able no well -tested set of values for these - Black's mobility) throughout a master

to do very much, whereas if they have features. We must therefore devise our game, you will almost certainly discover

plenty of scope to move they will be own.

that whoever wins the game has a lead

more likely to help you improve your In an earlier article I gave a simple in mobility throughout much of its

position; thus it is important for your evaluation function for solving the 8 - duration. The two key elements of

pieces to have as many moves as possible. puzzle. Since the object of the exercise pawn -structure, isolated pawns and

Everyone knows that the king is the is to move tiles from their present loca- doubled pawns, are also easy to measure

most important piece in chess, so ob- tion to some target location, it seems - we can simply count them.

viously one should look after one's own logical to measure the merit of a config- But what about king safety? This is

king. Expert advice will tell you to keep
it away from the centre of the board

uration by summing the straight line distances that the tiles need to be

not so easy because there are so many aspects of the position to take into con-

until the final stage of the game has moved before they will all be on target. sideration. The king is usually safest

been reached; castle during the opening Similarly, for any feature in any other when it hides behind a few of its own

stage so as to put your king nearer a cor- game, we look for a logical explanation pawns, but when these pawns advance

ner, where it will be safer than on its of why that feature is important, and they offer considerably less protection. original square; and don't rashly advance this will often lead us to a possible A king is normally much safer near a

the pawns in front of it once you have method of quantifying the feature. In corner of the board, but not if the

castled. You can learn all this from any chess, as we have discovered, control of opponent has many of his pieces trained

decent book on the game.

central squares is important because on that particular corner. It is usually

A fifth feature, whose importance is from the centre of the board a piece advisable to castle early in chess, to put

often underestimated is pawn -structure. exerts more influence (i.e. it attacks the king into safety, but if queens are

Good chess players know that "isolated more squares) than it does from an edge exchanged during the first few moves it

pawns", that is pawns which do not or corner square. So to determine the may be better to leave the king nearer

have any supporting pawns on adjacent relative values of the squares, from the the centre, since it will be relatively safe

columns, are weak, because if the oppon- point of view of centre control, we during the middle -game and better placed

ent attacks them they can only be de- should, perhaps, count how many moves for the end -game. With so many factors

fended with something more valuable can be made by each piece, on each to take into consideration, the quantifi-

than a pawn, and it is always best to use square, when the remainder of the cation of a feature such as king safety

your less valuable pieces for defence. board is empty. Of course the remainder can be rather prone to error, but some

Also, it is usually a disadvantage to have of the board is never empty, and some- attempt to do so is essential, so don't

"doubled" pawns, i.e. two of your own times it is very cluttered, but this ap- be put off if you encounter difficulties

pawns, one in front of the other, since proach does have a logical foundation of this sort.

Weighting the they will not be able to defend each and provides us with a first order mea-
other and the front one will block its sure of central square values. A detailed

features colleague's path.

discussion of this method can be found

To summarise this stage of function in Jack Good's paper, to which I refer in

building: Read some good books on the game and try to get advice from a strong player. You need to know which features
in a position are important, and you need to understand why they are im-
portant so that you can measure roughly how much of each feature is present in
a position.

the bibliography. Let us assume that we decide to assign
square values as follows: each of the four
central squares counts 4, those next nearest the centre count 3, the next group 2 and those on the edge of the
1

Having decided which features to include in your evaluation function, and worked
out a suitable method of quantifying each of them, you must then decide which of them are the most important, and assign some numerical weighting to each, to indicate its importance relative to the other features.
Let us suppose that we are writing a

Quantifying the

2

2

chess program and that we have decided to employ only two features in our eval-

features

3

3

uation function, material and mobility. We quantify material using the scale of

I have already explained how to measure the material situation in a chess position. The scale of values: queen=9, rook=5, bishop=knight=3, pawn=1 is a very useful guide. Some programmers find that giving the bishop a value between 3 and

2

4

3

4

values given above (9,5,3,3,1) and we measure mobility by counting how many moves each side can make from a given position. Let us denote the material difference (program's material - opponent's material) by Ma, and the

31/2 leads to a more accurate assessment, 1 2 a 3

but it is useful to work with integer

values since integer arithmetic is faster

2

2

2

than floating point. So if you do decide

to use non -integer values, scale every-

thing up so that the final calculations

1

::

mobility difference (program's mobility opponent's mobility) by Mo. If we
were to compute a score for a chess position simply by adding Ma and Mo, the result would be unrealistic. The reason for this is that one unit of material (in

are all integer.
These values of 9, 5, 3 and 1 are
known to work well, though there is no logical explanation as to why they are

our case one pawn) is not of equal value

board count 1. We might then count the total centre control for a player by summing the square values on which his

to one unit of mobility (a move). A pawn is more valuable than a move (other things being equal) and so we

better than some other set of values. It pieces stand, or by summing the values must weight the material feature accor-

has simply been shown, throughout the of all the squares that his pieces attack. dingly, multiplying Ma by some numermodern history of chess, that a knight is This may sound like a rather ad hoc ical weighting WMa. If we set WMa at

worth roughly three pawns, but that a statement, but the quantification of fea- 3, we are telling the program that one

player with four pawns is better off tures is something of a trial and error pawn is equivalent to three extra moves,

than a player with a knight, while the process. Since you are a computer pro- so if it sees an opportunity to increase

man with only two pawns will probably grammer you must have a logical mind, its mobility scores by 4, the program

lose to the man with the knight.

so apply some logic to the feature in would be willing to sacrifice a pawn to

Features other than material are not so easy to quantify. This is probably be-

question and you will come up with a quantification that will serve as a use-

do so.
The best method of arriving at a

cause the material count is something that can be performed quickly by any-

ful model. How easy or difficult it is to quantify

good set of weightings for an evaluation
function is to start with values that

one who can add, while a count of (say) a feature varies enormously. To take seem to be in the right range, and then

the number of squares that your pieces some more examples from chess: mobi- improve these values in the light of the attack is not an easy matter for a human lity (the freedom of movement of the program's performance. With our two player to accomplish when thinking pieces) may be measured simply by featured chess function, if we were to

ahead. Because human players do not counting how many moves each player play a number of games we would almost

use any method of quantifying centre has at his disposal. In fact mobility is certainly discover that with WMa set at

PCW 81

Shopping List

Super software from the world's leading microsoftware supplier.

L

DIGITAL RESEARCH

Soh..re
/Ma,.
Manual Alone

0 CP/M FDOS - Diskette Operating System complete with

g Text Editor. Assembler. Debugger. File Manager and system

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North Star. Helios II. Micropolis, ICOM (all systems) arid Alter

Supports computers such as Sorcerer. Horizon. Cromemco

-thio Scientific. RAIR Black Box, Research Machines.

)ynabybe, etc.

1751(15

0 CPIM version 2 (not all formats available immediately)

195/115

MP/M

(195/125

MAC - -808D Macro Assembler. Full Intel macro definitions. Pseudo Ops include RPC, IRP, REPT, TITLE, PAGE, and MACLIB. Z-80 library included. Produces Intel absolute hex output plus symbols file for use by SID Isee below) (561(10

0 SID - 8080 symbolic debugger. Full trace, pass count and

breakpoint program testing system with back -trace and

histogram utilities. When used with MAC, provides full symbolic

display of memory labels and equated values

(451(10

0 ZSID Includes 720 mnemonics. requires Z80 CPU

E501110

0 TEX - Text formatter to create paginated. page -numbered and justified copy from source text Mee directable to disk or printer
(451110

0 DESPOOL - Program to permit simultaneous printing of data from disk while user executes another program from the console (30/11

MICROSOFT

O BASIC -80 - Disk Extended BASIC Interpreter Vernon 5, ANSI

......... compatible with long variable names, WHILE/WEND, chaining,

variable length file records

E1551E15

0 BASIC Compiler -- Language compatible with Vernon 5 Microsoft interpreter and 3-10 times faster execution. Produces

standard Microsoft relocatable binary output. Includes

g Macro.80. Also linkable to FORTRAN -80 or COBOL -80 code

modules

(1 951(15

0 FORTRAN -80 - ANSI '66 (except for COMPLEXI plus many 0 extensions. Includes relocatable object compiler, linking loader,
library with manager. Also includes MACRO -80 (see below) (205/(15

0 COBOL 8D - ANSI '74 Relocatable object output. Format C) same as FORTRAN -80 and MACRO -80 modules. Complete
ISAM. Interactive ACCEPT DISPLAY. COPY, EXTEND
E32S/E15

0 MACRO -13D - 8380/2813 Macro Assembler. Intel and Zilog C) mnemonics supported. Relocatable linkable output. Loader,
Library Manager and Cross Reference List utilities included E75/E10

0 XMACRO-88 - KM cross assembler. All Macro and utility © features of MACRO -83 package. Mnemonics slightly modified
from Intel ASM86. Compatability data sheet available (1551(15

0 EDIT -SO - Very fast random access text editor for text with or

C) without line numbers. Global and irate -line commands

supported. File compare utility included

E45/E10

EIDOS SYSTEMS

0 KISS - Keyed Index Sequential Search. Offers complete Multi-

() Keyed Index Sequential and Direct Access file management.

Includes built-in utility functions for 16 or 32 bit arithmetic,

string/integer conversion and string compare. Delivered as a

relocatable linkable module in Microsoft format for use with

FORTRAN -80 or COBOL -90 etc

(1901(15

KBASIC - Microsoft Disk Extended BASIC with all KISS

(j) facilities, integrated by implementation of nine additional

commands in language. Package includes KISS REL as

described above. and a sample mail list program.

(2951(25

To licensed users of Microsoft BASIC -80 IM BASIC) E215/E25

MICROPRO

SUPER -SORT 1 - Sort, merge, extract utility as absolute 0 executable program or linkable module in Microsoft format.
Sorts fixed or variable records with data in binary. BCD. Packed Decimal, EBCDIC, ASCII, floating, fixed point, exponential, field justified, etc. etc. Even variable number of fields per record!
(125/(15

©0 SUPER -SORT II - Above available as absolute program only (1051(15

00 SUPER -SORT III - As N without SELECT. EXCLUDE (751115

0 WORD.MASTER Text Editor - In one mode has super -set of

© CP/M's ED commands including global searching and

replacing, forward and backwards in file. In video -mode,

provides full screen editor for users with serial addressable -

cursor terminal

(751(15

0 WORD -STAR - Menu driven visual word processing system

© for use with standard terminals. Text formatting performed on

screen. Facilities for text paginate, page number, justify, center,

underscore and PRINT. Edit facilities include global search and

replace, read/write to other text files, block move, etc. Requires

CRT terminal with addressable cursor positioning

(2551(15

0 WORD-STAR/MAIL-MERGE -``44 above with option for

production moiling of personalis.7curnents with mail list from

Datastar or NAD

E315/E15

0 OATASTAR - Professional forms control entry and display

system for key -to -disk data capture. Menu driven with built-in

learning aids. Input field verification by length, mask, attribute

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arithmetic capabilities using kcegeJata, constants and derived
values. Visual feedback for lase of forms design. Files

compatible with all CP /M.MP /M supported languages.

Requires 32K CP /M

(1951(25

=AMON

Sotroare
v /Manual
Manual Alone

8 PAYROLL - Designed in conjunction with the spec for PAYE

routines by HMI Taxes. Processes up to 250 employees on

weekly or monthly bees. Can handle cash. cheque or bank

transfer payments plus total tracking of all year to date figures.

Prints amp master, payroll log, payslips and bank giros.

Requires CBASIC-2

(4751(15

0 COMPANY SALES - Performs sales accounting function.

© Controls payments of invoices and prints sales ledger and aged

debtors report. Suitable for any accounting period.

Comprehensive VAT control and analysis of all sales invoices.

Requires CBASIC-2

(4251(15

0 COMPANY PURCHASES - Performs purchase accounting Q function. Controls invoices, credit Er debit notes. Prints
purchase ledger, aged creditors report and payment advices. Comprehensive VAT control and analysis of all purchases, Interfaces with the ADO system. Requires CBASIC-2
(4251(15

Q GENERAL ACCOUNTING - Produces Nominal Ledger, Trial

(1) Balance, P/L and Balance Sheet. Define your own coding

System. Interactive data entry plus optional data capture from

Company Sales and Company Purchases. Requires CBASIC-2

(3751(15

0 STOCK CONTROL

Maintains stock records, monitors stock levels to ensure

© optimum stock holding. Details include stock dmc., product

code, unit. unit price,, quantity on hand on order/ minimum.

Stock analysis reports can be weekly, monthly, quarterly etc.

Interfaces with Order Entry Invoicing system. Requires

CBASIC-2

E325/C15

0 ORDER ENTRY 6 INVOICING

(D Performs order entry and invoicing function. Handles invoices for services and consumable items, part orders and part

quantities. Sales Analysis report shows sales movemets and

trends for user -defined period Interfaces with Stock Control.

ADD and Company Sales systems. Requires CBASIC-2

(3251(15

13 ADD - Complete control of all your names b addresses

C) including suppliers, clients, enquiries etc. Assign your own

coding system and select all output via the report generator. Will print anything from mailing labels to directories. Requires

CBASIC-2

(225/112

0 COMPLETE ACCOUNTING PACKAGE

Combined

© Company Sales, Company Purchases. General Accounting, and

ADD systems

.

1950/145

SALES ORDER PROCESSING PACKAGE -Combined Stock 0 Control, Order Entry and Invoicing and ADD systems
(5501(30

STRUCTURED SYSTEMS GROUP

0 ANALYST - Customised data entry and reporting system.

User specifies up to 75 data items per record. Interactive data

entry. retrieval and update facility makes information

management easy. Sophistic.ted report generator provides

customised reports using selected records with multiple level

breakpoints for summarisation. Requires CBASIC.2. 24 x 80

CRT, printer and 48K system

(125/110

LETTERIGHT - Program to create edit and type letters or other documents. Has facilities to enter, display. delete and move

text, with good video screen presentation. Designed to integrate with NAD for form letter mailings. Requires CBASIC2

(1051(15

0 NAD Name and Address selection system - interactive mail list

creation and maintenance program with output as full reports with reference data or restricted information for mail labels. Transfer system for extraction and transfer of selected records

to create new files. Requires CBASIC-2

(46/112

0 ()SORT - Fast sort/merge program for files with fixed record

length, variable field length information. Up to five ascending or

descending keys. Full back-up of input files created. Parameter

file created optionally with interactive program which requires

CBASIC-2. Parameter file may be generated with CP/M

assembler utility

E50/E12

SOFTWARE SYSTEMS

0 CBASIC-2 Disk Extended BASIC - Non -interactive BASIC

g with pseudo -code compiler and runtime interpreter. Supports

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MICRO FOCUS

0 STANDARD CIS COBOL - ANSI '74 COBOL standard C) compiler fully validated by U.S. Navy tests to ANSI level 1.
Supports many features to level 2 including dynamic loading of COBOL modules and a full ISAM file facility. Also, program segmentation, interactive dubug and powerful interactive extensions to support protected and unprotected CRT screen
formatting from COBOL programs used with any dumb terminal
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0 FORMS 2 - CRT screen editor. Automatically creates a query Q and update program of indexed files using CRT protected and

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11001E12

OTHER
HOBS - Hierarchical Data Base System. CODASYL orientated with FILEs, SETs, RECORDS and ITEMs which are all user defined. ADD, DELETE, UPDAT,F44EARCH, and TRAVERSE commands supported. SET orriVC.,, is sorted, FIFO, LIFO, next to prior. One to many set relaNnship supported. Read/Write protection at the FILE level. Support FILEs which extend over multiple floppy or hard disk devices.

82 PCW

Software for most popular 8080/Z80 computer disk systems including
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HOBS -280 version

(135)125

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0'44

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EFFECTIVE MARCH 1960

3, the program would not be sufficiently careful about its own pieces, and that as WMa was increased to 5 or 6 the program's performance would also improve.
The task becomes more difficult and more time consuming when using a multi -feature function. I would recommend building up your function slowly, starting with two features and getting their weightings adjusted satisfactorily,
then adding a third feature and adjusting its weighting while keeping the other
two constant, then add your fourth
feature, and then add new ones in descending order of importance. As you add each new feature you should carry out some experiments, if you have sufficient memory, by playing the new version of the program against the previous one. You may discover that the addition of a particular feature, while giving a more accurate position assessment, results in such an increase in computation
that the program can search only a
much smaller tree and the end result is weaker play.
Making your program learn
You will have gathered from the previous
paragraph that it is often a very time consuming and difficult matter to reach an optimal set of weightings for your evaluation function. One way to help overcome this is to make the program learn from its experience and improve its own evaluation function!
A simple example is the case of our two featured chess function:
WMa x Ma + Mo
We could modify our program so that it was able to play against itself, using two different values of WMa in each of the two "versions" of the program. If we start out in total ignorance,
we could make WMa=1 in version 1, and WMa=100 in version 2. We then set the
program to play a large number of
games against itself, in half of which version 1 would be White and in the other
half it would be Black. At the end of the series we would discover that version 1 had lost almost all, if not all, of the games. (I have already explained that one pawn is worth much more than one move.) We then set WMa to be 2 in version 1 (or we could reduce WMa in version 2) and keep the other value constant. After another series of games we would find that version 1 still lost very
heavily, but possibly not quite so heavily as in the first series. If WMa was kept at 100 in version 2, we would discover that as the value of WMa reached 3 in version 1, version 1 would start to win a few games; when it reached 4 or 5 its results would improve considerably, and by the time WMa was 6 it would possibly be outscoring the version with WMa= 100, because although material is more important than mobility there are situations in which the sacrifice of a pawn or two can advantageously increase a player's mobility, and WMa=100 will never recognise those situations.
This process of adjusting the weighting in accordance with the program's
results can, of course, be fully automated, so you could switch on at night, go to sleep for a week, and when you woke up your program would be play-

ing like a Grandmaster. But with more
than two features in the evaluation function this type of learning process can be difficult to operate - the self learning reaches a local peak in the n -
dimensional surface representing the various possible weightings and their
results (n is the number of features), and it becomes difficult to climb out of the local peak in the search for a global peak. A method of overcoming this problem was discovered by Arthur Samuel, author of a famous draughts (checkers) program, but more about that in a moment. First I would like to describe a simple method of learning called "Boxes", which can be applied to equally simple games with surpris-
ingly effective results.
Boxes
Boxes is a method of decision taking that allows for a certain amount of pro-
gram learning. A task (such as making the
best move in a game) is split up into a number of sub -tasks (such as making a move in a particular game position) and a box is assigned to each sub -task. Inside the box is the information that is used by the program to guide its decision, and this information can be updated in the light of the program's experience.
Boxes was originally tested on the game of noughts and crosses. Donald Michie has calculated that there are 288
essentially different positions with which
the player moving first may at some time be confronted. To each of these 288 positions is assigned one box
(matchboxes were used) and inside each box there are a number of beads. The beads each have a number on them, the numbers indicating vacant elements in the noughts and crosses array (i.e. places in which the box "program" can make its next move). If one box corresponds
to a situation in which elements 1, 2
and 3 are vacant, then that box,will start
out life with an equal number of "1
beads", "2 beads" and "3 beads". When this box is opened (i.e. when
the "program" has to make a move
from the configuration corresponding to that box), a bead is drawn out at random, and the move is made according to the number on that bead. The bead is then replaced but the "program" makes a note of the fact that this box was used,
and that the bead chosen was (say)
numbered 2. When the game is over, the
boxes which were opened during the game are referred to again. If the "program" won the game, then each box
used during the game has one bead added
to it, the number on the new bead
corresponding to the move made from that box. If the game was a draw the contents of the box remain unchanged, but if the game was lost then one bead is removed from each box in order to reduce the probability that the same move will be played again should that situation ever arise in a future game.
The interested reader is referred to the paper (1968) by Michie and Chambers, which is mentioned in the bibliography. The authors describe how the boxes method, with some modification, learned so well that it could win at noughts and crosses between 75% and 87% of the time when it had played a series of 1,000 games against a program which played first in every game and always moved at random. Of course

methods such as this are far too simple to be able to cope with games of the complexity of chess or bridge, but it is interesting to see how effective a learning mechanism it can be in a simple environment.
Samuel's draughts
program
Probably the most famous game playing program up to the late 1960s was the draughts (checkers) program written by Arthur Samuel of IBM. I shall be discussing Samuel's work in some detail in a future article so here I shall restrict myself to a description of two methods of learning which the program employed.
The simpler of the two methods is called rote learning. Each time the pro-
gram conducts a tree search from a position (the root of the tree), it provides an evaluation of this position based on the results of the look -ahead search. This
evaluation is therefore more accurate than the evaluation which would be achieved by applying the evaluation function directly to the root position. Thus the evaluation of the root position
is stored, together with the position itself, and when the program next encounters the same position, but as a terminal node, instead of applying the evaluation function to the terminal node it looks up the stored evaluation. The process is relatively fast, since the positions can be hash
coded and stored in such a way as to make retrieval easy; it results in more accurate play because the evaluation taken from the store is more reliable
than a superficial evaluation. The obvious disadvantage of this method, from the micro -user's point of view, is
the large memory required to make
effective use of the rote learning process. (By the time that the program reached the peak of its playing ability, quite a high proportion of all reasonable draughts positions were in its store, and the program played at or near championship level).
A more generalised approach to learning was Samuel's method for the self -
modification of the weightings in the evaluation function. Samuel used the argument that if an evaluation function was ideal, the score obtained by applying the function directly to a position would be the same as the score obtained as a result of a look -ahead search from that position. The fact that the two scores are often different was employed
in the following way.
Let us assume that our evaluation function has three features, A, B and C, and that the features are weighted with WA, WB, and WC respectively, so that
the whole function is expressed as:
(A x WA)+(B x WB)+(C x WC)=score
where A, B and C are the quantities
present of each feature. We shall denote the backed -up score for a root position by Sb, and the score which was backed -
up to that same position during the
previous tree search (two ply ago)
as Si,. Note that if the tree search is
normally n -ply, the score Sb will be the result of an n -ply search, whereas the score Sp, although arrived at during an
n -ply search, is only the result of a search to depth n-2. Sb is therefore a

-84 riCW

more reliable score than Sp.
Samuel computed, for each such pair of values, the difference, which he called delta. If Sb-Sp (i.e. delta) was positive, then he argued that Sp was in error and terms in the evaluation function which contributed positively should have been given more weight, while features which contributed nega-
tively should have been given less weight. Whenever delta was negative he used the converse argument that
features which contributed negatively should have been given more weight, and those which contributed positively should have been weighted less.
Samuel kept note of the correlation existing between the signs of the individual feature contributions (i.e. the signs of A, B and C) and the sign of delta, and he updated these correlation coefficients after every move of a game. He then selected the feature with the largest correlation coefficient (other than material advantage, which is always the most important feature), and he set the weighting for this feature at a presribed maximum value, with the weightings of the other features adjusted in accor; dance with their correlation coefficients. In fact Samuel set all the weightings to be integer powers of 2, so that if the ratio of two correlation coefficients lay between n and n+1 then the ratio of their feature weightings would be 2n. (If a correlation calculation gave rise to a negative sign, the sign associated with the weighting itself would be reversed.)
The obvious advantage of Samuel's generalized learning method is that it can be implemented on a microcomputer with little difficulty, because it is

not necessary to store an enormous
number of board positions. When your program makes a move from the root of the tree, you need only store all the 2 -ply positions in the relevant, part of the tree together with their backed -up scores. (In chess this would normally
be in the region of 36 positions, in
checkers probably less than 10). A problem arises when the alpha -beta algorithm prunes off the branch actually selected by the program's opponent, since the relevant 2 -ply position will not have been stored, but it is reasonable to argue that this will only happen when
the opponent makes a mistake (or a
move which the program thinks is a mistake), so such instances, could be ignored. More accurately, if the program's opponent makes an unexpected move, before computing its reply move the program could first re-examine
the relevant part of the tree from the Previous root position, searching along the path represented by the opponent's move. This refinement would permit the program to take into consideration the Sb and Sp comparison for positions which, in the first instance, had been
pruned away.
Task for the month
Write a noughts and crosses program, using an evaluation function in which the features are: c3: The number of cross' "3 -rows" (i.e. the number of rows containing 3 cros-
ses).
c2: The number of cross' 2 -rows (2
crosses and an empty space).
ci : The number of cross' 1 -rows (1

cross and two empty spaces). n3, n2 and n1 : Corresponding features for noughts. Your program should perform a 3 -ply exhaustive search (without alpha -beta
pruning) and the evaluation function should start with all weightings equal. Modify your exhaustive search noughts and crosses program ("Task of the Month" in article 3) so that it can act as a sparring partner for the present program, and set the two programs playing each other. After every move of every game, the 3 -ply search program should modify its weightings using Samuel's method. After each game, print out (or display, if you have no printer) the result of the game and the new weightings in the evaluation function. Observe how the 3 -ply program improires its
performance.
Bibliography
Chambers, R.A., and Michie, D : BOXES: an experiment in adaptive control. Machine Intelligence 2 (Ed. Dale,
E. and Michie, D.), Oliver & Boyd,
1968, pp. 137-152. Good, I.J.: A five-year plan for auto-
matic chess. Machine Intelligence 2 (ed. Dale E. and Michie, D.), Oliver & Boyd, 1968, pp. 89-118.
Samuel, A.L.: Some Studies in Machine Learning Using the Game of Checkers. I.B.M. Journal of Research and Development, vol. 3,
1959, pp. 211-229. (reprinted, with minor additions and corrections, in Computers and Thought, edited by Feigenbaum and Feldman, McGraw-
Hill, 1963).

CALCULATOR CORNER EXTRA

PUTTING SOME THOUGHT INTO CALCULATORS

"Noughts and Crosses" is not one of the world's more intellectually demanding games to play; to program a computer
to play it is more challenging, but it's now so thoroughly worked out that David Levy, in his excellent series on
games, sets "noughts and crosses" programs as homework exercises for the
reader!
So why, you'll be asking, are we publishing a noughts and crosses program? This example, written by Peter
Brooks (a medical researcher from Oxford), is interesting for three reasons.
1. It's written for a programmable
calculator (the increasingly popular Casio FX502P) and despite using less
than 256 bytes and 18 memories, it
nevertheless plays an "intelligent" game.
This must surely make it one of the
most compact strategic games programs
around.
2. The programs structure will repay
study, as it makes ingenious use of data packing, indirect addressing and subrou-
tine calling to achieve its brevity. It shouldn't be too hard to translate into other calculator dialects, or into machine code/assembler for Mk 14, Acorn and the like, or to incorporate it into a more sophisticated game program (3D for instance). 3. The way the program has been docu-

mented is exemplary. Would that all the programs we receive, whether in BASIC or whatever, were as comprehensively explained as this one.
Movescoring
The opponent's moves are given a
weighted value of 4 against the calculator's move value of 1. Because of the method used by the program of testing for a calculator win (it checks to see if the move made was in response to a match with a comparison value for a possible win line - i.e., a line in which
one position is empty, and the other

Occupied by Calculator
0 0 0 0 1 2 3
1
2
1

Occupied by Opponent
0 1 2 3 0 0 0 1 1 2

two positions are held by the calculator
- rather than making the move and
then searching again to find out whether
a winning line has been made), the opponent's move value is low enough to prevent a line of two opponent's moves and one empty position adding up to a two -digit number, but large enough to enable,a distinction between lines with only one position occupied (by the opponent) and lines with two
positions occupied (both by the calculator). The full list of values given by different line positions can be found in the table below. It can be seen from the above that the only positions worth considering are
Total line Value
0 4 8
12 (this position not tested for)
1 2
3 (this position not tested for)
5
6 (this position not tested for) 9 (this position not tested for)

PCW 85

those in which the calculator already has one or two moves; those in which the opponent has one or two moves; those in which neither player has any moves; and those in which both players have one move each, leaving one position empty. After some trial and error, the preferable (or one of the preferable) sequences to test was discovered to be 2, 8, 4, 1, 5, 0 (with the possibility of interchanging the last two numbers). Originally it appeared that a good rule of thumb for the strategy sequence was 2, 8, 1, 4, 5, 0, but more often than not the calculator forced a win upon the opponent (i.e., if all the opponents did was to block calculator winning lines, and not attempt to create their own winning lines, they would win because the sequence of moves made by the calculator would result in the creation of opponent winning lines by default.
If you don't believe me, try the exchanging 1 and 4 in the instruction ".28415 Min .1 Min .F" in the program, and playing a few games). The strategy therefore is to search for the following:
2 : winning line for calculator - move to win
8 : winning line for opponent - move to block
4 : one move made by opponent -
move to disrupt possible opponent strategy.
1 : one move made by calculator move to create possible winning
line 5 : two out of three positions occupied
by opponent and calculator - move into position left 0 : empty line - move into centre position of the line.
In tactics terms, the priority is: Win/
Block/Disrupt/Possible win/Complete

disrupted line/Begin line. The number is
entered as a fraction in the program because fewer steps are required to extract the values one at a time from the sequence; e.g., .28415 x 10 = 2.8415; the fractional part is already in the correct position for storing back in the working memory, and the integer part
is easily separated from the whole number and stored in the comparison memory ready for testing.
Move making
Once a subroutine returns and the total score for the particular line matches the value tested for, the program jumps to a section that determines which position the calculator will move into according to a rule of thumb.
The rule is to move into the centre position of the line if unoccupied, and to the end positions (whichever is unoccupied) if occupied. Again the positions are stored as a fraction to enable easy operation to extract the moves in the
right sequence.
The decision as to which line to
search first (i.e., 1-2-3, 4-5-6, 7-8-9, etc) was purely arbitrary; the only drawback is that because the program only searches until the number returned by the subroutine matches the strategy value, other possible matches are not searched
for, so the calculator will, quite frequently, ignore positions which are, tactically, highly advantageous to it. That will apply especially to positions
where one move can create two winning
lines - the opponent can only block one of them, and so the calculator would automatically win. This might perhaps give the opponent a better
game; certainly it's not difficult to draw. But it also opens up possibilities for ex-

CASIO fx502P : NOUGHTS AND CROSSES PROGRAM : OUTLINE FLOWCHART

RO

INITIALISE

NO CALCULATOR FIRST

NO

YES

PENALISE

NO

YES END

DETERMINE CALCULATOR RESPONSE

CALCULATOR. MOVE
NO YES
END

86 PCW

perimentation with the program for
those seeing the effect of different strategies (which might help underline some of
the points in David Levy's series on Computer Games). Juggling with the
section on subroutine calling could conceivably remove redundant searching; the only limit to the experiments would be the user's imagination.
The subroutines are called, incidentally, in reverse numerical order; that is, P8 first - the reason for this is, again, that fewer steps are involved.
Symbols used in the
program listing
After seeing the difficulties experienced by the magazine over correct printing of certain symbols in listings, I have attempted to avoid, wherever possible, the use of symbols which could be misinterpreted. I have therefore chosen to use standard computer symbols in two cases: the asterisk "*" in place of the multiplication sign (to avoid confusion with X), and the oblique "/" in place of the division sign (to avoid confusion with the minus sign). I could not think of a viable alternative to the decimal point (except perhaps dp or D, but that could still lead to problems) so it has
been left in the lap of the gods (!). I
have also included all INV second function statements for clarity if not brevity.
Input-output protocol: Summary
1. Initialise: press PO 2. If Opponent is to move first go to (3) Otherwise calculator moves first: press EXE, move displays 3. Key move using layout of numbers
1 - 9 on keypad: press EXE; calculator's response appears after about 9
seconds 4. Further opponent's moves entered as in (3)
5. If calculator wins, flashes winning
move alternating with '2'
6. If game drawn, last move made is
flashed, alternating with '9' 7. Sequence of moves made in a game may be recalled, (before re -initialisation) using MR .4 8. Attempted entry of illegal moves will cause opponent to lose the chance to move, the sequence record will show that the opponent attempted to cheat,
and the calculator takes the move
instead. 9. Display format:
M.1234567890N
where M = calculator's move; 123456789 = board positions, with '1' for calcula-
tor's position, '2' for opponent's; N =
number of moves made so far. 10. While the HLT status indicator is visible, a game is in progress, and moves may be entered whenever the display settles.
Input-output protocol
1. To start a game press PO. The HLT status indicator will appear, and the display will show zero. 2. Decide whether the calculator or the opponent is to move first. If the opponent is to move first, go to (3). If the

calculator is to move first, press EXE and the display will show the first move
thus:
5.00001000001
where 5 is the move position .000010000 is the entire board position, numbered 1
to 9, giving '0' for empty box, '1' for

the calculator's move, and '2' for the opponent's move, and the exponent shows the number of moves made so
far.
3. The opponent must decide on his/ her move within 15 minutes (!), otherwise the calculator will automatically switch off, preventing further moves

in the game in progress, and a new game will have to be initiated.
Use the numeric keypad to enter the
move, with the noughts and crosses
board corresponding to the same layout of the keypad (i.e. to move into the top left hand box, key '7', etc).
Cont. on P. 127

PROGRAM MEMORY : TITLE AND LABEL ALLOCATIONS

PO

Main program

- initialisation

- calculator's random first move generation

- test for entry of opponent's move

Label 0 Execution of calculator's move

- update move counter

- update board positions

- update move sequence record

- refresh game strategy in working memory

- check for calculator's win

- check for end of game

- display current move, current board current move count

Label 1 Opponent's response

- take absolute integer of opponent's entered move

- test for illegal entry; penalise if illegal, update move sequence record,

and give move to calculator

Label 2 - if move legate accept and execute opponent's move

- update move counter

- update board positions

- update move sequence record

Label 3 - check for end of game

Label 4 - initialise search for calculator's response

Label 5 - indirectly call subroutines P1 to P8 until condition satisfied

Label 6 - recall move sequence stored by last subroutine called. Find the empty

position and begin response.

Label 7 - initialise end of game loop: prepare current move, board positions, and

move count; put into Y - register. Recall reason for end of game and

put into X - register.

Label 8 End of game loop

- exchange X with Y register prepare display format, pause to display,

loop to beginning of label 8

Label 9 Penalty for attempting to cheat

- set current move memory to zero and update move sequence record,

This will cause a zero to be included as an indication that the oppon-

ent attempted to cheat (except for an illegal move on the opponent

taking the first move in a game) without affecting the board or current

move count

PROGRAM MEMORY : TITLE AND LABEL ALLOCATIONS PI Subroutine for bottom row total P2 Subroutine for middle row total P3 Subroutine for top row total P4 Subroutine for left column total P5 Subroutine for centre column total P6 Subroutine for right column total P7 Subroutine for first diagonal total P8 Subroutine for second diagonal total P9 Subroutine for move sequence record

DATA MEMORY ALLOCATIONS

Memory Content

0

Move position; Subroutine call; Indirect operations

1

Board position: bottom left

2

Board position; bottom centre

3

Board position; bottom right

4

Board position: middle left

5

Board position: middle centre

6

Board position: middle right

7

Board position: top left

8

Board position: top centre

9

Board position: top right

.0

Move sequence from subroutine

.1

Game strategy : refresher memory

.2

Current board positions ready for display

.3

Ongoing move counter

.4

Ongoing move sequence record

.5

10 (a constant)

.6

Unused

.7

Unused

.8

Unused

.9

Unused

F Comparison memory for game strategy, wins, endgame

.F

Game strategy: working memory

CASIO fx502P : LISTING AND RATIONALE FOR

NOUGHTS AND CROSSES PROGRAM

PO

INV MAC

10 Min .5

.28415 Min .1 Min .F

INV RAN

*9 Mm F

+ 1 = INV INT

Min 0

AC HLT INV x = 0 GO TO 0 GO TO 1 LBL 0 1 INV IND Min 0

M+ .3 MR 0 INV 10x INV 1/x M+ .2 GSB P9 MR .1 Min .F 2 INV x - F

GO TO 7

9 Min F MR .3 INV x > F

Clear all memories Store constant Store game strategy Generate pseudo -random number Multiply by 9 (store 9) Add 1, take integer part Store in move memory. This is the calculator's first random move, ready to begin a fresh game Clear display and stop Was there an input ? No. The calculator is to move first Yes. The opponent is to move first Calculator's move. Store 1 for calculator in memory 0 Increment move counter by 1 Recall move position Take antilog Take reciprocal Add to board contents memory Store move in sequence record Refresh game strategy working memory Was the condition before the calculator's move a check for calculator's win? Yes, and the winning move was made. Go to end of game loop Store end of game (draw) check value Was it the last possible move?

GO TO 7 INV 10x *(MR 0 + MR .2) = INV RND 0 HLT LBL 1 INV ABS INV INT INV x = 0 GO TO 9 Min 0 - MR .5 = INV x > 0 GO TO 9 INV IND MR 0
INV x = 0 GO TO 2 GO TO 9 LBL 2 4 INV IND Min 0 1 M+ .3 MR 0 INV 10x / 2 = INV 1/x M+ .2 GSB P9 1,131, 3 MR .3 INV x > F GO TO 7 LBL 4 MR .F
MR .5 - INV INT
Min F = Min .F 8 Min 0 LBL 5 INV IND GSB 0 = INV x = F GO TO 6
INV DSZ GO TO 5 GO TO 4 LBL 6 MR .0
* MR .5 - INV INT Min 0 * Min .0
INV IND MR 0 INV x = 0 GO TO 0 GO TO 6 LBL 7 MR .3 INV 10x (MR 0 + MR .2) = INV x+oy MR F LBL 8 INV xi+y INV RND 0 INV PAUSE GO TO 8 LBL 9 0 Min 0 GSB P9 GO TO 4 P1 .213 Min .0
MR 1 + MR 2 + MR 3 P2 .546 Min .0
MR 4 + MR 5 + MR 6 P3 .879 .0
MR 7 + MR 8 + MR 9 P4 .417 Min .0
MR 1 + MR 4 + MR 7 P5 .628 Min .0
MR 2 + MR 5 + MR 8 P6 .639 Min .0
MR 3 + MR 6 + MR 9 P7 .519 Min .0
MR 1 + MR 5 + MR 9 P8 .537 Min .0
MR 3 + MR 5 + MR 7 P9 MR .4
MR .5 + MR 0 = Min .4

Yes. Go to end of game loop No. Take antilog of move count Multiply by (move made plus current board position) Prepare to display to zero decimal place Stop and display move made, current board positions, and current move count Opponent's move; take absolute integer of move value Was move entry zero? Yes. Illegal move. Penalise opponent Store move, and subtract 10 Is remainder equal to or greater than zero? (i.e., the move value is 10 or greater) Yes. Illegal move. Penalise opponent Recall contents of memory addressed by memory 0 Are contents zero? Yes. Move permitted. Go to opponent's move label No. Illegal move. Penalise opponent Opponent's move. Store 4 for opponent in memory addressed by memory 0 Increment move counter by 1 Recall move position Take (antilog of move divided by 2) Take reciprocal Add to board contents memory Store move in sequence record Recall move counter (9 is still stored in F) and check for last possible move Yes, it was the last possible move. Go to end of game loop No, it wasn't the last possible move. Recall game strategy Multiply by 10 and take integer Store integer in F Subtract integer from (10 times strategy) and store remaining strategy back in .F Set memory 0 to 8 ready for subroutine calls Call subroutines addressed by memory 0 Does value returned match contents of memory F ? Yes. Row/column/diagonal in which calculator's move is to be made has been found. Go to label for deciding which position is to be used No. Decrement memory 0. Is value in 0 zero ? No.. Go to beginning of label to try next subroutine Yes. Go to label 4 and try next value in game strategy Recall the row/column/diagonal sequence stored by the subroutine which caused a jump to this label Multiply by 10 and take integer Store integer in memory 0 Subtract integer from (10 times move sequence) and store remainder of sequence back in memory
.0
Recall contents of memory addressed by memory 0 Are contents zero ? Yes. Go to label 0 to make calculator's move No. try next in move sequence End of game loop. Recall move counter Take antilog Multiply by (move made plus current board position) Put result in Y register Recall contents of memory F (contains the value whose matching caused the jump to this label) Exchange contents of X and Y registers Prepare to display contents of X register to zero decimal place Pause to display Go to display contents of Y register Prepare to penalise opponent for attempting illegal move. Store zero in move memory Add zero to move sequence record to show that opponent cheated Award move to calculator Store .213 in memory .0; this is the move sequence for the bottom row which will determine which moves the calculator looks at first if the move is to occur in this row. All such sequences give priority to the centre position, followed by the end positions, for each row/column/diagonal Total value of all moves in the bottom row. The other subroutines follow the same pattern
Recall move sequence made so far Multiply by 10 and add value from memory 0 Store updated sequence in memory .4

PCW 87

WAVE -MAKING
ON A NASCOM

Don Finlay of the City University describes a synthesis program which adds fundamental and six harmonics - for use in acoustics demonstrations or in music.

Fourier analysis ...
In principle, any repetitive waveform may be analysed into an infinite series of sinewaves. For instance, a square wave contains a fundamental, a third harmonic which is one third as large as the fundamental, a fifth harmonic one fifth as large, and so on through all the odd harmonics up to infinity, as given by the expression
f(x)=7(sin x + sin 3x + sin 5 x+ )
where x = wt, an angle which increases constantly with time t.
The mathematical process for determining the magnitudes and relative phases of the components of any given waveform is generally referred to as Fourier analysis. Aswith so many mathematical operations, computers are now used to speed the process and display a graph showing harmonic amplitude with frequency. Microprocessors can be used, with algorithms based on the Fast Fourier Transform (1) although they are limited in accuracy and speed. Dedicated instruments in the form of spectrum analysers are more efficient at dealing with continuously varying signals, but are very expensive.
... and synthesis
A process which is generally easier is the inverse of analysis, i.e. synthesis. If we know what harmonic content we need in a given waveform, we can synthesise that waveform by generating and adding together these harmonics. This was the principle of the Hammond organ from its introduction, some 50 years ago: a
series of mechanically driven "tone wheels" provided all the frequencies needed for the notes of the scale and their harmonics. Nowadays, sinewaves for synthesis are usually generated electronically, including digitally.
This program enables the owner of a Nascom 1, with a small amount of added memory, to generate a 256 -byte waveform table using 2nd, 3rd, 4th, 5th, 6th and 8th harmonics of a sine wave fundamental. The 7th is not used because it is "discordant". The sine wave table is assumed to be already entered into memory, in 2's complement form, in locations 1000H to 1OFFH, and the new waveform table is calculated and entered automatically into locations OEOOH to OEFFH. From the latter

alotcuantioen, sa,ssamI pdleessccrainbebde

taken to play in December

1979 (2)

The method
Data for the harmonic weightings are entered into locations 1100H to 1106H. These are the relative amplitudes of the required fundamental and six harmonics, in ascending order. The principle of the program is that the first 8 -bit sample in the sinewave table is multiplied by the 8 -bit weighting of the fundamental, and the 16 -bit result stored in locations 110FH and 1110H. Next, a sample one place further on in the table is multiplied by the 2nd harmonic weighting and the result added to the previously stored result. For the nth harmonic, the weighting is multiplied by a sample n places further on in the sine table, and added in. Finally, the sum of all these products is taken from the store and divided by the total weights, so that the result fits within 8 bits again, forming the first new sample. This is repeated, with appropriate pointer increments, for each of the 256 samples required.
It would be possible for the sum to exceed 16 bits if too large a sum of weights were used; for this reason, the total of the weights must not exceed FFH. If the operator disobeys this, an error message is displayed and the program does not run.
Pointers are needed for the new sample (location 1107H) and for the
fundamental and each harmonic (1108H to 110EH). The sum of the weights is stored in 1111H, and the 256 samples to be calculated are counted by decrem-
enting from an initial zero stored in
1112H. The pointers must be initialised;
if all are initialised to zero, then the
resulting waveform consists of sinewaves all starting from zero. If any pointer is
set to 40H, then a 90°phase shift is

introduced, giving a cosine wave; 80H gives phase inversion and COH gives 270° phase shift. Any phase angle can be allowed for, within the 256 -bit resolution for a full cycle.
Execution starts at 1113H. The
seven weights are first added and the result tested for excess, as indicated by the labels in the program listing. At label FT8, the pointer for the fundamental, which corresponds to a rank of pipes whose largest is 8 ft long, is loaded into
register HL and the corresponding sample is fetched from the address now pointed to by HL and loaded into the E register. The weighting for this sample is fetched from 1100H and loaded into register C.
Subroutine MULT is then called; this multiplies the weight and the sample and adds them into temporary store 110FH, 1110H, which is initially set to zero. Since the sample may be 2's complement negative and is stored as an 8 bit number, it's tested and if necessary converted to 16 -bit negative by putting FFH into the D register, which holds the more significant byte, with the less significant in E. Normal multiplication to a 16 -bit result can then take place.
Similar procedure is followed for the harmonics. Labels FT4, FT2 and FT1 refer to octave -related harmonics in
imaginery 4 ft, 2 ft and 1 ft pipes.
NASARD indicates the 3rd harmonic, TIERCE the 5th, and LARIGO the 6th; these names come from the builders of pipe (and electronic) organs.
At the end of the FT1 section, the sum of all the harmonic products for one new sample is in store and must be
divided by the sum of the weights. Again the number may be negative, so a test is made at label SIGN and if the MSB is
high then a jump is made to COMP. This routine complements before and
after calling an ordinary subroutine DIV
which does long division.

TABLE 1
1100H 1108H 1110H

Fund.
8 0
(0)

HARMONIC

2nd 3rd 4th

8

0

0

40H 0

0

(0)

(0)

5th 6th 8th

0

0

0

(0)

0

0

0

(0)

Locations of weights and phases which must be entered before running a program.
Initial values shown are fora waveform with only fundamental and 2nd harmonic, with the second harmonic phase -shifted by 90°. Terms in brackets are pointers and temporary stores which are always pre-set to zero.

88 PCW

Running the program

To make use of the program, it's loaded,

together with the sine table, into loca-

tons 1000H to 1243H. The sine table is

at 1000H to 1OFFH; weights, pointers,

temporary store and count at 1100H to

1112H; and the program from 1113H to

1243H. Decisions must be made about

the weights and phases required. Table 1

makes it easy to keep track of the require-

ments; it's arranged so that weights and

corresponding angles are in columns. As

an example, a simple waveform with

equal fundamental and 2nd harmonic

amplitudes but with the phase of the

2nd harmonic shifted 90° is entered.

Executing from 1113H causes the new

waveform table to be calculated and

entered in about a second (there are 256

sequences each of which includes seven

multiplications, seven 16 -bit additions

and a division).

To see the waveform, a simple pro-

gram can be devised to output all samples

in page OE consecutively and continu-

ously to a digital to analogue converter,

and thence to an oscilloscope. The

accompanying photographs were taken

using such a program, and the example

quoted appears in No. 7.

Alternatively, the waveform can be

used in my tune -playing programme(2).

To use this program, a further execution

from EF79H is needed. However, I found

it necessary to shift the frequency and

duration data from the area of memory

just below 1000H, as the stack opera-

tions always corrupted the top of this.

This is simply achieved by changing the

contents of memory location ODAOH

from OF to 12, and copying the data,

1E bytes, from a starting address OFCBH

to 12CBH.

Sources of information for waveform

synthesis include mathematic texts deal-

ing with Fourier; The Dictionary of

Hammond Organ Stops by Stephens Some demonstration waveforms, gramme is used to step through page OE

Irwin (Chappell & Co, 1968); and various obtained by pre-setting the harmonic continuously, and output each step to a

numbers of Computer Music Journal (3) weighting factors and phases as shown. digital -to -analogue converter. The two
(available from LP Enterprises, 313 All other locations between 1100H and flutes can be used to demonstrate the

Kingston Road, Ilford, Essex 1G1 1PJ). 1112H are pre-set to zero. Executing similarity of sound, although the phase The Hammond book gives a series of from 1113H enters the waveform table of the second harmonic is shifted 90°

numbers for each voice, representing the into page OE, using samples already in the second one. The oboe phase shift

amplitude of each harmonic, but these stored in page 10. A further, simple pro- was inserted in error!

are weighted to give roughly equal in-

crease in loudness for each increment of

WEIGHTS

PHASE

the setting 0 to 8, i.e. they are logarithmic. A way of interpreting them in this program would be to regard each of the Hammond numbers as a power of .1-2, giving a 3dB increase at each step, or double the amplitude for each 2 steps.

Address 1. Sinewave 2. Squarewave 3. Clarinet 4. Triangle

1100 1101 1102 1103 1104 1105 1106 1108 to 110E Any 0 0 0 0 0 0 All 0 F 0 5 0 3 0 0 All 0 7 0 3 0 5 0 0 AllO DD 0 19 0 9 0 0 (110A) <- 80H

Hence the numbers would be converted as follows:

5. Ramp 6. Flute

50 28 1B 14 10 OD OA All 0 8 8 0 0 0 0 0 All 0

Hammond
1

Program weight
2

7. Flute 8. Trumpet

8 8 0 0 0 0 0 (1109) <- 40H C C C 9 4 3 3 All 0

2

3

9. String

1

3

1

7

5

2

2

AllO

3

4

10. Oboe

4 3 5 4 6 1 0 (1109) .4- 40H

4

6

5

8

6

11 = OBH

0000'

0001

ORG 1113H

7

16 = 10H

1113 0607

0002 NGTS LD 8,7

8

22 = 16H

1115 210011

0903

LD HL, 1109H

Many pieces of music arranged for electronic organ have a similar numbering system to the Hammond, and these conversions could be used on them.

1118 1119 II/R II1C

7D 86
3808 2C

9004 9005 SUM 0006 0007

LD R,L RDD 19,010 JR C, EXCESS INC L

The Computer Music Journal articles

111D 10FR

0008

DJNZ SUM

emphasise how inadequate is this syn-

111F 321111

0099

LD (1111H),R

thesis in imitating musical instruments, since each harmonic grows and decays at its own individual rate, and may also

1122 1821 1124 EF

0010

JR FT8

0011 EXCESS RST 28H

Ak

PCW 89

vary in frequency. In synthesisers, a limited provision is made for this. Per haps it could be the next step in the development of Nascom-based sound although some of the waveforms I have generated are not bad imitations of

1125

References steady, organ -like tones.

1. William D. Stanley and Steven J Peterson: "Fast Fourier Transforms on Your
Home Computer" (The Byte Book of Computer Music, pp.97-103, Byte Pub-
lications Inc. 1979). 2. Don Finlay: "Words and Music by Nascom" (Personal Computer World, Dec. 1979 pp.61-65).
3. James A. Moorer and John Grey: "Lexicon of Analysed Tones" (Computer Music Journal Vol.1 No.2 pp.3945, violin tones; Vol.1 No.3 pp.12-29, clarinet and oboe tones; Vol.2 No.2 pp
23-31, trumpet tones).

113E 113F 1142 1145 1148 1149 1148 114C 114D 114E
1154 1155

Acknowledgements are due to The City University, as before, for equipment and finance; and to Stan Butler for his invaluable help in photographing the wave
forms.

1158 1158 115C 115E 115F

1160

1161

1162

1165

1168

Program continues on P.124

116C 116F 1170 1172

45584345 53532057 45494748 54533820 52452041 57534947
CE 00 CD4002 C38602 3A0811 6F 2610 5E 2C 7D 320811 .za0011
4F CD0212 3A0911 6F 2610 5E 2C 2C
7D
320911
31-70111
4F CD0212 3R0A11 6F 2610 5E

0012.

DEEM 'EXCESS WEIGHTS; RE-ASSIGN

0013

DEFB 0

0014

CALL 0240H

0015

JP 0286H

0016 FT8

LD 131 (1108H)

0017

LD L. A

0018

LD H., 10H

0019

LD H. (HL)

0020

INC L

0021

LD A. L

0022

LD (1108H); A

0023 0024

LD C.. A LD A. (1100H)

0025

CALL MILT

0026 FT4

LD A. (1109H)

0027

LD L1 A

0028

LD H; 10H

0029

LD E; (HL.)

0030

INC L

0031

INC L

0032

LD A. L

0033

LD (1109H); R

0034

LD 17, (1101H)

0035

LD C, R

0036

CALL MAT

0037 NASARD LD A, (110191-1)

0038

LD L. A

0039

LO H; 10H

0040

LD E. (HL)

M

RO

ONT RO

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PET PRINTER PEP -UP and removing the shift bit (bit 7) from all characters enclosed between string quotes which represent letters of the

"When I got the new CBM 3022 printer for the PET I found its speed and clarity of print to be a tremendous help
in program development. However it wasn't long before
I also discovered the printer to be not fully compatible with the PET character set." J. C. Moore continues.. .

alphabet. Graphics obtained from the

other keys are untouched as they still

print correctly on the printer. The only

exceptions to the latter rule are the 4

characters

and : (Hex 29, 5F, 7F,

If you have tried using the POKE 59468, 14 statement in your programs to allow the use of mixed lower case, upper case

(a salutary reminder of the slowness of interpreters).
As the PET has no means of saving

3A) which produce two different graphic characters each - did you know about these? As they are not documented or marked on the keyboard it was decided

and graphics on the screen, you will have binary programs, use the BASIC loader to ignore them. If you particuarly wish
found the printer failing to respond. In- version of the assembly language pro- to cater for them, you must add the

stead it prints lower case as upper case and upper case as graphics. This, of

gram given in Listing 3. Load it first, execute it and it will then be available

four individual tests to either program. Finally, having unshifted your pro-

course, turns listings and printouts into by typing "SYS 826" anytime until you gram, it only remains to remove any

gobbledegook.

switch the power off.

POKE 59468, 14 statements and it will

The solution is either to rewrite all Both the BASIC and the binary ver- run successfully on both the screen and

your existing programs or (and this is sions work by scanning the program text the printer.

the point of the article) to use one of
the programs given here to rewrite them

Listing 1

automatically. Listing 1 was the first attempt (written in BASIC). Load it

70 REM ** THIS PROGRAM WILL LINSHIFT ANY LETTERS BETWEEN STRING QUOTES IN SO REM ** YOUR PROGRAM. ENTER THIS ONE'FIRST, RUN IT, THEN LOAD YOUR 90 REM **.OWN -PROGRAM. TYPE SYS 826 TO EXECUTE.

first, list it on the screen (it has been

100 DATA162,15,169,2.133,15,169,4,133,16,161,0208,1,96,230 101 DATA15,208,2,230,16.230,15.208,2,230.16,230,15,208,2,230,16,161,0,208

made as compact as possible for this pur-

102 DATA15,230,15,208,2,230,16,230,15,208,2,230,16,76,58,3,201,34,208,227,230

pose), load your own program, and then

103 DRTA15,208,2,230,16,161,0,240,227,201,34,240,213,201,193,144,8,201,219,176 104 DATA4,41,127.129,0,76,114,3

re-enter the unshift program directly off

110 FORI=02670910

the screen using the screen editor. Finally, type "RUN 35000" to execute it. To show how things are progressing it

120 READJ:POKEI,J,NEXTI 130 END READY.

a

will display each line number of your

Listing 2

program as it processes it. When tried on
a test program of about 700 lines it took 18 minutes to do the job which,

033A A2 OF 033C A9 02 033E 85 OF

LDX£ POINTERLOW LDA£02 STA POINTERLOW

although relatively slow, is quite painless!
To achieve a faster result use the

0340 A9 04 0342 85 10

LDA£04 STA POINTER HI

assembly language version in Listing 2.

0344 Al 00

$3 LDAA(00,X) high byte of link address

This is loaded into the second cassette

0346 DO 01

BNE$4

buffer area of memory. It doesn't display line numbers, it processes the 700 line test program in less than one second

0348 00 0349 E6 OF 034B DO 02

BRK exit $4 INC POINTERLOW
BNE $8

Cont. on Page 128

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PCW 91

THE COMPLETE

to:etpx-
va3-ss

PASCAL

BY SUE EISENBACH AND CHRIS SADLER

CHAPTER 9: ADVANCED PROGRAMMING TECHNIQUES

In this chapter the PASCAL implementation of a number of powerful
programming tools is discussed. The use of these techniques can affect a programmer's style as profoundly as the "structured" control and data structures met earlier in this series.

Introduction
As programmers become more experien-
ced the pressures imposed on them
while engaged in program writing begin to resolve themselves. Some of these
pressures emerge from the run-time environment where particular restrictions as to memory usage or execution time may require the overall programming strategy to be considerably modi-
fied. These pressures are often alleviated by hardware enhancements - like adding more memory or by the availability
of such software tools as optimising compilers which reduce the effort required by the programmer to meet the run-time specifications of the program.
Other, more numerous, pressures
exist at what might be described as
"write -time". These may be imposed by the nature of the problem itself, by the algorithm which enables its solution, or
by the syntaxof the language in which the program is being written. In this series we have discussed the top -down design approach and shown how it can help the programmer to make a complex prob-
lem more manageable. Likewise, the constructs of structured programming can help the programmer to express the solution (i.e. the program) simply and effectively. Finally, we have described how programming languages have evol-
ved to allow these programming philosophies to be formulated in a natural and
concise manner, thus reducing these
pressures. Hardware improvements, software
tools, sophisticated design techniques and a sympathetic language all contribute towards easing the programmer's load. But programming is still a tricky business that requires planning, concentration and skill and, inevitably, experienced programmers will learn to develop ploys to cut down coding, speed up some forms of manipulation or generally take further action to reduce both the write -time and run-time pressures. In this chapter we discuss a small but popular sample of these techniques recursion, dynamic data structures and variable field records - and show how PASCAL deals with these. The chief problem, however, is not so much how the language realizes the required constructs, as how the underlying logic can be formulated to take advantage of the elegance or efficiency offered by the indicated technique. Like any skilled accomplishment, these methods will

take practice and perserverance and many programmers may (legitimately) decide, after investigation, not to bother. Others may find them familiar or at least interesting. Either way, they complete the major features of PASCAL
as a programming language.
Recursive programming
Recursion, or recursive programming is a concept to conjure with. To some it
represents the peak of "intellectual" programming while to others it seems like a logical trick or an ineffectual waste of time. The truth must lie between these points of view since, while some desirable or even necessary outcomes are only possible by means of recursive methods, for most applications the result could often have been
achieved with less effort and with greater machine efficiency by means of an
iterative method. At the same time,
however, a language which incorporates the facility to perform recursive algorithms offers an opportunity to produce elegant and concise code which, once the general principles are grasped, is usually more readable than the iterative alternative.
Consider the problem of searching a character string (called SENTENCE, say) for the first occurrence of some particular character (say "space"). Let us say that it will be convenient to write this as a function which returns an integer value equal to the position of the first space in the string, if one exists,

and equal to zero if no space exists in the string. The call
I := FIRSTSPACE (SENTENCE)
will initiate the iterative version of the function (Box 1, lines 1 to 11). Tactically the function must search the character positions one -by -one, keeping count of the number of characters inspected and keeping a lookout for the end of the string. The REPEAT -UNTIL construct controls the search, moving from character to character until something happens (i.e. until one of the UNTIL conditions in line 7 is met).
In the second example, (the recursive
case, lines 13 to 23), control of the search is handled in a subtly different
way. The call
I :=FINDSPACE (SENTENCE, 1)
initiates this version, the constant '1' indicating that the search is to start at the first character position. First note that lines 15 and 18 are testing for the same conditions stipulated in line 7 and that the resulting assignments corres-
pond (i.e. line 9 and 22; line 10 and 20). The search however, is controlled by means of the recursive function call in line 19 which has the effect of restarting FINDSPACE but with a modified starting character position HERE + 1 (=2 in the first case).
In an elementary example such as
this the similarities between the iterative and recursive techniques are much more evident than the differences. Nevertheless
it should be possible to discern the
major features of the recursive approach. Firstly, a recursive procedure "calls

1: FUNCTION FIRSTSPACE (SENTENCE : STRING) : INTEGER ;

T

2: VAR J : INTEGER ;

3: BEGIN

4:

J*:= 0 ;

5:

REPEAT

6:

J := J+1

7:

UNTIL (SENTENCE(J) = ") OR (J = LENGTH(SENTENCE)) ;

8:

IF J = LENGTH(SENTENCE)

9:

THEN FIRSTSPACE := 0

10:

ELSE FIRSTSPACE := J

11: END ; (FIRSTSPACE)

12:

13: FUNCTION FINDSPACE(SENTENCE:STRING; HERE:INTEGER) : INTEGER ; 14: BEGIN

15:

IF HERE < LENGTH(SENTENCE)

16:

THEN

17:

BEGIN

18:

IF SENTENCECHERE) <> -

19:

THEN FINDSPACE := FINDSPACE(SENTENCE. HERE+1)

20:

ELSE FINDSPACE := HERE

21:

END

22:

ELSE FINDSPACE := 0

23: END ; (FINDSPACE)

92 PCW

1:PROGRAM ANAGRAM ; 2:VAR I, LENGTH : INTEGER ;

O

3:

LETTER, NEWWORD : ARRAY C1..10) OF CHAR ;

4:

USED : ARRAY El..10) OF BOOLEAN ;

5:PROCEDURE PERMUTE (COUNTDOWN : INTEGER) ;

6:VAR J : INTEGER ;

7:BEGIN

8:

IF COUNTDOWN = 0

9:

THEN

10:

BEGIN

11:

WRITELN ;

12:

FOR I := LENGTH DOWNTO 1 DO

13:

WRITE (NEWWORDCI))

14:

END

15:

ELSE

16:

BEGIN

17:

FOR J := 1 TO LENGTH DO

18:

BEGIN

19:

IF NOT USEDCJ3

20:

THEN

21:

BEGIN

22:

USEDEJ] := TRUE ;

23:

NEWWORDCCOUNTDOWN] := LETTERCJ3 ;

24:

PERMUTE (COUNTDOWN - 1) ;

25:

USEDCJ) := FALSE

26:

END

27:

END

28:

END

29:END ; CPERMUTE) 30:BEGIN CMAIN PROGRAM)

31: WRITE ('Please type in your word --->') ; 32: READLN ;

33:

I := 0

34: REPEAT

35:

I := I + 1

36:

USEDEI] := FALSE ;

37:

READ (LETTERCI])

38: UNTIL (I=10) OR EOLN ;

39: LENGTH := I ; 40: PERMUTE (LENGTH)

4I:END.

PROCEDURE TRYAGAIN (parameter list); FORWARD ;

(*No "body" follows as this is the forward reference*) PROCEDURE TRY (parameter list); BEGIN
IF NOSUCCESS THEN TRYAGAIN(parameters) END 1

PROCEDURE TRYAGAIN ; (*No parameter list!*)

BEGIN

(*Body of TRYAGAIN*)

- (*Somt code dealing with NOSUCCESS*)

TRY(parameters) END

BEGIN (*Main program*) TRY(parameters)
END .
'tself" - (line 19). Programmers often experience a "Russian dolls" feeling when they first encounter this aspect of recursion, the implication being that an infinite sequence of nested procedure calls will ensue. Secondly, however, a recursive procedure always contains an escape clause - so there is a "mole" inside the innermost Russian doll. In FINDSPACE this consists of the different paths indicated by the conditionals on lines 15 and 18. Since these are of exactly the same nature as the loop -terminating conditions in FIRST SPACE (line 7), the recursion is no more likely to "go infinite" than the loop (although careless programming can always bring this about).
Thirdly, compared with iteration, recursion tends not to produce code which executes particularly efficiently. Every procedure call implies another stack frame and set of local variables loaded onto the stack. This tends to eat up memory and also to slow down the program execution somewhat. On the other hand, recursion can be highly effective at write -time, producing concise, readable code which expresses the underlying algorithm clearly and elegantly. Proponents of recursion claim that recursive algorithms are more

Z.
"natural" than their alternatives and certainly many mathematical relations may implicitly be expressed in recur-
sive terms. Finally, once a programmer becomes accustomed to thinking along these lines, a recursive procedure is probably more "top -down" than its iterative equivalent in the sense that it usually requires less detailed analysis to realize a precise solution.
At run-time, the recursive mechanism depends heavily on the stack -oriented procedure call, as described in Chapter
7, to control the different levels of recurrence and to ensure the proper returns. Of course the depth of nesting
possible depends on how much memory is available for the stack to grow into. Some innocent -looking mathematical recursive algorithms can nest to a fantastic depth very rapidly so that the program runs out of memory and crashes. Languages whose compilers are not so dependent on the stack, especially in the context of its procedure -calling mechanism, do not offer recursive facilities although the determined pro-
grammer can usually get away with building his own "software stack" to control the nesting depth and returns.
Program ANAGRAM in Box 2 is an example of a slightly more complex

recursive task which would be very
messy if tackled with iterative techniq-
ues. The idea is to print out every
permutation of the letters of a particular input word (<= 10 characters). In the main program (lines 30 - 40) the word is read in and its length calculated.
In line 40 the recursive procedure
PERMUTE is called. This procedure produces all the permutations before it
exits. The algorithm hinges on the Boolean
array USED[ ] which keeps track of which letters have already been used in the current permutation - the letters being held in LETTER[ ] in their
original order. The array NEWWORD[ ]
is used to accumulate the re -ordered letters one -by -one and the re -ordering is achieved by recursively calling PERMUTE (line 24) until every letter has
been used (COUNTDOWN = 0) at which
point the escape clause (lines 9-14) is invoked, printing out the current word and exiting. Control then shifts back one level and one element of USED is de -allocated (line 25) and so on until a new permutation can be formed. How far back control must go will depend on the combined states of USED, J and COUNTDOWN but when all the letters have been shuffled around to the original word, control returns to the
main program. Take the unlikely situation where a
procedure is required to call a second procedure which in turn calls the first procedure. Since a procedure can only be called if it is on at most the same level or nested in the calling procedure, the problem here arises as to which procedure to declare first. The remedy lies in the PASCAL facility to make 'a "dummy" procedure declaration called a forward reference. The format of a forward reference is as shown in Box 3.
This ploy provides the compiler with enough information (i.e. the parameter list) to set up that part of the stack frame which deals with communicating beyond the scope of the procedure whilst FORWARD tells the compiler
to pick up the rest of the procedure
when it is next declared. Although the example is somewhat artificial, the necessity of the forward reference can be seen by considering the reaction of the compiler if the forward reference were omitted. Exercise: Desk -run PERMUTE on your favourite four letter word. Keep track of NEWWORD, USED, J and COUNTDOWN, especially COUNTDOWN which
provides a measure of the depth to
which PERMUTE has been called.
Dynamic data
structures
At any point in a program the data which is being processed is normally
held, either internally or externally, in one of the predefined data structures. Internally, the record is used to associate complex and varied data items together while an array offers the ability to contain a number of similar data items simultaneously and manipulate them at random. In a typical data processing application therefore, the most flexible arrangement is probably an array of records since the bulk of the processing is likely to be concerned with

PCW 93

MEMORY MAP STACK
Pointer
free space Record

Bottom of Stack Top of Heap

HEAP
manipulating matching fields within a group of the records.
This is not as flexible as it might be however. One problem is that the precise number of records needed in memory at run-time is not necessarily known when the program is written and will in any case vary from one run to the next. The programmer must therefore declare the array as large as the maximum number of records likely to be required even though at least some of this space will be wasted on most runs. For this reason, the array is known as a static structure. PASCAL is often criticized for not providing for dynamic (i.e. run-time) allocation of array space. In fact PASCAL does provide a dynamic data type via the pointer type. Instead
of some particular variable (say a
record) being embedded in the stack, as
with other declarations, the pointer type declaration enables a pointer
variable to be placed in the stack, associ-
ating (or binding) that pointer to the required data type (i.e. the record).
When the record is created (dynamically) the memory locations will be allocated
in a region of memory known as the heap, and the starting address of the record will be placed in the pointer variable on the stack. The heap is usually located at the bottom of memory while the stack is located at the top. As the program proceeds, the stack and heap grow towards one another, the former as a result of successive procedure calls and secondary processing; the latter as a result of the creation of new dynamic records see Box 4. If the stack and the heap touch, the program has run out of
memory. The pointer type is declared as
follows: TYPE MARKERS =ADATATYPE
where MARKERS is the name of the pointer type and DATATYPE is the name of the data type - which need not be a record - to be dynamically allocated. The statement
VAR POINTER1, POINTER2, DUMMY : MARKERS then binds the variable names POINTER1 etc. to the data type DATATYPE.

To initialise a pointer variable on the stack, a value NIL is assigned. This is a reserved word indicating that no address in the heap is being pointed to.
A variable of type DATATYPE may then be created by executing the statement
NEW (POINTER1)
at which time the memory locations in the heap will be allocated and their starting address will be placed in POINTER1. Note that the variable has no name of its own and can only be referred to by means of POINTER1 as
follows:
POINTER1A.REFNUMBER := 301
assuming that DATATYPE is a record type and that an integer field REF NUMBER has been declared.
In this way, a series of records may be built up in the heap, each of which has its own pointer on the stack through which it may be referenced. If extra pointers have been declared (e.g. DUMMY) then one such record may have more than one pointer pointing to it. So
DUMMY := POINTER1
implies that DUMMY^ and POINTER1 refer to the same record on the heap. A record can be de -allocated by
POINTER2 := NIL
which means that the record will become inaccessible even though the space on the heap will stay occupied.
The business of clearing up the de -

allocated regions of the heap is known as "garbage collection" and is handled so differently, if at all, on the different systems, that we won't discuss it here.
The advantage of this scheme is that different records of the same type can easily be amended, enhanced or sorted into a different order. In a static array a record is accessed by its position in the array (e.g. NUMBER[3] will refer to the third element of an array NUMBER
[1. .N]) and if the elements must be re -ordered,, or one element eliminated
say, a considerable amount of manipulation is required. A dynamic "array' on the other hand, can be created by defining an array of pointers and re -ordered simply by redirecting the pointers. Like-
wise, one record could be deleted by setting its pointer to NIL without disturbing the other elements at all.
A really powerful application can be brought about by declaring one of the fields within the dynamic record as a pointer type. By this means, one record in the heap can be set up to reference another record simply by assigning its pointer to the relevant field in the first
record. In this way, a linked list of records can be built up, consisting of a set of records whose structure (i.e. order) is defined implicitly by the sequence of pointer fields rather than explicitly by some static format arbit-
rarily declared at compile -time. The
last element of the linked list must
always have its pointer field set to NIL
and the first element (and only the first) will be referenced by a pointer in

POINTER (Liathead)
I

/HEAP

I

0.

STACK

record

---
POINTER

POINTER

POINTER 0---11a.NIL

1gPRORAM ESTATE ;

2:TYPE DATE = RECORD

3:

DAY 1 1..31 ;

4:

MONTH : 1..12 ;

5:

YEAR : INTEGER

6:

END (DATE)

7:

NAME = PACKED ARRAY (1..20) OF CHAR ;

81

OCCUPATION = (VACANT, FILLED) ;

9:

POINTER = ^FLAT

10:

FAMILY = RECORD

11:

SURNAME : NAME ;

12:

SIZE C 1..20

13:

END ; (FAMILY)

14:

FLAT = RECORD

13:

NUMBER : INTEGER ;

16:

ROOMS g 1.. 10 ;

17:

NEXT : POINTER ;

18:

CASE STATUS : OCCUPATION OF

19:

VACAN) : (LASTDATE : DATE) ;

20:

FILLED : (TENANTS :FAMILY)

21:

END ; (FLAT)

22:

23:VAR FIRSTFILLED, FIRSTFREE, LINK : POINTER

24:

CHOICE INTEGER

25:

NEWDATE : DATE ;

26:

27:PROCEDURE STREADLN(VAR N : NAME) ;

281VAR I, J : INTEGER ; 29:BEGIN

Box 6 Cont. on P. 130

94 PCW

the stack. Thus one pointer in the stack, sometimes called the listhead, grants access to the entire structure of records in the heap - see Box 5.
Instead of continuing with a description of the data -handling capabilities
offered by linked lists, we prefer to
illustrate these capabilities by means of the sample program ESTATE in Box 6. The purpose of this program is to assist a housing estate manager to keep track of the tenants in a block of flats. Initialy, the flats are created as a linked list

Pointer Type:

G

of records, called FLAT, in the heap. (FLAT is an example of a variant field record which will by fully discussed in the next section.) As flats are allocated to different people, the relevant fields in FLAT are updated, and as families move out the vacant flats are returned to the pool. Thus two linked lists will be maintained - one consists of the empty flats, beginning with the one that has been vacant longest; the second containing the occupied flats in alphabetic order of the tenants surnames.
0
type identifier

Individual flats will be transferred
between these two as the occasion
Cont. on Page 128
Look up table
Computer Jargon Compile -time / Static Run-time / Dynamic Recursion
Forward ReferencePointer
Heap Binding Linked List Listhead Garbage Collection Variant Field Record Tag Field

Pointer Variable:

Record Variant:

gn

variable identifier identifier

0
type identifier
J

Or

constant

1111

fiel d list

III

Pascal Words FORWARD NEW NIL ORD
UCSD Exceptions There is rudimentary garbage collection
within the heap by means of standard procedures MARK and RELEASE - see
UCSD User Manual.
Exercises: 1. Desk -run ANAGRAM 2. Write procedures to handle communication between linked lists and disc files. 3. Amend ESTATE to fit families into correctly -sized flats.

ACKNOWLEDGEMENTS:

0

1. LOGITEK - for loan of ALTOS
8000-2 with word-processing facilities. 2. TRANSAM - for CP/M version of TCL PASCAL system.

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PCW 95

nE

c

BOOKFARE

Good programming practice and robots are the diverse subjects that appear under the Malcolm Peltu microscope this month.

In 1968 he wrote a letter to ing the IF -THEN -ELSE

sense approach to such subjects

the journal of the ACM (the statement which is available as program documentation,

American equivalent of

in languages like Algol and choosing a language (if you

the British Computer

Pascal, and reducing to a

have a choice), working in a

Society) headed "GOTO

minimum the number of

programming team, testing

statements considered harm- GOTO statements.

and debugging, and improv-

ful" in which he stated why

The argument against

ing run-time performance.

it was bad practice to use the GOTOs is that they com-

There are also detailed

GOTO statement. This letter plicate logic flow; it's

looks at specialist problems

triggered off wide discussion in the computer profession

difficult to understand a program when the flow can't

such as heuristic program. ming (as used in artificial

which coalesced around a

be followed in detail. In a

intelligence work) and real-

variety of structured programming methods.

sideswipe at BASIC, he points out that this

time programs. By distilling the

So what if it

However, Dr I. D. Hill of the Medical Research Council,

language provides the most obvious examples of bad

experience of decades of mainframe and mini pro-

works!

who wrote the section in the Guide on structured pro-

logic flow because every statement is numbered and

gramming, credits one of

can be gone to from any

gramming, the Guide provides a necessary and effective insight into the kinds of

At an international confer- the fathers of Algol, Peter

other line; therefore any

techniques that ought to be

ence in 1977, one of the most Naur, as the source of the

respected of computer

first public analysis of

clump of code could be entered at any point.

in-built into everybody's programming style. This

scientists, Professor Edsger "GOTO-less programming",

The Guide, which is

would help to avoid the

Dijkstra (sic) made a violent in 1963. This is not sur-

intelligently edited by Brian painful period of trial and

attack on hobbyist pro-

prising because Algol was

Meek of Queen Elizabeth

error when moving from

grammers in general and the designed from scratch as a

College, London and Patricia simple educational pro-

BASIC language in particular. clear and elegant pro-

At the same conference, a

gramming language; it wasn't

Heath 'of Plymouth Polytech- grams to something more nic, enlists Dr Hill as one of its complex that will need to

pioneer of data communications techniques, Paul

scraped together in the more ten contributors. Although be used and developed over a

cobbled -up, pragmatic

the mixed authorship leads to long period of time. The

Barran, opined that the standard of hobbyist pro-

style of languages like Cobol, Fortran and dear old BASIC.

some variability in the style and clarity/complexity of the

book also provides further support for the growing

gramming often betters that

As Dr Hill explains,

descriptions, there is a strong popularity of Pascal

of so-called professional

although GOTO became the editing hand which ties the (although it doesn't push the

programmers.

cause célebre, the main

Although these comments objective of structured pro-

seemed to be contradictory, gramming and good pro-

sections together and draws general conclusions from detailed examples of

language explicitly) because Pascal, as a descendant of Algol, falls more in line with

Dr A.N. Walker of Nottingham University pointed out, in a letter to Computer Weekly, that both observations could be true: amateur programmers may be awful but professional ones

gramming practice in general is not directed towards eliminating or promoting any particular instructions or languages. The objective is to produce progMms which are as simple and logically lucid

particular languages (Algol and Fortran are used most frequently). The editors even point out that the sequence they chose to present the subjects is not necessarily the best one and they provide

the suggested good programming methods than BASIC.
The Human Side of Information Processing, is the proceedings of a conference held in Copenhagen in 1978

are even worse. As if this kind as possible, eliminating any

of onslaught on their

clever -clever trick program-

pointers to other sequences and lacks the cohesiveness which a reader might prefer of a strongly directed book

technical abilities was not

ming, and structuring in such to follow.

like the good programming

enough, professional

a modular and clearly

In addition to structured guide. However, a sound

programmers and systems

documented way as to

programming, the Guide take theme does emerge from the

analysts are increasingly

assist in developing and

takes a practical and common papers, as summarised by its

being criticised for failing

testing and in subsequent

to take organisational and

maintenance or enhance-

human factors into sufficient ment.

account when designing

Professor Dijkstra was

systems.

"appalled" by the programs

Two new books make a he read in the US hobbyist

significant and positive

mags (PCW was not around at

contribution to the debate the time) because they broke

about programming and

the rules of structured pro-

systems practice.

gramming and because

The Guide to Good Pro- BASIC, which grew in

gramming Practice goes to the popularity on the back of the

heart of Professor Dijkstra's personal computer boom, is

criticisms - the need to

generally regarded as a poor

understand and implement language for writing elegant

techniques which not only code and for handling

produce programs that work complex data structures. The

but that are also of a high

hobbyists had put back

standard in terms of bug -

programming by 25 years,

counts, simplicity of under- he bitterly commented.

standing and ease of main-

Dr Hill lists seven basic

tenance. The Human Side of principles of good pro-

Information Processing is a gramming, starting with the

collection of papers which avoidance of any tricks .

shift the focus of computer never use a complicated

systems design from purely method where a simple one

technical issues to include will do, is a piece of advice

wider sociological and

which applies' to any

psychological factors.

language. But some of the

Professor Dijkstra's most other points he makes would

popular claim to public fame be difficult or impossible

is that he originated the move to carry out fully in BASIC -

towards the software develop- for example using meaningful

ment techniques now known names for variables (i.e. more

as structured programming. than just A or Al), employ-

96 PCW

BOOKFARE

editor, Niels Bjorn -Anderson of the Copenhagen Business School: "For too long the design of information systems has been treated as a technical problem only. Some benefits have certainly been achieved but the major benefits with this technology lie in the broader perspective."
That broader perspective, according to the book, includes factors as varied as the politics of organisational change, using computers to design more humane working environments, user participation in systems design, the impact of computers on the working class (sic) and the future of systems designers. Inevitably, as a book based on papers given at an international conference, it's heavy going in some parts, particularly as there are some obvious translation boobs. There are also some ghastly poems by the editor at the start of each paper, which rhyme words like Lancashire and bank cashier (for an article written by Enid Mumford from Manchester on an experiment in systems design at a bank.)
The human factor is being given growing priority in the design of computer systems and the book provides much food for thought. For the professional computer person, a challenging picture is painted with new social responsibilities thrust on to the already pressurised analysts and programmers. And Per Groholt of the Norwegian Standard Telephone and Cable company goes as far as to suggest that "most so-called 'professionals' in systems design will disappear during the 1980s although a few will remain and become real professionals, i.e. hardware/software experts with an academic background." He believes that computer users will eventually become their own systems designers, taking into account their organisational needs and the wider social and human context.
The user as designer is, of course, a trend that was initiated in the personal computer world, which is one reason why personal computers, with colour TVs , graphics, synthesisers, et al, are so much more "user friendly" than their opposites in the traditional computer business. But if the "amateurs" do inherit the computing earth, I hope that they first read and assimilate the valuable advice offered in these two books.
Oy robot
One of my first robot loves recently made a guest appearance on Wonder Woman. He is called Robby and sci-fi buffs will know

that he first appeared in Forbidden Planet in 1956. Since then Robby and robots have come a long way.
Now teenagers like Tod Loofbourrow not only build their own computer controlled robots that can "see" and "hear", they also write DIY books on how to do it. But although Loofbourrow's robot, called Mike and based on a KIM -1, may be very clever, it doesn't have the twirly ears, flashing eyes and chubby arms of Robby.
Anyone interested in a DIY robot will find How To Build A Computer Controlled Robot a good starting point, although some of the US -oriented details are inappropriate to the UK and, anyway, new products have come on to the market since it was published last year that will enhance any Mike look-alikes. Each step in the construction is described in full, from building the metal frame to fitting voice recognition equipment.
But for those who, like me, still enjoy fantasising about human robots, like Wonder Woman herself, a magazine called CineMagic presents a superb alternative DIY robot called ON/OFF, the Wonder Robot! ON/OFF (I wonder if he has any relations with four-letter Christian names) is motivated by human power and the jargon in the detailed guide includes references to rubber gloves and tin -can couplings.
Having twinned a serious book like Loofbourrow's with all this tine -freaking, I will now, Houdini-like, escape from this review with a neat punchline that draws the threads together: Did you know that the name of the forbidden planet on which Robby first appeared was, would you believe, Altair ( a name which was of course assigned to the first of the personal computers). Another strange stream of unconsciousness is generated by the thought that the human in Forbidden Planet was called Dr Morbius, which reminds me of a Mobius Strip . . . and Strip makes me think of Wonder. .. oh well!
Featured in Bookfare this month were: Guide To Good Programming Practice edited by Brian Meek and Patricia Heath (Ellis Horwood/John Wiley, £10.50); Computer Programming in Basic by Ian Williamson, Rodney Dale and Tim Eiloart (Cambridge Learning Enterprises, Rivermill Lodge, St Ives, £7.50 for four volumes); How to Build a Computer controlled Robot by Tod Loofbourrow (Hayden/ Butterworth, £4.80); CineMagic, (75p, obtained from Dark They Were And Golden Eyed, London);

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RANDOM Various distributions (and un-equal probabilities) Using the fact that the probability of an event occurring is equal to the length of the part of the line we associate with it,

we can see how to make events occur

WRITINGS RESUMED with unequal probabilities. For example a three -sided dice with the probability 0.5 of being 1, 0.25 of being 2

By Michael James

and 0.25 of being 3 can be simulated by

dividing the line as shown in Fig. 3. In

a BASIC program we would generate a

random number and test if it was in the
In Random Writings (PCW Vol. 1, No. 10) I consider what a random interval 0 to 0.5, 0.5 to 0.75 or 0.75 to 1.

number is and go on to examine methods of generation. Now,

In fact this can be done in a simpler

picking up the threads, I move on to deal with some of the uses to way. By asking if RND is less than 0.5

which random numbers can be put. Most of the time the text will steer clear of explaining the theoretical foundations of the results;
rather just state the useful conclusions. (The more advanced

and then if less than 0.75, we can decide which interval it is in. If it is less than
0.5 it is in 1. If not and it's less than 0.75 it's in 2, and if it is not less than

reader might like to consult "further reading" listed at the end). For 0.75 then it must be in interval 3.

compactness, the BASIC function RND will be used in all the examples. However, if any of these methods are used for purposes
other than game playing, then a good congruential generator should be used (such as the one included in the previous article).

This simple observation gives us a routine way of obtaining any unequal probabilities. Given a set of probabilities pi ,p2 ,p3, . . . , pn, form the set of numbers pi, pi + p2, Pi + P2 + P3,

. . . pi + p2 + p3 + - + pn. Generate

a random number. If RND is less than

Making things happen
(with a fixed probability)

50 IF RND < .5 THEN 80 60 PRINT "COIN TWO = TAILS" 70 GOTO 10
80 PRINT "COIN TWO = HEADS"
90 GOTO 10

Pi then event one happens. If not, and it is less than pi + 132, then event two happens and so on. (See Fig.5, subroutine 7000.)

Continuous events The most elementary act in any simula- However, when a number of depen-

tion or game is making something happen with a known probability. This
is easy given a random number generator supplying uniformly distributed numbers between zero and one. First recall that
the words "uniformly distributed between zero and one" mean that any number between zero and one is as likely to be produced as any other. Suppose we want an event to happen with a probability of 0.75. If we write:

dent events must occur with specified probabilities this simple method will not work. If we were trying to simulate a dice, then only one of the numbers between 1 and 6 must be produced each time and each with the probability 1/6th. To solve this problem we must resort to our general principle. If each digit 1,2,3,4,5,6 is assigned a piece of a line 1/6th of the total length and, if we say that when the random number

Until this point we have been considering a finite collection of separate events. It is possible that we could want to generate a set of random numbers distributed over some range with something other than a uniform probability. This is, in general, a very difficult thing to do. It is possible to give a few methods for the commoner distributions without
going into too much theory and a
collected list will prove useful to the

IF RND < .75 THEN "event happens"

falls in a number's sixth this number has
"come up", we have a dice. For

more advanced or ambitious programmer. (If you don't recognise the distribu-

in a program, then the event will occur example, we could divide the line up as tions named below then it is unlikely

75 percent of the time. The reason is in Fig.2. If RND falls in the interval that you would even want to use them,

not difficult to see. Simply ask yourself 3/6 to 4/6 say, then we have thrown a so skip to the next section.) what proportion of the time the random 4, etc. This satisfies our requirement

number will fall below 0.75 if it is that only one number is produced at a Fig. 3

equally likely to fall anywhere between time and, as the length of each piece of

zero and one. The answer is about three- line is one -sixth (and hence is the pro-

1

2

3

quarters, ie. 0.75 of the time. In fact the bability of RND falling there), we have

general principle is just as easy to under- a fair dice.

0

0.5 0.75

stand: The probability of a uniformly distributed random number falling in any part of the line between zero and one is equal
to the length of that part (see Fig.1). Thus in general if we want an event
to occur with a probability .P then we

Fig. 2
1111111 1 2 3 4 5 6
01/6 2/6 3/6 4/6 5/6 6/6

1. THE NORMAL DISTRIBUTION As this is a very important distribution two methods are given.
CENTRAL LIMIT THEOREM 10 F = SQR(3/N) 20 Z = 0

use:

A BASIC dice program can now be 30 FOR I = 1 TO N

IF RND < .P THEN "event happens"

written. Instead of simply testing, using 40 Z = Z + RND IF statements, whether RND falls in any 50 NEXT I

Fig. 1

0

0.75

Many happenings
The above method is simple and OK for producing any number of events happening with various probabilities so long as the events are required to be independent. For example, a program for the tossing of two (fair) coins would be:

10 IF RND < .5 THEN 40 20 PRINT "COIN ONE = TAILS" 30 GOTO 50

given interval, we can use a trick to
speed things up. If RND lies in the interval n/6 to (n+1)/6 then RND*6 lies in the interval n to n+1 and INT(RND*6) equals n. Thus INT(RND*6) is either
0,1,2,3,4 or 5 with equal probability
one -sixth. In general, to produce random integers from m to n with equal probability, the statement:
10 R = INT(RND*(N-M+1)) + M
can be used. For example, a dice would use R = INT(RND*6) + 1. In the same way, to produce random numbers uniformly distributed from a to b:
10 R = RND*(b-a) + a

60 Z = F * (2*Z - N) Z is normal with a mean of zero and a standard deviation of one. N should be chosen between 20 and 50, the accuracy of the approximation improving with larger N.
BOX-MULLER METHOD 10 Z = SQR(-2*LOG(RND)) * COS (3.145*RND)
Z is normal with a mean of zero and a standard deviation of one.
2. THE CHI -SQUARED DISTRIBUTION 10 X = -2 * LOG(RND)

40 PRINT "COIN ONE = HEADS"

can be used.

X has a chi -squared distribution with

PCW 101

two degrees of freedom. 10 U = 1 20 FOR I = 1 TO D 30 U = U *RND 40 NEXT I 50 X = -2 * LOG(U) X has a chi -squared distribution with
2D degrees of freedom. To generate intermediate degrees of freedom use
10 Z = X + Y*Y where X is chi -squared with 2D degrees
of freedom, Y is normal (mean = 0 S.D. = 1) and Z is chi -squared with
2D 4- 1 degrees of freedom.
3. THE EXPONENTIAL DISTRIBUTION 10 X = - ( 1/L) * LOG(RND)
X is distributed as 1 - exp(-LX).
4. THE LOGISTIC DISTRIBUTION 10 U = RND 20 X = A - B * LOG((1 - U)/U) X is distributed as 1 + exp(-(X - A)/B).
5. THE GAMMA DISTRIBUTION
10 U = 1 20 FOR I = 1 TO K 30 U = U * RND 40 NEXT I 50 X = -(1/L) * LOG(U) X is distributed as
(XX) K-1 exp (-LX)
P
These distributions are the ones most often found in simulations. Others may be obtained from the reference.
I have ignored one very important distribution - the Poisson. The reason is that, unlike the others, the Poisson is concerned with the non -negative integers and is more complicated. The following program gives values of K(=0,1,2,...) distributed as (exp(-L))LK/K!.
10 U = 0
20 K = 0 30 U = U - ( 1/L) * LOG(RND) 40 IF U > 1 THEN 70 50 K = K + 1 60 GOTO 30 70 rest of program
Improving random number generators
Any random number generator can be improved by shuffling. A typical shuf-
fling alogrithm is:
1. Fill an array of size N with random numbers. 2. Generate an integer random number R in the range 1 to N (see earlier) and swap the contents of the first array element with the Rth. 3. Repeat (2) for each of the array elements until all have been swapped. 4. Use the N random numbers in the array as the next N in the sequence. A subroutine for shuffling in BASIC is:
10 DIM A(N) 5000 FOR I = 1 TO N 5010 A(I) = RND 5020 NEXT I 5030 FOR I = 1 TO N 5040 T = A(I) 5050 R = INT(RND * N) +1 5060 A(I) = A(R) 5070 A(R) = T 5080 NEXT I 5090 RETURN

I

0001 LINE. 200

0005 REM DIFFUSION SIMULATION

0010 DIM B(4),P(4) 0015 REM INPUT BOX SIZE N BY N AND APERTURE SIZE A 0025 REM AND PROBABILITIES 0030 GOSUB 1500

0035 REM CLEAR AND INIALISE VDU 0040 GOSUB 1000

0045 REM MOVE TO ABOUT THE CENTRE OF THE SCREEN

0050 FOR I.1 TO 5

0060 PRINT 0070 REM015 T I
EDRAW BOX

01 1 PRINT TAB(0 10)

0120 R=INT(01-A)/2;) 0130 GOSUB 2000

0140 FOR I.1 TO A
0150 PRINT " "; 0160 NEXT I 0170 R.M-R-A+1

4° 0180 80SUB 2000 0190 PRINT

0200 FOR I.1 TO N

0210 PRINT TAB(10);"*";TAB(10+M);"*"

0220 NEXT I
0230R OM

0240 PRINT TAB(10);

0250 808UB 2000

0260 GOSUB 3000

0270 80SUB 5000

0280 809UB 5000
0290 x.11 0300 Y=N 0315 REM SET BOUNDARY FLAGS

0320 80SUB 9000

0330 TO

0585 REM START DIFFUSION

0595 REM GET DIRECTION

0600 GOSUB 7000

0610 FOR J=1 TO Z

0615 REM IF ON A BOUNDARY THEN REFLECT DIRECTION IF NECESSARY

0620 GOSUB 8000
- 0625 REM MOVE CURSOR
0630 ON D GOSUB 3000,6000,4000,5000

0640 IF Y<1 THEN OOTO 700

0645 REM SET BOUNDARY FLAGS

w 0650 8OSUB 9000

0660 T.T+1

0670 NEXT J

0680 GOTO 600

0700 IF E.1 THEN 8010 600

0710 GOSUB 3000

0720 Y.Y-1

0730 X.-11

0740 E=1
. 0750 PRINT "ESCAPE 0760 8010 600

III AFTER ";T;" TIME UNITS"

0999 END 1000 PRINT CHRS(30);CHRS(19);CHR4(12);

1010 RETURN

1500 PRINT "WIDTH OF BOX"; 1510 INPUT N 1520 PRINT "HEIGHT OF BOX"; 1530 INPUT N 1540 PRINT "SIZE OF HOLE"; 1550 INPUT A

1560 FOR 1.1 TO 3
1570 PRINT "PROBABILITY OF MOVING IN DIRECTION ";I; 1580 INPUT NI) 0 1590 IF 1=1 THEN 1650

1600 P(I)=P(I-1)+P(I) 1650 NEXT I 1660 P(4)=1

1670 IF 1-1)(3)<0 THEN GOTO 1560

1680 RETURN

2000 REM SUBROUTINE TO PLOT R s'S IN A LINE
2010 FOR 1=1 TO R

2020 PRINT "s";

2030 NEXT I

2040 RETURN

2905 REM SUBROUTINES 3000,4000,5000,6000 MOVE THE CURSOR

2915 REM UP,DOUN,LEFT AND RIGHT AND ADJUST THE 2925 REM X Y COORDINATES

3000 PRINT CHR1(1);

3010 Y=T -1

102 PCW

Fig. 5
0

.

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itntr
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res

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PCW 103

There are many ways of shuffling and the general rule seems to be that the more you shuffle the better the random numbers! Of course the trouble is that shuffling takes time and if you need a lot of random numbers it's probably better to work on the quality of your generator. Even so shuffling can make a very poor generator very good - if in doubt, shuffle!
More than one dimension
Using a random number generator which gives uniformly distributed num-
bers in the range zero to one to generate coordinates of a point in say two dimensions has its problems. Most people would agree that X = RNDI, Y = RND2
would give a pair of numbers which could be interpreted as a point in the unit square (see Fig.4) which was uniformly distributed. That is, every point is as likely to be produced as every other. Unfortunately, and surprisingly,
this is not so.
Fig. 4
1
Y

3020 RETURN 4000 PRINT CHR1(2); 4010 YY+1 4020 RETURN 5000 PRINT CHRI(4); 5010 XX-1 5020 RETURN 6000 PRINT CHR1(9); 6010 XX+1 6020 RETURN 7000 ZINT(RND$M/2)41 7010 ORND 7020 I.1 7030 IF P(I)>0 THEN 7400 7040 II+1 7050 BOTO 7030 7400 DI 7410 RETURN 7415 REM SUBROUTINE TO REFLECT DIRECTION IF NECESSARY 8000 IF 8(81.0 THEN RETURN 8010 BD+2-INT((D+1)/4)x4 8020 RETURN 8095 REM SUBROUTINE 900 SETS BOUNDARY FLAGS B(I>1 MEANS "ON BOUNDARY I" 9000 FOR 1.1 TO 4 9010 8111.0 9020 NEXT I 9030 IF XM THEN B(2)1 9040 IF X.1 THEN 8(41=1 9050 IF Y1 THEN B(111 9060 IF YN THEN B(311 9070 IF 11(1)01 THEN RETURN 9080 IF X<INT((M-A)/2) THEN RETURN 9090 IF X>INT((M+A)/2) THEN RETURN 9100 DIU.° 9200 RETURN

0

X

If a random number is generated by any of the usual methods then X, Y will not be uniform over the unit square! There will be regions where no points fall. These regions usually take the form of strips and may be clearly seen if random points are plotted on a graphics display device. How important this is depends, as always, on the application. For game playing it can usually be ignored. The point is - do not always expect pseudo -random numbers to behave like truly random numbers. The solution to the problem seems to be to use two different pseudo -random number generators or to use shuffling to produce two separately shuffled streams of numbers.
An example
Finally we come to a simple example. The program listed in Fig.5 simulates, not very seriously it must be admitted, a gas molecule in a box! The molecule collides with other invisible molecules and the walls of the box until it find a hole (of variable size) in the top of the box. Thus the process bears a passing resemblance to diffusion of gas through a hole.
The program actually demonstrates another technique as well as simulation. By using the cursor of a VDU to represent the gas molecule and the cursor up, down, left and right commands to
move it, we can produce a moving
graphics display. This technique is sometimes known as pseudographics.
The program begins by asking for the size of the box, the size of the hole and the probability of the molecule moving in the various directions shown in Fig.6. The next major part of the program (45 - 250) draws the box on the screen using asterisks. This part

is fairly straightforward and produces the box shown in Fig.7, leaving the cursor in the bottom right-hand corner.

Fig. 6
4

1
2

1
3
At this point we reach a VDU specific part of the program. Subroutines 3000 to 6000 move the cursor in directions 1 to 4. The control characters which will move the cursor of your own VDU in each direction must be found and substituted in the PRINT CHR$(code) statements.
If you don't know your VDU's cursor control characters, try
10 FOR I = 1 TO 128 20 PRINT I, CHR$ (I) 30 FOR J = 1 TO 200 40 NEXT J 50 NEXT I
As the program runs each ASCII character will be sent to the VDU - watch for
the ones that move the cursor! If the cursor does not move in all the required directions then you cannot use pseudo graphics on your VDU. (If your VDU
has a page and a scroll mode try again in page mode.) Subroutine 1000 must also be adjusted to initialise, i.e. clear, the screen and home up your VDU.
The part of the program that actually simulates the diffusion is 600 to 760. A call to subroutine 7000 gives a random value of Z between 1 and (M/2 + 1) as the distance that the molecule will travel before a collision (unless it hits

a wall of course) and a random value of D equal to 1,2,3 or 4 as the direction of motion. Examination of subroutine 7000 will reveal two of the methods we have been discussing. Lines 610 to 670 move the cursor Z places in direction D. After each move, subroutine 9000 is called to discover whether the cursor is on a boundary and, if so, which. Notice that it could be more than one and that the hole does not count as part of boundary
one. Subroutine 5000 checks to see whether the next step would take the
cursor across the boundary and if so the direction of movement is reversed. The only other function is telling when the molecule passes through the hole and this is achieved by line 640. On leaving the box, the number of moves made is printed as a final result.
The program is not a particularly good simulation of a gas molecule, but it is fun to watch and provides an ideal
starting point for a more ambitious program. Even so, the relationship between aperture size and time to escape can be investigated as, say, a classroom exercise. Interesting extensions of the program might include adding more directions and a more realistic distribution (the exponential - see sections on continuous distributions) of times between collisions.
Reference
J.M. Hammersley and D.C. Handscombe, Monte Carlo Methods, Methuen
Further reading
Yu. A. Schneider (Ed.), The Monte Carlo Method, Pergamon Press, 1966. R. B. Coates and A. Parkin, Computer Models in the Social Sciences, Edward
Arnold, 1977.

104 PCW

Fig. 7
RUN WIDTH OF BOX? 40 HEIGHT OF BOX? 10 SIZE OF HOLE? 10 PROBABILITY OF MOVING IN DIRECTION 1 ? .25 PROBABILITY OF MOVING IN DIRECTION 2 ? .25 PROBABILITY OF MOVING IN DIRECTION 3 ? .25

Side 4
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PCW 105

CALCULATOR CORNER
This month Dick Pountain has handed over to reader N. Horwood who relates his experience of using the T159 with printer for accountancy; the moral being that the calculator can often provide a
cost effective alternative to the micro if you make a realistic analysis of the data requirements of your application.

NEWCOURSES FOR TEXAN HORSES

I was in two minds when I bought the cleared by the local VAT office, but, is loaded into that register and

TI59 some two or three years ago, believe it or not, they were most helpful. summed to what is already there, the

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the Texas dialect. I have nothing but row, but it can easily be folded concer- for each entry to be completed. About

praise for the great assistance, patiently tina -wise, and for less than £300 the right tempo for the small keyboard

given to me by the TI people at Bedford, complete (including VAT) it must be and for the type of data analysis com-

usually with me on the phone in yards good value.

monly required in say a Work Study

of paper tape, having forgotten to read I am not an accountant, although office or laboratory. This program is

the excellent manual properly!

for my sins I have much to do with that shown in detail as it gives the encoding

Once having gained confidence both fraternity. One of the mysteries associa- of numerical characters for loading into

in my ability to write useful programs ted with the running of any business is the No.4 print register. The Nop state-

and in the reliability of the machine the manipulation of the simple figures ments are left in the program in case it

mechanically and electronically, it derived from the purchase and sale of is required to speed up the action slight-

occured to me that here was a very various items or services. The end result ly by converting to direct addressing

powerful device. Admittedly the storage has to be a set of accounts. One of the without having to change the program

capacity for bulk data was limited, beauties of the "59" is that data as well location numbers.

but the logic and arithmetic capacity as program steps can be stored on Another useful method of auto -

was of a very high order. I experimen- magnetic cards. This means that data routing data is to incorporate within a

ted with some simple applications in can be input and processed and stored number a two digit code, or a series of

industrial costing and accountancy and in RAM and then transferred to magne- two digit codes which may be deccded

found that by choosing the type of pro- tic card, just like tape or disc. The data after splitting out of the original

gram structure which gave user prompt- may then be saved for future addition number. The example shown uses stan-

ing on the printer (which doubled as or modification. This is possible due to dard Op. codes, and can split a number

result annotation and dealt with the the four way split of the data banks, of the form abcdefgh into four pairs,

general form of the data processing so with each bank independent of the i.e. ab; cd; ef; gh, stored in four data

that a program was as flexible as possible others.

registers ready for use as indirect addres-

- thus minimising the need to change Admittedly relatively small volumes ses. There is a more complicated

magnetic cards for slightly altered of data can be stored at a time, but approach available, using the pseudo -Op.

requirements) it was possible to use this even so there is enough to allow a full code HIR. This utilises the eight "pend-

machine in a commercial context. set of analysed company accounts. The ing result" registers, not normally avail-

There are drawbacks. For example technique is to print and annotate able to the user except by inference

the 20 column printout is a little narrow automatically every cash book entry, when using nested parentheses. The

for traditional layout, and while the giving a clear audit trail and hard copy great advantage in using them in the printing rate of about two lines per of the input. This can be organised to Code Splitter and similar programs is

second free running is acceptable, the segregate Capital and Revenue and Dr that precious data registers are not sacri-

data transfer rate round logic loops and Cr in batches of register locations. ficed in the splitting up process, and

and into the four print registers is slow, Program No. 1 carries out the trial may be utilised for the safe storage of

and complex programs can be frustrat- balance with full annotation; with the working data. However, be warned!

ing. There are ways of speeding up loops data still intact a second program is There are many pitfalls in using these

by using direct addressing, but this is only to be recommended after you are

overlaid from another magnetic card to produce the Profit and Loss A/C in more

pseudo-ops., which is probably why they have not been included in the stan-

certain that no further changes will be or less standard format, and yet another dard manual; however, used with care

required to the program and where program is overlaid on this data to give they increase the capability of this great

there is plenty of spare space. Another the Balance sheet. For presentation little machine even further.

trick is to use any spare data registers purposes a matching set of descriptive Another word of warning. If this

for print code instruction storage, thus headings may be preserved on another machine, or similar magnetic card

releasing program space for logic magnetic card to suit the user's needs. readers, are to be used more generally

instructions. There's no doubt that The whole set can be put together and in industry, commerce, and schools

commercial type programs use enormous Xeroxed for filing etc. It looks almost (as their price level warrants) care

memory space for text, but in spite of traditional!

must also be taken to ensure that the

these limitations I have been able to One of the side benefits of the card reading mechanisms of different

apply this machine to a wide variety of wider use of the TI59 has been the machines which have to share families

office and factory applications.
One of the first of these was my

development of some "utility" programs which might be of general use.

of magnetic cards are matched. I have occasionally needed to adjust the card

own (self-employed) accounts, incor- One is what I have called "Auto -Folio". feed speed of a satellite machine to

porating all the requirements for VAT This enables any value to be keyed match the one which originally wrote

and the Inland Revenue, apportionments in, along with its destination regis- the program on to the card. This is not

etc. Of course the program had to be ter number. Upon entry the value Continued on P. 127

106 PCW

Code Splitter

Sample Output

000 76 LBL 1234.56. 78

001 11 A

12.

007 99 PR T

34.

002: 42 STO

004 04 04

005 59 INT

00A 48 EXr 007 0 4 04-

OOR

I NV

0 0 8 59 I NT 010 A5 x

78. 4. 05
IJ.
4.

011 01 1

012 130 II

AUTO FOLIO

01:::
014 015 OiA 017 018 019 020 021
072. 072:
024 075 026 077
029
0311 0:::1
02:7
O. }
02:4 02:5
036
OR7
ORR
02:9
040
041 042 042: 044 045 04A 047 04R 049
05 Ci
051 052
052:
054 055 05A 057 05R
0II5I9I
0A 1
LI b
OAR
0A4

00 0
95 = 48 EXC 04 04

01 1 00 0
00 0

95 =
42 S TO

119
59 I 1:1-1 48 EXC

132:

c12:

22 INV 59 I NT

01 1

00 0

0 0 II

=

4:3 EXC

I I'2

CI 3

ill 1
IIII 0
0 0 Ii

95 42 STO 07 07

INV
C I NT
A5 x

01 1 00 0

1111

0

95 =

48 EXC

07' 02 59 INT

42 STO

01 01 PPT

4:3 R 0 L
07 irk

99 F'RT

4:3 RCL

02: OR

99 PRT

RCL

04 04

99 PPT

11 r,5 98 AD"/
06A 9R AD'./

CI r,7 9R ADV
CIAR 91 R/S 0A9 00 0
Press A to enter data.

Press B to list and clear

000 001 002
!DOR
0[714
1111
II Ire
007 00R 009
010 011
0 12 017: 014 015 016 017 01R
01.9
0";.0
021 02 022:
024 075 026
1-177
07R 079., 02:0
02:1
0:34
035
0
Cl :7: 7
ORR
11 :7:9
040 041 042
04:3
044 045
0145
047
4
049
0 0
051 052.. 05R
054 055
057 05R 059 OA°

76 LBL

LNX

65

01 1
00 II
00 II

95

R7 HIP

217 32

R2 HIP.

12 12

A9 OP 04 04

INV RA STF

01 01

82 HIP

15 15

A9 OP 06 ois.

74 SM*

00 00

91 R/S

76 LBL

CLR
R5 +

0 R

95 =

Ril7l

IFF
Ill

23 LNX

AR NOP

82 HIP 02 02.

7A LBL

34 TX

RA STF

01 01

R2 HIP

r1q4

14 INT

61 GTO

24 CE AR HOP

7A LBL

11 A

82 HIP. 05 115

91 R/S

42 STO 00 00

01 1 Ci 0 II
95 HIP
04 04 INV
59 INT 65

061 110

062 95

OAR 0A4 065
or.A.
0 7
0A 069

7A LBL 24 CE 82 HIP
CI_: II_' 137 7
T

070 071 070
0173
074 075
1376
077
1378
079 ORO OR1
01 _,0
07.:
OR4 OR5
RA
OR7
R
0P9 090 091 092
0198
094 095 096 097
09:::1

13 13 -- GE
CLR AR NOP
01 1
95 = 07 IFF
131 01
LNX AR NOP 82 HIP 00 00 61 GTO 34 FX 62 NOP 7A LBL
12 B
9P. A py-
9P. AD",. 01 1
INV
90 LST 9R ADV 9R ADV 98 ADV 47 CMS 91 R/S 00 0

Press A to enter data.

Press R/S to enter address

DR. PLAYGOOD
FOR PET, APPLE, TRS-80

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Send to: Mkrotrend Ltd.,
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PCW Harrogate, North Yorkshire HG3 5DP

PCW 107

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108 PCW

SOMEBODY'S GOING TO BE SORRY
Your business is not exactly the same as any other and neither are its problems. Any solutions are probably unique and must be tailored exactly for you.

You know your business better than anyone else and any system designed should use your knowledge. The
micro -computer specialist should show you how to use the computer to meet your business requirements.

You should be able to get the micro -computer which best suits your business. It should be chosen after your
requirements are specified.

You and your staff have a right to know all about YOUR system, including helping to program it if you want to. Training is your right - not an additional service.

If microcomputers cannot satisfy your business needs, you want to know - you don't want false promises.

67 Nova Road, Croydon, Surrey CR0 2TN.

Telephone: 01-688 6013

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PCW 109

INTERRUPT
From one of our regular contributors, a slightly jaundiced look at how governments attempt to reach their infinitely wise decisions; plus, a warning from Ted Cluff, Secretary -General of the IDPM, on the danger to companies of allowing the uncontrolled acquisition of micros.

Too much monkey business
Here is an idea to while away the dark hours before World War III (if it hasn't
already begun by the time this is
published). The object of the game is simple and
is well-known to those who drift around the corridors of power. Starting with a
hot -potato -issue like "What is to be
done about Britain's industrial decline?"
ti KNOW-ALL
C 0 4/ J04, 6'

each player aims to spend as much time as possible studying the issues to produce answers that are as self-evident as possible but which get the maximum amount of mashed media coverage. I call it the Infinite Wise Monkey game based on that well-known theory that an infinite number of monkeys banging away at an infinite number of
typewriters for an infinite time will produce all the works of Shakespeare, Tom Sharpe and Saatchi and Saatchi.
Make those monkeys wise and you have commissions galore.
In true modern socio-psychopseudary style, Wise Monkeys is a role playing game - of the "imagine you are king for
a day, so how many palaces can you
build with a Lego Kit" ilk. Each player in Wise Monkey chooses
a role. Those of a civil service bent can select an obscure sounding but
pronouncable acronym, say ACARD, and then suggest it stands for something as modern but uncontroversial as Advisory Council for Applied Research
and Development. Such players are represented by a Prime Minister's Ear to which they have access via Cabinet Office connections. They are also supplied with special Working Party cards which they can shuffle about to create confusion amongst onlookers. These players start with the media handicap of complete facelessness.
More ego-tripping players can take the role of the Big Name in the Big Name Commission, as in the Longford Commission on porno or the Finniston Commission on engineers. These players start off with extra media "high personal profile cards", although they can be trumped by the political "change of government" joker which invalidates all their results if there is new government installed by the time the
report is made - or if the new
government was elected on a manifesto totally opposed to your conclusions (as in a recent Labour -initiated study of the National Health Service). On the other hand, this political joker can turn to your Big Name advantage if, as with Sir Monty Finniston's commission on engineers, the incoming government decides to take the glory for the last lot's initiative.
Although Wise Monkeys is a game for
a large, if not an infinite number of
players, some exclusivity must be
maintained to separate the know-alls

and think -we -knows from the honest don't -knows. So, in addition to playing at Government Working Party or Big Name Commission, those taking part can become Consultants and Pundits.
Being a Pundit is a bit like being a banker at Monopoly - you are the focus of attention, your power over
pretend (or pretentious) resources gives you status, and you can become involved with the activities of all the other players - the unscrupulous can pocket fortunes under false pretences.
Points in Wise Monkey are awarded
for time taken to investigate, study, research and think about the subject, and its resultant media coverage, etc, etc. But the crucial point which must
be reached by each player eventually is the Magic Answer to complete that well known phrase "The reason for Britain's decline is
An exciting feature of the game is that ratings vary with time. For example, during the early part of 1979, top points were given for those best sellers "failure to adapt to the microelectronics revolution' and "too much government interference". However, in the 1980s, with the public still awash with the media Chip Crap, that culminated in the Chip joining Neasden, Talbot and Situations amongst Private Eye's Galaxy of Cliches, any reference
to microelectronics in the Magic Answer now leads to the award of two -yawn backsteps while an answer on the lines of "Government's failure to direct/
stimulate . . ." could result in a swift budget cutback and an "Do Not Pass Go, Do Not Collect Your Department of Industry £2,000 Consultancy". And as the "too much government" thesis begins to wear threadbare, you get more points by blaming "the people" for failing to swallow their nasty medicine.
For advanced students of Wise Monkeys, the (real) ACARD and Finniston reports provide some interesting insights into shrewd game plays. Way back in early 1978, Jim Callaghan thrust the mantle of glory on to ACARD (which then - as now-
was little known). He set up three
ACARD working parties; one looked at the industrial and business impact of semiconductors; another at innovation in small businesses and the third at the social impact of technology.
Since then, the Working Party cards have been played with sheer mastery.

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2.1
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0
0. 110 PCW

Pip'
4,0 s, 12

INTERRUPT

The semiconductor study, rudely reach a Magic Answer that was

stimulated by the Horizon Chips film, perceptive and original enough to have

seemed to break all the rules of Wise practical meaning. In 1977, for

Monkeys - it took months not years to example, Iann Barron at a conference
do the study and was acted upon organised by a British Computer

immediately, with the setting up of Society group and Computer

various Department of Industry micro Weekly gave a paper which succintly

awareness and support schemes backed analysed the impact of Information

by millions of pounds.

Technology and laid out a clear

The once eagerly awaited small national strategy to deal with it; given

business innovation report was silently the will, the power and the insight,

slipped out by the social impact study, Barron's plan could have been put

after running the whole gamut of to effective use in helping Britain get

rumours about arguments, suppression, ahead in Information Technology.

delays because the chairman broke a The infinite Monkeys thesis, says the

leg, etc. It received many points for the spoil -sport, forgets or obscures the

time it was dragged out, eventually simplicity of one person at one

appearing so late in the day that everyone typewriter producing works of

had forgotten about it.

originality and value. And as American

The Finniston report, however, comedian Bob Newhart pointed out on

achieved even dizzier heights of one of his records, when somebody

successful play. It managed to take a watching one of the infinite monkeys

couple of years to discover the same banging away at a keyboard eventually

thing that has been found out by other finds something of interest, his report

studies in the last 100 years - that might go along the lines of . . . "Hey,

British society, led by the Oxbridge/ we've really got something with this

Public School intellectual ethos has monkey . . . he's typing ..TO BE . .

failed to give engineers/technologists
the status and pay they deserve. The Finniston Commission scored heavily for producing a weighty document to

yeh . . . OR NOT . . . go on boy .. . TO BE, THAT IS THE KRIPST*"DT . "
Malcolm Peltu

A question of support its self-evident thesis. There was also a nice end -game ploy.
boundaries For months (it seemed like years)
before the report was published in

January, details of the main conclusions
were published in the press - for To keep one's feet on the ground whilst

example in New Scientist. Yet when measuring one's ability to reach up to

Sir Keith Joseph was interviewed on the new levels - that is the problem. Such a

day of official publication, he accepted surfeit of superlatives has been used in

the "urgency" of acting on it but said he the popular press about micros, lay

had not had a chance to study it yet and people can almost be forgiven for

needed time for more consultations believing that problems fly out of the

before announcing a response. Doesn't window having merely made a decision

he read the press, or get his minions to acquire one. The first myth we have

to read it for him? And why wait for to dissipate is that a microcomputer can

yet more consultations after such a organise data input by a disorganised

thorough study? Answers to these person.

questions get no points at all.

I don't know whether it's the micro

Wise Monkeys, like most games, vendors or the press who are the more

can be ruined by spoil -sports. They to blame for the misconceptions

point out that the Wise Monkeys, like surrounding the new technology's

the Emperor, have no clothes to cover undoubted benefits, but perhaps the

their nakedness and they suggest that message is getting through. One week

one reasonably intelligent, unbiased before the Department of Employment

person, given a month of quiet produced a report saying that "micros

research, could come up with similar will cause fewer job losses than feared"

conclusions. And a particularly a one -day seminar I had hoped to attend

intelligent person, with experience of on the social implication of micros was

the subject and imagination could cancelled due to lack of support.

ugz
-1,--V7I6A4/ZVALI
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zZ 0 iyANor

Presumably no one believes anything is going to happen.
I am on record as being opposed to the marketing of micros as small business systems with very low cost software which cannot possibly be supported and hardly ever has the back-up needed to cater for the inevitable changes in business requirements resulting from growth or legislation. Every day brings more evidence that this warning is necessary if small businesses are not to be jeopardised by their unjustified faith in the efficacy of a system acquired at a much lower price than that charged by houses equipped with the resources to provide the necessary back-up.
There is, however, yet another key area where micros are being oversold although not necessarily by the vendors. I refer to companies who already have centralised dp installations, some of which have problems of understaffing, or other causes of user dissatisfaction. The view is now widespread that users can achieve Nirvana merely by sneaking a micro in the backdoor without consulting the dp manager; superficially this may even be true.
Continued on Page 125
9

*

//

PCW 111

TIRAINAM

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SN74LSOON 22 SN741554N 21 SNI4LS138N 95 SN74LS195AN 15 SN7415325N 2.55 SN74LSO1N 22 SN74LS55N 21 SN741S139N 95 904151965 120 557415326N 2.55
5N741.502N 26 SN741S636 1.50 5A174L5145N 120 SP/1415197N 1.20 SN741S327N 2.55 SN74LSO3N 26 SN741573N 35 SN74LS148N 1.75 5614152216 125 597411352N 1.35 S674L5045 26 5N741.S74N 40 SA174LS151N 85 5N741.S240N 220 54174153535 1,50 56741.505N 26 SN741S75N 48 SN7411153N 60 SA1741524IN 110 SN7415365N 65 S57411086 20 SN74LS76N 35 SN741S154N 110 S11741.52426 1.90 SN74LS366N 55 5N741S09N 22 SN74LS78N 35 SN7415155N 125 567415243N 195 557415367N 65 567415106 18 S5141.58309 1.15 551741515651 125 56741.52446 2.10 SN74LS368N 65 SN74LSI1N 26 SN74LS85N 1.10 SN741S157N 60 5574152455 3.80 SN74L5373N 1.75 S574L5I 2N 25 5N74L58611 40 51174151581k 99 SN7411247N 125 SN74LS374N 1.70 9174L51 3N 55 SN74L590N 65 SN741S160N 1.15 SN7415248N 195 55746315N 72 557405145 89 SN74LS9IN 99 SN7411161N 1.15 5N741S2495 1.30 SN7415317N 1.75 511741S155 25 56741592N 90 SN74L51625 1.15 SN741.5251N 1.45 S61141.5378N 112 S674152011 20 SN74LS938N 65 S574L5163N 90 SN14LS253N 125 56174153795 1.10 SN741521N 26 56174L595AN 120 SN74LS164N 1.50 5N741.5257N 119 SN74LS381N 3.65
SN74LS22N 26 SN7415966 1.75 S117415165N 1.70 5574152585 95 557415386N 57 SN741526N 29 SN74LS107N 39 SN741S166N 1.75 S11741S25911 115 SN746390N 1.98 SN74152714 35 S11741510911 39 SN74151 68N. 195 SN741526011 39 557411393N 1.50 SN741S28N 35 S1174151125 39 SN74LS169N 195 SN74LS26 I N 3.50 557415395N 190 567415306 25 SN74LS113N 44 S1174L5170N 2.60 SN741.5266N 39 56174153966 1.70 5514153211 21 SN74LS114N 44 SN741517311 220 5074112735 195 SP4141S398N 2.15 SN741S33N 39 SN74151226 79 SN741517411 1.15 507415279N 79 SP1141S399N 1.60 5574L5375 29 S11741512311 90 SN74LS175N 105 5N741S2805 1.75 51174154245 4.50 51174L53861 29 917415124N 1.50 9114151815 2.15 SN7415283N 110 SN7415445N 125 5N74L5405 25 SN74151255 65 S11741.51905 1.75 5H74LS2905 110 557415447N 125 SN74LS42N 79 5717415126N 65 SN74151915 1.75 S11141S2935 110 SN741S490N 115 SN74LS47N 95 S5741513211 75 5074151921k 145 557415295M 220 SN741.5668N 95 SN74LS48N 95 SN74LS133N 39 SN74LS193N 1.75 SN7415298N 220 5674156695 95 157415495 1119 S574LS1365 40 SN74151944N 119 SN741132481 LSD SN741S67011 2.70

SUPPORT

8212

210

8216

2.80

8224

210

38531181 10.00

8228

4.20

87264

1.75

1.90

6522

8.75

8251

5.00

8253

11.00

8255

5.00

8257 fl 1 00

8259

12.50

8155

12.50

6402

600

6821P

4.50

6850P

4.80

6852P

650

AS .5 2376 11.50

MC14411 12.00

M57109 1243

M57160 10.00

M57161 1000

TMS6011 5.00

81L595

1.80

81L596

110

811597

1.80

811198

110

RAMS

2101

132

21021 4

120

2111

2.32

2112

216

6810

1.00

8154

1160

21141450 510

21141250 790

74C920 11.00

74C921

11.00

740929 11.00

4027

5.00

4044

7.00

4045

7.00

4060

700

2107

710

41161581ot 8110

4118

20.00

280P10

11.00

Z80CTC

8.00

2804P10 150 ZBOACTC /50

(PROMS

1702

5.00

5204

5.00

2708

8.00

2516

2100

2532

50.00

C p/M AVAILABLE NOW FOR
TRITON Disc operating system complete with teat editor,
assembler, debugger, system utilities and complete file management. Makes Triton hilly CP/M compatible and able to run CP/M based software. Triton will support up to
four 51 or 8" drives single or double density full CP/M
software user group facilities available. SAE for details.
CP/M Disk + manuals (6) £75.00

DISK DRIVES & POWER SUPPLIES

SHUGART

SA400 5'" drive SA800 8' drive
Power one quality power supplies CP249 1 5 PSU
CP3 2 3 2 5 PSU CP205 1 8" PSU CP206 2 . 8" PSU

£205.00 £380.00
£33.00 £60.00 £56.00 £76.00

TCL PASCAL CP/M compatible
A standard Pascal compiler available on a resident (20k) Eprom based configuration or available to run under CP/M on 8" disc plus documentation. CP/M version £120.00 .e.o.A.
TCL Pascal Manual and Specification £6.50

D1L PLUG SOCKETS & SWITCHES

W/WRAP SKIS

BOIL

0.20

14011

0.35

16011.

042

18011

0.60

24611

0.52

28011

0.74

40011

0.95

OIL SATS 8011 14011 16011 18011 20011 24011 2801L 4801L

0.14. 0.15 017 0.24 0.27 0.30 0.36 0.50

OIL PLUGS

14010

0.60

16011

015

SCOTCHFLEX

14011

110

16011

110

24011

210

Ell I. SWITCHES

4011

120

7011

1.15

NIL

110

16w ZIF 4.95

24w ZIF* 8.20

ZERO INSERTION FORCE

DOUBLE DENSITY S100 DISK CONTROLLER
Suitable for Triton,
DPS-1 etc. Built and tested will drive Shugart compatible 8" or 514". Drives single or double sided. Uses the 1791 chip and CPU independent crystal. Manual 50p + SAE. BOARD £195.00 + VAT

DPS.1 MAINFRAME - PASCAL SYSTEM

S100 to IEEE spec

ITHACA

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Send 50p for our ITHACA catalogue

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Complete system. £2,910.00

8k Static RAM board 145Ons)
8k Static RAM board 125Ons1
280 cpu board 12MH0/ 280 cpu board 14MH t) 2708/27 16 EPROM board Prototype board (bare board/ Video display board 164 0 16, 128U/L Ascu) Disc controller board K2 disc operating system
ASSEMBLE/2 Macro Aurn PASCA L.12 compile, PASCAL/2 CP/M 16k Static RAM

E99.00
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£57.00 EISA°
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DOUBLE DENSITY CP/M NOW AVAILABLE - CONTACT US FOR DETAILS

MULTIWAY CONNECTORS

INSULATION PIERCING

20 way plug

2.30

26 way plug

2.70

34 way plug

3.30

50 way plug

4.80

20 way ski

3.10

26 way ski

4.00

34 way ski

4.80

30 way skt

6.00

EOGE CONN PCB
GOLD .1" PITCH 22/44 25/50 28/56 30/60

3.20 3.60 3,90 4.15

35/70 36/72 40/80 43/86 50/100
GOLD 158 PITCH 6/12 10/20
12/24 15/30 18/36 22/40 28/56 36/72 43/86

110 44111 .14,7,11"
1.74
5.00 650 510

1.25

1.50

200

220

2.30

185

3.30

3.90

4.84 64 way DIN male

2.60

64 way DIN female 410

VISIT OUR SHOWROOM
WE ALSO STOCK a comprehensive range of books and magazines, VERO products including S100 and Eurocard and Wire Wrap equipment, Weller soldering equipment, Ribbon Cables, tools, tapes, diskettes, connectors and OK Tool range.
Systems continuously on display in our showroom.

CRYSTALS 100k 200k 1MHz 1008k 1843k 2MHz 2457k 3276k

3.00 330 3.60 3.50
3.00 1.50 305 2.70

4MHz

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2.70

6MHz

2.70

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2.70

7168M

2.50

8MHz

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18138501 80804 6809 Z80 Z804 8085A 6502 SCMP11 6802

9.50 6.33
24.00 8.00 15.00 1215 810 1000
13.85

ALL PRICES
Exclude VAT & P/P
VAT 15% P. & P 40p on small orders
IFor larger items please Tel. Telephone credit card orders accepted subject to f 5 min. I RAPID MAIL ORDER SERVICE

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VISIT OUR SHOWROOM SOON 9.30-5.30 Mon -Fri 1.30-2.30 closed lunch 9.30-5.00 Sat Thursday half day 1.30

1 I vat to

Tel: 01-402 8137 Telex: 444898

112 PCW

YOUNG COMPUTER WORLD
There's a new name at the top of the page this month. For personal reasons John Coll has decided to stand down (although, happily, he has promised his continued part-time support); stepping into his shoes we welcome Derrick Daines.

Thanks
Those of us who know John Coll are aware of the tremendous pioneering work he has put in over the years to lift
computer education off the ground in all sorts of ways. Thousands of youngsters were first introduced to the computer by John and Charles Sweeten, and many of them have grown up to join the computer industry. There must be quite a number of successful young business men in computing today who owe a lot to John's inspiration. He is quite a guy to follow and I just hope that I will be able to do nearly as well. In taking over
from him, I must say that I find it a comfort to know that he is only as far
away as the nearest telephone. Thanks,
John - and keep taking the tablets!
Installations
Once I had agreed to join YCW (and the editor had taken his foot off my neck), one of the things that he gave me to look at was the report from Mr. Hemmings about the mother -and -daughter computer system they've got running in Sandbach High School. It looks a great idea to me and neatly solves several problems
at once. Look out for a report next
month.
The installation is a real step up with the added advantage that there's
little necessity for hardware uniformity. In theory at least, any micro could talk to any other, with software taking care of translation problems. This thought brings in its train a whole lot of other questions that I would like your views on. For instance, given a certain amount of cash to spend on school computing and Heaven knows, there 's little of it would it be better to have three or four identical microcomputers, the same number of different kinds of computer, or one large machine? With recent new hardware and price reductions, more and more schools will be in the happy position of making this sort of decision; I'd like to hear, not only from young readers, but also their teachers, many of whom will be trying to make up their minds on this very point.
Competition
Would you like a badge or tee-shirt that
tells those in the know that you're a computer freak? I'm sure that many would. Well, here's your chance. I'm
after designs for a YCW logo and I'll give book tokens for the best. The winning design will appear monthly at the top of
this page and we'll get somebody to make us a supply of metal badges for sale at cost - hopefully tee-shirts, too. Just think, your design could be the one
that everybody's wearing! I don't much mind what you put in
your design, but it should convey something of what it's all about - computing
- and, of course, it must look good. Don't worry too much if your artwork
is poor - we've got some tame artists on
the staff who can tidy it up. Oh, and

since metal badges are usually circular, I suppose your logo design ought to be circular, too. Get doodling - I'll close the competition in a couple of months,
Him -um -her
You'll probably notice in my writing that I tend to assume my readers to be "hims", whereas they could just as well be "hers". It's YOUR fault, girls; you don't write in! Are there any girls out there? I want to hear from you, too! I
know girls ARE interested in computing - I see them in their hundreds, tapping away at consoles all round the country
- but they never get in touch. Now
that's a pity because I just don't believe that good ideas spring only from boys' minds; girls are just as clever. Perhaps they'll prove it in our competition.
Programs
Keep 'em rolling in! We'll give book tokens for all small programs published in connection with this page and super ones will qualify for publication at nor-
mal rates - which can't be bad. Of
course, we don't undertake to publish all those that we receive, but we'll do our best.
An example of this policy at work is this month's teleprinter/printer con-
version article by Tim Steele. Tim is only

16 and a pupil at Solihull School. He originally submitted his article to this page, but it's so good that it deserves a wider audience; so it gets "the treatment" and Tim gets a fat cheque. Well
done, Tim! Another program deserving of a wider
audience was sent in by D.J. Danziger of Manchester Grammar School. This is a BASIC renumber package running to five
pages - representing an awful lot of work by its author. We're having it rewritten in the more common Microsoft
BASIC so that more of you will be able to use it when it's published.
PROGRAMS RECEIVED SNAP - by Paul Bowden of Truro (11) BASE CONVERSION - by Jonathan
Roberts of Ilford (15) WORD PROCESSOR - by Tony Hailes
of Camberley (15) EQUATION PROGRAM, GAMBLING
- by Mark Taylor of Leeds (15) MAZE GAME - by A Stirges of
Wolverhampton (15) ALIEN INVADERS - by T Carter of
London (17) NUMBER GUESSING, MEMORY
CLEARER - by Richard Powell of Coventry (13) Thanks a bunch to all of you! Take a look at the program listings to see which the editor has managed to get in this
issue!

SIMPLE WORD PROCESSOR - by Tony Hailes
10 CLEAR4500 11 PRINTTAB(10):"SIMPLE WORD PROCESSER"
12 PHINT 15 DimAvinn) 16 FORA-1135:READA1:NEXT 17 FORAm0T014 19 READAI
20 FOKEA,A1 21 NEXTA 25 DATA76.80.65.70.57 27 DATA245.253,126,61,246.128,253.119.69,211.254.241,195,18.224 45 PHINT"TYPE IN YOUR TEXT, EACH LINE STARTING WITH A ":CHR$(34)

46 PHINT-AT THE END OF EACH LINE. PRESS RETURN." 47 PRINT -WHEN YOU HAVE FINISHED. TYPE LENDJ 50 N=N+1
60 INPUTA$(N) 80 IF ACN)<5.-LENDJ-THEN50 85 N -N-1 90 PRINT:PRINT:PRINT 100 PRINT -YOUR LETTER 110 PRINT 115 PRINT -LINE" 120 FORA.1TON 130 PRINTA;CHR$(34);A$(A) 140 NEXTA 150 PRINT 160 PRINT"

161 PRINT

165 IFB.1THEN240

170 PRINT:PRINT'EJITING."

180 PRINT"COMMANDS:"

190 PRINT:PRINT-LIST - TO LIST LETTER"

200 PRINT"PRINT - TO PRINT LETTER ON PRINTER"

210 PRINT"ctINE NUMBER> - TO CHANGE THAT LINE"

211 PRINT" -<LINE NUMBER> - TO DELETE THAT LINE"

212 PRINT"(LINE NUMBER>+0.5 - TO INSERT A LINE"

213 PRINT"ADO - TO ADO LINES ONTO THE END"

214 PRINT"FIND - FINDS ANY SEARCH STRING IN THE TEXT"

215 PRINT"CHANGE - TO INSERT OR DELETE ANYTHING IN ONE LINE" 220 PRINT

230 Elm1

240 INPUT"COMMAND":A$ 250 AmVAL(A$)

Program Cont. on Page 126

PCW 113

CPoemrsopnaul ter World
FEATURE INDEX
Index to current volume, up to, and including, last month. (Previous volumes were indexed in March and April 1980
issues).

Hardware Projects

Sound to colour

280 Homebrew

3-1 conversion

3-3

Selective PROM copier 3-3 American report

3-3

TV to Monitor

Simple approach to

conversion

3-3 programming

3-3

MK -14 Expansion

3-4 Communication aid for

Benchtest Evaluations

disabled

3-4

Luxor ABC 80

3-1 Imphex - intelligent

WH 89

3-2 game PET

3-4

ACT System 800 Panasonic JD 700U Sinclair ZX-80

3-2 House of Commons

3-3
34

report

3-4

Package evaluations (systems)

Challenger C2 4P

3-4 Sales Ledger

3-1

Series

Purchase Ledger

3-2

PASCAL

3-1,2,3,4 Payroll

3-3

David Levy's

Word Processing

3-4

games

3-1,2,3,4 Indexes

On the line

3-1,2,3 Back Issues 1-1 to 2-4 3-2,3

Viewdata

3-4 Back Issues 2-5 to 2-8 3-4

Fact Sheets (Fax)

Programs

6800 opcodes

3-1 BASIC Star Wars

3-1

6502 opcodes

3-2 PET Alien Attack

3-1

Personal Opinion (Interrupt) Revas (conclusion) Reverse

The end of work? Lord

assembler for Z80

3-1

Avebury

3-1 Planet name generator

Protest against technological - 6800

3-1

determinism

3-3 Naming Nascom files

3-2

Who needs the CRA? 3-4 380Z Pictures

3-2

Schools computing -

Fuel tank calculations -

David Firnberg

3-4 PET

3-2

Evaluations (Checkout)

PET large numeral

Video Genie

3-2 generator

3-2

Vector Graphic

PET tank battle

3-2

Flashwriter II

3-2 BASIC string handling

Apple II Symtec light pen 3-3 routines

3-2

Calculator Corner

MK -14 scrolled messages 3-3

TI 58/9 Pseudo opcodes 3-1 6800 Keyword retrieval

Casio Fx 502P Brag

3-1 system

3-3

Casio Fx 501/2P Master

PET Kaleidoscope

3-3

Pack

3-2 Efficient character storage

TI 58/9 Economics Simulations. . . . .
Programming efficiency Casio random number
generator HP 41C review

Z80 Assembler

3-3

3-2 3-3

UK101 Dodgems TRS-80 Fox and hounds

3-4 3-4

3-3 3-4

MZ 80K Sine wave addition

3-4

Special Features

Computer Retailers'

Association

3-1

Christopher Evans tribute 3-1

Show chess results

3-1

The British Computer

Society

3-2

Astrology - case study 3-2

IEEE -488 bus explained 3-2

Economic simulation 3-3

r PLEASE NOTE THAT THE FOLLOWING

ISSUES ARE

SOLD OUT

VOLUME 1 Nos. 4, 5, 6, 7, 9, 11, 12

VOLUME 2 Nos. 5, 6

C'pegr at r World

BACK NUMBERS

THINK OF THE FUTURE -LOOK BACKWARDS!

PCW has long been regarded as by far the most authoritative journal in its field. Every issue published has contained a wealth of detailed technical information on all aspects of the rapidly growing Personal Computer Market. Demand for our limited stock of back numbers has also become something of a rapid growth industry! Consequently, early back numbers of PCW are going to be increasingly difficult to get hold of, so make absolutely certain of getting yours by checking the coupon at the foot of the page.

Volume 1 No. 1 May 1978 Nascom 1/77-68: The Mighty Micromite/A charity system Volume 1 No. 2 June 1978 Research Machines 380Z/ Computer in the classroom/ The Europa Bus. Volume 1 No. 3 July 1978 Buzzwords -A to Z of computer terms/Pattern recognition/Micro music

Volume 2 No. 4 August 1979 The North Star Horizon/High Speed Cassette Interface for the SWTP 6800/Garage Accounting program/Apple Medical Application.
Volume 2 No. 7 November 1979 PCW Show issue/6800 Bug/Hard disc security/ Detecting literary forgeries/ Benchtest - the Challenger
C3

Volume 1 No. 8 December 1978 Computers and Art/3-D Noughts and Crosses/Mickie - the interviewing micro.

Volume 2 No. 8 December 1979 Micro -controlled toys/ 'NASCOM - words and music/Systems - stock con-

Volume 1 No. 10 February 1979 Review - the Attache/ Word on word processing/ Micro assembler for the 6800/Sinclair to MPU interface/Draw pictures, written

trol/Benchtest - the Micromation Z -Plus. Volume 3 No.1 January 1980 CRA aims/Benchtest ABC 80 /Homebrew Z80/Computer Games - Series

in Tandy Level II

Volume 3 No. 2 February

Volume 2 No. 1 May 1979 1980 Benchtests - ACT 800,

Small computers for small WH89/Micro Astrology/

organisations/Sorcerer graph- Checkout - Video Genie/

ics/Chess Programming Hints/ IEEE -488 analysed.

Parkinsons Revas.

Volume 3 No.3 March 1980

Volume 2 No. 2 June 1979 Benchtest - Panasonic JD-

MSI 6800 /Witbit - disassem- 700U/Checkout - Symtec

ble your programs/The Multi- Light Pen/Introduction to

lingual Machine /Polytechnical programming/TV to Monitor

Processing.

Conversion.

Volume 2 No. 3 July 1979 Volume 3 No. 4 April 1980

Vision link : Interfacing and Benchtests: Sinclair ZX80

Software for the Superscamp VDU/Pet Preening/Extended cursor graphics for the TRS-

and Challenger C2-4P/Viewdata - Part 1/Mk-14 Expansion/Word Processing

80.

Packages/

I Any one issue 95p; Any two issues £1.75; Any three

NMI

issues £2.50; Any four issues £3.00. All additional issues

@ 50p each. Binders @ £2.95. All prices include post and

packing. Cheque or P.O. payable to (PCW) Sportscene Pub-

lishers Ltd., 14 Rathbone Place, London W1P 1DE. Please

allow up to 3 weeks for delivery and don't forget to state

clearly your name and full address with your order.

Please send me the following copies of PCW. I enclose a

cheque/P.O. for £

Volume 1

Volume 2

Volume 3

E1 ID2 E3IC8 I 010111112 113 D4EE7 C8IC1IE2113104

Name Address

ALL OTHER ISSUES MAY BE

ORDERED USING THIS FORM.

*Tick appropriate boxes

a
111PCW

THE INTE 5N Ip Et
3 IfT1plJTENlf1f11

London
48 Tottenham Court Road London W185 4TD Tel. 01-6360647
Ilford
426/428 Cran brook Road, Gants Hill, Ilford, Essex 1G2 6HW Tel. 01-554 2177

Birmingham
94-96 Hurst Street Birmingham B5 4TD Tel. 021-622 7149 Telex. 336186
Manchester
11 Gateway House Piccadilly Station Approach Manchester Tel. 061-236 4737 Telex. 666168

Nottingham
92a Upper Parliament Street Nottingham NG1 6LF Tel. 0602 40576 Telex. 377389
Glasgow
Magnet House Waterloo Street Glasgow Tel. 041-221 7409 Telex. 779263

Your six main computer centres, stocked up with new equipment for 1980. Complete systems carefully chosen for their reliability and availability. Plus the widest range of software for business, education and industry. For expert advice on which system suits you best call into one of the Big Six.

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PCW 115

Introducing the

PE/11 -COLLECTION

- isommans

...
\

A

suite of powerful business programs budget price from ACT Petsoft, the

at

a

professional software specialists!

ACT SALES

LEDGER £120

Commodore Disk £95 Cassette version

Full facilities for the maintenance of the Sales Ledger, the

preparation of a list of outstanding balances and printing of

statements. All data including new customer details, invoices,

credits, cash and transfers are entered under step by step guidance on the display screen. Printed results include Audit

List, Aged Debtors List, Control Account and Statement.

For 32K

Wits,

Both Sales Ledger and

t

ec2

Purchase

Ledger are

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ctEft

56)

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PURCHASE

LEDGER £120

Commodore Disk £95 Cassette version

Full facilities for maintenance of the Purchase Ledger, the preparation of a list of outstanding balances and printing of remittance advices. The system produces the following

printed results: Audit List, Aged Creditors List, Control

Accounts, Purchase Ledger Record, Remittance Advice,

Cheques and Payment List.

For 32K PETs

INVOICING WITH STOCK £75
A powerful, easy -to -use system for the CompuThink Disk, handling 1200 or 2400 stock items per diskette.
PAYROLL 200 £50
For up to 200 employees, on disk or cassette.
WORDCRAFT £325
The ultimate PET Word Processor, now on CompuThink Disk.
... and over 200 more business programs, games and programming aids in the NEW
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116 PCW

oft rIPTEel S

Ih1s4s9z:.s.

IN STORE

Britain's most up-to-date and comprehensive guide to the selection of microcomputer equipment, compiled for PCW by Richard Olney of Heuristic Consultants.

Machine (Price from)

Main Distributor , (No. of Dealers)

Hardware

Software

Miscellaneous (Documentation)

ABC 80 (£790)
Act System 800 (£3950) Alpha Micro (£8,200) Altos ACS 8000 (£3,398) Apple II (£695) Athena 8285 (£7955)
Atom (£120) Attache (17,000) Billings BC-12FD (14,295)

CCS Microsales: 01444 7739 (TBA)
ACT: 021-455 8585 (50) Alpha Micro (UK) Ltd 01-250 1616 (TBA) Logitek: 02572 66803 (TBA) Microsense: 0442 41191 (190) B07u0te3l-3C9o8m90co(TLBtdA: )
Acorn: 0223 312772 (N/A) R.H.Thorpe Ltd: 0276 29492. R.J.Spiers Ltd: 0603 416573 (TBA) Mitech: 04862 23131 (TBA)

1166-x:4O0Kb&RwAMVD: ZU8:04A6:8C0:b1u2s":, IEEE 488: RS232 port: option dual 51/4" F/D (160K, own DOS), £895

48K RAM: 6502: dual 514 (800K): 12", 30x64 VDU:

1FS/D/P:

1 P/P

64K -16M RAM: 16 bit: dual 8" F/D (2.4MB): 6 S/P: modular

684"KF/RDA(M1M: ZB8):02: 1RKS2R3O2M: 1: dPu/Pal 16-48K RAM: 650Z: 81/0 slots: option -single 51/4" F/D (116K) £349

6F4/DK (R6A4M4K: )8:01825"A, :2d5uxa8l051V/4D"U: 150 cps printer: RS232C port: options - dual 8" F/D (2MB)

2-11K RAM: 6502: Full keyboard: C int: T.V. int: 20 I/O lines: 1 P/P

48K RAM: 8080: dual 8" F/D (616K): 9", 16x64 b&w VDU: 180 cps printer

64K RAM: Z80A: dual 5" F/D (640K): 12", 24x80 b&w VDU

DOS: BASIC:

Graphics loudspeaker with 128 effects: Viewdata compatible: (S)

MDOS: BASIC: A: PL/M: Fifth

Fully IBM compatible K/B: high resolution graphics: available with dual 8" F/D (2.4MB), £4950: (E)

multi-user O/S: BASIC: Expands to 1200 MB, 32 terminal

M /A: Pascal: U

system: (E)

CP/M: BASIC: Fortran: (S&H) Cobol: Pascal: M/A

O/S: BASIC: Pascal: games:

280x192 high res graphics: integer BASIC in 6K ROM (S)

AMOS: T/E: BASIC: Cobol: Fortran: Pascal: APL: M/A BASIC in 8K ROM: A: Cass OS ExBASIC: Fortran

Extended ASCII K/B with numeric pad: graphics: many fully integral configurations possible: (S) Hmiogdherle: scoolluotiuornmgorahpithoicrs0o/Pn:bigger loudspeaker (B)
(S)

DOS: BASIC: Fortran: 8" F/D (2MB) to replace 5",

Cobol: A

£6,000: additional dual 8" F/D,

£2,750 (S)

Canon BX-1 (£3,850) C(£B5S90M0k;£28&6438)

Canon Business Machines (UK) Ltd: 01-680 7700

64K RAM: 6800: Single 51/4" F/D (65K): 12", 25x80 VDU: 5xV24 ports: options -single WA" F/D (65K), £1,500

Compelec: 01-636 1392 64K RAM: Z80: dual 8" F/D

(N/A)

(c1oMl, B30):c1p2s"p, r2i4nxte8r0: 2VSD/UP:; 113P2/P

Challenger 1P & C2 CTS: 0706 79332: (1P, £238; C2, £404) MBM: 01-980 3993.

4-32K RAM: 6502: C int: RS232 port:

Mutek: 0225 743289.

Millbank Computing:

01-549 7262. U -Micro-

computers: 0606

853390. Byte Shop: 01-

518 1414

Challenger C3 (£2,334)

As above

32-56K RAM: 6502, 6800, Z80: dual 8" F/D (1.15MB): 2-16 S/P

Comma VO3 (£4,200)

Comma: 0277 811131: (N/A)

32K RAM: LSI 11: dual 8" F/D (512K): 4 serial DLU11S ports: modular

Compucolor II (£998)

Abacus: 01-580 8841: 8-32K RAM: 8086: 13", 32x64

(6)

8 -colour VDU: single 51/4" F/D

(51K): RS232 port

Compucorp 625 (£6,000)

Compucorp: 01-952 7860: (17)

60K RAM: Z80: dual 51/4" F/D (700K): 9", 16x80 b&w VDtJ: 40 cps printer: 1 RS232 port

Comp Workshop System 1 (£1,600)

Comp Workshop: 01-491 7507 (N/A)

32K RAM: dual 51/4" F/D (170K): 9", 16x64 b&W VDU: modular

Cromemco System 2, Comart: 0480 215005;

System Z2H, System 3 (£1,995/14,998/

Datron: 0742 585490; Microcentre: 031 225 2022 (20)

£3,293)

6(344K6KRA) SMy:sZ28a0n: dduZa2l H51../.4d"uFa/lD8" F/D (1.24MB) Sys. 3: S/P: P/P

D(1A9I98 48K version)

Data 0285

Applications 2588 (TBA)

(UK):

1224-x4680KVRDAUMin: t8:0R8S02: 3C2ipnot:rt: Over 20 industrial ints:

2 C ints

Diablo 3000 (19450) Digital Microsystem D(£S5C,3-295)

Business Computers 01-207 3344
(TBLtd:A)
Modata: 0892 39591 (TBA)

32K RAM: 8085: dual 8" F/D (1.2MB):12", 24 x 80 b&w VDU: 45cps printer 64K RAM: Z80: dual 8" F/D (2.28MB): 4 RS232 ports: EIA port

DOS: ExBASIC: A: CP/M: BASIC
O/S: BASIC: A: ExBASIC
0S65U: BASIC: CP/M: Fortran: Cobol RT11 0/S (X750): BASIC: Cobol: Fortran ExBASIC (ROM): A A: BASIC: U A: BASIC: Fortran: Flex: Pascal: Pilot CFoDrOtraSn:;BMAuSlItCi-:uCseorbol: BASIC: A: BASIC (ROM): U (ROM) DOS: DACL: A: U: CP/M: BASIC -E: CBASIC: Cobol Fortran: Pascal

Also supplied with integral thermal printer instead of VDU: (S&H)
Mk. 2 with 2MB F/D, £5,900. Can upgrade to Mk.3 - £8,150 (11MB H/D and 4 more S/Ps): Desk mounted: Up to 44MB H/D possible, £4,529 extra: multi user system with 208K RAM, £10,648: (S&H) D/A cony: col capability: 8K microsoft BASIC in ROM: option -dual 51/4" F/D (160K), £550: for C2, dual 8" F/D (1.15MB) and 20MB H/D: runs OSI business software on 8" F/D. (S)
Also C3B & C3P H/D modules: 74MB for about £10,000: (S&H)
Many configurations possible: (H)
16K module, £1,078: 34K, £1,209: maintenance and pro gramming manual available: (I) Also 655 model with 320K F/D c-a£p4a,b3i4li5ty(Ban)d 12", 20x80 VDU This is an example configuration from a fully compatible modular range: (E) Auslel rsy(2st-e7musseexrsp)a,n£d3a,b4l5e5to multi £6,400: 11 and 22MB options: also dual 8" F/D (996K) on Sys. 2 and 3: (E) cUs:p3tono2t5e5sxa3n3d5nroesisoelugteionnergartaopr:hiPAL output to TV: games paddle
Selection of business packages sup plied in price: (S)
Up to 6 additional F/D units possible: (H)

Durango F-85 (£8,250) Dynabyte DB8/1 (£1,500) Equinox 200 (£7,500)

Comp Ancillaries: 07843 6455 (12) Dynabyte UK/Europe Ltd: 0723 65559 (6) Equinox: 01-739 2387 (N/A)

64K RAM: 8085: dual 514 F/D (1MB): 9" 16x64 green VDU: 132 col 16'5 cps printer: N/P 32-64K RAM: Z80: 5100 bus: 2 RS232 ports: 1 P/P

0/S: DBASIC CP/M: BASIC: Cobol: Pascal

64-256K RAM: Z80: 10MB H/D: 1 S/P: 1 P/P

CcoPb/Mol:: CFBorAtrSaInC::

iTnatekgersautepdtosy5stweomrk: osptattiioonnss:-fully additional dual 51/4" F/D (1MB) and 12 MB H/D: (S) Expands to multi-user system: option - dual 8" F/D (1MB), £2,000: also DB8/2 with dual 51/4" F/D (400K), £3,000 (E)
Multi-user MVT/FA(S MOS available in place of CP/M: /H)

List of Abbreviations A Assembler B BASIC C Cassette E Extensive

F/D Floppy disc

G/C Graphics card

H Hardware

H/D Hard disc

I
Int

Introductory Interface

M/A Macro assembler N/A Not available N/P Numeric pad 0/S Operating system P/P Parallel port S Software

S/P Serial port T/E Text editor TBA To be announced U Utility

Please note: Software items listed in italic are not included in the basic price of the equipment. All prices are exclusive of VAT.

PCW 117

RNA,
.

IN STORE

Machine (Price from)

Main Distributorts (No. of Dealers)

Hardware

Software

Miscellaneous (Documentation)

Euroc (£7,995) Epuxteecrutive MinicomExidy Sorcerer (£650)
HP 85 (£2,240) IMS 5000 (£1,935)

Eurocalc Ltd: 01-405 3113 (TBA) Binatone 01-903 5211 Liveport Data Products 0736 798157 (27)
Hewlett Packard Ltd: 0734 784774 (16) Equinox: 01-739 2387 (20)

64K RAM: 8080A: dual 8" F/D (113M2Bco):l 1154"0,c2p5sxp8r0inbte&rw VDU: See Video Genie

CP/M: CBASIC: A: U:

A year's maintenance and station ery supply inc: (S)

8S-13020KcRonAnMec:toZr8:03:0RxS26342V: 1DPU/PJ/:O

EOd/Sit:oEr:xAB:ACSPIC/M(R: OAMlg)o:l: Fortran

High res graphics capability: 16K v£e9r6s0io:no,p£ti7o6n0-: 3d2uKal £5815/29": F4/8DK, (630K), £1,200: User program-

mable character set: (I)

16-32K RAM: C.P.U.: 5" 16x32 BASIC: b&w VDU: C (200K): 64 cps Printer: RS232 port: 4 P/P

Fcoumll pdaocttmpaotrrtiaxbgleraupnhiitc: s(:SN) /P:

32-64K RAM: Z80: dual 51/4" F/D (320K)

CP/M: CBASIC: Cobol: Fortran:

3 drives option: (S&H)

IMS 8000 (£3,515) IMSAI VDP 42 (£3,900)
IMSAI VDP 80 (£6,200) ITT 2020 (£867)

As above Computermarket: 0603 615089 (TBA)

64-256K RAM: Z80: dual 8" F/D (1MB) 32-64K RAM: 8085: dual 51/4" F/D (400K): 9", 24x80 b&w VDU: 1 S/P: 1 P/P

As above ITT: 0268 3040 (15)

32-64K RAM: 8085: dual 8" F/D (1.2MB): 12", 24x80 b&w VDU: 1 S/P: 1 P/P 16-48K RAM: 6502

CP/M: CBASIC: Cobol: Fortran: MicroCOBOL IMDOS (CP/M comp): A: ExBASIC: U: CBASIC: Cobol: Fortran IMDOS: A: ExBASIC: U: CBASIC: Cobol: Fortran Monitor: A: ExBASIC: Dis A:

Multi-user MVT/FAMOS available in place of CP/M: (S&H) Supports 8 additional F/D drives: a(7ls8o0aKv)a,i£la4b,l4e0, 0V:D(HP)44 with F/D (H)
3B6A0Sx1IC92inhi6gKh rResOgMra:pohpictsio: nEsx-single 51/4" F/D (116K), £425; 16K RAM, £110; RS232 port, £96: 32K system, £931: 48K system, £995: (B)

LSI M -One
(£5995)

LSI Computers: 04862 23411

LSI M -One Model 5 (£9900)

As above

LX -500 (£3,500)

Logabax Ltd: 01 965 0061 (13)

Megamicro (£6.080)

Bytronics: 0252 726814 (5)

Microstar 45 Plus (£4800) M(£1S,I260830)0 MSI 6800 System 1 (£2,175)

Microsense; 0442 41191 (30) Strumech: 05433 4321 (5) As above

MSI 6800 System 2 As above (£7,500)

MSI System 7 (£5,200) Nanocomputer (£420)

As above Midwich: Waltham Cross 29310 (TBA)

North Star Horizon (48K, £4,650)
Oxford Minicomputer PJDan8a4s0oUnic(£J4D575400,U; £5500)

Comart: 0480 215005; Comma: 0277 811131; Equinox: 01-739 2387 (20) Binatone 01-903 5211
Teletronix: 01-262 3121 (10)

Pascal Microengine Pronto: 01-599 3041

(12,080)

(TBA)

Periflex 630/48; 1024/64 (£2500; £3300)

Sintrom:0734 85464 (5)

PET 8K,16K & 32K Commodore: 01-388 (1550, £675 & £795) 5702 (150)

Powerhouse 2 (£1,175)
Rair Black Box (£2,300) Research Machines 380-Z (£1,048)

Powerhouse Micros: 0422 48422 (TBA)
Rair: 01-836 4663
(N /A) Research Machines:
0865 49791 (N/A)

SDS 100 (£4,290)

Airamco: 0294 57755 (11)

8K RAM: 8080: dual 8" F/D (1.2MB): 12", 24 x 80 b&w VDU 16K RAM: 8080: dual 8" F/D (2.4MB): 2x12", 24x80 VDU's: 120cps bidirectional printer 32K RAM: Z80: dual 51/4" F/D (180K): 12" 25x80 b&w VDU: 100cps printer 256K: 8080A: dual 8" F/D (1MB): 12", 20x80 b&w VDU: 120cps printer: 2 S/P: 2 P/P 64K RAM: 8085: dual 8" F/D (1.2MB): 3 S/P: RS232 port 16K RAM: 6800: C: 9", 16x64 b&w VDU: 1 S/P 32K RAM: 6800: dual 51/4" F/D (160K): 9" 16x24 b&w VDU: 1 RS232 port 56K RAM: 6800: single 8" F/D (312K): LOMB H/D: RS232 port: 9", 16x64 b&w VDU (5664K0KR)A: M9":, 61860x02:4duVaDl 5U1:/41"PF//PD 4K RAM: 2K ROM: Z80: C int: 8 digit LED: K/B: RS232 port: 4 P/P 24-56K RAM: Z80A: dual 51/4" F/D (360K): 15", 24x80 b&w VDU: 150 cps printer: 2 1 P/P See Video Genie
56K RAM: 8085A: 2-4K PROM: dual 51/4" F/D (570K) JD740U: dual 8" F/D (2MB) JD840U: 12", 24 x 80 b&g VDU: 3xRS232 ports. 6p4oKrtsR: 2APM/P::MopCtPio1n6s0-0d:u2alR5S12/342" ' F/D (1MB), £1550: dual 8" F/D (2MB), £1950 48K RAM 630/48: 64K RAM; 1(603204K/6)4,:6Z3800/4: 8du: adlu5a1l /84"" FF//DD (1MB), 1024/64: 2xRS232 ports: I P/P: Options - dual 51/4" F/D (630K) £859; dual 8" F/D (1MB) £1025 8-32K RAM: 6502: C: 9" '' 25x40 VDU: IEEE488 port
32-64K RAM: Z80A: 5" 27x96 b&w VDU: 1 P/P: RS232 port
32-64K RAM: 8085: dual 51/4". F/D (160K): 2 RS232 ports 16-56K RAM: Z80A: C: RS232 port:
64K RAM: Z80: dual 8" F/D (1MB): 12", 24x80 VDU: 5100 bus: RS232 port: N/P: 1 P/P

FMOS: A FMOS: A DOS: BASIC: A CP/M: U STARDOS: CP/M: BASIC: Cobol: Fortran BASIC: Mini A: U DAO: FSo: rBtrAaSnIC: U: DOS: BASIC: Multiuser BASIC: A DOS: BASIC: A Machine language: BASIC: A: TIE: DOS: BASIC: CP/M Cobol: Fortran: Pascal
CP/M: BASIC: Microcobol
BASIC: Pascal
CP/M: BASIC: Fortran: Cobol: A
OPi/lSo:t:BASIC: A: Forth
FDOS: BOS: BASIC: ExBASIC:
(14K EPROM), £260 CP/M: BASIC: Cobol: Fortran: M/A Tiny BASIC: graphics: A: ExBASIC: CBASIC: Cobol: Fortran: Algol: CP/M: U: CP/M: A: ExBASIC: Cobol: Fortran

A choice of standard business pack age included in price: (S) One of the VDU's is for inquiry only: (S) Other printers available: (S)
(H&B)
(E) Up to 8 serial or parallel mts Possible: (S&H)
As above: option -dual 8" F/D (624K), £1,640: (S&H) Rack mounted: options -dual 8" F/D (624K), £1,640; 10MB H/D, £4,250: (S&H) Choice of FDOS, SDOS or Flex: also option - 10MB H/D: (H&S) Designed for hardware education: expandable to 64K RAM system ,with F/D: (E)
(E)
Also available -JD700U with 140K disc capacity, £4175; JD800U with 1/2 MB disc, £4750 CPU has user written word set:
One day installation training on site included in price (S&H)
BASIC in 8K ROM: options dual 5i/4" F/D (353K), £795; same, but (800K), £995, plus, with the 2001-8, £30 for the disc operating ROM: (I) Graphics card available, £190: option -dual 51/4" F/D (700K):
(I) 16K RAM expansion, £250; dual 51/4" F/D (520K)' £1,000: (II)
Designed for education: high res graphics being developed: options -dual 51/4" F/D (168K), £895 and dual 8" F/D (1MB), £1,695: 56K version, £1,654: (S) Facility for 8K PROM: (E)

118 PCW

Whether you're a software engineer looking for the best hardware an educationalist requiring versatility and the ultimate in reliability - or an OEM demanding
flexibility, the finest
- documentation available,
and 'realistic' margins Zenith Data Systems is your automatic choice.

Z89 Series Microcomputer.

This highly advanced

Microcomputer is the

star of the Zenith range.

Specification includes:

Floppy disc storage.48K RAM.

`Intelligent' video terminal.

Two Z80 Microprocess-
ors. Choice of operating

fessio

systems including CPM. Standardised communication, RS 232. Prices from £1570

a microcomputer price. With memory* to 32Kwords (64K Bytes). Seven additional I/O positions. PDP 11/03

111A Series 16 -bit computer.

compatible. Systems from £4335.

Based on the powerful new *Memory boards available from

KD11-HA CPU (LSI - 11/2) it £562 per 16K.

offers you the speed and

WH14 Serial Printer.

versatility of a minicomputer at

Microprocessor based elec-

tronics makes it capable of a

wide variety of uses in most

computing applications.

It features .5 x 7 dot matrix.

Impact print. Operator/

software selectable line width -132, 96 and 80

characters per line. And

sprocket paper feed with

adjustable spacing.

Price. 1510

Z19 'Intelligent' Video Terminal.
Z80 based, it is capable of a multitude of high- speed
functions. It has an
easy- to -read,
high resolution CRT. Heavy duty keyboard. 128 characters. Addressable cursor, relative and direct. Versatile edit functions. And E.I.A. RS 232/c at 110 to 9600 baud. Price. £735

Zenith
data s terns HHEATH
4wr"

I HI

11\1 \ II I\ \IICkkk(\111,1ERS
I

If you like more information about any,or all of the Zenith Data Systems range, just contact us at Zenith Data Systems Division, Heath Electronics (U.K.) Limited, Dept PCW , Bristol Road, Gloucester GL2 6EE. Telephone (0452) 29451 All prices are exclusive of VAT and delivery charges.
Generous OEM discounts available.

PCW 119

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Machine (Price from)

Main Distributor /s (No. of Dealers)

IN STORE

Hardware

Software

Miscellaneous (Documentation)

mik C lir 1

S.E.E.D. System One (£2,175) Semel 1 (£2,900)

Strumech: 05433 4321 (4) Strutt Electrical: 0822 5439 (N/A)

3F2/D-56(1K6R0KA)M: :96",81060x:2d4uabl&51w/4" VDU: RS232 port

DOS; BASIC: U: Fortran: Cobol: M/A

16-64K RAM: Z80: single 8" F/D BASIC: Cobol: Fortran (R2S502K32):p1o2r"t, 24x80 b&w VDU:

dUripvetos:8opI/tOionpo-rtdsu:aml a8x" oFf/D4 F/D (624K): (E) Supports up to 8 drives option single 8" F/D (250K), E500: (I)

Sharp MZ-80K (£520) Sinclair ZX80 (2100) Sirocco (23,900)

Sharp Electronics (UK) Ltd: 061 205 7321 (22)

b6&-3w4VKDRUAM:

Z80:

C:

10",

24x40

BASIC:

A:

0S2c2ie3nc3e11o4f 8C8am(Nb/rAid)ge: Elvingate Computers: 069 245189 (TBA)

i1n-t1:6fKullRKA/MB::47480p-i1n:eCxpinatn:sTio.Vn . port 64K RAM: Z80: dual 51/4" F/D (940K): 12", 24x80 VDU: RS232 port

4K BASIC in ROM CP/M CBASIC: Cobol: MBASIC: Fortran

Ginra1p4hKicRs:AloMud: s3p4eKakmera:cBhAinSe,IC £740: (B)
CPU is NEC 3.25 MHz version of Z80A: available as kit, £80: mains adaptor £9:(S) Direct memory addressing: mstaenmdoirnygmkaepypbeodarVdD: oUp:tiforene10MB H/D

Smoke Signal Chieftain 1 (£3,050)

Windrush Micro Designs 32-64K RAM: 6800: dual 51/4" DOS: BASIC: DBASIC: Also Chieftain 3 with dual 8" F/D

069 245189 (TBA)

F/D (160K): 12", 24x80 VDU: RBASIC: A: Fortran: (1MB), £3,950 (E)

112 cps printer: RS232C port U

Solitaire WP & BS200 (£6,750&£7,950)

Solitaire KPG: 01-995 3573 (TBA)

64K RAM: 8085: 14" VDU (with DOS: BASIC (optional own CPU): 45 cps printer: CPU on the "WP") port: dual 51/4" F/D (700K) with "WP", and dual 8" F/D (960K) with "BS200"

All Solitaire systems are compatible: graphics on 11x13 dot matrix: (S)

Solitaire/HBS100 As above (£9,500)

6V4DKUR(AwMith: o8w08n5C: 1P0UM):B20H0/Dcp:s14" DOS: BASIC printer: CPU port

Up to 8 interface terminals can be used: also HBS200 with 20-80 MB of H/D: HBS100 limit is 40MB: (S)

Sord M100 ACE (£2,650)

Midas Computer Services Ltd: 0903 814523

48K RAM: Z80: single 514"

O/S: BASIC

F/D (143K): 12" 24x64 col VDU

RS232 port

With colour graphics: 8K ROM: option - single 514" F/D, £300: (I)

Sord M223 (£3,500)

As above

6F4/DK (R3A5M0K: )Z:8102:"si2n4gxle8051b4&" w VDU: S100 bus: RS232 port

O/S: BASIC

Other configs possible: extra F/D, £450: (I)

Superbrain (£1,995)

Icarus: 0632 29593 (TBA)

64K RAM: 2xZ80: dual 514" F/D (320K): 12", 25x80 b&w VDU: 5100 bus: 115232: TRS80 port

CP/M A: BASIC: Cobol.: Fortran: APL Pascal

Limited graphics: mainframe int available: options -dual 51/4" F/D (320K): dual 8" F/D (2.4MB): 8-120 MB HID: (S&H)

Tandberg EC10 (£5,000)

Tandberg: 0532 35111: (N/A)

50K RAM: 8080A; single 8" F/D (250K): 12", 25x80 b&w VDU: RS232 port

ExBASIC (24K):

(S&H)

Multi-user BASIC: A:

U: Cobol

Tandy TRS 80 Level 1 (£380)

Tandy: 021 556 6101 (200)

4-16K RAM: Z80: C: 12", 16x64 b&w VDU

BASIC: A:

BASIC in 4K ROM: upgradable to level 2: (I)

Tandy TRS 80 Level II (£515)

As above

4-48K RAM: Z80: C: 12", 16x64 b&w VDU: RS232 int: 1 P/P

BASIC: M/A: Fortran

16K machine includes. N/P: 4-16K upgrade, £120 (£85 without pad): max config, £1,005: option single 51/4" F/D (78K), £478 (max of 4): (I)

Tandy TRS80

As above

Model 2 (£2290)

32-64K RAM: Z80A single 8"
F/D/P (500K)1P/P 12", 24x80 VDU: 2S

DOS: BASIC

Keyboard has numeric pad: 64K version, £2250: (S)

TECS (£1,600)

Technologies: 051 724 2695 (TBA)

16-56K RAM: 6800: 8K PROM: BASIC: T.DOS:

RS232 port: C int

Prestel: Monitor:

256 ch graphics: Prestel compatible: plugs into standard TV: option - dual 51/4" F/D (320K), £800: (S&H)

TEI 208 (£3,841)

Abacus: 01-580 8811 (5)

32-60K RAM: 8080/8085: dual CP/M: BASIC: Cobol: (S&H)

514"n F/VDU:D (320K): 9",P/P 24x80

Fortran: Pascal: Algol

gree

3 S/P: 3

TEl 212 (£4,886)

As above

382"-F6/0DK(R1MAMB)::81058"0, /2840x8850: dgureaeln

CP/M: BASIC: Cobol: Fortran: Pascal: Algol

(S&H)

VDU: 3 S/P: 3 P/P

Terodec DPS 64/1-4 (£3,014)

Terodec (Micro -systems) 64K RAM: Z80: dual 8" F/D

Ltd: 0344 51160:

(1MB): 12", 24x80 b&w VDU:

(TBA)

2 S/P: 3 P/P

CP/M: BASIC: Cobol: CBASIC: Fortran: Algol: Pascal

TMZ 80, enhanced model in

integral work station £5 495

(with 4MB F/D): DPS 64 with

2MB F/D is £3,319: options -

d8u"aFl

8"
/D

F/D (2M B(),

E5:
£1,451MB),

1,150: dual (S&H)

Vector Graphics (£2,595)

MZ

ASitnmtroorme: M06ic0r2os6h2o5p0:35:

(5663K0KR)A:M3 :SZ/P8:0:2dPu/aPl 51/4 F/D

0734 85464: Metrotech 0895 57780: (5)

Video Genie EG 3003 (£378)

L06o2w9e2E8l1ec7t:roBniincast:one: 3126xK64RATMV :inZt8: 0e:x5tr0a0CbpinstC: 1: P/P 01-903 5211 (N/A)

DOS: BASIC: A: CP/M2: Algol: CBASIC: Cobol: Fortran: Pascal BASIC: M/A: Fortran

Includes PROM burner: also Sys tern B with graphics and N/P, £3,195: (E) BASIC in 12K ROM: graphics amveanilta:bBlei:nFat/oDnuencdaelrl tdheevierlo1p6Kmodel "Executive MinicomputMeri"niacnodmap4uKterv"e-rspiorinc,e"sOTxBfoAr:d(.I)

Zenith WH-11A (£4,359) Zenith Z89 (£1,490)

Heath Ltd 0452 29451 LSI 11: 16-32K RAM: 25x80 and 01-636 7349 (N/A) VDU: S/P: P/P

As above

16-48K RAM: Z80: single 51,4" F/D (102K): 12", 25x80 b&g VDU: 115232

O/S: BASIC: Fortran: A: U: BASIC: A: H.DOS: CP/M: MBASIC: CBASIC: Fortran

PDP 11 compatible: option dual 8" F/D (512K): (S&H) 3 drives option: (I)

Zentec (£5,700)

Zigal Dynamics Ltd: 02405 75681 (1)

32-64K RAM: 2x8080: dual 51/4" O/S: A: U: BASIC:

F/D (512RS23K): 15"o,rt25x80 b&w

Micro Cobol

VDU:

2 p

Uopsteiropnro-dguraaml m8"abFl/eDch(1arMacBte)r: s(eSt):

Z(piolorgtaMbleC)Z: M1/C05Z 1 /20A (24200, £4800) Z Plus (£4,000)

Micropower: 0256 5048142412:1M54em71ec(:N/A) Rostronics: 01-874 3665 (TBA)

64K RAM: Z80: dual 8" F/D (AH6/00o0,n2Kl7y)1:..0R. 01SP23/P2:pooprtt:ioMnC-1Z0M1/2B0 32-64K RAM: Z80: dual 8" F/D (1MB): 2 S/P: 2 P/P

RIO: O/S: Cobol: B1/A05S.I.C.M: F/oArt:raUn: Pascal 1/20A. . .PLZ: U CP/M A: U: BASIC: Cobol: Fortran: Pascal

Available desk top or rack mount ed: Debug in 3K PROM: 1/20A runs multi-user Cobol and has up to 5 terminals and 40MB possible: (S&H) (S&H)

List of Abbreviations A Assembler B BASIC C Cassette E Extensive

F/D Floppy disc G/C Graphics card H Hardware H/D Hard disc I Introductory Int Interface

M/A Macro assembler N/A Not available N/P Numeric pad 0/S Operating system P/P Parallel port S Software

ST//PE STeerxiatlepdoitrotr TBA To be announced
U Utility

Please note: Software items listed in italic are not included in the basic price of the equipment. All prices are exclusive of VAT.

PCW 121

litill \

IN STORE

SINGLE BOARDS

Machine (Price limn)

Main Distributor's (No. of Dealers)

Hardware

Software/ Firmware

Miscellaneous (Documentation)

A(£c6o5r)n
Aim 65C (£265)
Crnmemco SC (£260) ELF II (£114) Explorer (£295) H8 (£262) Hewart 6800S (£'299) Hewart 6800 MkIII (£152) Mk 14 (139.95)
Microtan 65 (£69) Nascom 1 (£165) 7(£79/608) SBC 100 (£135) Superboard (1188)
S(£Y1M60-1) Triton 4.1 (£286) Triton 5.1 (£294) T(£u1s7c0an) UK 101 (£219)

Acorn: 0923 312772 (N/A)
Pelco: 0273 722155 (4)
Comart: 0480 215005 (17) Newtronics: 01-348 3325 Newtronics: 01-739 1582 (15) Heath: 0452 29451 (TBA) Hewart: 0625 22030 (N/A) As above
Science of Cambridge: 0223 311488 (N/A)
Tangerine: 0353 3633 Nascom: 02405 75155 (20) Newbear: 0635 30505 (N/A) Airamco: 0294 57755 (11) MBM: 01-981 3993 (N/A) Newbear: 0635 30505 (N/A) Transam: 01-402 8137
(N /A) As above As above Computer Shop: 01-440 7033

1.1/8K RAM: 6502: EPROM socket: Hex K/B: C int: 8 digit LED display: up to 16 ports: options - Eurocard 64 way connector: VDU card: Full K/B card

1/4K monitor: BASIC

Kit: programmable address link ing; on board 5V regulator: available assembled, £79(S&H)

1-4K RAM: 6502: 12K ROM: full A: Dis A: T/E: 8K K/B: 20 char LED display: 20 char monitor in ROM thermal printer: Cx2: RS232 port.

Available as S100 system with A or BASIC in ROM (£480) from Portable Micros (0280 702017): they also have briefcase version (£750) (E)

1K RAM: Z80A: 8K EPROM sockets: RS232 port: 3 P/P: option - S100 bus.

Monitor and control BASIC in EPROM

1/4K RAM: RCA 1802: Hex K/B: 2 digit LED: TV int: C int:

1K monitor: A: Dis A: T/E: BASIC: 244

RS232 port: options - 4K RAM,

£69; full K/B; VDU card

4pKortR: AS1M0:08b0u8s5::CHienxt:Ko/pBt:ioRnSs2-32

2K monitor: BASIC

CP/M:

6 slot S100 £32; 8K EPROM

sockets £50.

4K RAM: 8080A: Octal K/B: 6 digit LED: speaker: options single 51/4" F/D (102K), £399; 16K RAM, £314; C int, £72

1K monitor: BASIC in RAM: FORTRAN: T/E: A: U:

i1n6t:K2RxCAMin:t;6180S0/:Pf:u2llPK/P/B: :oVptDioUn 1K monitor: A: T/E - 16K RAM, £90

1K RAM: 6800: VDU board:

1K monitor

options - single 51/4" F/D

(75K), £350; PROM programmer, £32: calculator board, £32

p5upt roowgrnaBmAinStIeCrvparlotgimraemrss:icnan EPROM (E) TTY, n -line decoders: low resolution graphics (high resolution available) kit (H) Programmable 14 bit counter: kit (S&H)
Kit (S&H)
Can be upgraded with 6809 (H) (H)

8060: 1/4-2K RAM: Hex K/B: 7 char LEb: options - VDU int (32x16 with graphics), £29; C int, £6; PROM prog, £10, 2K memory expansion, £15 1K RAM: 6502: 16x32 T.V. int: options - TANEX board 7K RAM, 6K ROM, 8K BASIC; 3S/P

Machine code 1K TANBUG monitor: BASIC

Designed for control applications rather than high level computing expansion (H) Optional 64x64 pixel graphics:(E)

4K RAM: Z80: full K/B: TV int: 2 P/P: 1 S/P 4K RAM: 6800: LED: C int: VDU int.

2K monitor: BBASIC: tiny BASIC: A: T/E:
U
1K Monitor: BASIC:

Now available as Nascom 2 with 8K RAM and 8K microsoft BASIC in ROM, £295 Expandable to racked Nascom compatible system: (B)

1K RAM: Z80: 8K ROM: 5100

-gl/ 1 S/P: 1 P/P: option - voltage
regulator

4-8K RAM: 6502: 10K ROM:

full K/B:

C int: options

RS232 VDUV e 4" 5int:, F/D

(100K), £316; 8K RAM, £188

1K monitor: DOS in ROM BASIC in 8K ROM:

kit: available assembled, £196 (E) Available with 32K RAM and single 51/4" F/D, £867 (S&H)

1b-p4sKCRinAtM: V: D65U02i:nt: 2x6522 ports: option - TV int.

4K monitor: BASIC: A Can be expanded to 64K RAM
(S& H)

2K RAM: 8080: 3K ROM: full K/B: 16x64 VDU or TV int: C 1 S/P: option - 2K RAM, £30 2K A AM: 1K VDU RAM: 8080: C int: T.V. int
8K RAM: 8K ROM: Z80: 6xS100 slots: RS232 int: T.V. int: C int 4K RAM: 6502: full K/B: 16x48 VDU or TV int: C int: RS232 port: option - 4K RAM, £49

1K monitor: 2K BASIC: 64 character graphics: 8 levels

U

interrupt: kit (S&H)

11/4K monitor: 21/2K BASIC: A: Dis A: 8K BASIC: Pascal
8K monitor: or 8K BASIC

Graphics facility: disc interface running CP/M, about £200: (S&H) DD disc controller, £195: graphics: (S&H)

D1Kis

Am:oUnitor:

8K

BASIC:

Graphics: software

will

run

Superboard

(S&H)

TRANSACTION FILE

The classified service that's FREE to readers (but not companies, please). Advertisements 50 words

maximum to: PCW Transaction File, 14 Rath bone Place, London W 1P 1DE.

For sale
PET 2001-8K... good condition, little used, 5 months old - £495 ono. Contact C H Towns, 57 Woodend Walk, Armadale, West Lothian, EH48 3QN Teletype ASR 35... ASCII code, good condition, some manuals. Will haggle around £250. Phone Welwyn Garden (07073) 23742. MK 14... with latest monitor, extra RAM, cassette interface, single step addition and improved

II...Software with FA -1 data storage adaptor.
Plus "Master Pack" software pack Package, manual (with over 100 programs) and many games £75. Phone South Benfleet 52147. mtSaupopedieunrltbaetoroafrardcaenIdIc.o. nnpeocwteeBdrl,asanuldplfpolyrd, fully working - £200. Ring A. Forster on 0323 30742 (Sussex).

Challenger C2.4P model 2 ... one

month old, 8K Microsoft BASIC;

8K RAM; RS232 port; D/A con -

vertex; audio output to speaker; 3

32 lines by 64 ch display; 53 -key

keyboard with full auto repeat;

can be expanded to disc system.

renumbera-re£g3a9m5eosnaon.dPBhAoSnIeC

01-560 8806 anytime.

(Tony

Chow)

-

TRS 80 Level II... 16K, plugs into own TV and cassette, hardly used. Offers to Ely 721508

PET 2001... with Expandamem to 32K; nearest offer to silly price of £550 will secure. Phone Henry Barnett on 01-843 1288 (day), 01

K/B - £40. Phone Ashby -de -laZouch 6231.

MK.14... extra RAM, cassette interface, new keyboard, revised

PbEoTa-r8dK,...cnaeswsReOttMes,, gbirgekeeny-
of pages, £400. Phone Biggin Hill 71742 (eves).

scmbardoeodanerreidntsosw,r. ,ialtsnhoidnatgIls/llOed-sal.titenape, s.cEaovnxattreilonalsb,iloen. Extensive SC/MP documentation and PSU - £50. Phone Robin

Casio FX502P... programming Lowis on Bristol 30124.

calculator (see PCW Sept '79)

01-954 5588 (eve). Nascom 1... PSU, buffer board, T2 monitor and CCSoft Level A TmiennytBatAioSnI,Cf.uIlnlyclufudnesctailolndaolc-u£125 ono. Also non-functional 8 8K memory board with 8K dBaAmSaIgCeRdObMy s(tRatAicM) -cohniplsyb£e2li5e.ved

Phone Mark Burgis on 01-567 2024 (West London), eves. TRS 80 Level 1&2 (switchable) ... plus some software including chess and T -Bug - £450. Phone 061-320 8512. Tourittoonf 8Msootchkeertbso-a£rd4.5... wPriitnhte5r Mechanism... impact dot matrix, D2 esvteipcpese.r.s.,tnoouclohgkiceb-o£a5r0d. -Star £25. TV Monitor, .. 12" in strong chassis - £50. Elektor TV Oscilliscope... needs attention, hence £120. Ring David Pearce on Biggin Hill 73585.
TRS 80 Level II... 16K with video and cassette deck. Plus editor, assembler, RSM 2D monitor, T Bug, Renumber, Starwars and other games. Phone Al on Andover 61486.

122 PCW

UK101.. . cased, some extra RAM and programs, modified cassette - £315. Phone 061643 2343. ITT 2020... 48K version with
Wanted floppy disc drive and control-
ler card. Also included - colour modulator for TV and printer controller card. Total rig, £1300. Phone (0385) 61765. Expandoram... S.D. Sales RAM memory board, 32K, for S100 bus; assembled & tested - £120 inc. p&p. Phone Portsmouth 67865. Tandy TRS 80 Level II... 32K, comprising VDU, DOS 2.2 plus; 2xdisc drive; tractor feed line printer; quick printer and many
extras. Will separate; £2750 ono.all or part of your system (PET, Phone 021-558 2468. (6-9pm)
Volt PSU, revised monitor, singleAndrews on 01-520 2230. Nascom 1... PSU and T2 moni-
tor with all documentation and some games tapes. Best offer secures or exchange for audio equipment. Phone Watford . 48096 anytime. Tseenxda/sreSceilievnetp7r0in0t.e..r kteerymbionaarld, ,

RS232 interface and acoustic coupler. Complete with case and 110 V transformer. Brand new - £650. Phone 01-427 8634 (after 7pm) MK.14. . built and working, full fully socketed,. revised monitor and decoding, RAM I/O, extra RAM, tape interface, click switch, keyboard in case with PSU, manual and 2 SC/MP guides - £60. Phone Ken on Southend (0702) 335380 (eves). PET 2001-8K... fitted upgrade ROM, hobby use only. With manuals and many programs (tutorials, utilities and games) - £425. Phone Blackpool (0253) 869108 evenings/weekends, MK.14... with VDU, 5 Amp 5
step, RAM I/O, click keyboard,
32x16 VDU (has own 1K ofRAM).
Also full documentation, useful programs - bargain at £65! What's the catch? Buyer must collect from Kensington. Phone 01-937 8632

PET Bargain .. 32K business PET with 2040 'dual floppy disc. 8 months old and little used £1200 ono. Phone Gerrards Cross (02813) 83095. Compukit 4K ...onto bigger things! Fully assembled and wasosrekminbgle-r/£e1d9it0or()i.nAclulsdoinKgim ... hardly used, with power supply and First Book of Kim - £89. Phone 01-866 3326 (evenings/ weekends). PET 2001-8K ... with 24K memory expansion and Computhink disc drive. Also second cassette unit, external keyboard, TIS Workbooks and a vast selection of software and tapes s-s£te1m60.0Pohnoon fBorrigthhetocnom20p2le9t1e8 (office hours) orStorringt n 2663 (evenings /weekends). TRS 80 ... 48K, expansion interface, including Level III and Mon 3 with games galore. As new, cost £1000, now asking £700 ono (cash preferably).

Contact I. Wilkinson, 234 Union Road, Oswaldtwistle, Lancashire BB5 3JB.
National Charity would welcome the donation of a microprocessor and/or printer. We can collect. Cancer Prevention Research Trust, 36 Roehampton Vale, London SW15. September and/or October issues of PCW Must be in good co tion. Phone 01-848 0020 or 01-868 4411 and ask for George. PET system ... if you're selling discs and/or printer) contact Mr

DIARY DATA

London, England Liverpool, England Brussels, Belgium Manchester,England
Anaheim, USA Dallas, USA London, England
Dublin, Ireland Geneva, Switzerland

All Electronic Show. All Electronic Show, 34-36 High Street, Saffron Walden Essex. Tel: 0799 22612 Mersey Micro Show. Online Conferences Ltd., Cleveland Road, Uxbridge UB8 2DD. Tel: 0895 39262
Compec Europe Exhibition. Iliffe Promotions Ltd., Dorset House, Stamford Street, London SE1 9LU. Tel: 01-261 8000. Business Efficiency & Office Equipment Exhibition, Gwen Shillaber Design, 81 Whiteladies Rd., Clifton, Bristol BS8 2NT. Tel: 0272 312850 National Computer Conference and Exhibition (NCC). 210 Summit Ave., Montvale, NJ 07645 Int. Telecommunications Exbn - INTELCOM. Horizon House Microsol Inc., 25 Victoria Street, London SW1H OEX. Tel: 01-222 0466
International Word Processing Exhibition and Conference. Business Equipment Trade Association, 109 Kingsway, London WC2B 6PU. Tel: 01-405 6233 International Computing Exhibition - COMPUTEX. SDL Exhibitions Ltd., 68 Fitzwilliam Square, Dublin 2, Ireland. Tel: Dublin 763871 International Microcomputers, Minicomputers, Microprocessors & Datacommunications Exhibition - IMMM/DATACOMM. Kiver Communications S.A., 171/185 Ewell Road, Surbiton, Surrey. Tel: 01-390 0281

Apr 29 - May 1 April 30 - May 2 May 6 - May 8 May 13 - May 15
May 19 - May 22 May 19 - May 23 May 20 - May 23
June 17 - June 19 June 17 - June 19
/111\11110...- -

FAX

LSB SC/MP MNEMONICS ARRANGED BY OPCODE

MSB\ 0

1

2

34

5

6

7

0

HALT XAE CCL SCL DINT IEN CSA CAS

1

2

3

XPAL*

4

LDE

5

ANE

6

XRE

7

ADE

XPAH*

8

89 NOP
ORE DAE CAE

AB

9

JMP

DISP*

A

JP DISP*

B

C

LD

DISP 4

LDI DATA

D

AND

DISP A

ANI DATA

E

XOR

DISP 4

XRI DATA

F

ADD

DISP A

ADI DATA

0

1

2

34

5

A Bits 0-2 auto index flag and pointer register

JZ DISP*

ILD DISP*

DLD DISP*

ST DISP4

OR
DI SPA

DAD DISP4

CAD DI SPA

6

7

89

AB

* Bits 0 and 1 = pointer register

'ACES

C

D

EF

SR

SRL RR RRL

XPPC*

JNZ DISP*

DLY DISP

ORI DATA

DAI DATA

CAI DATA

C

D

EF

PCW 123

.
MICROIVIART

NASCOM Z-2
4K EDITOR -ASSEMBLER
Professional package equivalent to IBM large Systems Package specially written for Nascom-2 and includes many powerful features * Full screen edit fully utilises Nas-2 cursor control. * File scrolling feature. * Multi -tabbing facilities allows compressed files saving RAM. * No wasteful line numbering to remember. Powerful string search/replace facilities. * Named files saved/restored to cassette using NAS-SYS routines. * High speed VDU output puts listings, etc. straight to VDU memory. * High speed assembler supports all pseudoops/arithmetic operators. * Output to printer tape or VDU, with many listing options. * Repeat key feature
Supplied on cassette with user manual for only £14.00 inc. VAT.
Mail orders to DPSS Dept. S1, 14 Vale Rd, Claygate, Esher, Surrey.

SPEED - VERSATILITY - ECONOMY

AID riti

iderioN

e

-----n4J111121"UavBroO
eatanamety Ihrouglr hout Yid., educaoon and reseas. rch ROADRUNNER u used Im riolkikyola. ams. lecnn.oans. dasygnare and ngula', io carry No work on P.C. REPAIRS ANALOGUE BACROBOAROING 'SIMPLE LOGIC WIRING CORIPLES INTERCONNECTING OF MICROS ARO MEMORIES
EURO INTRONI1 E15.73. PROJECT INTROEIT MG PENCIL WITH LOADED BOBBIN [IM. WIRE DISTRIBUTION STRIPS GLUE FIX 20101 11- LONG 0.10. ADHESIVE COSS TUBE PRESS FIX 201£1 2 LONG MY, 5INGLE EUROCARD HIGH DENSITY
PLANE a5. %PIN DILSI C2.50 DOUBLE EI.I.W.D. WITH CAPACITY OF SA It 16 PIN OILS [7.25. PROJECT CARD HIGH DENSITY SSIDED20. 141 PIN DILS MRS BOBBINS BLUE 4051E2.12 GREEN P11..1121 PINE .1101 E2.10 GOLD ANN. E2.12. 1 OF EACH COL 00.20. TINNED COPPER WIRE MEM E2.72. RECOMMENDED SOLDERING IRON FOR ROADRUNNER HOBBYIST C410
Please add 40p for pip 0 15% VAT 10 AS NOATA
FOR FURTHER INFORMATION ON ROADRUNNER PRODUCTS SEND LARGE S.A E TO T.J. BRINE ASSOCIATES
5613. HIGH STREET. HASLEMERE. SURREY
IN ADDITION TO ROADRUNNER WE PROVIDE A SPECIALIST MICROPROCESSOR PRODUCT DEVELOPMENT SERVICE.
PLEASE PHONE 0425.53850 FOR MORE DETAILS.

"SUCKER" the unique game of chance which simulates
artificial intelligence. Basic listing for all machines: £5
25 programmes for Sinclair ZX80: £20 For enquiries or orders: UMC (PCW)
Manor House, Rathl in Island, County ANTRIM Tel: 02657 71220
COURSES
1. Micro computer programming
2. Basic programming 3. Micro appreciation for
industry All courses with 'hands on' experience to be held in: London, Bristol, Manchester,
Birmingham, Leeds. LIMITED NUMBERS: 'Nrite early for a date to: NDP Ltd, Microsystems Div, 69 Northampton Road, Rushden, Northants.
124 PCW

Wave -Making on a NASCOM I cont from p.90

1173 2C
1174 2C
1175 2C

0041
0042 0043

INC L INC L INC L

1176 70

0044

LD A, L

1177 320A11 117A 3A0211

0045 0046

LD (11013H), R LD A. (1102H)

117D 4F 117E 000212 1181 31301311

0047 0048
0049 Fr2

LD C. A CALL MILT LD A. (110BH)

1184 6F 1185 2610

0050 0051

LO L,13 LD H, 10H

1187 5E

0052

LD E, (HL )

1188 3E04

0053

LD R, 04'

118R 85

0054

RDD A, L

118B 320B11

0055

LD (11013H), R

118E 3R13311

0056

LD R, (1103H)

1191 4F

0057

LD C, R

1192 CD0212

0058

CALL MULT

1195 3R0C11

0059 TIERCE LD R, (110CH)

1198 6F

0060

LD L, R

1199 2610

0061

LD H, 10H

119B 5E

0062

LC, E, (HL )

119C 3E05

0063

LE) A, 05

119E 85

0064

ADD A, L

119F 328C11

0065

LD (110CH.), R

11R2 3A0411

0066

LD R, (1104H)

11A5 4F

0067

LD C., R

11R6 CD0212

0068

CRLL MULT

11A9 3ROD11

0069 LARIGOT LD A. (110DH)

11RC 6F

0070

LD L, R

11RD 2610

0071

LD H, 10H

11RF 5E

0072

LD E, (HL)

11130 3E06

0073

LD A, 06

11132 85

0074

ADD R. L

11133 3201)11

0075

LD (110DH), R

1186 38051.1

0076

LD R.. (1105H)

11139 4F

0077

LD C, Fl

1113R CD0212

0078

CALL MULT

11BD 3R0E11

0079 FT1

LD A, (110EH)

11C0 6F

0080

LD L. A

11C1 2610

0081

LD H, 10H

11C3 5E

0082

LD E, (HL)

11C4 3E08

0083

LD R, 08

1106 85

0084

RDD R, L

11C7 320E11

0085

LD (110EH), A

11CR 3A0611

0086

LO A, (1106H)

11CD 4F

0087

LD C, A

110E CD0212
11D1 CB7C
1103 2010

0088 0089 SIGN 0090

CALL MULT
BIT 7, H
JR. NZ, COMP

11D5 CD2012

0091

CALL DIV

1108 260E

0092 STNS LD H, OEH

11DR 31-10711

0093

LD A. (1107H)

11DD 6F

0094

LD L. A

11DE 79

0095

LD A, C

11DF 77

0096

LD (HL), A

11E0 2C

0097

INC L

11E1 7D
11E2 320711

0098 0099

LD R, L
LD (1107H), A

11E5 11E8 11E9
11EC 11EF 11F2 11F3

3A1211
3D
321211 024511 C38602
7D
2F

0100 COUNT 0101 0102 0103 0104
0105 COMP 0106

LD R. (1112H)
DEC R
LD (1112H), A JP NZ, FT8 JP 0286H LD A, L
CPL

11F4 6F 11F5 7C
11F6 2F

0107 0108 0109

LD L. A LD R, H
CPL

11F7 67

0110

LD H, A

11F8 23

0111

INC HL

11F9 CD2012

0112

CALL DIV

11FC 11FD 11FE 11FF 1200
1202 1204 1207 1209 1208 120D 120F 1210 1212 1214 1215 1217 121B 121C 121F 1220 1223 1224 1227 1228 1229 122B 122D 122E 122F 1231 1233 1234 1236 1238 1239 123B 123D 1240 1243

79 2F 3C 4F
18D6 0608 210000 1600 CB7B 2802 16FF 29 CB21 3001 19 10F8 ED5B0F11 19 220F11 C9 010008 59 3R1111 57 R7 CB1A Cele E5 R7 ED52 3003
El 1802 DDE1 3F Cell 10EB
210000 220F11 C9

0113 0114 0115 0116 0117 0118 MULT 0119 0120 0121 0122 0123 0124 SHIFT 0125 0126 0127 0128 DEC 0129 0130 0131 0132 0133 DIV 0134 0135 0136 0137 MOVE 0138 0139 0140 0141 0142 0143 0144 0145 0146 NXT 0147 FLAG 0148 0149 0150 0151 0152

LD A, C CPL
INC R LD C,R JR SINS LD B4O8 LD HL,00 LD D,00 BIT 7,E JR Z,SHIFT LD D, OFFH ADD HL,HL SLR C JR NC, DEC ADD HL,DE DJNZ SHIFT LD DE,(110FH) ADD HL,DE LD (110FH),HL RET LD BC, 0880H LD E,C LD R, (1111H) LD D,R AND R RR D RR E PUSH HL AND R SBC HL,DE JR NC,NXI POP HL JR FLRG POP IX CCF RL C DJNZ MOVE LD HL, 00 LD (110FH),HL RET

Interrupt cont. from p.111
However what lies below the surface is of longer term importance. If one user
can get away with it, doing his own
programming in BASIC perhaps, there's nothing to stop another trying and yet another . .. all from the same company. And with at least 164 different micros on the market the chances of several
users in one company all acquiring different and probably incompatible units and then writing programs in
different versions of BASIC are high. What are the chances of them being
able to communicate with each other either by wire or on disc? Ah, you will say, why should they want to? My reply is that, as the number of user operated micros increases, so the chances of
requiring interchange of data or programs will probably be squared. But not only will incompatible equipment tend to preclude this, so will the lack of
any standards or disciplines to which the users should conform.
The problem really is that personal computing assumes expertise in several areas that a user may not have, because it goes against the concept of area specialisation; that's why we have accountants, salesmen, lawyers, etc. It's a false assumption to say that a specialist in one area may also become an efficient computer programmer. At best, their computing function will be

secondary to their main job.
I recently heard of a top man
planning to replace his central dp installation with 1,000 micros (if true, a nice order for someone). But personal computing is contrary to the principles of functional management. A group of individual department managers would be replacing the dp manager in deciding on which applications are to be most cost/effective, construction of files, the documentation of the systems. Instead of increasing the overall efficiency of the organisation, there will tend to be increased empire building and departmental isolation. It would become increasingly difficult for one department to know what another was
doing, to co-ordinate efforts and to
control costs. It's a fallacy to believe it is possible
to demolish a centrally managed structure and replace it completely by a distributed structure that has no management. It's also a fallacy to
believe that with multi -users, the dp skills of the professionals will be
unnecessary. Its a question of
recognising the boundaries of what is
possible.
Edward G Cluff, Secretary -General,
Institute of Data Processing Management

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* VAT and carriage extra all items.
PCW 125

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.4111 4
-111
ii kb,
1111115. 11
N"--- ----

126 PCW

YCW cont. from p.113

255 IFA<>0 THEN290

256 RESTORE

260 F0RA1.1 TO5

270 READA2

275 IFASC(AC.A2 THEN279

277 NE XTA1

278 GOT0180 279 0NA1G0T0100.500,50,750,820

280 IFA.0 THEN240

290 IFA>N THENN=A

292 IFA<0 THEN690 295 IF INT(A)<>ATH.EN630

300 PRIN TA -1: CHR$ (34 ) :A$( A-1 )
310 INPUT" ": AVA)

330 PRIN TA+1 : CHAS ( 34 ) : AS (A+1 )

340 G0T0240

500 POKE8142.0

510 A1=PEEK (A144 )

520 A2.PEEK (8145 )

530 POKE8144,0

540 P0KE8145,0
550 NULL4

555 PRINT:PFUNT: PAINT: PRINT

560 FORA=1 TON
570 PAIN TAV A )

580 NE xTA
590 P0KE8144 , A1

600 P0KE8145, A2

610 NuLLO
620 END

630 FOR I=N TO ( IN T(A )+1 ) STEP -1
640 AS(I+1 )=AVI )

650 NE XT

660 N=N+1
670 A=INT(A)+1

680 GOT0300
690 An,ABS(A)

700 FOR I-,A+1TON
710 ACI-1)=45(I)

720 NEXT

730 N=N -1
740 6010240

750 INPUT -ENTER SEARCH STRING: ":B$

760 8=LEN (8$ )

770 F0RI.-.1T0N

780 GO6u81000
782 IFCW"THEN800

784 PAIN TI :CS: PAIN TI :

785 IF T= 1 THEN795

786 FORJ=1 TOT -1
788 PAINT" ": 790 NE XTJ

795 PAIN T" f "

800 NE X TI

0

810 GO T0240

820 INPUT"EN TER LINE NUMBER": I 830 INPUT -ENTER OLD TEXT":B$

835 B=LEN(B$)

840 GOSUB1000

0

850 IFC$<>--THEN885 860 PRINTI:A$(1)

870 PAINT -ERROR - TEXT NOT FOUND"

880 (3010240 885 INPuT"ENTER NEW TEXT -; CS

887 C=LEN (CB)

888 At6=AS (I ) 890 AS(I )=NID$( A$ , 1 , T-1 )+C$

892 IF T-1+B>A THEN900 895 ACT )=AS( I )+MIDS(A$, T+B ,A -8-T+1 )

900 PAIN TI :AS( I )

910 GQT0240
1000 OW -

1010 A=LEN (AS( I ) ) 1020 FORT= 1 TOA-B+1

1030 IFIIIDS(45(I ). T.8)<>13$THEN1060 1040 C11 -411M

1050 GO 1010/0

1060 NEXTT
1070 RETURN
READ Y
-

(program for an 8K Exidy Sorcerer)
_

SNAP-FOR A NASCOM 2
10 CLS

3020 PRINT TAB(20); "SNAP" POKE 3200,25311

5040 POKE 3202,312 POKE 3204,18351

7060 POKE 3206,10927 POKE 3208,-8179

9080 POKE 3210,233 POKE 4100,3200

100 LET A=INT(RND(1)*13)+1

110 LET B=INT(RND(1)*13)+1

120 LET X=INT(A/4)+1 : IF X>4 THEN 100

41

130 LET Y=INT(B/4)+1 : IF Y>4 THEN 110

140 FOR H= 1 TO 13

150 IF A>H THEN 170

160 PRINT CHR$ (X+187);

170 NEXT H : PRINT

180 FOR H= 1 TO 13

190 IF B>H THEN 200

195 PRINT CHR$ (Y+187);

200 NEXT H : PRINT

210 IF A=B THEN 300

220 FOR A=1 TO 100: NEXT A:S=S+1

225 IF S+G+L >52 THEN 500

230 GOTO 10

300 FOR A= 1 TO 180

310 LET X=USR(0): IF X<>0 THEN 330

320 NEXT A

330 IF A>60 THEN 400

340 FOR A=1 TO 100

350 PRINT "YOUR SNAP"

360 NEXT A

370 G = G+1

380 GOTO 10

390 PRINT

FOR A=1 TO 100

400

410 PRINT "MY SNAP"

420 NEXT A

430 L=L+1 440 GOTO 10

0

500 PRINT "FINAL SCORE"

510 PRINT "YOURS";G;"MINE";L

Calculator Corner cont. from p.107
too difficult when you know how, but it should not be necessary. Texas Instruments please note.
In spite of the minor problems, and no machine is perfect, I hope that I have
been able to demonstrate the extra
scope available with the application of some imagination to the use of these inexpensive but powerful calculators.
Postscript
Mr Horwood has expressed his willingness to answer any further enquiries about these applications. You can write to him at: 11 Melville Hall, Holly Road, Edgbaston, Birmingham B16 9NJ (and not to PCW please!).
Here, to stop you all pestering me, is the
answer to the problem which Rolf Howarth set in his TI59 Pseudo Op
codes article: -
It is possible to examine the internal routines which perform the P/R, decimal/sexagesimal and statistic operations by keying in the following:
10 Op 17 (6 Op 17 for the TI58) 99 STO 00 Pgm 01 A CLR D.MS

Then press LRN and examine the program using SST. Note that on pressing BST, Del or Ins they do not behave normally, and may crash the calculator. The program is 380 steps long, after which garbage is found - which must presumably have some purpose. Any
guesses?
The routines start at the following
steps:

Op 12

000

Op 15

047

Op 14

058

x

067

Op 11

084

INV x

107

Op 13

149

E+

192

INV E+

213

INV P/R

250

P/R

284

D.MS

303

INV D.MS 341

Noughts and Crosses cont. from p.87
Key the move, and press EXE. Moves need not necessarily be positive integers, as the program will correct the negative,
integer + fraction moves, taking the integer part only, but all moves must lie on the interval (1,9); attempts to enter either moves outside this range, or moves which have already been made, will cause the opponent to be penalised by having the move denied, and the calculator will be given the option to
move.
The calculator will display its move as above, together with the current board positions and move count. 4. If the calculator wins, the HLT status indicator will disappear, and the winning move, together with the updated

board position and move count, will flash alternately with '2' in the same format. No further moves can be made. If either player's move completes the board, that move, together with the updated board and move count, will flash alternately with '9'.
To stop the flashing, press HLT (not AC, as this only stops the flashing temporarily); (if you are impatient to play
another game, don't bother pressing
HLT, just press PO); and if you want to review the moves made by both players during the game, press MR .4; a zero in the number indicates an attempted illegal move by the opponent (except when the illegal move was attempted on
the opponent's first move in a game where the opponent moves first - not

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as daft as it sounds). For example, a game played to a draw might yield a
sequence thus:
635419827
if the calculator moved first, its move sequence would be the 1st, 3rd, 5th,
etc., numbers: i.e., 6,5,1,8,7. If the
opponent attempts to cheat, the sequence might look like this:
63504
In the above example, the opponent attempted an illegal move at the fourth
move in the game (i.e., his second move),
whereupon the calculator took immediate advantage, and won. Note that if the opponent takes the option to move first, and then enters an illegal move, the calculator will discard its original random move, and determine a first move based on its game strategy. For most games this is unlikely to occur, but when it does, the calculator always takes the centre position (5) which for-
ces a draw.
5. The program does not possess the

facility to check for an opponent win (the move time would increase) and it has remained unbeaten to date. I have learned that it is unwise to tell a prospective opponent that they cannot possibly win; either they give up immediately, or they go to the other extreme and spend hours trying to prove you wrong. It is therefore highly embarrassing when they find the only flaw in the program that allows them to win (and they never let you forget it!). So this program is not unbeatable, only unbeaten. If anyone CAN beat it, I'd be interested in the move sequence (naturally).
For users of other calculators or com-
puters the following notes may be
useful: Min n = Enter Memory n (STOn) MR n = Recall Memory n (RCLn) INV is merely a SHIFT (2nd Function) instruction and may be ignored. GSB = GOSUB RNDn = Round off to n digits

Pet Printer Pep -Up cont. from p.91

034D E6 10

INC POINTER HI

034F E6 OF

$8 INC POINTERLOW

0351 DO 02

BNE $9

0353 E6 10

INC POINTER HI

0355 E6 OF

$9 INC POINTERLOW

0357 DO 02

BNE $10

0033559B

E6 Al

10 00

INC POINTER HI
$10 LDA (90,X) get byte

035D DO OF

BNE $1 end of line?

035F E6 OF

$6 INC POINTERLOW

0361 DO 02

BNE $11

0363 E6 10

INC POINTER HI

0365 E6 OF

$11 INC POINTERLOW

0367 DO 02

BNE $12

0033669B

E4C6 1404

03

$12

INC
JMP

POINTER HI $3

036E C9 22

$1 CMP gX`22' opening quote?

0370 DO E3

BNE $9

0372 E6 OF

$7 INC POINTERLOW

0374 DO 02

BNE $5

0376 E6 10

INC POINTER HI

0378 Al 00

$5 LDA 00,X) get next byte

037A FO E3

BEQ 6 end of line?

037C C9 22

CMPEX'22' closing quote?

037E FO D5

BEQ $9

0380 C9 Cl

CMP£X`C1'

0382 90 08

BCC $12

0384 C9 DB

CMPEX`DB'

0386 BO 04

BCS $12

0388 29 7F

AND 2X`7F' remove shift bit

003388AC841C 7002 03 $12 JMSTPA

(00,X)
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Listing 3

35000 I=1027 -REM UNSHIFT PROGRAM

35010 F=1,A=256*PEEK(1+1)+PEEK(I):IFFD34999THENPRINT PRINT"FINISHEDEND

35020 PRINTA:I=I+1

35030 I=I+1,X=PEEK(I),IFX=OTHENI=I+3,007035010

35040 IFX=34THENF=-1*FOOT035030

35050 IFF=1THEN35030 35060 IFX>192ANDXC219THENX=X-128,POKEI.X 35070 G0T035030 READY.

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Checkout cont. from p.76
ed, legs down, into a layer of antistatic foam, and timing is initiated by closing the lid. At the end of the 8 minutes (or so) the light switches off and a beeper sounds with a pleasant but insistent note to attract attention.
The box is well sealed against escape
of UV light. I examined it in a dark
room with the light operating and could detect only a very faint leakage, right at

the back. There is thus no risk of inadvertently exposing the eyes to UV
light.
Overall then my conclusion is that the UV8 is well made, good value at the price, and very efficient at its job. It would certainly be a good buy for any industrial user of EPROMs and even some hobbyists could find it a worthwhile investment.

Pascal cont. from p.95

pointer type POINTER (line 9) and the

arises.

declaration of the pointer variables

The first thing to notice in program
ESTATE is the declaration of the

FIRSTFILLED etc. as type POINTER in line 23. The record FLAT is declared

in lines 14 to 21 and line 17 declares the
field NEXT as a field of type POINTER. It is this mechanism which allows the
linked list to be formed since the address of the next flat will be stored in
NEXT.
In order to make the program both interactive and complete, the main program offers the user a MENU of different options (lines 50 - 55) including: INITIALISE - which "commissions" the block to start with. MOVEIN and MOVEOUT - which manipulate the flats between the two
linked lists.
FREEFLATS and TENANTLIST which offer the user the opportunity
of listing the vacant or occupied flats at any time. Procedure INITIALISE (lines 67 - 87)
constructs the entire linked list once the number of flats is known (line 71). First, two listhead pointers are initialised (72 and 73) and a record of type FLAT is created in line 76. Then the relevant data are assigned to the fields of the variable LINKtN(77 - 85). Note the two pointer assignments on lines 79 and 84. NEXT is the pointer field within the record so that the first time through, NEXT is set to NIL and this record will always be the last record in the list. In line 84, the pointer to this record (LINK) is assigned to FIRST FREE so that when the next record is created, this value can be placed into its NEXT field (line 79 again). The second record is thus linked to the first.
Procedure MOVEIN is designed to allow a predefined number of flats to be allocated to families. In order to do this a second linked list is formed although no new FLAT records will be created. Instead, some of the links in the current vacant list will be broken and new ones forged to build up a list of occupied flats. Procedure FIND FLAT tests for the first vacant flat and, if one is there, passes its pointer address to the pointer NEXTFLAT so that when the next procedure, FILLFLAT, needs the flat record it has merely to reference NEXTFLAT n (line 140). FILLFLAT however also has the tricky job of linking the new flat into the list of occupied flats so that the tenants' names are in alphabetical order. This is done in SETPOINTERS with the help of the Boolean function BEFORE (106 - 117) which returns the value TRUE provided that the first string passed to it (N1) comes before the second (N2), taken alphabetically. BEFORE is a recursive function (line 116) which recalls itself as long as there are still uninspected characters left in the string (tested for in lines 108 and 110) and as long as corresponding characters in the two strings (referenced by the integer P) are identical (checked in lines
112 and 114). Note the use of the
PASCAL standard function ORD which
maps its argument (which must be a
character) onto a set of integers, one for each character in the character set. The letters of the alphabet form part of this character set so that two letters can be compared as in line 112 and alphabetically ordered by placing the lower one first. (i.e. A<B<. . .<Z).
SETPOINTERS itself is an example of the ease with which a linked list can be used. Line 121 (and 128) ensures that the search loop will run until the end of the list is reached if necessary.

Line 130 drives the search through the list by redirecting the search pointer (LINK) to the record indicated by the current record's pointer field. Once the correct place in the list has been found, control moves to the final sequence of SETPOINTERS (133 - 137), where the new flat is detached from the list of vacant flats, its link pointer being assigned the address of the next record up the list while its address is passed to the pointer field of the last record down the list (or the listhead pointer if necessary). Procedure MOVEOUT performs the opposite process, seaching out specified occupied flats and removing them from the list (EVICTIFTHERE) and ensuring that the flat that has been vacant longest will be the first to be filled (TIDYUP). Further use is made of recursion in EVICTIFTHERE and TIDYUP, demonstrating how concisely a linked list may be traversed (lines 181 and 194). In comparison the procedures FREEFLATS and TENANTLIST access the same lists but iteratively. Note how EVICTIFTHERE deletes a record, pinpointing the flat to be cleared in line 178 and excluding it from the list by linking its immediate neighbours together in line 179. Exercises: (1) No-one would use a program like this because as soon as the machine is switched off all the data would be lost. Write procedures to dump both lists onto disc files at the end of each day and to build up a new heap from the same disc files when the system is booted up next morning.
(2) Modify FINDFLAT so that it finds the first vacant flat in the list with sufficient rooms to provide at least one
room per person.
Variant field records
It is a frequent occurrence that the data one wishes to associate together in one record will not fit conveniently into any fixed record format. For these occasions PASCAL provides a means of building variants into the record declaration so that a portion of the record can contain alternative (and different) formats depending on the nature of the items in the fixed part of the record.
An example of this feature appears in the program in Box 6. The information required in the record of a vacant flat (e.g. date last occupied) is quite different from the information needed for an occupied flat (name of tenants and size of family). Consequently, in the record declaration of FLAT (lines 14 - 21) the first few fields are common to both types of flat but at line 18 some sort of split has to be made. This is done by means of a CASE statement which must enumerate the different possibilities open at this point.
The format for such a variant field
declaration is as follows: CASE tag field : type OF
constl : (fields of constl) ; const2 : (fields of const2) ;
Note that there is no "END" reserved word to close off the case statement. The tag field is a variable (common to all records) which acts as a selector, picking out the appropriate variant format. In ESTATE the tag field is STATUS (line 18) which can be either VACANT (implying a variant field

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Exam Questions

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MICROTYPE
STAK- PAK CASSETTE STORAGE SYSTEM FOR EASY PROGRAM FILING.

Each drawer section takes 2 cassette.

OPP'

Og
0011
.00. ./IF

Chewers lock together vertically.
Each twin pack comes with 2 C10 digital cassette.

,, .....1 So
PM, ..- 1P-00
il-,...
iroo. l'

Zish, ciattruu7Pd=il="
FIVE TWIN PAKS 110 CASSETTES/ FOR 06.60 INC. VAT & P&P. Send cheques or Postal Orders to: MICROTYPE, PO Box 104, HEMEL HEMPSTEAD. HEATS HP2 70Z.

PCW 129

1
MICRO

SURPLUS EQUIPMENT

MUST GO

Heath WHI4 Printer.

built and tested

360.00

Teletype ASR 33 (with tape read

and punch) recently refurbished (300.00

S.S.M. 104 SIO0 2 serial/4 parallel

2Oma 0 RS232. built and tested 90.00

S.S.M. SI00 Extender Board

8.00

Exidy Sourcerer 32K 0 5100 850.00

Expansion Box

Sinclair Mk14 Boxed with P.S.0

and decent keyboard

30.00

Vero S 100 W .W bare board

8.00

Newbury Labs professional 80 x 21

VDU 110/300 Baud. RS232

180.00

TASA ASCII Touch

Keyboard uc/Ic

32.00

Attention Micropolis Mod II owners

Phone toi details of Users Club

Phone 0670 822790/733125

WHAT "Turns a board into a real computer"?

MICROCASE!

We make cases for micros. Stylistly designed. Beautifully made.
Room for extensions + PSU.

SUPERBOARD COMPUTKIT
NASCOM 2 or UNCUT FOR OEM USE

From your dealer or write to: MICROCASE
Simple Software Ltd 15 Havelock Road Brighton BN1 6GL.

+ SOFTWARE FOR SUPERBOARD +

SMALL TURNKEY SYSTEMS

Applications specialists with

CROMEMCO/CENTRON ICS/CI F ER

systems in:

Financial Planning

Budgeting
Schedule Order Handling filk

Invoicing

1111110

Ledgers
Information Index

411111.

TANDY/CENTRONICS in

Builders Commercial Systems

in BASIC - source available
Expandable to: -Multi-user systems -10 Mb Hard discos We aim to solve YOUR problems.

Supply : Support : Service

Contact: Alan Perry 01-272 3530 or 01-263 1951

APPLE II : ITT 2020 RELOCATED INTEGER

A large number of programs written for the Apple II in Integer Basic will not run on ITT, Palsoft or Apple II Plus machines without an Integer Basic Card. The problem can now be overcome using

RELOCATED INTEGER, a revised software version of Integer Basic which will accept

all Integer programs.

Relocated Integer remains co -resident in memory with both disc and cassette system

and also makes available the Mini -Assembler facility.

Cassette Version £12

Disc Version E14

Specify whether 32K or 48K system.

D.J. BOLTON, TH E OLD SCHOOL HOUSE, 1 BRANCH ROAD, PARK STREET, ST. ALBANS. TELEPHONE 10727172917.

named LASTDATE) or FILLED (implyMg FENANIPS).
When a record is assigned (e.g. lines
140 -- 143), as soon as STATUS is defined, the required variant field is
selected and can itself be subsequently
assigned. If STATUS is altered (lines 189 -- 192) the new variant is auto-
matically switched in and overwrites

the previous data. Note that a record type may only contain one set of variant
fields (i.e. one CASE statement)
although record types (with their own variant fields) may be nested within the ,variations. Box 7 contains the syntax diagrams for both pointer types and
record field variants.

30: READLN ;

31:

I := 0 ;

Pascal Box 6 cont. from p.94

32: REPEAT

33:

I := I + 1 ;

34:

READ(NCID

35: UNTIL EOLN OR (1=20) ;

36: FOR J := I+1 TO 20 DO

37:

NEJ] := '

38:END ; (STREADLN)

39:FUNCTION LENGTH(N : NAME) : INTEGER ;

40:VAR I : INTEGER ;

41:BEGIN

42:

I := 20 ;

43: WHILE (DO) AND (N[1]=' ') DO

44:

I := I-1 ;

45: LENGTH := I

46:END ; (LENGTH)

47:

48:PROCEDURE MENU ;

45:BEGIN

50: WRITELN('O. EXIT FROM THIS PROGRAM.') ;

51: WRITELN('1. SET UP A NEW ESTATE.') ;

52: WRITELN('2. MOVE NEW TENANTS IN.') ;

53: WRITELN('3. MOVE TENANTS OUT.') ;

IF 54: WRITELN('4. SEE FREE FLATS.') ;

55: WRITELN('5, SEE LIST OF TENANTS.')

56:END ; (MENU)

57:PROCEDURE GETDATE ;

38:BEGIN

59: WITH NEWDATE DO

60: BEGIN

61:

WRITE('DAY--->") ; READ(DAY);

62:

WRTTE('MONTH--->") ; READ(MONTH) ;

63:

WRITE('YEAR--->') ; READ(YEAR)

64: END

65:END I(GETDATE)

,...

66:

67:PROCEDURE INITIALISE ;

68:VAR NUM, I : INTEGER ;

69:BEGIN

70: GETDATE ;

71: WRITE('NUMBER OF FLPTS--->') ; READ (NUM) I 72: FIRSTFILLED := NIL ;

73: FIRSTFREE := NIL ;

74: FOR I := 1 TO NUM DO

75: BEGIN

76:

NEW(LINK) ;

77:

WITH LINK^ DO

78:

BEGIN

79:

NEXT := FIRSTFREE

;80:

WRITE('FLAT NUMBER--->") ; READ(NUMBER) ;

81:

WRITE('NLIMBER OF ROOMS--->') ; READ(ROOMS) ;

82:

STATUS := VACANT ;

83:

LASTDATE := NEWDATE I

84:

FIRSTFREE := LINK

85:

END

86:

EN'

0

87:END ; (INITIALISE) 88:PROCEDURE MOVEIN ;

0

89:VAR I, NUM : INTEGER ;

90:

FOUND : BOOLEAN ;

91:

NEXTFAMILY : FAMILY ;

92:

NEXTFLAT, PREVIOUSLINK : POINTER ;

93:PROCEDURE FINDFLAT ;

94:BEGIN

95: IF FIRSTFREE = NIL

96: THEN FOUND := FALSE

97: ELSE

98: BEGIN

99:

FOUND := TRUE ;

100:

NEXTFLAT := FIRSTFREE

101: END

102:END ;

103:PROCEDURE FILLFLAT ;

104:PROCEDURE SETPOINTERS ;

.., 105:VAR CONTINUE : BOOLEAN ;

vg 106:FUNCTION BEFORE(NI, N2 :NAME ; P:INTEGER) : BOOLEAN ;

107: BEGIN

108: IF P = LENGTH(N2)

109: THEN BEFORE := FALSE

110: ELSE IF P= LENGTH(N1)

III:

THEN BEFORE := TRUE

112:

ELSE IF ORD(N2EP1) < ORD(N1CP1)

113:

THEN BEFORE := FALSE

114:

ELSE IF ORD(N1CPJ) < ORD(N2CP])

115:

THEN BEFORE := TRUE

116:

ELSE BEFORE := BEFORE(N1,N2,P+1

117:END ; (BEFORE)

118:BEGIN (SETPOINTERS)

119: LINK := FIRSTFILLED ;

120: PREVIOUSLINK := FIRSTFILLED ;

130 PCW

121: 122:

CONTINUE := LINK C> NIL ; WHILE CONTINUE DO

123: 124: 125: 126:

BEGIN IF BEFORE(NEXTFAMILY.SURNAME, LINK".TENANTS.SURNAME, 1) THEN CONTINUE := FALSE ELSE

MICRO_....`RT

-

i

127:

BEGIN

128:

CONTINUE := LINK <> NIL ;

129: 130:

PREVIOUSLINK := LINK ; LINK := LINK^.NEXT

TRS80 or PET

131: 132: 133: 134:

END END ; FIRSTFREE := NEXTFLAT".NEXT ; (TAKE FLAT OFF FREE LIST) NEXTFLAT-.NEXT := LINK ; CLINK NEW FLAT INTO OCCUPIED LIST)

16K 'THE ANTIQUE GAME'
A realistic instructional business
simulation including auctions, realistic

135: 136: 137:

IF (FIRSTFILLED = NIL) OR (PREVIOUSLINK=LINK) THEN FIRSTFILLED := NEXTFLAT ELSE PREVIOUSLINK-.NEXT := NEXTFLAT

pricing from £50 to £5,000. Stolen property. Thousands of different items

138:END ; (SETPOINTERS)

to buy and sell. Interesting characters

139:BEGIN (FILLFLAT) 140: WITH NEXTFLAT^ DO

to deal with. One to four players.

141:
0 142:
143: 144:
145:

BEGIN STATUS := FILLED ; TENANTS := NEXTFAMILY ; SETPOINTERS
END

Price £15 inclusive (VAT, post and packing.)
from

146:END ; (FILLFLAT)

,... 147:BEGIN (MOVEIN)148:

IP

WRITE('HOW MANY NEW TENANTS--->") ;

149: READ (NUM) ;

150: FOR I := 1 TO NUM DO

151: BEGIN

Island Software
132 Ashleydown Road, Bristol 7. Telephone enquiries to: 0272 513121

152: 153:

WITH NEXTFAMILY DO BEGIN

'NESTFARTHING COMPUTERS

154:
W... 1'5:
156: 157: 158: 159:

WRITE('SURNAME--->') ; STREADLN(SURNAME) ; WRITE('SIZE--->") ; READ(SIZE) ; FINDFLAT ; IF FOUND THEN FILLFLAT ELSE WRITELN('CAN-T BE DONE.')

Thinking about a computer? Get independent professional advice
Also PERSONAL CLIENT SERVICE

160: 161:

END END

for potential home users.

162:END ; (MOVEIN)

Phone Helston (03265) 4098

163:PROCEDURE MOVEOUT ;

164:VAR LASTNAME : NAME ;

165:

FOUND : BOOLEAN ;

for brochure.
Please note: we do not sell computers or

166:

I, NUM : INTEGER ;

accept commissions on sales.

167:

EMPTYFLAT : POINTER ;

168:PROCEDURE EVICTIFTHERE ( VAR EMPTYFLAT, LINK:POINTER ); 169:BEGIN 170: FOUND := TRUE ;

0

MICROCOMPUTER

CONSULTANTS

171: 172:

IF LINK = NIL THEN FOUND := FALSE

SOFTWARE FOR THE NEW ROM PETS

173: 174: 175: 176: 177:

ELSE BEGIN
IF LINK-.TENANTS.SURNAME = LASTNAME THEN BEGIN

COMMAND KEY A 300 byte machine -code routine that turns the shift key into a
commend key when used outside quotes. Single key entry of BASIC words. Squeeze complex IF & DE F's onto one line.
Logical layout with template provided. Also gives optional repeating keys and a onekey monitor call. E3&0

178: 179: 180: 181:

EMPTYFLAT := LINK ; LINK := LINK'',NEXT END ELSE EVICTIFTHERE (EMPTYFLAT, LINK -.NEXT)

LIBRARIAN Keeps a commented catalogue with fast -forward location of ell
subsequent programs on a tape. New programs of any length can be added at any time Not a tuturial - ready to run.
E4.50

182: END 183:END ; (EVICTIFTHERE) 184:PROCEDURE TIDYUP (VAR LINK : POINTER ; EMPTYFLAT :POINTER) ; 185:BEGIN

PALETTE Four test machineicode subroutines in one program to fit in the second
cassette buffer. Set or clear a quarter pixel, instant screen reverse. block transfer and screen wash.
E3.50

., 186:
W 187:
188:
189:

IF LINK = NIL THEN BEGIN
LINK := EMPTYFLAT ;

Mail order only. Send or phone for free list.
MYCROFT 262 Francis Chichester Way, London SW11 SHY,
Tel. 01720 0991

190:

LINK^.NEXT := NIL ;

191:

LINK^.STATUS := VACANT ;

192:

LINK^.LASTDATE := NEWDATE

10n: END

r

194: ELSE TIDYUP (LINK^.NEXT, EMPTYFLAT) 195:END ; (TIDYUP) 196:BEGIN (MOVOUT)

TOPMARK

197: 198: 199:

GETDATE ; WRITE ('HOW MANY FAMILIES ARE LEAVING--)') ; READ (NUM) ;

Computers

200: FOR I := 1 TO NUM DO

201: 202:

BEGIN WRITE ('WHAT IS THE SURNAME OF THE LEAVING FAMILY-->') ;

dedicated to

203: 204: 205:

STREADLN(LASTNAME) ; EVICTIFTHERE(EMPTYFLAT, FIRSTFILLED) ; IF FOUND

APPLE II

206:

THEN TIDYUP (FIRSTFREE, EMPTYFLAT)

207:

ELSE WRITELN (LASTNAME, ' DONT LIVE HERE.')

kA,

208: END

209:END ; (MOVEOUT)

_____-,,, 0_

210: 211:PROCEDURE FREEFLATS ;
212:BEGIN213:

-0-6,-gf.gg*3,,-cOgo-'"

WRITELN ('FLAT NUMBER

ROOMS') ;

214: LINK := FIRSTFREE ;

215: 216: 217:

WHILE LINK <> NIL DO
BEGIN WRITELN(LINK^.NUMBER,

',LINK -.ROOMS) ;

Simply the best!

218: 215:

LINK := LINK".NEXT END

Fuil details from Tom Plercy on

220:END ; (FREEFLATS)

Huntingdon (0480) 212563

221:PROCEDLIRE TENANTLIST ; 222:BEGIN

L-

_J

223: 'WRITELN( NAME

FLAT NUMBER') ;

-A

PCW 131

MICROIVIAR1'

A COMPILER FOR
TRS-80® BASIC

Southern Software ACCELERATOR speeds execution of BASIC programs
by compiling the common statements to Z80 machine -code.

Develop and debug normally. Compile for production work.

Properly -structured, error -free

level 2 programs only.

£19.95

SOUTHERN SOFTWARE,PO Box39 Eastleigh Hants. S05 5W0

50 HZ SUPER BOARD NOW FROM ONLY
£15995
Plus P&P & VAT
Include 8K BASIC, 4K RAM
KEYBOARD etc FITTED MODULATOR EXTRA
CTS 1 Higher Calderbrook,
Littleborough, Lancs, OL15 9N L Tel: Littleborough (0706) 79332
anytime

224: 225:
226:

LINK := FIRSTFILLED ; WHILE LINK <> NIL DO BEGIN

227:

WRITELN (LINK^.TENANTS.SURNAME, LINK^.NUMBER) ;

228:

LINK := LINK^.NEXT

229: END

230:END ; (TENANTLIST)

231:

232:BEGIN (MAIN PROGRAM)

233:

REPEAT

234:

MENU ;

235:

WRITE('YOUR CHOICE-->') ; READ(CHOICE) ;

236:

WRITELN ; WRITELN ; WRITELN ;

237:

IF (CHOICE>5) OR (CMOICE(0) THEN CHOICE := 0 ;

238: 239: 240:

CASE CHOICE OF 0 : WRITELN('GOOD BYE') ; 1 : INITIALISE ;

241: 242:
243: 244:

2 : MOVEIN ; 3 : MOVEGUT ; A : FREEFLATS ; 5 : TENANTLIST

245:

END ; (CASE)

246:

WRITELN ; WRITELN ; WRITELN

247:

UNTIL CHOICE = 0

w 248:END.

PROGRAMS

PET Backgammon
by J. Aughton

We figured that as "Programs" is somewhat short this month we would give you a real treat.
This program is one of the best that we have ever received at PCW; it will more than repay the effort involved in keying it in.
You will notice a POKE in line 9010.

This is because the original program used lower case letters in the "instructions" section. As you probably know this produces gibberish on the PET printer. We've left the POKE there in case you decide to restore the instructions to their former glory.

<S>UTME300,g`fr

2.0 REM*************************

40 REM*

BACKGAMMON

*

- WE TRY HARDER All the extras for your machine

50 REM*

*

60 REM*

EY J.ALIGHTON

*

in our latest catalogue. Racal Zonal C12 cassettes (10 for £3.95); Verbatim 5'4in. diskettes (10 for £25), Bin single density (10 for £321 or double density (10 for £39); PET parallel interface £39 or £65 with decoding; ribbons, paper etc. etc. PLUS nearly 40 great PET programs at £1-£12. Post free but add 15%
VAT to all prices.

70 REM*************************
0 80 14(1)=-300:14(2)=500:W(3)=100
90 W(4)=-300:14(5)=-500,14(6)=-1200
100 4l(7)=70,14(8)=700,REM WEIGHTS
110 DIMFiS(6),A%(.25),P%(.12),0%(12)
120 11$=".IIIIII1.-DWKOI4QKKODIMPI"
130 DEFFNA(X)=INT(X*RND(7)+1)

SUPERSOFT 28 Burwood Avenue, Pinner, Middx.

140 A$(1)="8 AWN im MOM "
Mill " 150 A$(2)="N 0011111 AMMO "
A$(3)=" N MUM

160

STOP PRESS PET GAMES PACK: 17 GREAT GAMES FOR JUSTUS

170 A$(4)=" J 04111 OM 0"

180 A$(5)=" i SIMONI AMEN 0"

190 A$(6)="Ns 'MOM 0:1111110 si"

e 200 Z$="

":00T09000

500 REM INITIALISE

510 F=0:BH=0:EP=0,NH=1541P=15

30 ST. JOHNS ROAD ...s, TUNBRIDGE WELLS

520 PESTORE,FORI=1T012,READAVI) 530 AV25-I)=-A%(I),NEXT

KENT

540 DATA2,0,0,0,0,-5,0,-3,0,0,0,5

Telephone 11 ,bridge Wells 10692141956

550 PRINT"OFRESS SPACE TO START ";

560 PRINT" IN THE USUAL WAY

(0) DIGITAL MICROSYSTEMS

570 GETWIFA$0" "THEN570

LOW COST BUSIVESS COMPUTERS

575 POKE59468,12

580 PRINT":10101000119 PET YOU

ONE to 29 MEGABYTES DISK STORAGE

585 PRINT"OI PLAY ill - YOU PLAY 0

64 Kbytes of Men Memory - STANDARD

590 GOSUE4000,IFP=OTHEN590

DSC-2

Digital Research CP M operating system STANDARD
TEXT PROCESSING BASIC COBOL FORTRAN evadable

600 GOSUE5600:60SUB5600,00SUE6000 610 GOSUP.5000:F=1:FM=1,IFP>OTHEN2000 620 0001040 1000 REM HUMAN MOVE 1010 GOSUB5500

32 to 96 MEGABYTES DISK STORAGE

HEX 29

32 USER & 16 TASK capabety STANDARD Reentrant ASSEMBLER Et BASIC STANDARD

1020 PRI- NT"PRE SPACE TO ROLL DICE 1030 GETWIFAVD" "THEN1030 1040 GOSU84000:K=0:M=2:IFP=OTHENM=4 1050 FM=0:60SUE5500:60SUB1510

Floppy disk based development system evaiable

1060 PRINT"YOUR MOVE WITH THE"P;"? " 1070 GETWIFAS=""THEN1070

MODATA slo need DEALERS in parts of U K and IRE t ANC

1080 N=ASC(A$)-64 1090 IFN>260PW1THEN1050

1100 PRINTWIRI=25THEN1330

132 PCW

PROGRAMS
1105 IFN=26THEN1370 1110 IFBH=OTHEN1140 1120 308035500,PRINT"YOU'RE ON THE BAR
1130 G03U35600 , GOTO 1 050 1140 REM
1150 IFA%(N))0THEM1180 1160 GO8035500:RRINT"NOTHING THERE 1170 nOT01130 1180 I- FN+P(25THEN1220 1190 IFHI=NHTHENF=0:GOT01410 1200 GO%B5500:PRINT"OFF THE BOARD
!
1210 G0f01130 1220 IFAVN+P)>-2THEN1250
1230 003035500: PRINT"SORRY IT'S BLOCKED 1240 GOT01130 1250 A%(N)=A%(N)-1:GOSUB5000,N=N+P
1270 1260 IFA%(N)>-1THEN1290 A%(N)=0:BP=BP+1:GOSUB5500
1280 PRINT"OUCH !-YOU GOT ME 1290 AVN)=A(N)+1,M=M-1GOSUB5000 1300 P=0:IFM>OTHEN1050 1310 GOT02000 1330 IFBHTHEN1350 1340 GOT01160 1350 IFA%(P)<-1THEN1230 1360 N=0:BH=BH-1,110101250 1370 IFK=OTHEN1400 1380 G08U35500,PRINT"YOU'RE STUCK(?)
1390 0031 IB5600 : 00102000
1400 K=P:P=O:Q=K:G0T01050 1410 IFN+P>25THEN1460 1420 HH=NH-1:IFNHTHEN1450 1430 GOSUB5500:PRINT"YOU WIN
1440 1305UB5600:00-107000 1450 A7.:(N)=A%(N)-1:N=0,60101290 1460 FORI=I9TON-1 1470 IFAVI)<=0THEN1500 1480 00SU35500:PRINT"YOU CAN'T -YOU 1490 PRINT"CAN MOVE AT ";CHR$(1+64),GOT01130 1500 NEXT,GOT01420 1510 HI=0:FORI=19T024 1520 IFK:( I )>OTHENH I =HI +AV I ) 1530 NEXT:RETURN 2000 REM PET MOVE
. 2010 K=0:GOSUB5500:PRINT"IT'S MY MOVE w 2020 GOSUB4000:M=2:IFP=OTHENM=4
2030 FM=0,IFBP>OTHEN2240 2040 PI=0:FORI=1T06 2050 IFA%(I)<OTHENPI=PI-AVI)
. 2060 NEXT:IFFI=NPTHENF=0:GOT02320 w 2070 GO5:UB4500:GOSUB3000
2080 IFOM>OTHEN2210 2090 IFPWATHENN=PM):GOT02120 2100 GOSUB5500:PRINT"I CAN'T MOVE
. 2110 GOSUB5600,00-101000
'' 2120 GOSUB5500,PRINT"WITH THE";P; 2130 PRINT"I"LL MOVE ";CHR$(64+N) 2140 A(N)=A%(N)+1:GOSUB5000:N=N-P 2150 IFAVN)<1THEN2180 2160 AVN)=0:BH=BH+1,GOSUB5500 2170 PRINT"TAKE THAT ! 2180 A(N)=A%(N)-1,M=M-1:005UB5000 2190 K=1:P=0:IFM>OTHEN2030 2200 00101000
. 2210 IFPM=OTNEN2230 w 2220 IFFMCQMTHENN=PVX):00T02120
2230 H=0%(Y):K=P:R=0:0=K:001-02120
0 2240 IFA7.:(25-0)<2THEN2280
2250 IFFO.:(25-P)<2THEN2270
. 2260 GOT02100 w 2270 N=25:BP=BP-1:0102120
2280 IFAV25-P..<2THEN2300 2290 K=P:P=Q:O=K:GOT02270 2300 GOSUB4500:IFOM<=PMTHEN2290 2310 0OT02270
w 2.320 IFAVP)>=0THEN2390
2330 GO33UB5500,PRINT"I WILL BEAR " 2340 PRINT"OFF WITH THE"j' 2350 HP=NP-1:IFNPTHEN2380
2:360 GOSU35500 : PR INT "1 WIN 370 GOB UE5600 : G0708000
2380 N=P:A%(N)=A7.:(N)+2:00702180 2390 FORI=6TO1STEP-1 2400 IFA%(I)<OANDI)PTHEN2070 2410 IFA%<I)<0THEN2430 2420 NEXT 2430 GO5;U35500,PRINT"I CAN BEAR OFF "; 2440 PRINTCHR$(64+I)" WITH THE"j'
2450 P=I : BOT027.;50
3000 REM INTELLIGENT MOVES
3003 IFKTHEN3010 3005 GrISUB5500,PRINT"LET ME THINK.. 3010 IFFII=OTHEN3170 3020 IFHI=NHTHEN3500 3030 E=-9999:F0RI=1TOPM,H=0

MICROMART
i

Horizon Business Systems Incomplete Records, Sales, Purchase, Nominal Ledger, Letter Writers, Stock Control,
etc. We write packaged or bespoke
software for North Star Horizon MICOSYS LIMITED 58 High Street, Prescott, Merseyside L34 6HQ. Tel: 051 426 7271
Computer bureau service now available.

PASCAL SUBSET FOR NASCOMS

The first PASCAL subset for cassette -based

systems
- produces Z-80 objbct code directly: no P -

codes

-- occupies only 4k RAM all major PASCAL statements, integer

arithmetic, - WRITE(LN) (formated), READ(LN),INCH,

(D)PEEK, (D)POKE, USER, RANDOM, HALT

- fully recursive procedures 12K BASIC FOR NASCOMS

All the features of a Microsoft BASIC plus:

- 12 digit precision

- PRINT USING, list variables, 0/P to printer

- Multi -line recursive user functions
- IF. . .. THEN .... ELSE, logical operators
- Renumber, auto line numbering

- line editor, + lots more. Above run under a new monitor, NASMON,

suitable for Ni and N2 systems with memory

board. PRICES:

NASMON monitor supplied in

3 EPROMS:

£30

PASCAL supplied on tape:

£35

BAS 12K supplied on tape:

£30

NASMON, PASCAL, BAS12K:

£85

Available Soon: Extended PASCAL (special

terms will be available for owners of initial

version), Assembler, Disassembler.

Contact:

HISOFT, 27 AVENUE DU BUDE,

1211 GENEVA 20, SWITZERLAND.

TRS-80

HIGH

PERFORMANCE

MODULE

Increase the speed and power of your

TANDY TRS-80 Level II

by

000/0

5 0°1° -co 1 EFFICIENT INTERNAL MODIFICATION

Send SAE for full details to

CENTRAL BUSINESS ASSOCIATES

P 0 Box 14

EPSOM, Surrey.

KIT: £30

Excl. VAT FITTED: £55

PERSONAL COMPUTER WORLD APOLOGISES TO FARMPLAN FOR THE TYPOGRAPHICAL
ERRORS IN THEIR AD ON PAGE 20 OF OUR MARCH ISSUE.

PROGRAMS

MINE OF INFORMATION LTD
1 FRANCIS AVENUE, ST ALBANS AL3 6BL
ENGLAND Phone: 0727 52801
Telex: 925 859
MICROCOMPUTER CONSULTANCY Et
BOOK SELLERS
,

SOFTWARE FOR TRS-80

Minimum 4K level II

NIM

Up to 9 piles and up to 50 matches per pile.

User defined or randomly generated piles and

pile sizes. Graphics used to represent piles of

matches

23.00

3TDheNgOaUmGeHTisSpAlaNyDedCRinOtShSeES64 cells of a 4 x 4 x 4 cube. With 76 possible winning
rows, the computer blocks the players' rows to the best of its own advantage. . . . 23.00

MThAeSpTlEayReMr IcNhoDoses the difficult of the game

by defining the number of colours (up to 10)

and the width of the code (up to 6 columns).

The scoring is done in the conventional way

using a 'B' to denote a black peg and a 'W'

to denote a white peg

22.00

MEMCARD Is your memory as good as you think? Well MEMCARD will reveal the truth. The com-
pguivteernrsaunidtoomr lpyipa.sAksryeocuortdo isstahteelad caasrtdootfhea nisumbabseer dofotnimpersoabcaabridliitsychaonsdena.sTthheesgcoarmineg progresses and the cards become scarcer, the bonus increases and the forfeit decreases.
23.00

HTAryNtGoMgAueNss the word before the graphic

hangman is complete. A wide range of words

from easy to diffiult

E2.00

Minimum 16K level II STARTREK Destroy the Klingons in your allotted time
limit. Beware of space storms damaging your phasers and scanning sensors . . 24.00

ANY 4 for £8.00

27 CavendNisLhCCSrOesFcTenWt,AERlsEtree. Herts.

a pp Ie li
susinsex
complete user service
Apple & Microstar, hardware & software
systemsfor Micropad handprint data entry

OVaicemputer systems
elm park. ter ring. %Northing, west sussex tel 0903- 44831
134 PCW

3040 U=P%(I):V=W(7)*U 3050 A:4(U)=A%(U)+1:IFM(U-P)<1THEN3070 3050 H=1:AX(U-P)=0:V=V+W(8):IFU>t8+PTHENV=V+450 3070 AX(U-P)=AX(U-P)-1 :3080 FORJ=1T024:IFAVJ)>=0THEN3130 3090 L=5:IFF1%(j)>-6THENL=-M(J) 3120 V=V+W(L)-200*(L=1)*(J<7) :3130 NEXTJ:IFV>ETHENE=V:X=I
3140 A7.:(U)=A%(U)-1
3150 IFH=1THENAMU-P)=0 3160 A%(U-P)=A%(U-P)+1:NEXTI 3170 IFKOR(QM=0)THEN3400 3180 D=-9999:FORI=1TOOM:H=0 3190 U=MI):V=W(7)*U
3200 A7.:(U)=A71.(U)+1:IFA%(U-0)<1THEN3220 3210 H=1:M(U-Q)=0:V=V+W(8):IFU>18+QTHENV=V+450
3220 AM-0)=AN(U-0)-1 3230 FORJ=1T024:IFAWJ)>=0THEN3270
3240 L=6:IFM(J).,.-5THENL=-A74(J)
3260 V=V+W(L)-200*(L=1)*(J<7)
3270 NEXTJ:IFV>DTHEND=V:Y=I 3280 14%4U)=M:(U)-1 3290 IFH=1THENAX(U-Q)=0 3300 AVU-0)=FMLI-Q)+1:NEXTI 3310 OM=12:IFD>ETHENPM=12 3400 RETURN 3500 X=PM:41=QM:PM=SON(PM):0M=SON(OM) 3510 GOT03400 4000 IFFMTHEN4050:REM DICE 4010 P=FNA(6):Q=FNA(6):T=TI 4020 IFTI-T>120THEN4040 4030 P=P+1:IFP>6THENP=1
0 4040 0=Q+1:IFQ>6THENC1=1
4050 PRINT"1011411";DCWP);"111111";A$(0) 4060 IFTI-T<210THEN4020 4070 RETURN 4500 REM GENERATE AVAILABLE MOVES
4510 PM=0:QM=0:FORI=17024 4520 IFM(I)>=0THEN4590
0 4530 IFI-P<1THEN4560 4540 IFK(I-P)>1THEN4550
4550 PM=PM+1:P7.(PM)=I 4560 IFK>00RI-OUTHEN4590 4570 IFAX(I-Q))1THEN4590 4580 OM=QM+1:OX(0M)=I 4590 NEXT:RETURN 5000 REM PRINT PIECES
v 5010 B$="411MW":W$="All":T=0:00SUB5110
5020 B$=B$+D$+LEFT$(D$.8):W$="711"
5030 T=1:GOSUB5110 5040 PRINT"38";WSPC(21); 5050 IFBP=OTHENPRINTZ$:001.05070
5060 FORI=1TOBP:PRINT"O Ir;:NEXT 5070 PRINT"A";14;"MM";SPC(21); 5080 IFBH=OTHENPRINTZ$:GOT05100 5090 FORI=1TOBH:PRINT"0 II";:NEXT 5100 RETURN 5110 FORI=1T012:V=T*(25-I)-I*(T=0) 5120 IFVONANDF>OTHEN5200 5130 A$=" ":IF(VAND1)=OTHENA$="S P" 5140 PRINTB$SPC(3*I-(I>6)-1); 5150 IFM(V)=OTHEN5190 5160 K=209:IFF174(V)>OTHENK=215 5170 FORJ=1TOABS(FWV)) 5180 PRINTCHR$(10;W:NEXT 5190 PRINTA$ 5200 NEXT:RETURN 5500 REM CLEAR PAGE 5510 PRINT"39";2$;ZCZCZ$;"1";:RETURN 5600 REM DELAY 5610 FORI=1T02000:NEXT.,RETURN 5000 REM DRAW BOARD
6010 B$="1 MUISH MENU RIM AM INWHHI !MIMI IMIN U"
IMMO a lie "
0 6030 PRINT":7101":FORI=1T021
6040 PRINT"S ";SPC(18);" ";SPC(18);" " 5050 NEXT:PRINT"MV":J=65:1<=1 6060 GOSUB6130:GOSUB6130 6070 PRINT" ";MLEFT$(D$;9):J=88:1<=-1 6080 GOSUB6130:GOSUB6130:PRINT" 410g" 6090 GOSUB6150:00SUB6150:PRINTD$
0 111 IP 6110 W$=" 1-1 MIMI 1:011111 IXENUI 141111 RINE RIM NMI I"
6120 GOSUB6150:00SUB6150 6125 PRINT"=";WSPC(19);"SYV":RETURN 6130 FORI=1T06:PRINT"S ";CHRS(J) 6140 J=J+K:NEXT:PRINT" ";:RETURN 6150 PRINT"N";:FORI=1T03
6150 PRINTWUCNCLIC:NEXT:RETURN
7000 REM HUMAN WIN 7010 PRINT":1THANKS FOR THE GAME!V
7020 PRINT"YOU WERE TOO GOOD FOR ME 7030 PRINT"$PLAV AGAIN? (Y OR N) 7040 GETWIFFa=""THEN7040

PROGRAMS

IFFIt="Y"THEN5(30 7060 END

R000 REM PET WINS;

::010 PRINT"340W !!-I WON !!V

:.020 PRINT"I REALLY ENJOYED THAT !
8030 GOT07030

9000 REM INSTRUCTIONS

9010 POKE59468,14:PRIHT"1" TAB(13);

0

9020 PR INT" EACKOAMMONN

9030 PRINT" I PLAY ALL THE USUAL,RU"; 9040 PRINT"LES; , WHICH YOU SHOULD K";

9050 PRINT"NOW BEFORE YOU PLAY ME. k1

91350 PRINT" FROM NOW ON THE ONLY ";

0

9070 PRINT"KEYS YOU NEED TO PRESS ";

9080 PRINT" ARE AS; FOLLOWS.N

9090 PRINT" A-`{ TO MOVE FROM A POINT"

9100 PRINT" Y TO RETURN FROM THE BAR"

9110 PRINT" 2 TO PLAY THE DICE IN REVERSE ORDER"

9120 PRINT"SPACE AS INDICATEDN"

9130 PRINT" IF YOU PRESS 2 TWICE YOU";

9140 PRINT" WILL SURRENDER YOUR MOVE.";

915'3 PRINT"REMEMBER THAT YOU MUST ";

9160'PRINT"USE ALL OF YOUR MOVE IF TH"

40

9170 PRINT"IS IS POSSIBLE. I WILL TRU";

9180 PRINT"ST YOU IN THIS; WAFTER A";

9190 FRINT"LL YOU HAVE TO TRUST ME";

9200 PRINT"-WHO ROLLS THE DICE?)N

9210 00T0500

READY.

LEISURE LINES

With J. J. Clessa

An excellent response to the cube pro- and travels towards Glasgow at 90mph.
blem - 127 entries were received Which train is nearest to London when

(including one from Norway), not to they pass each other (I don't believe

mention a further 25 late entries for the it - Ed).

previous palindromic square puzzle

(sorry chaps, the prize had gone). Of PRIZE PUZZLE

the 127 entries, 102 plumped for A turkey farmer has 100 cages ranged

green, 19 for yellow I wish I could say

and 6 for blue. the answer was

arinounthde

thfeoprmeriomfeatecroonftihnisuofaursmc.irTchlee

red, but the statistical evidence is too strong - GREEN is the correct solu-

cages are numbered clockwise sequentially from 1 to 100, with cage number

tion.
The problem is not too difficult to solve by trial and error (since the number of possibilities is small), if you realise that, of the five colours: 1) if a colour is present on two faces, then obviously the other four colours can

100 completing the circle and immediately adjacent to cage number 1. In each cage is a turkey.
The farmer decides to kill one turkey only per month, and in order to make his monthly selection, he counts clock -
wise N birds from the cage of last

only be on one face each, and b) when month's victim (N being the number of

a colour is only present on one face, days in that month) to obtain his cur -

then successive views showing this rent month's turkey dinner. colour must, of course, be of the same Assuming his first bird comes from

cube face. One reader, by the way, said it took
him 30 seconds to solve, whereas the

cage number 31 in January 1980, a) which will be the last bird to be eaten, and b) which bird will be Xmas dinner

Irish crossword took him 15 minutes... in 1985?

sorry to hear that, Patrick!

Note that the count is made on

Anyway, the winning entry (as BIRDS, not on cages.

picked by our biased random number Answers please on a postcard to

generator) comes from a lady (at last!). Puzzle No. 9, Personal Computer

Congratulations to Miss V. Mason of World, 14 Rathbone Place, London

Cobham, Surrey. . . your book token is W1P 1DE. All solutions must arrive

on its way.

by May 12th latest.

QUICKIE

PRIZE OF THE MONTH

A train leaves Edinburgh at 8.00am Winging its way towards the lucky

and travels to London at 60mph. At winner will be a pack of ten, C-90 blank

9.00am another train leaves London tape cassettes.

BLUDNERS

March 1980. Page 80: Macronoia needs a bit more tweaking. Line 875 should
read (J-1) not (J - I) and line 1680
should read INT(P1(J)*1000)/10 at the end of the line.
March 1980: Page 107: Mark Franklin's Ds were misread as 2s, accordingly OF36

now reads CD01 and OF4D reads C8DA.
April 1980. Page 73: Imphex lost a line immediately above Figure 2. It reads: "computer is limited to 26 single letter' Now you know why you should
feel cuckolded.

MICROMART

MICROSALES, MICROHIRE, MICROLEASE.
Micros bought, sold or exchanged
Moving to new premises in Wood Green Shopping Precinct We are also dealers in the best in micros.
See Promglow Ltd (Icarus) also in Practical Computing for details on
Intertec Superbrain.
Sales & Lease: APPLE, Intertec Superbrain, Horizon,
Sorcerer, TRS80, PET, Disk drives, printers.
Hire: Some less than £12 per week. No delivery
or collection charge in London. All systems sold complete or in parts and
there is no charge for VAT.
Bargains: Three complete TRS80110 Ils + 32K + disk
drive + 800 L's worth of software free for only £1000.
Two Sorcerer 32K £600 Two ITT2020 32K £600 Complete Horizon with disk drive £1250. PET 8K with software £400
NASCOM I for £100. Expansion 5100 available.
Challenger system
Phone for what you would like. 01-368 9002 Monday to Sunday
(evenings more convenient).
PROMGLOW LTD

CARDIFF MICRO CENTRE

PETs +
SHARP MZ-80s +
HEWLETT PACKARD
+
COMPUTER BOOKS

SIGMA SYSTEMS

54 Park Place 1

Cardiff 21515/34869

1

EAST ANCLIAN MICRO ENTHUSIASTS SEE US FIRST}

EASICOMP 'COMPANION.-Superboard,smart case,

8KRAM,BASIC & manual -,UK spec,lyr gtee £28C

SUPERBOARD 4KRAM,BASIC,manuals,UK spec £155

MICROCASES red/black or ivory/brown £28

PSU KIT for S'bd. etc £15. MODULATORS £4.50

4KRAM 2114 £34. Range of components in stocK

DATA CASSETTES C12+case 55p or 10 for £4.85

REGULATORS various V/A eg 5V 3A L2.50 (KIT)

SOFTWARE for Superboard,PET,Nascom,Research

Machines-lst class new programs £1.50-13.50

WANTED -Software for Superboard,FET,Nascom

send tape/listing for approval must be good

original material, Highest commission rates

S.A.E. details / lists. Enquiries welcome

Callers any time (By appointment). Prices

include post(discount to callers)BUT NOT VAT

E.060-41352/ so

add 15% VAT to total. All ex..atoc,

ncompitd.3

4076923

57 Parana Court, Sprowston, Norwich.

eCW 135

MAIL ORDER DEPARTMENT CASH WITH ORDER ONLY

PET

2001-8

£ 495.00

3016

675.00

3032

795.00

C2N Cassette Deck

55.00

IEEE to IEEE Lead

25.00

PET to IEEE Lead

20.00

3040 Disk

795.00

Computhink 400K for

8K via exp/PET

825.00

For 16/32K

895.00

800K Unit

1145.00

24K Expandapet

320.00

INTERFACES

Small sys, Serial C

120.00

Serial B Bi-Dir

175.00

TNW2000 Bi-Dir

165.00

All IEEE/RS232

PETSET 1 A/D

166.00

Stockists of PETSOFT &

COMMODORE SOFTWARE

PAPER TCM100 Roll Anadex/PET 80 Col Teletype 132 Col PR -40 Roll

2.50 15.00 25.00 1.00

CASSETTES C12 Cass Highgrade Per 10 in library cases
DISKETTES PET 3040 per 10 APPLE " " C/THINK D/D Per 10

4.00
25.00 25.00 35.00

DEMAGNETISERS Curved Head (Mains) Cassette (Battery)

4.00 12.00

WORKBOOKS

TIS WORKBOOKS (NO VAT)

Set of 6

18.00

CONNECTORS

PET USER/IEEE PORT 1.25

PET 2nd CASS PORT

.95

Covers for USER/IEEE

PORT Connector

2.50

D52 RS232 Connectors

Male/Female

3.25

Covers

2.50

KIM KIM 1 KIM 3B KIM 4

99.95 99.95 69.95

NASCOM Nascom 1 (kit) Nascom 1 (Built) Nascom 2 (Kit) Power Supply (kit)

125.00 140.00 295.00 29.50

SEND FOR OUR FULL SOFTWARE & MAIL ORDER PRICE LIST -

DUST COVERS PET (All models) PET 3040 COMPUTHINK DISK T/T 43 PRINTER Anadex DP8000 Printer

£5.75 £3.50 3.00 5.75 3.50

ALL PRICES ARE EX. VAT. PLEASE ADD 50p p&p ON SMALL ITEMS £2.50
ON LARGER ITEMS
ALL GOODS DESPATCHED BY RETURN OF POST OR YOU WILL BE NOTIFIED OF ANY DELAY & OFFERED AN ALTERNATIVE OR THE
RETURN OF YOUR MONEY
Don't delay SEND NOW!

Ir
Name Address

Phone

Item No
11 INTEX DATALOG LIMITED VGLESCLIFFE INDUSTRIAL ESTATE, EAGLESCLIFFE, STOCKTON ON TEES. CLEVELAND TS 16 OPN. ENGLAND, TELEPHONE EAGLESCLIFFE 781193 (STD Code 06421
CABLES INTEXRAD. STOCKTON ON TEES. TELEX 58252.
__0,,:0,,_,0,,__,_i_,_i,_i_nr,n_,i__,_i_,_i,
11 1111 I11I 111111
136 PCW

i

You've heard about it

Read about it - HERE IT IS

AVAILABLE EX -STOCK COMPLETE KIT AS PER

0+?fr+.ts. 411-,

MANUFACTURER'S SPECIFICATION -0 44 4

With provision for 8K on board eroahsion Excludes 4118x8+ 4ii.

INCLUDES FREE 16K EXPANSION
114111E Et 40 includes ALL parts wi h every kit

41, 4,e
4

NASCOM-2

£295

+15% W VAT FREE

ON DEMONSTRATION NOW 16K EXPANSION WORTH £140

9to fr

AVAILABLE ONLY FROM US ON THE COUPON BELOW

OPTIONAL EXTRAS
3 AMP POWER
SUPPLY VAT 15% E29.50 Post £1.50
For NASCOM-2

8 OFF 4118* For NASCOM-2
Purchasers
Early E80 Delivery

RS232 COMPATIBLE
80 COLUMN PRINTER brand new
List price £550 If sent by carrier £5 extra

OUR PRICE
£39R + VAT
'4" 15% :

FULL MANUFACTURER'S WARRANTY - DON'T DELAY. ORDER TODAY

Please send me my NASCOM-2 KIT with the FREE 16K EXPANSION for £295 + VAT.

I enclose remittance

In i over

Name & Address

Also in stock NASCOM-1 ELF TR S80 as previously advertised

HE/g5
Computer Kit Division 404 Edgware Road, London, W2, England
01-402 6822

r,--imam. vc==.4

MICROCHIPS AT MICRO NEW SYSTEMS

Z8001 16 Bit CPU with seg-

PRICES

mented address space to 8

Megabytes

£125.00

CMOS SALE
401113 brand calk factory prime from HITACHI
Your choice (while stocks last) only 24p 25 - 99 22p
100 + 19p
5000 pcs. in stock!

Z8002 16 Bit CPU with non

segmented address space to

64K bytes

E95.00

Z8000DM A single board

micro computer Mit interfac-

es directly to any Zilog micro

system. It contains a 28002

CPU, 16K words of Dynamic

RAM, a dual channel serial I/O

port, 32 parallel I/O lines and

MEMOR

a wire wrap user area E1099.00

2102 LHPC Low power 0.99 High performance 250NS

2114 Low power 30ONS 2.95.95 4118 250NS

4315-45L 4K CMOS SRAM Low power

45ONS
4116 30ONS 4116 200NS
EA

12.95
3.50 3.75

15.95

WD9000B The Pascal Micro engine chip set. The set of 5 chips including the 1E164 CPU which will directly exe.
cute Pascal generated P code
(UCSI3 P -machine instruction set - Revision 2.0). The only CPU in the market designed to directly execute a high level
language at speeds five times faster than most typical computer systems. E199.00

1702A 2708 450 NS 2716 Single 5V (INTEL TYPE)

3.95 4.50
13.

WD0090A Single board mico computer containing WD9000 chip set, 64K drive bytes and single sided 8 inch disk
£1,495.00

AY -3-1015D

3.98

IM.. r2 PL

3.98

CHARACTER

G; ENERiiA1T11O1R11mmmo
KEYBOARD

ENCODER

Y-5-237.

7.95

FLOPPY

CONTROLLER
F01771 B r Ing e

Density IBM Compa-
tible FD1791 B-01 Dual

19.95

Density IBM Compati

9.95

3341PC FIFO 700K1-12 4.

3341APC FiFo 1MHz 5.50

3342PC 64 bit shift

dig -

4.95

MC14412 VL

7.97

NEW GI COMPUTER

SOUND CHIP

CPU'S

6402

7.95

6504

7.95

6505

7.95

6800

6.95

6802 8080A 8085A

9.95 4.75 10.95

Z80

7.95

280A

9.95

Z8001

125.00

Z8002

95 00

WD9000

199.00

INTERFACE IC. DM8123 75150 75154 75182 75322 75324 75325
75361 75363
75365

1.25 1.25 1.25 1.95 2.50 3.25 3.25 2.50 3.50 2.95

MICRQBYTE MICIWBYTE

75451 74491/2 8T26 8T28
8T95
8T97
SUPPORT DEVICES 6520 6522 6532 6551 6810 6820 6821 6850 6852 8212 8216 8224 8228 8251 8253 8255 8257 8259 MC14412VL

50p 75p 1.75 1.75 1.75 1.75
4.95 7.95 8.95 10.95 3.75 4.25 4.25 4.25 4.25 2.00 2.00 2.75 3.95 4.95 10.50 4.75 10.50 11.95 7.97

NEW GI COMPUTER
SOUND CHIP
AY -3-8610 As featured in July BYTE. Fantastically powerful sound & music generator. Perfect for use with any 8 bit microprocessor.
Contains 3 tone channels,
noise generator, 3 channels
of amplitude controls, 16 bit envelope period control, 2 parallel I/0, 3 D/A converters plus much more. All in 40 pin DIP. Super easy to inte interface to the S-100 or other Busses. ONLY £8.25 + VAT. Add
£2.25 for 64 page data manual

ORDERING INFORMATION: Postage free on orders over £10 otherwise add 25p. Add 15% VAT to to,al.
MICROBYTE Unit 9-10 1-t
Block E, 38 Mount Pleasant, London WC1X OAP Tel: 01-278 7369 Telex: 8953084

\ Buy here at discount prices ! A

Save 11111C, moon -

* Full after -sales service in our own workshops 4- One year guarantee on all machines

p to 1.6111) for PET! and

'on-line'

with

the

Computhink Disc System
using 16 Extra

°BdA'apwSPTAisrlorAolriuSeomviDgtsrcIwetcCsrieptsarhelsnclcymaecmoppsOboimrmbnseomuopltteceewsaLo.mesriernSe,wstad1euFrsysingf6tsiuspuhnd0e1stplgesr3(pfR,,m.nu2bplSTioElKaue'lEitcsnndlRodPakiagnAcntaiEsirfeRnkggNfeyTsieeuOce,Csstesau;,oMCoprgalidftrnncOeuv.oegtoapl'gBrltRsniroaralsOoaauneilnel,cbmepLeadetldPpe,cdmdooPtCaymufe-ryAaorsttSaerponmSo-nasrdCloBmullrtefuuaoAeueesslntsLsrcerci,ssan.e-i,iun-amoeFudp"lpnsORespblsaumeelRoligleBafuybTulsdAneHl-.drS),aICrie,BsdaussaBy1ilcs.O6dte4OiMsm0cK0bKOE2A,1S90

PILOT & CESIL.

FIFTH, PLM,

dual disc

expansion with

24K Memory

for r

oldew n

ROM BK PET ROM 8K PET

£275 £320

The only 16k complete computer for under £400

Keyboard computer, power

supply, UHF modulator

and all cables to plug

into your own TV set and

cassette recorder and gol

TRS-80

16K of user RAM for decent.s

size programmes and data,

sophisticated level II Microsoft BASIC.
Complete with level I and level II programming manuals.
What more could you ask?

381'
Expansion interface £199.09 4K level I computer £251.30

This must be today's best buy!

IBM golfball printer

Anadex DP 8000 ideal for dot-matrix printer word-processing

'Speedy 112 ch/s bide. ' F its A4 page -up to 80 cols.
'Up to 4 copies. 'Precision

'Forget expensive SpinWheel printers - the
Golfball produces equal quality at up to 15 ch. per

ffdopeoraemupdbe.-'lSrefiPlflowienricmgdiatawhltihtctheohasmadpiranrsotgc.cs'hMkueAost4idneg rntysti*npeCtceeo.rwmc*hMrpiatalenetgrcteehsalytvbyalrleeerislhoiaeuwbasidltehs.-IBeMach

tiling systems. 'Other paper machine rebuilt by IBM

sizes with adj. sprocket. 'Full punctuation, U/L case,

trained engineers and fully guaranteed. 'Precision

f sign, 96-ch. set. 'Reliable - strongly built,

form -filling possible with 15 in. pin -feed platen.

100 M.ch. head.

Knock down price! Limited supply!

T CM 100 Thermal Printer
'Stop disturbing others with noisy printout! 'Neat, clear, 96-ch.set, OIL case& symbols. *Matches Pet/Apple line lengths. 'Fast, 40 ch/s
bidir.*Reliable- robust -
only two driven parts. 'Plug in and go, built in PSU, detailed manual. *Thermal paper 4Y, in wide x 80 ft, less expensive than electro, sensitive paper.

Interfaces Pet £45 Ohios El 0 T RS -80 £40 Sorcerer £8 Apple £45

£595
Interfaces Pet £45 Ohios £10 T RS -80 £35 Sorcerer £8 Apple £45

Interfaces Pet £45 Ohios £10 T RS -80 £40 Sorcerer £8 Apple £45

PET 2001-8N (8K RAM New large keyboard)

£469

22E00x0t0e11rn--al13c62aNNss(e(13tt62eKKdRReAcAkMM, saaunnitaddbnnleeewwfollraararggileePkkeeetsyybbooEaa£7rr5d4d35))

£590 £890

CTBraMctdourafel derdivperimntienrigwfrlaoiptphhpicyPset2g0r0apxh3ic2s0

£499 £259

Pet high-res.

You can afford to
start computing
now!_ with the Ohio CI -P
As imported, fully tested, complete with 4K RAM, but unconverted to UK std. (conversion instructions supplied).

Add f24 for converted model. Extra 4K RAM f39.

'Powerful programming possible - 6502 processor, fast 8K Microsoft floating-point BASIC (easy to learn). Superior utilities, 53 key key -board, giving upper and lower case, user -definable keys, gaming and graphics chs. Ultra -fast and powerful machine code from keyboard. 'No intricate soldering or metal work. Computer supplied
assembled in ready-made case. 'Reasonable sized
programmes in 4K RAM. 'Expandable to 24K RAM in case, drives discs, printer; available items include Assembler/ Editor and Extended Monitor. 'Programme inter-
changeability/reliability - Kansas City tape interface. 'Save programmes on own cassette recorder - all cables supplied.

Your dealer for Bath, Bristol and S.W.

Tel: Bat (0225) 28819

PCVV 4

We stock co onents,test instruments,tools etc.

LTD.

TANDY
DEALER

Computerama Ltd.

VISA
1.1111=1
J®VISA

Harpers Kensington Showrooms London Rd. Bath, Avon

Credit card orders accepted by telephone for immediate despatch.

Loads of software -ask for list!

PCW 137

"'©

PAJ .... 011PUTERS

0

I 111.

KEEN & COMPETITIVE! WE ARE SPECIALISTS.

64.. 0000

'PET' SPECIALISTS.

HARDWARE & SOFTWARE. 111111111=11.\

WE HAVE EXCELLENT STOCKS OF BOTH

11111111111a

Inc. a full range of Commodores and Petsoft; and, of course, our own, such as:

Stock Control & Invoicing Random Entry & Analysis Delivery Services Work Study Monthly Planner etc. etc. (SAE for descriptive leaflet)

£ 60 £ 40
£220 £150
£7

We will also write programs for you that you are unable to do or get written.

YOU ARE WELCOME TO TRY, BROWSE & PURCHASE AT OUR PREMISES .. . TRY US!

ORDERS TAKEN BY POST OR PHONE: ACCESS BARCLAYCARD -VISA

3 CRUNDALE AVENUE, KINGSBURY LONDON NW9 9PJ 01-204 7525

Happy Memories

4116 2114
2708 21L02

200ns 200ns 450ns 450ns

£4-50 £4-75 £4-95 85p

4116 2114 2716 21L02

15Ons
450ns 5volt 250ns

£5-50 £4-25 £16-95
£1-25

VERBATIM mini discs soft sectored - - with FREE library case £19-95 per ten

SALE
We're moving shortly to new premises and don't want to carry much. Bargains from Sat. 26th April

All prices include VAT. 30p postage on orders below £10. Access & Barclaycard. All orders to:
Dept. PCW
19 Bevois Valley Road, Southampton, Hants. SO2 OJP TeL (0703) 39267

IN-HOUSE VIEW DATA
SYSTEM
Full specification colour viewdata system, compatible with Ceefax, Prestel etc.
Implemented on Cromenco, North Star or an existing S100 machine. Uses unmodified tv. Single or multi-user, up to 11,000 frames stored.
Intelligent `soft -key' frame -editing. Modem/autodialler will allow interface to Prestel,
the Post Office Viewdata system, or other distant viewdata bank.
Prices from £800 to £15,000
hi -tech electronics
1 Richmond Gardens, Highfield Southampton SO2 1RY Telephone (0703) 555072
138 PCW

Hi -tech Electronics
Telephone 0703-555072
The Hi -tech electronics Colour YOU is a standard 11100 card suitable for the wide range of $100
co=lers an the
The board will drive standard T.V.wet
(Oritish 6211 and is compatible with:11Viewriata
Ceefam *Teletest *Oracle *Preetel-the
Post Office dor tee *Hi-tewt intelligent
viewdata swates

ENSIG

13-19 MILFORD STREET, SWINDON

WILTSHIRE

SN1 1DW

Tel: (0793) 42615 Telex: 449703

Make more time available Enhance your quality of life
Improve your business

COMPUTER SALES HARDWARE SOFTWARE CONSULTANCY MEDIA STATIONERY ETC

We will consider purchase of second-hand equipment:
TRS 80 ITT 2020 APPLE COMMODORE PET CROMENCO etc.
Good allowance given for part -exchange against the 64K Twin 280 Superbrain
PROGRAMS
for: TRS 80, APPLE, ITT 2020, PET, COMPUTHINK, SUPERBRAIN.
Business complete package including sales, purchase, nominal, stock, invoicing etc. Also plenty of games.
:f1Iffiliffiffifflififfiffifillififfiffiffaff.WIIIIMMIffifff
SUPERBRAIN £2,300 64K + DUAL DISK DRIVES Keyboard and Numeric Keypad
Fortran, Cobol, Measic, Wordstar, etc., available
'F.11.1.11.111.1.1.1.111111.1.11.11.111.11If fffiffiffiliffifIffiffilff11111.110

We are continually adding new products to our range and would be pleased to receive your enquiries. Quantity Discounts available.

TRS 80

16K Level 2

(c/w K/bd, VDU, T/Red

OK I nterfaceito add printer & disk drives)

16K Upgrade kits (for k/bd or interface) Disk Drives, single (125K)

Disk Drives, dual (250K)

Disk Drives, cable 2 & 4 way from

ex. VAT inc. VAT

500.00

575

195.66

225.

65.22

75

260.88

300

456.53

525.

21.74

25.

ITT 2020

1 6K

(c/w K/bd & Palsoft ROM) 695.65

800.

16K Upgrade kits

65.22

75

Disk Drive, single with cable

347.83

400.

Printer Interface

108.70

125.

COMMODORE PET

2001-32N

(New keyboard & 32K)

2040 Dual Disk Drive 343K

3022 Printer with graphics

Printer cables, each

Computhink Drive 400/800K

782.61 782.61 608.70
26.09

900 900. 700
30. POA

MEDIA LIST

51/4 " Verbatim

from (Qty 5)

10.43

12.

51/4 " Verbatim

from (Qty 10) 17.39

20.

51/4 " Dysan

from (Qty 10) 26.09

30.

8%2" 3M

from (Qty 10) 30.44

35.

Blank 51/4 & 8Y2- Diskettes, Soft/Hard Sectored, Formatted/Unformatted.

We have diskettes to suit many systems. When ordering please quote:

SYSTEM MANUFACTURER, MODEL, MEDIA TYPE, AND DISK SIZE.

Available in smaller or larger quantities.

CONSULTANCY Please write or telephone if you require advice on
BEGINNING or EXPANDING your computer installation.

STATIONERY Listing Paper, Continuous Forms, Labels.

Listing paper 11" x 8'6", 11" x 9%,", 11" x 12". boxed 2,000 incl. VAT

Et 0

Labels 2'/," x

white, fanfold, £5 per 1000 12.000 inc) VAT

£40

Software programs customised to your requirements.., Post/Packing/Insurance extra. Delivery by Registered Post, Securicor, etc
Price List correct at time of going to Press, subiect to change without notice E & 0 E
REPRESENTATIVES required in various areas - please Standard Warranties apply All stocks subiect to availability. contact us for full details.

OUR BUSINESS EXISTS ON IMPROVING YOUR BUSINESS. Your enquiries assist us in forward purchasing.

Please send Full Details & Price Lists

My requirements are for

HOME E

HOBBIES E

STUDENT E

BUSINESS D

Name Street Town County Post Code Telephone Name of Co Position

PO/Chq No
Mail order Cheque/Bankers' Draft/Cash/Barclaycard/Access etc - allow 28 days for delivery

Requirements

Description

Microcomputer

Upgrade Kit

Interface

Disk Drive

Printer

Cable/Interface

Cluster System

Colour TV

Media

Stationery

Stationery

Software

Post/Pkg/lns :(please tel. for cost

TOTAL

inc VAT

PCW 139

ELECTRONIC SERVICING LTD.

11111111Ella

Petact authorised distributors for central Southern England

for the full range of Computhink disc systems (dealer

enquiries welcome)

Computhink Old ROM 400K

£795.00

New ROM 400K

£895.00

New ROM 800K All + VAT

£1145.00

Large Keyboard PETS in stock 32K PET £795 + VAT 16K PET Ask for delivery on 16 2040 Disc System and C.B.M Printers. Large Extension Keyboard for the PET £89.50 + VAT.

Stockists for Petact Business Systems (Sales accounting, purchase invoicing, payroll, Stock Control, Nominal Ledger and management information. A wide range of Printers available i.e. Teletype 43, Anadex C.B.M, Printerm

COMPUTER BOOKS - for professionals, hobbyists, businessmen and newcomers.

ACCESS, BARCLAYCARD

If you require any more information or demonstration regarding the PET 2001/8 or any associated equipment,
programs, etc., please contact: Mr. P.J.A. Watts or Mr. D.W. Randall at:
PETALECT ELECTRONIC SERVICES LTD 33/35 Portugal Road Woking Surrey
Tel: Woking 69032/68497
Shop at: PETALECT Chertsey Road
Woking Surrey Tel: Woking 21776/23637
1t0 PC'W

Micro -Computer Centre for the MIDLANDS
Nascom and Commodore Specialists
A full range of micro computers and peripherals are available, whether buying or browsing we can give helpful and friendly advice.
Commodore Business Systems are suitable for the professional office, the small business or the sole trader. We will be pleased to give advice and a demonstration.
Nascom 2 systems can be fully built and tested to order. We are sole distributors for the Micro Type case for Nascom 1 and 2, also stockists of the William Stuart colour graphics and full range of 'add-ons'.
[0] 7 --
Business & Leisure Micro Computers
16 The Square, Kenilworth, Warwickshire CV8 1EB. Tel: (0926) 512127
LITTLE GENIUS
If you find self -instruction manuals difficult to follow, then meet our Little Genius.
Little Genius floppy diskettes are the fastest, easiest way to master your micro.
Little Genius will save you time and effort, teaching you to exploit all your micro's facilities.
Courses now available: 1. Applesoft basic 2. Advanced Applesoft 3. Using your Apple
4. Pet basic 5. Advanced Petbasic
6. Palsoft basic 7. Advanced Palsoft 8. Using your 2020
For further information ask your local dealer or contact:
Peter Brown at Suite 504, Albany House, 324 Regent Street, London VII1R 5AA.
Telephone 01-580 6361.

FOFF THE SHELF fiVRILABILITY
FROM COMPUTER CENTRE

KIT PACKAGES
I KIT
e lowest priced CP/MZ80 Micro in UK. Add power and terminal. Minifloppy 16KB , Z80, CTC, serial + parallel I/O, S100
therboard, connectors, manuals, CP/M tem. Free basic and Algol tional two drive case illustrated power supply £149.00
KIT
drive, CP/M disc operating tem, 16K bytes, Z80, ial and parallel I/O,
motherboard, ectors and cables
tional power pply kit. £77.00
THE MEGABOX
GABOX - S
in 8" single sided drives plus Power Supply it in an attractive box p to two megabytes Attractive 3 U case Fan cooling Mains switch)
GABOX - D in 8" double sided Ives plus Power Supply
it in an attractive box £1090.00p
8 INCH DRIVE
I
gle/dual density disc drive sembled and guaranteed
ouble sided rsion £450
MINI FLOPPY
uble/single density hard or soft sector, used r TRS80, North Star etc. Assembled and
otiltguaranteed
'4,44.130,1if 00'
TRS 80 EXPANSION
ISC DRIVE
4 " disc drive+ power supply attractive case

PRICE LIST

OEM RANGE

OEM PACKAGED SYSTEMS

ASSEM

OEM1 Z80, 32KB, 1SER, 1PAR 2 x'/4 MEG Disks 1970.00

OEM2 Z80, 48KB, 1SER; 1PAR 2 x 1/2 MEG Disks 2270.00

OEM3 4MHz 64KB; 2SER, 1PAR 2 x 1 MEG Disks 3570.00

DISC DRIVES

SA400 mini floppy disc drive

175.00

DRI 7100 8 inch drive (single sided)

350.00

DRI 7200 8 inch drive (double sided)

450.00

VDU'S

Pentland (full spec)

0590.00

PRINTERS

DRI 6320 (140 cps Max) 132 chts, Tractor Feed

1500.00

ANADEX 8000

499.00

SOFTWARE

CP/M operating system + 6 manuals + basic E

70.00

Library index (33 volumes available)

2.80

Library copies on 8 inch media

4.40

Library copies on 8 inch media (10 or more)

3.40

Microsoft BASIC

193.00

Microsoft FORTRAN

267.00

Micro focus compact COBOL

376.00

Micro focus forms

75.00

UCSD PAScAL

193.00

Microsoft BASIC compiler

211.00

WORDSTAR

193.00

MPU

ASSEM

CB2 Z80A IEEE 5100

112.00 136.00

IDS Z80A CPU BOARD SBC 100 Z80 + serial + parallel

115.00 155.00 197.00

SBC 200

182.00 242.00

DISC CONTROLLERS

Tarbell single density

132.00 188.00

Tarbell double density

188.00 244.00

Versafloppy 1 single density

135,00 190.00

Versafloppy 2 double density

184.00 241.00

Nat Mux double density

215.00

Tarbell Cassette Interface

104.00

MEMORY

8K bytes Econoram 2 (4MHz) static ram 84.00 100.00

16K bytes Econoram 4 (4MHz) static ram 145.00 178.00

24K bytes static

214.00 259.00

32K bytes static ram

302.00 349.00

Expandoram 2 (Dynamic) 64K population ° 663.00 713.00 Expandoram 1 (Dynamic) 64K population 366.00 416.00

I/O

2S10 ( 2 serial full hand shaking uarts)

105.00 136.00

104 2 serial/parallel

86.00 129.00

SPECIAL BOARDS

VDB-8024 (80 chts x 24 lines) video

194.00 263.00

PB1 2716/2708 eprom programmer

78.00 122.00

Memtech 3MHz floating point board

280.00

Prototype board

16.60

2708 prom board (ex proms)

52.00 63.00

VB1 16/32x64 video

78.00 107.00

MT3 11 slot motherboard

21.00

S100 extender + logic probe

31.20

Dealer, Educational and Quantity Discount Available.

FROM UNDER
DUp to 2 Megabytes of floppy disc storage
DHigh speed Z80 micro DUp to 64K bytes fast ram
storage DHigh level operating system
(supports Cobol, Fortran, APL, Basic, Pascal, Wordstar) 02 drive minimum system under £2000
Available off the shelf in an attractive case, the Computer Centre OEM 2 provides a powerful main frame computer
System builders are free to add peripherals to suit the final applications. The operating system provided with the OEM's is a powerful upward compatible extension to CP/M and will support up to 128 mega byte disc storage.
A 10 mega byte fixed disc is already planned and should be available as an extra during 1980
Another remarkable extension to the OEM range is the availability of the multi terminal operating system. But with hardware costs as low as the OEM, the market for sharing the system is likely to be small!!! OEM's are invited to write or call for
details
r- NEW PRODUCTS
Now available from stock, new plug in card/ cards to enableTandy owners to run CP/M and/or two 8"disc drives.
Full range of power supplies, Firmware, Connectors and IC's

=11111111111111111.111...111 =MEI= = IIII =ME =..1=111.1,

All advertied items generally in stock. Cash with order ensures same day despatch. Add 2% postage and 15% VAT to

Send

OCatalogue

(please

tick)

advertised prices. I enclose cheque for £

Name

Send

Address

I

III

iI

COMPUTER CENTRE THE DISCOUNT COMPUTER STORE

I I

ll

9 De la Beche Street, Swansea, SA13F.X. Tel: 0792 460023 Telex: 48638

MINIIIIIIIMMOMMII=IMIIIIIMMMIINIMII=MMENIIIMIIIMIIMINIM

acu

>ACULAB 735, a fully self-contained interface for

IBM 735 output golfball typewriters

The ACULAB 735P INTERFACE is a self-contained controller for IBM I/O typewriters and printers. The 735P accepts standard 7 -bit

parallel ASCII data and provides all of the handshake protocol, code

conversion and solenoid voltages to run the printer at full speed

using any correspondence or ASCII golfball to produce letter

quality printing at 15 chars/sec

.£155.00 + VAT

The TRS-1 PARALLEL PORT DECODER plugs into the bus

connector on the TRS-80 keyboard and decodes the port used by

the ELECTRIC PENCIL and the LPR INT and LUST commands

in TRS-80 BASIC.

...£55.00 + VAT

The IEEE TO PARALLEL PORT CONVERTER plugs onto the

PET IEEE bus connector and converts it into a parallel printer

port. It also converts PET's unique version of ASCII to standard

ASCII and provides a switch to give UC/LC compatibility with the

new PET

.. .£45.00 + VAT

The ADDRESSABLE IEEE PARALLEL PORT DECODER has all of the features of the converter but may be set to answer to any
of the available addresses on the PET IEEE bus and so be used along
with the PET disc or any other bus compatible devices .. .£66.00 + VAT

These last three devices are all fitted with 2 metres of heavyweight cable and a metal shrouded Centronics compatible connector.

(aculab) Ltd.
24 Heath Road, Leighton Buzzard, Beds. LU7 8AB

For further information Telephone. 0525-371393.

DISCOIJNIT PIE111
NEW 8K PET £445 with large keyboard, 16K £540, 32K £640, Dual Floppy £670, Programmer's Toolkit £45, Printer £400. BASE 2 PRINTER £350 compatible with PET 3 Interfaces: IEEE, RS232, Centronics parallel, 3 Character fonts -one downloadable, programmable horizontal & vertical densities, stepping motor, tractor feed, contiguous plotting. TEXAS TI 99/4 £800 with 13" colour monitor. The most advanced home computer. AIM 65K SYSTEM £400, cased, powered and with optional assembler and BASIC. Also memories & motherboards for AIM 65/KIM by Seawell. Disk system (2 x 5" drives) with DOS £800. S-100 SYSTEM £1000 based on North Star with single disk drive, Z-80, 2 ports, 32K memory, completely assembled and tested. Runs all North Star software. Dual Disk version £1200. NORTH STAR HORIZON II 11400 SOROC IQ 120 VDU £550 S-100 BOARDS assembled and tested only. 16K fully static 2MHz memory with bank select, optional wait states, write protect etc. £150. 4MHz £200. Jade 4MHz A-80 CPU £140. SD PROM -100 EPROM programmer £140. 2 serial & 1 parallel I/O card £120. SOFTWARE COMPLETE ACCOUNTS PACKAGE FOR NORTH STAR £520 e.g. BOUGHT & SALES LEDGERS, VAT, AUDIT TRAIL, PAYROLL for NORTH STAR on two disks £56. (also for PET, Listing only £50. SUPER BLAKE 7 game for PET on disk£23, for Challenger 8" disk £15, PET cassette £20, listing only £10, self -learning noughts and crosses (NS, PET, OSI) £13 disks, £11 cassette.
Send for list or call:
CAMBRIDGE ROAD, ORWELL, ROYSTON, HERTS.
Telephone: Arrington 689

22 NEWLAND STREET, KETTERING NORTHANTS. Tel. (0536) 83922 & 520910 Telex 341297
142 PCW

evi Produced and widely used in England and U.S.A.

COMPLETE BUSINESS PACKAGE
INCLUDES EVERYTHING FROM INVENTORY TO SALES SUMMARY PROMPTS USER AND VALIDATES ENTRIES. MENU DRIVEN
BUS VER 3.00 TO VER 9.00 PET AND CP/M APPROXIMATELY 60-100 ENTRIES/INPUTS REQUIRE 2-4 HOURS WEEKLY AND ENTIRE BUSINESS IS UNDER CONTROL

* PROGRAMS ARE INTEGRATED 01=*ENTER NAMES A ADDRESSES 02=*ENTER/PRINTj INVOICES 03=*ENTER PURCHASES 04.*ENTER A'C RECEIVABLES 05=*ENTER A'C PAYABLES 06=*ENTER'UPDATE INVENTORY 07=ENTER'UPDATE ORDERS 08.*ENTER'UPDATE BANKS 09=*EXAMINE'REPORT SALES LEDGER 10.*EXAMINE'REPORT PURCHASE LEDGER 11=*MONITOR INCOMPLETE RECORDS 12.*EXAMINE PRODUCT SALES ENTER WHICH ONE

SELECT FUNCTION BY NUMBER 13=*PRINT CUSTOMERS STATEMENTS 14=*PRINT SUPPLIER STATEMENTS. 15=*PRINT AGENT STATEMENTS 16=*PRINT TAX STATEMENTS 17=SENERAL HELP 18=ALTER VOCABULARIES 19=PRINT YEAR AUDIT 20=PRINT PROFIT'LOSS A'C 21=ENDMONTH MAINTAINANCE 22=PRINT CASHFLOW FORECAST 23 -ENTER PAYROLL NO RELEASE 24=EXIT SYSTEM

DATABASE MANAGEMENT INCLUDES
s** FILE CREATE'DELETE'SEARCH. *** RECORD CREATE'DELETE'SEARCH'4 OPTION PRINT. *** RECORD SORT ANY FIELD ALPHA OR NUMERIC. *4* INDEX SEARCH OR GENERAL SCAN'PRINT IN ANY FIELD (E6 TOWN OR NAME). *** 4 ARITHMETIC FUNCTIONS TO USE AS CALCULATOR ON LAST 4 FIELDS..*** AUTO CHECK TO PREVENT DOUBLE ENTRY TO FILE MANAGEMENT SYSTEM, DYNAMICALLY ALLOCATING INFORMATION TO MINIMISE DISK SPACE CONSUMPTION

VERY FLEXIBLE.EASY TO USE
G.U.COMPUTERS U.K. ARE THE PRODUCERS OF THIS BEAUTIFUL PACKAGE VER 3.00 (EXC PROS 19,20,22,23)=475.00, VER 4.00 INCLUDES AUTO STOCK-UPDATE=575.00, VER 5.00 INCLUDES AUTO BANK UPDATE=675.00, VER 6.00 IN CORE=775.00, VER 7.00 (INC 19,20,22,23)NOT YET RELEASED=875.00,
VER 8.00 RANDOM ACCESS=900.00, VER 9.00 TRANSLATEABLE=975.00. +++EACH LEVEL OVERRIDES LOWER ONE

WE EXPORT TO ALL COUNTRIES

CALLERS ONLY BY APPOINImENT

CONTACT TONY WINTER IN 01.636.0210

09 BEDFORD COURT MANSIONS, BEDFORD AVENUE, LONDON W.C.1.

NOTE!!! ALL VERSIONS, ESPECIALLY 9.00 USE BROAD FINANCIAL PRINCIPLES AND 7.00 IS ONE 161; CORE PROGRAM RELEASING BOTH DISK DRIVES FOR DATA SIURAGE, AS WELL AS BEING IRANSLATEABLE INTO ANY FOREIGN LANGUAGE

We also sell the Hardware to do the above tasks so you can do the complete purchase at one source.

OFFER A GENERAL FILE DATABASE MANAGEMENT SYSTEM (VALUE 100 POUNDS) PLUS 1 YEARS SOFTWARE SUPPORT (VALUE 50 FOUNDS) FREE WITH A TOTAL SYSTEM PURCHASE
.

PET + PET + PET + PET + PET + PET

SOFTWARE + SOFTWARE + SOFTWARE ......

CBM 32K 3032 CAM 3040 FLOPPY DISKS CBM 3022 PRINTER CBM CABLES FOR ABOVE CARTON PAPER AND 10 DISKS

795.00 795.00 525.00
45.00 57.00

SUPERBRAIN

SUPERBRAIN

ZZ2Z1112ZIZZZ===.====ZZZZLZUSZZr===.

TWIN 280CPU TWIN D'D/DRIVES

64K RAM AND CRT VIDEO

1950.00

OPTIONAL 5100 BUS ADAPTER 250.00

ADD-ON 11 MEGABYTE DISK

P.O.A.

PRINTERS + PRINTERS + Z XXXXXX ZMX.Z.Z.Z=ZZ
PAPER TIGER 195CPS TELETYPE 43KSR 30CPS DEC-LA34 TRACTOR 30CPS NEC-SPINWRITER OUNE SPINWRITER SPRINTS

PRINTERS ZSZZAIZZZ
575.00 875.00 875.00 1650.00 1950.00

SPECIALS + SPECIALS + SPECIALS ZZZOZZZZZ=ZZZ

INS 48K TWIN D'D/DRIVES 1750.00

N'STAR QUAD DRIVES .7 MEG 2150.00 INTERTUDE III TERMINALS 495.00

COMPUTHINK BOOK DRIVES

895.00

CORDLESS TELEPHONES IN'OUT 195.00

TELEPHONE ANSWER MACHINE 230.00

CORDLESS PHONE IN'ONLY

80.00

CBM CONMACCOUNTS

650.00

CBM CONPAY

150.00

CBM COMBIS'CONSTOCK

150.00

CBM WORDPRO II

75.00

CBM VORDPRO III

150.00

BUS VER 3.00

475.00

BUS VER 4.00 STK OR BNK 575.00

BUS VER 9.00 R'ACCESS 975.00

CPM U'STAR Tr1PROCESSOR 250.00

CPM WORD -MASTER TX'ED 75.00

CPM MBASIC 40

150.00

CPM COBOL to

320.00

CPM PASCAL 2

150.00

CPM FORTRAN 80

200.00

CPM ED'ASCETC S'BRAIN FREE..

CPM PASCAL -M

250.00

CPM BYSTAM

75.00

CPM SUPERSORT

120.00

CPM BASIC COMPILER

190.00

CPM DESPOOL

30.00

CPM BYSTAM IMS'N-STAR

75.00

CPM TEXTWRITER

75.00

CPM POSTMATER

75.00

CPM SELECTOR 3

180.00

CPM CBASIC INS

75.00

CPM MACRO 80

75.00

WARRANTY + WARRANTY + WARR ANTY
09 ZZ XXXXXXXXX ZIZZZZEZEZZZZZSZ.
90 DAY FREE REPLACEMENT
oosi

fSS

Pat Nyc:. eret$

V.

°4.. \°v s2*51

0.(%,(

Jqs.%`nesscOcciptieN

++++++++ SPECIAL INSTITUTION AND UNIVERSITY DISCOUNTS ++++++++++ STOCK AND COMING ROUND. (BARCLAYCARD WELCOME OTHERWISE CHEQUE WITH ORDER)
CONTACT TONY WINTER 01.636.8210 07 BEDFORD CT MANS, BEDFORD AVE W.C.1.

PCW 113

Q700111,
ELECTRONICS
PET PERIPHERAL SPECIALISTS

PLESSEY MEMORIES 32K WORDS

PETITE (add on)

£270

INPET (mounted inside) £240

I EEE-488 SERIAL OUTPUT INTERFACE

BOXED WITH POWER SUPPLY

£ 65

TERMINALS:-

DECVVRITER LA34

£795

TELETYPE 43

£785

TVI-912 VDU

£595

TERMS:- ALL EQUIPMENT EX -STOCK

CASH WITH ORDER PLEASE -

VAT EXTRA. 3 MONTHS' WARRANTY.

TERMINAL DELIVERY £15 EXTRA.

FULL BACK UP SERVICE AVAILABLE

TELEPHONE 021-643-3540
Q-COM ELECTRONICS LTD., 5TH FLOOR, ST. MARTINS HOUSE 10 BULL RING, BIRMINGHAM B5 5DT

Interactive Data Systems
14 Buckman Close Greenleys Milton Keynes MK12 BAB ' Telephone (013081 313097

DATA PROCESSING SYSTEMS - INDUSTRIAL CONTROL SYSTEMS

Sales

Desar

Menuledulle

THE BRITISH S100.

Ht last you can buy a range of S100 boards manufactured

to the highest standards in the U.K., compatible with the

new I.E.E.E. S100 specification and competitive in price

with anything the Americans can throw at us_

Z80 CPU.

A basic 4MHz CPU board with all the logic

and buffers required to drive the S100 bus.

Kit

£84

A & T £105

SBMC

A 4MHz Z80 single board microcomputer featuring 2 RS232 ports (or 20mA) with full handshaking, 1K of scratchpad memory, up to 16K of EPROM and a 4

channel counter/timer/vector interupt.

Kit £178

A & T £235

16K SRAM This is a 16K static memory board utilising

the industry standard 2114 memory chip.

Kit £174

A & T £198

FDC

Any combination of 8" and 5", single or

double sided floppy disk drives can be

handled in single or double density with

TERM 40

this board.

Kit £216

A & T £255

Active termination board for reduction of

crosstalk and ringing in the bus.

Kit £25

A & T £32-50

Information now available on the following: -

PCI

Process Control Interface, 8 channels relay

isolated output, 8 channels opto-isolated input, 8 bit TTL I/O, 4 x 8 bit D/A, 4 x 8, bit A/D.

IOC

2 channel serial I/O, 2 channel parallel I/O.

12 bit

16 channels 12 bit D/A, 16 channel 12 bit

Analogue A/D.

Details from the Distributors:MENDIP COMPUTERS 57 Bath Road, Wells, Somerset, BA5 3HS. Telephone: (0749) 75249

INTERTRONIX 83 West Street, Farnham, Surrey GU9 7EN. Telephone: (0252) 722011

BRITISH 5100 BOARDS

(Manufactured in the United Kingdom by
INTERACTIVE DATA SYSTEMS)

Z80 CPU

Basic 4MHZ CPU board

Kit: £ 84 A&T £105

SBC 40

4MHZ, Z80 board, 1K RAM, up to 16K EPROM, 2 SERIAL
PORTS, 4 channel Counter/ Timer & 4 Vector Interrupts Kit £178
A&T £235

16K SRAM 4MHZ Static RAM

Kit £174 A&T £198

FDC

Double/Single density, Double/

Single sided Floppy Disc Controller, up to 4 drives

Kit £216 A&T £255

£15 OFF ABOVE PRICES for

Cash orders received before 10th June 1980

CHIPS

2114, 200 ns, low power

2716, Single supply

Z80A, 4MHZ CPU

2708

4116

£ 4.75 £19.95 £11.20 £ 6.65 £ 5.95

OTHERS

1/0, TERM, A/D, KEYBOARDS, DRIVES, MAINFRAMES, PERIPHERALS, MOTHER BOARDS, SOFTWARE etc.

Please ask for full details of our range.

COMING SHORTLY By the time this advert appears, we expect to have full
details of a new VDU board AND,

PCI 10
p&p, 50p under f 15.00 Add 15% VAT to all prices Mad Order only Telephone 0749 75249

Process Control Interface, 8 independent relay outputs, 8 opto-isolated inputs, 8 bit TTL input channel, 8 bit TTL output channel, multichannel analogue I/O.

MENDIP COMPUTERS 57 BATH ROAD WELLS, SOMERSET BA5 3HS

COMPUTERS

FOR HOME

BUSINESS

EDUCATION

Exidy Sorcerer
16K - £860 32K - £918 48K - £976
S100 Expansion Box 6 -slot - £276.00 Micropolis Dual Disc Drive - £1,380.00 NEC Spinwriter (receive only) - £2185

Z-89 ALL -IN -ONE COMPUTER The new all -in -one computer from Zenith is the most versatile microcomputer available today. 'Intelligent' video terminal two Z80 microprocessors floppy disc storage system expandable to 48K RAM Easy to programme. Simple to operate. It is capable of a multitude of high-speed functions and speaks the language of today's most popular software. Price from £1805
The most advanced microcomputer yet.

Wv 14 SERIAL
PRINTER W. a compact

Microprocessot based. d is compatable vv. arty

;2;7:,°.,°X',7';1". =:1`.°°1''''

variety fuses a broad or 20mA current

variety of uses .r. a, loop treerlace

.MtrOng

camections Price

environment

11586 50

olo

SA FLOPPY DISK TRS 40
Dual Dove 1506 00 Integra, Pow.' Suppe

video WOO .!.OVVZ:g.
00.4.110/1
E90.00

RADAT 5- 10MHz Scopes only 1189.00
SELECTION OF SOFTWARE GAMES & BUSINESS

MO LEVEL
2 1111(
ONLY IMO XEIDONL EXPANSION BOX 121, 1340 00

Large range of computers etc. books. Send for List SAE with all enquiries - All prices inclusive.
SUPPLIERS TO BUSINESS, EDUCATION & HEALTH AUTHORITIES

NEIN
61 Broad Lane, Tottenham, London N15 01-808 0377

r-,I Tri,1!.71
tfrCu=cad

144 PCW

%ENV: lila: dlil'i

Oil : 111411112,411

OLIVETTI TE318
ONLY
£130
+ CARR + VAT
The cheapest way to I/O to your computer, 80 column high quality printer, friction feed, serial ASCII in and out, RS232, feather light keyboard, and inbuilt 8 bit paper tape punch and reader.

IBM SELECTRIC 1/10 GOLFBALL TYPEWRITERS

In stock now test equipment,

sig. gen's, motors, periP era

vIcdoeerraerlssfpoioronwndoerndacpedrouvcseeessrs.toSirsuapepppldielicdaaitnitognoosov,dwewilrloarlkciicmnegpoot radwehro.esAt fotmoefnrdlyusifefseeritengnbt teypemfcaparacrinedtserfaar sakll interqgaun0is2pfm0or5emn0et0,rsIm, Cipcor'swos, tweoriotSclsuh,pecpsoli,emVs,pDsocnotJep'nsetss.s,uvbaarisascesm, bkleieysbo+atrhdosu, sands of

Why pay a fortune? Even if your computer f I s you still have a first class typewriter at your disposal! ACULAB interface unit for PET, TRS80, SORCERER f165.00 a VAT.

transistors, other stock lines. displayed below.

Just a mere fraction 100's of bargains for

of our vast callers

range,

is

OPTO SMA H ! T I L 302/MAN 7 7 segment LED readout

SUPER 77 KEY

HOW TO GET HERE

common anode direct drive (via
resistors) from 7447 El .10 each TIL 119/0072 Darlington opto isolator 3 for El 00.
TIL305 0.3 7 x 5 matrix LED
alphanumeric readouts £3.75 each.

KEYBOARD KIT
We'vedone it again! We've purchased a large quantity of C PCLARE top quality keyboard reed switches plus full QWERTY keytop sets and thrown in a PCB to enable you to customise the keys just as YOU want them, just add and wire an

Victoria, London Bridge or Holborn
Viaduct to Thornton Heath.
1 minute from

PHOTO TRANSISTOR Fairchild FPT-100 NPN silicon 30v

,encoder chip and you can arrange ASCII, BAUDOT, anything! Adding up to a quality keyboard which would normally cost around £100.00. Supplied with

Thornton Heath Station.

25ma. 4 for £1.0s

;layout and assembly inf o at only £26.99 + £1.50pp.

Supplied in good condition with interface data and accessories but untested, unguaranteed. What more could you ask for. 1" Paper tape 75p per roll + pp 40p. HURRY WHILE STOCKS LAST.
RACAL C10 "Supergrade" cassettes. 66p each, 10 for £5.45

VENTEK WORD PROCESSOR VDU TERMINALS

Still a few available. The VDU with the GREEN screen. Made by the VENTEK Co. with the following spec: 12" monitor, 24 lines x80 characters, upper and lower
case with descenders, 85 + keyboard, auto repeat, ASCII, RS232 interface, adjustable baud rates, full cursor control, edit function, character(s) flash etc., etc. Latest technology used, mostly 74LS with dynamic rams.
Supplied in 2 grades
Grade 1 Complete tested and working £275.00 + VAT
Grade2 Condition asseen or described f225 .00 + VAT Carriage Extra
Although Grade 1 sold tested and working no guarantee offered. Anyone with circuits/ manuals please contact us.

HY GRADE SMOOTHING CAPS

MULLARD - PLESSEY - MALLORY -SPRAGUE

1500mf 3300mf 10,000mf
100mt

100v 60p* 3300mf

40v 50p

63v 70p* lmf 600v MYLAR 28p

15v f 1 T 22,000mf 16v El .10-i

250y 45p 2100mf 200v E2.50T

'Ex equipment tested

'fP.P. 40p

SEMICONDUCTOR 'GRAB BAGS'

DISPLAY 1:C ABNADRGAINS TRANSISTOR INT\;ER CHEAPER
AA I.C.'s and Transistors by well known manufacturers and fully
guaranteed. No fall outs. Comprehensive data on I.C.'s 15p per type. 2N4351 N channel MOS FET. 2N4352 P channel MOS FET. 60p each E1 .00 per pair. HIGH VOLTAGE NPN POWER SWITCHING transistors BVcbo 600v BVceo 500v BVebo 15v lc 5 amps Pc 125 watts HFE 60 typ ft 2.5 mhz ideal invertors, etc. T03 £1.60 each 4 for £5.40. BF258 NPN 250v @ 200ma 45p each 3 for £1.08. I.R. BSB01 2.5 amp 100v bridge rec. P.C. mount long leads 35p each 4 for £1.08. IN4998 4 amp 100v P.C. mount diodes long leads 14p each 10 for El .10. LM309K +5v 1.2 amp regulator £1.10 each 6 for £5.35. 2N167113 unjunction 450mw 30v 48p
each 3 for ET .00. IN4004 SD4 1 amp 400v diodes 7p each 18 for f 1.00. I.R. 12 amp BRIDGE RECS. 400 volt £1 25 each.
POWER DARLINGTON SCOOP'
MJ10011 NPN 60v 90w 8 amps 1113 95p each
2P45385 NPN 80v 100w 10 amps T03 f 1.25 each
MJ4030 NPN 60v 1513w 16 amps 11130225 each

S.C.R.'s 2%3001 30v 350 ma 1018 22p each 6 for OR 25505160v Burma 1018 27p each 4 for ROO 254441 50v 8 amps 10220 45p each 10 for E4.00 C106D1 400v 5 amps 10202 55p each 10 for f5.00
TRIACS

G.E. 12 amp 600410220AB 95p each 10 for £8.75 E.C.C. 1.6 amp 400v T05 38p each 3 for 0.00 A.E.I. 10 amp 400v ready mounted on 23 a 23 heatsink ft 00 each 4 for E3.75

LOW PROFILE I.C. SOCKETS

8 D.I.L. 10p each 12 for ELM 14 OIL 14p each 8 for ROO 16ot L. Gold Plated mil. grade 22p each 6 for f1.01 12 D.I.L. 27p each 5 forf 100 24 011 35p each 3 tor f 1 00

OTHER GOODIES

253055 IR

65p each

2145943 R.F. output 40 volts. 1 wan up to 1000MH1

1.05 55p each 10 for £5.00 254304 WN120 F.E.T. transistor 37p each 3 for f1.00

1.1438015ISL6051 14 0.1 L. 2 watt A F amp 80p

each 8 for £6.00 CA30218 DC 120 MHZ differentialicascode amp

CI DO each 3 for 02 50 CA3011 20 MHZ wideband amp 1099 case 65p

each 2 for £100 TMS3114 DUAL MOS 128 bit static shift reg. 131 2.5 MHZ El 50 each 4 toi 14.25 NE555 10 for 02.55 GE424 zero voltage switch, mac SCR relay driver 105 can f110 each 7 for E6.50 ESA2719 8 independent diodes 1N4148. 15914 type in 16 01 pack 38p each 3 lot fl OD FP03725 4 NPN 50v 500ma transistors in 14 O.; L pack 70p each 2 for E1.00

DECADE 0-9 THUMBWHEEL SWITCHES. Stackable, gold plated contacts, dim. 33 x 43 x 8 mm. 90p each, 10 for £5.50. Miniature Continental Series 12VDC 4c/ o plug in relays £1.30 each.
Greenpar 5002 BNC Chass. socket single hole fixing 65p C90 Audio Cassettes screw type construction 45p each 3 for £1.00.
Bulbs 24v 14 watt white frosted S. B.C. 8 for E1.00. Bulbs 12v 100 watt clear, base similar S.B.C. 45p each. S.B.C. Bulb Holders All steel cad. plated panel mount easily fixed via nut and round hole, ideal disco displays, scoreboards, etc. 4 for E1.10.
VMOS VMPI Siliconix T03 power FET 0-60v, DC -200 mhz will drive direct

POWER SUPPLY UNITS
5 VOLT 2.5/8 AMP TTL Made for TTL this compact ex computer systems unit features a 10 amp transformer. DC outputs of 5 volts @ 2.5 amps and 7.5 volts @ 5 amps are available. The 5v output is fully regulated and smoothed with electronic current limiting. May be easily moded for 5 volts @ 7-8 amps. Sold complete with circuit, believed working but untested. £8.25 + E1.60pp.
5 VOLT 5 AMP An extremely compact unit measuring only 125 x 175 x 83 mm, almost fully enclosed with terminal type connections. Features such as adjustable volts and current limit make it ideal for an MPU system. Sold as new. £14.99 +01.60pp.
" +" & "-" 12-15v @ 250 ma. ITT Powercard.
Measuring only 140 x 80 x 40 mm, this precision totally enclosed PSU should meet all your memory and negative rail requirements. Individual pots allow independent adjustment of both the plus and minus supply rails. Supplied BRAND NEW with circuit and edge connector at onlyfl2.75 + £1.00pp.

KEYBOARDS

* 76 KEY ASCII CASED *

At last a coded 75 key cased ASCII keyboard at the

right price. Housed in an attractive light grey case,

this unit was originally made for ICL for use in air-

port reservation systems so only

were used. It has everything, we think, to meet

your most exacting requirements, numeric

keypad, upper and lower case, cursor controls,

single 5 volt rail, serial and parallel data outputs,

plus eight LEDs mounted on the case. Supplied

with circuits, believed brand new, but may have

minor scratches on cases.

Only

50 + Et .60pp

Amazing value mixed semiconductors, include transistors, digital, linear I.C.'s, triacs, diodes, bridge recs. etc. etc. All devices guaranteed brand new, full spec. with manufacturers markings, fully guaranteed.
50 v BAG f2.95 100 BAGS £5.15
,
Keep your equipment Cool and Reliable with our tested ex equipment "Muffin Fans" almost silent running and easily mounted. Available in two voltages 110 V.A.C. f5.05 + pp 65p OR 240v A.G. £6.15 + pp 65p DIMENSIONS 4i a Of a 1
66%, ELECTRONIC
COMPONENTS & EQUIPMENT
DISCOUNT
Due to our massive bulk purchasing programme which enables us to bring you the best possible bargains, we have thousands of I C 's Transistors. Relays, Cap's., P C.B.'s, Sub -assemblies. Switches, etc etc surplus to our requirements. Because we don't have sufficient stocks of any one item to include in our ads we are packing air these items into the "BARGAIN PARCEL OF A LIFETIME" Thousands of components at giveaway prices, Guaranteed to be worth at least 3 times what you pay plus we always include something from our ads for unbeatable value', Sold by weight
7Ib f 5.25 + pp E1.25 14113£ 7.95 + pp E1.80 28Ib f13.75 + pp £2.25 56Ib £22.00 + pp 04.75
ISOLATED 240v 4 AMP Et 10 AMP
SOLID STATE RELAYS
Interface your MPU etc, with the outside world made by tree famous "Aatralux" Co. They consist of a miniature plastic module with mounting holes containing a reed relay for isolation, choke and Mac. 12-20 volts D.C. at a few milliampe enable on/off control of A.C. loads up to 10 amps' The 10 amp version shoed be mounted on a haatsink. 100's of uses including power control, lighting, etc, etc. Dimensions, 4 amp, ilk'!" k 1..10 amp, 11 x x 1. 4 amp £1.45 10 amp £2.10 complete with circuit

from CMOS etc, £1 .50 each, full date 30p. Heavy Duty Flat Insulated Earth Braid 100200 amp braided tinned copper in heavy clear PVC sheath 50p per metre. £6 for 15 metres + PP El per 15 metres.
BULGIN miniature 6 way male chassis mount socket and matching free plug 60p each, 2 for £1.10.
Red L. E.D.'s full spec. 0.2' 14p each. 10 for £1.25. Red L.E.D.'s 9.125- 10p each 10 for 80p1 Dynamic Stick Mice 60001 with built in on/off switch complete with lead and min. jack plug El .15 each. 10 for E10.00.
TO5 HEATSINKS "Thermaloy" black anodised press on aluminium finned type 18p each. 8 for f1.00.

BURROUGHS SELF SCAN DISPLAYS

A masterpiece of electronic engineering. This unit could be described as a miniature VDU. Module consists of an 18 digit display area, mounting bezel, on board

character generator and decoder driver circuitry, all measuring only 8.5" x2.25" x 1.34"

By inputing a 6 bit ASCII T.T.L. code 18 GIANT 0.4" full alpha

numeric characters may be displayed simultaneously, addition of external logic enables the unit to scroll
along just like a newscaster. Internal 64 character

repertoire, or external inputs for special characters

are provided. Power requirements +5v, -12,

and 250v.

Supplied brand new, complete with data

£55.00 a

£1.25pp.

10s0 MHZ

HC6iU

BARGAINS GALORE!
In our walk round Warehouse

e-

MHZ

rt 20 MHZ

H t81U
HC181U

NOW open Monday to Saturday 9.30-5.30

SPEC

* LOW PRICE CHASSIS *

EL.
A special hulk purchase enables us to offer the above keyboard at a lowest ever price. 49 coded keys encoded into a direct TTL compatible 7 bit output. Features such as delayed strobe, 5 volt D.C.single rail operation and rollover protection make this an absolute must for the MPU constructor, Supplied complete with connection diagram and edge
E20.00 + P.P. £1.60 connector, at a secondhand "no time to testprice of only
SUPER CASED VERSION Same as above spec. but housed in attractive two tone moulded, free standing case. Unit also includes an all M. parallel to serial convertor ino details)
etc.
£27.50 + P.P. £1 .85

TOROIDAL TRANSFORMERS

HP 240v pri. sec. 2 x 30v @ 4 amps 2 18v @ 1 amp E11.00p p £1.95

dimensions 4ii a 71U PR 2404 ler sec 15 0 15 @ 2 amps dimensions 3' a 23- f4.95 pp. 99p.

TM 240v1 10v pri. sec 15 0 15 8vA dimensions 23-

E1.95.p p 30p

All voltages measured off lead.

G ELE

S

Dept. P.C.W. 64-66 Melton Rd., Thornton Heath, Sum. MAIL ORDER

Telephone: 01689 7702

INFORMATION

Unless otherwise stated all prices inclusive of VAT. Cash with order. Minimum order value £2.00. Prices and Postage quoted for UK only. Where post and packing not indicated please add 40p per order. Bona Fide account orders
minimum £10.00. Export and trade enquiries welcome. Orders despatched same day where possible. Access and Barclaycard Visa welcome.

EFFICIEHNICGYH SMITHS

RADIAL BLOWERS

Are your hot parts sweltering? Then keep them cool

with our high of I iciency radial snail type blowers. Made

by Smiths. designed for continuous use in expensive

electronic equipment very powerful and quiet, gives

massive air flow to prolong component life and

reliability. Easily mounted, x 3'. Ideal linears etc.

air

apertu
BR

AND

NE

Please state 240v or 110v operation. 50 hz only.

55

P P. £1.60

PCW 145

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;SHARP;

IMZ8OKI

...when you need a dependable supplier, an authorised distributor with a comprehensive range of products at keen prices, backed by large stocks for fast delivery, with full after -sales support. We promise you a rapid response.
ANADEX DP8000
Exceptional value and high reliability. 84 lines per minute, 112 cps. Parallel and serial interfaces as standard. 96 ASal set, 9 x 7 font. Variable tractor, Forms handling facilities. 1K buffer store. Options include 2K extra store IEEE interface.
£516 from only
LEAR SIEGLER ADM -3A
The most popular visual display in the world. 1920 character screen capacity. Cursor addressing. Dual interfacing. Auxiliary port. Wide range of speed and word formats. Options include Tektronix 4010 compatible graphics.
£570 from only
LEAR SIEGLER ADM -31
Low cost VDU with two page display and full editing features. Dual interface, 509600 baud data rates. Upper/ lower case character set. Cursor addressing, editing, protected fields, dual intensity. Optional polling and addressing, printer port.

I THE FIRST °

1 DESKTOP

I COMPUTER
i TO STRIKE

1

THE

FULL RANGE OF SHARP GAMES ON CASSETTE NOW AVAILABLE

RIGHT CHORD!

I AT LAST! THE MICROPROCESSOR THAT BRINGS

SOUND TO YOUR PROGRAMME. COME AND LISTEN TO THE DIFFERENCE

I

AT COMPUTERIST SOUTH EAST ESSEX FIRST COMPUTER

SHOWROOM AND BOOKSHOP

I 642 London Road, Westcliffe-on-Sea, Essex

Dair Electronics Your North Essex

F.

Telephone Southend 335298 Computer Centre

and

33 High Street, Halstead

Essex. Telephone 2533

I NOW AVAILABLE

FROM

1 TIC COMUTERIC

I

ik

OPIIR
L. ELM-MO[11ES

4Ir4 ,:".

1

"."%*"...... If

from only £795
LEAR SIEGLER ADM -42
Semi -intelligent VDU with up to 8 pages of display. Full editing features, blinking, blanking, cursor addressing, format transmission, protected fields, dual intensity, separate function keys, status display. Optional alternative character set, programmable function keys, synchronous
£1049 interface, line &awing set. from only
TYPEWRITER TERMINAL
Two machines for the price of one. Typewriter style friction feed for single documents, letters etc. Pin feed for continuous business stationery. Electric typewriter keyboard layout and touch. Left and right hand margin setting. Crisp, high quality printout.
from only £825
TEXAS 810
Compact 150 cps 132 column printer. Optimised bi-directional printing. Adjustable tractor feeds, 3 - 15 inches. 9 x 7 dot matrix. RS212 interface. Forms control options. Other serial and parallel interface options. Compressed print option.
from only £1392

LOW COST GRAPHICS TERMINAL

4111111111111111 £1295
A low cost Tektronix 4010 software compatible option means that we can offer the well-known Lear -Siegler ADM 3A with powerful graphics capability. A Z -80A microprocessor andRAM sufficient to provide a 512 x 250 dot grid and automatic scaling from a 1024 x 780 dot grid enable point plotting, vector drawing and alphanumeric character display. Call today for a demonstration or more details.

PERIPHERAL HARDWARE LIMITED Armfield Close West Molesey Surrey Telex 922175

SOUTH 01-941 4806

NORTH Harrogate 501263/4

IRELAND Dublin 952316

146 PC%

[SP

D
76 Godstone Road, Kenley, Surrey (nr. Croydon). Tel: (01) 668 0761/2
Professional versatile computer system with comprehensive front panel facilities and 20 -slot motherboard. Units have substantial power supply etc. and come with 2 or 4 MHz Z80 CPU. BUS conforms to the IEEE S100 standard. DPS.1 from £695

DPS.1

Available with K2 operating systems & PASCAL/Z.
Companion Disc Drive Enclosure for on-line storage
for 250K Bytes to 2 M Bytes.
MIDAS

MIDAS 5.100 SYSTEMS

Substantial Mainframe to house your S100 system, with optional 5" or 8" disc drives. Special systems built to your requirements from Z80 CPU and other S100 boards held in stock

Mainframes from £239

MIDAS 1 : Z80 System from £680

MIDAS 2 Z80 Disc System from £1259

MIDAS 3 : Z80 Disc System 8" from £1595 DOUBLE DENSITY recording available on MIDAS giving up to 2M BYTES of on-line storage.

Software for MIDAS includes CP/M, FORTRAN, COBOL, PASCAL and several BASICS including XYBASIC for control applicaitons.

Board Kits - All available as built & tested

boards

Z80 Starter kit, featuring on -board Key-

board, 2K Monitor, 1K RAM, 2x8 bit

1/0 Ports, Prom Programmer etc. etc. £188.00

ITHACA MPU-80 A/T

£235.00

Z80 CPU, 2MHz, 1K RAM, up to 8K

EPROM, S/P 1/0 Port, four -channel

counter timer - SBC100

£159.00

Z80 CPU, as above but 4MHz SBC200

£177.00

Z80 CPU Board, 4 MHz, A/T jump -on -Reset 8080 CPU Board, jump -on -reset

£116.00 £92.00

8K RAM Board, low power 450 n Sec

(21 L02)

£79.00

16K RAM Board, low power 250 n

Sec Static A/T

£195.00

32K RAM Board, extended addressing,

Static

£343.00

- Memory Manager, allows memory
expansion addressing to 16M Bytes

IEEE spec

£39.00

Dynamic RAM Board, 2 MHz, 16-64K £129.00

Dynamic RAM Board, 4 MHz,

16-64k A/T

from £167.00

2708 EPROM 116k) Board

£60.00

2708/2716

EPROM

Prog

Board,

2 Textool Sockets

£90.00

PROM 100 Programmer Board

£110.00

I/O Board, 2S/2P, with DIP

switch selection

£100.00

I/O Board, 2S/4P, provision 4K RAM/

4K ROM

£135.00

I/O Board, 2S/4P, with interrupts A/T £235.00

Analogue I/O Board, 8 ch

8/10 Bit A/T Analogue I/O Board, 2 ch 12 bit

£295.00

A/D, 2 ch D/A Video Interface, 16 lines, 32 or

£287.00

64 ch/line (60 frames)

£93.00

Video Interface, 16 lines, 64 ch/

line (1/0 Port driven)

£99.00

Video Interface, IEEE spec, 80 ch

by 24 1, memory mapped up to 256 ch,

50Hz,

£230.00

Video Display, 24 1, 80 ch/1, keyboard

interface, 2K RAM, special characters

available etc

£198.00

Video Interface, 16 lines, 64 characters

(50 frames)

£104.00

High Density Graphics from Vector, inc

8K RAM Board A/T

£333.00

Real Time Clock Board from

Mountain Hardware A/T

£180.00

Motherboard (8 slot with active

£34.00

terminators)

Motherboard (13 slot with 4 edge

connectors)

£43.00

Extender Board with logic probe for

voltage level impulses

£29.00

FLOPPY DISCS Disc Controller, 5" or 8" Double density controller A/T
Software CP/M on 8" or 5" CP/M 2
C -BASIC 2 Microsoft BASIC V.5 XYBASIC Extended
Microsoft FORTRAN 80 Microsoft COBOL 80 PASCAL/Z CP/M Version
PASCAL (UCSD)
MAC Macro -Assembler 8080 with Z80 Library Z80 Ass, Linker & Editor
ZS1 D Trace & Debug Tool
Diszilog Diassembler Wordstar Text Editor
Supersort

£139.00 £280.00
£75.00 £100.00
£75.00 £155.00 £215.00 £205.00 £325.00 £165.00 £150.00
£55.00 £56.00 £50.00 £35.00 £255.00 £125.00

WRITE OR PHONE FOR CATALOGUE

PCW 147

%;:;,

NEW EUROPEAN PRINTER

* Versatile matrix printer with no hidden extras. * Fully compatible with all main computers - no
additional hardware needed; PET handshake routine, RS232 and V24 all standard features. * Has primary and secondary addressing capability allowing not only single and double width characters but also full PET graphics.
* Uses plain paper

* Choice of blue or black ribbon

80 column bi-directional 52 column bi-directional

£590 + VAT £490 + VAT

Journal printers etc. also available. For further details write to UK distributors:
Barnes Consultants, 36 Eaton Court, Boxgrove Ave., Guildford, Surrey

Tel: Guildford 60982

GATE FTEROSYSTEIT15 LIFT1ITEO

41$

Scotland's Complete Microcomputer Service

now supply and support:
HARDWARE: Apple II Systems and Peripherals
Commodore Business Systems A wide range of VDUs, printers, etc.

SOFTWARE: Incomplete Records Accounting
Sales Ledger Purchase Ledger Nominal Ledger
Stock Control Payroll
Word Processing
Database

Software can be tailored to your requirements or written completely to your specifications.
Our service is comprehensive, ranging from advice on system selection through installation and implementation, to operator training and comprehensive Hardware and Software maintenance.
You don't have to take our word for it. Call us and arrange a demonstration. GATE MICROSYSTEMS LTD., THE NETHERGATE CENTRE, 66 NETHERGATE, DUNDEE.
TEL: (0382) 28194.

148 PCW

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MICROCOMPUTING I.C.'s

Z8001

a

MC6800 MC6802

£142.50 £ 6.75 £ 8.50

a 6800/6809 MICRO SYSTEM
77-68 PricesWashed!

MC6821
a MC6850
MC6810AP MC6840

£ 4.63 Mak 4.99 111 3.61 12.72

Bearbag 1 77-68 CPU KIT
Bearbag 5 77-68 4K RAM KIT Bearbag 6 77-68 MON 1 KIT

£35.00 £55.00 £37.50

a

MC8602P MC14536P

MC3459

S

Z80 CPU 2.5MHz Z80 P10 2.5MHz

Z80 CTC 2.5MHz

S Z80 SIO
Z80A CPU 4MHz

a

Z80A P10 4MHz Z80A CTC 4MHz

SC/MP 11

2.8k 3.69
2.43
. £ 8.99 . £ 7.99
£ 7.99
25.57 . £ 13.99 . £ 10.00 as s
£ 10.00 £ 8.88 PI 61

Bearbag 12 77-68 V.D.U. KIT

£42.50

Bearbag 13 77-68 MON 2 KIT

£47.50

Bearbag 16 77-68 EPROM BOARD KIT . . £21.50

Bearbag 17 77-68 PIO BOARD KIT . . . . £40.00 Bearbag 23 77-68 32K DYNARAM KIT . . £75.50 Bearbag 18 CASSETTE INTERFACE . . . £12.50

STOP PRESS! **

6809 & FLOPPY DISC CONTROLLER BOARDS

(INS 8060N)

a

INS 8154N 8080A

6502

6522

6532

6545

6551

WED

8.18
5.50 9.90 7.30
12.76 16.66
10.79

Amamima one az sfflo
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NOW AVAILABLE - SEND/PHONE FOR DETAILS.

" am" KEYBOARDS

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computer keyboards £38.00 + £1.00 p&p + VAT

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4116 (16K Dynamic) £ 6.99

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2716 (INTEL) . . . £21.50

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TANDON TM100 51/4 Double sided disk drive £250.00 SHUGART SA400

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51/4" single sided disk drive £189.00

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PRODUCTS

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9600 MPU Module 9601 Motherboard (16 slot)

£330.00 £128.65

9603 Motherboard (8 slot)

£73.60

9602 Card Cage (Kit)

£55.00

9610 7`21°M'IlVggi Module,

N/A £191.00

9620 16 port parallel I/O (with

8 PIA's) -

£215.00

9620 16 port parallel I/O (with

2 PIA's)

£185.00

9622 Combination Serial/Parallel I/O Module

£250.00

9612 Buffered Utility Prototyptng

Board

T.B.A.

9627.8 16K Ram Module (470ns 8K bytes)

£235.00

9627 16K RAM module (470ns 16K

bytes)

£360.00

9627A 16K RAM Module (300ns

£410.00

.19213(0bLd)Extender

£45.00

9640 Multiple Programmable Timer £269.40

9640 Multiple Programmable Timer

(Part populated)

£205.00

9650 8 port Duplex serial I/O (with 8 x 685 o's)

£240.50

9650-2 8 port Duplex serial I/O (with 2 x 6850's)

£207.00

96702 Relay Contact Module 9690 Card Puller 96102 32/32 I/O Module
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£275.00 £9.95
£222.00
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6502 BASED MICRO KIT 8K RAM KIT MAINS ADAPTOR V.D.U. KIT

. £65.00 Nat 195.00 £ 5 00 aaaaa
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£88.00 ow*

NEWBEAR SYSTEMS FOR APPLE 11, ,..,'"w°

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TERMS. Official orders (min £10.00), Access and Barclaycard welcome. p&p 50p, PLEASE ADD 15% VAT. SEND FOR BOOK list and hardware catalogue.

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CALLERS AND MAIL ORDER: 40 Bartholomew Street, Newbury, Berks. Tel: 0635 30505 aaaaa

CALLERS ONLY: 220-222 Stockport Road, Cheadle Heath, Stockport. Tel: 061 491 2290 an

a division of Newbear Computing Storc Ltd.

PCW 149

WE'RE THE NEWEST AND MOST UP-TO-DATE COMPUTER CONSULTANTS AND SUPPLIERS. WE'RE SPECIALISTS IN HARDWARE, SOFTWARE AND CONSULTANCY.

JUST LOOK AT
THESE PRICES

SOFTWARE SALES LEDGER PURCHASE LEDGER INVOICING (FOR COMPUTHINK)
HSTOCKORD CONTROL PROCESSOR
ASSORTED GAMES AND INSTRUCTION COURSES

£350 EACH
INCLUDING TRAINING COURSE
PRICES ON
REQUEST

AND AVAILABLE ALMOST IMMEDIATELY:

HARDWARE SHARP MZ-80K
ITT 2020 (APPLE) DISC DRIVE COMMODORE PET 32K COMMODORE DISC DRIVE
3022 PRINTER COMPUTHINK DRIVE 400K
800K
VIDOGENIE 16K TEAC DISKDRIVES SINGLE
DUAL
ANADEX DP8000

From £575
£750 £370 £795 £795 £700 £955 £1245 £395 £275 £499 £499

77 TRACK 51/4" DISC DRIVE

INCLUDING
DOS

TRAINING COURSES FOR ITT, COMMODORE - BOOK NOW!
MEDIA 514" from £22 for 10 8" from £37 for 10
MAIL ORDER: PLEASE ALLOW 21/28 DAYS FOR DELIVERY. P&P EXTRA AT COST

ALL OUR PRICES INCLUDE VAT AND THE BEST SERVICE BACK-UP AVAILABLE

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Philips Mini -Digital Cassette Recorder.

CASSETTE RECORDER

,
(

The Mini -Digital Cassette Recorder

(Mini-DCR) can operate in the following

modes : Idle, Read, Write, Backspace

and Rewind. Complementing the quality

and reliability of the Mini -Digital Cassette

Recorder are Philips mini -cassettes

certified for digital data recording

applications. These mini -cassettes use

tape which is certified for freedom from

drop -outs. Mini -cassettes have been widely

used for program loading in Philips office

computers during the last four years, and

over half a million are already in service.

Low cost, low power consumption and

compact size of the Mini -Digital Cassette

Recorders mean they are ideal for

program loading and updating applications

as well as providing a highly convenient

data capture facility.

Ample capacity for program

loading and data interchange is provided

by the 128 k byte capacity, and the high

data transfer rate of 6000 bits/sec allows

quick reading and writing of programs and

data.

PRICES INCLUDING MANUAL

MINI D.C.R.

£95 ea. +VAT

INTERFACE

£37.50 ea. + VAT

INCLUDE £2.25 FOR CARRIAGE ETC.

Manual available separately price

£10.00. Refundable on receipt of

order.

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INTERFACE BOARD
This compact interface board was designed specifically for the purpose of interfac:ng the Philips Mini DCR to a Micro-computor. Power consumption is
very low, enabling it to be powered from the micro -computer that it is serving. hlexibility of the system was held as paramount, address decoding can be changed simply by moving
links
By using subroutines held in the micro -computer to control the system the user can make his controlling program to suit his own particular needs and can be as simple or as complicated as necessary.

CUR RAH

COMPUTER COMPONENTS

79 Crowland Rd. Hartlepool Cleveland. TS 242JN. Phone 0429/ 871900

150 PCW

X ITAN SYSTEMS

CROMEMCO SYSTEM 3
£4,412.00 for this system with vdu.
The ideal business system. System includes a full 64K fast RAM, dual full-size floppies (Persci 277), RS232 interface/20mamp loop for console device, parallel printer port (Centronics/ Anadex compatible), 21 slots for expansion, Lear Siesler 24 lines or 80 chars vdu, and CROMEMCO's CDOS operating system with their 14 digit BCD extended disk Basic - ideal for those accurate large numbers required by successful businesses. CDOS is CP/ M functionally equivalent, with many extra facilities. Optional extras from Xitan include Fortran, Cobol, Text Formatting, Z-80 macro -relocating assembler and DBMS at £59.00 each. CIS interactive screen handling Cobol at £425.00 (recommended to serious business users), Cromemco 5100 boards, CP/ M (we are an authorised oem distributor of Digital Research's CP/ MI for the System 3, Wordmaster, Wordstar, Supersort, and CPM374X utilities.

c.o.,."c°

COMING SOON! . . Full 7 -terminal multi-user operating system from Cromemco for System 3 users. Up to 48K per user, all running independently. This operating system has to be seen to be believed. It will run any of the Cromemco provided and supported software packages, in any combination. Features include partition rescue facilities, allocating more memory to users, real-time clock for time/date stamping of jobs and disk queueing techniques. Buy your System 3 now, expand later as you need it.
S100 BRITISH COLOUR BOARD
We are proud to offer the first BRITISH S100 Colour board. Manufactured by a local Southampton company - Hi -tech, we can thoroughly recommend this product. Features include true PAL colour generation for high -definition on your television or colour monitor, 15+ colours and black/white with 6 additional grey scales, 24 lines with 40 characters per line, with standard character set plus 44 numbers and symbols, and 64 computer selected graphics symbols. Symbols include fractions and the £ symbol. Plotting is available at 80 x 72 resolution. Single or double -height characters, with flashing on an on/off duty cycle of 3-1. The board is memory mapped on any 2K boundary, with its I/O port set at any of the 256 available on the S100 bus. Just plug into your S100 system and colour television and go! Driver software and documentation provided. Price £295 .00ex vat cash with order. Please specify if for television or 75 ohm monitor.

Z-2 H
eomputaform..,

ON DEMO NOW! The Cromemco Z2 -H. For onlyE5,380.00 set the reliability and quality of Cromemco, coupled with the capacity of the new IMI 11 megabyte hard disk drive. This is incredible value for money. Specification includes transfer rates of up to 10
times faster than the fastest standard floppy disk, DMA controller for up to 7 hard disk units, and the new extended CDOS operating system. Systems available in three configurations: - A) The Z2 -H complete integral system,
64K RAM, Z80A cpu, two double -sided mini -floppies, RS232 console port, parallel printer port, power supplies, cables, case and 12 -slot S100 motherboard (7 slots free). B) Additional hard disk subsystem for existing system 2 or system 3 users consisting of one hard disk, DMA controller, power supply, case and cable. C) As unit B but with two
hard disks. Prices: Unit A) £5,380.00 B) £4,330.00 C) £7,420.00

Xitan Systems also supplies and stocks vdus, printers, NORTH STAR HORIZON computers, Commodore Business Machines PETs, S100 boards, and books. We are here to demonstrate the range of quality microcomputer systems available for use today. Ring up for an appointment now! You'll not be disappointed. We have Osborne's Sales Ledger and Payable Ledger in source form for use on Cromemco System 3 with CBASIC2, and we can offer a customising service on these programs. Additional software includes Microsoft Basic Interpreter and Compilers, Cbasic, Macro80, and CP/ M for the North Star Horizon.

Xitan Systems Ltd., 23 Cumberland Place, Southampton SO1 2BB.

Tel: (0703) 38740

Hours Tue-Sat 9.30 am to 5.30 pm

PCW 151

CRYSTAL ELECTRONICS CC ELECTRONICS

XTAL Basic 2.2

NOW ON SHARP MZ8OK
All of the features of SHARP BASIC and more. Occupies 5K less
memory, thus effectively increasing memory size for programs.

MZ8OK 20K RAM

£520 +VAT

(with XTAL BASIC leaves 11K for programs)

XTAL BASIC for SHARP

£40+VAT

Coming Soon-PETSOFT* programs in XTAL BASIC format for SHARP & NASCOMPrices as PETSOFT list+20%.

NASCOM 1 & 2 owners-XTAL BASIC 2.2 £35 +VAT

NEW EPROM version

£100 +VAT

(please state monitor used)

EPROM version runs in E000H-FFFFH.

APPLE II PLUS OWNERS
APPLE INTEGER BASICon discfor32Kor 48K APPLE. Now you can run nearly all of your programs-

£20 +VAT

* PETSOFT is a tradesmark of ACT PETSOFT LTD.
Members of Computer Retailers Association & Apple Dealers Association

Shop open 0930-1730 except Wed. & Sun. 40 Magdalene Road, Torquay, Devon, England. Tel: 0803 22699

and Barclaycard welcome. 1RIL

COMPUTERS AND
COMPONENT,

Yourkey.

To MICROCOMPUTERS

r This coupon will bring you

details of our new complete

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home computer course. You will learn all the basic

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technology and receive full

instruction on computer functions and programming.

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Tuition is carried out at your

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Own pace on your own home

computer and is supervised by

our qualified computer staff.

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F2EE
BROCHURES

rIUTORCOURSE
HOME COMPUTER
Please rush me details of your ' HOME COMPUTER COURSE

Send today for a brochure I Name on this exciting new course.

I Address

Block Caps. Please I Post now, without obligation to:
I British National Radio & Electronics School.
P.O.Box 156, Jersey, Channel PC

SALE OF THE CENTURY
With every order received in the next week for 16K or 32K Pet, a Petsoft Programmers Toolkit (R RP £55) yours for only £5.00.
Specialise in supplying the business user. Software available:

BUSINESS PROGRAMS Sales Ledger
Purchase Ledger Nominal Ledger
Payroll

ACCOUNTANTS & AUDITORS Incomplete Records

PLUS

Other Software Guidance given to: Go It Alone, DIY,
Teach Yourself Customers.
DISKS, TAPES, AND PRINTER PAPER AVAILABLE

(Ask for Barry Blyth FCCA or Dave Trueman)

Comprehensive demonstration facilities available (by appointment) *Also call us for your component requirements *

Orchard Electronics Ltd 21 St Martins Street Wallingford Oxon OX10 ODE Tel: (0491) 35529

152 PCW

nwco

video display and EPROM option socket,leaving a 1K user RAM.

The MPU is the standard Z80 which

12" x 8" PCB carrying 5LSI MOS

is capable of executing 158

packages,16 1K MOS memory

instructions

packages and 33 TTL packages.There including all

is on -board interface for UHF or

8080 code.

unmodulated video and cassette or Built price

teletype.The 4K memory block is

£140 + VAT.

assigned to the operating system,

MEMORY 8K Microsoft BASIC 2K NAS-SYS 1 monitor 1K Video RAM 1K Workspace/User RAM. On -board 8 sockets provided for memory
expansion using standard 24 -pin devices:2708,2716,2732 EPROMS and
MK4118 static RAM. MICROPROCESSOR Z80A which will run at 4MHz but is selectable between 2/4 MHz. HARDWARE Industrial standard 12" x 8" PCB,through hole plated, masked and screen printed.All bus lines are f ully buffered on -board. INTERFACES s Licon 57 key solid state keyboard Monitor/domestic TV interface Kansas City cassette interface (300/1200 baud) or RS232/20mA teletype interface. The Nascom 2 kit is supplied complete with construction article and extensive software manual for the monitor and BASIC.

REVOLUTIONARY TOUCH ACTIVATED KEYBOARD TASA MODEL 55

THE MOST FLEXIBLE SYSTEM EVER!

Nascom System 80Total Option Concept

alMINIM.111011110

4111110111.11111111.0

Floppy disc system Double sided,double density 51 -in di. giving
280K bytes formattedincluding controller board/PSU/Housing and interconnects £480.
Controller board £127.50 Second Disc £240.
CP/ M £80

Designed and manufactured by TASA Inc of California,the TASA keyboard is a truly solid state system that has no moving parts and is virtually indestructible.Totally flat and measuring just 0.325" thick,6.25" deep,15.05" wide,the TASA has full 128 position 8 -bit ASCII output plus continuous strobe,parity select.The touch sensors are sealed in tough polycarbonate which is washable and can withstand rugged treatment in harsh environments.
Other features include: Built-in electronic shift lock.
Two -key rollover to prevent accidental two -key operation (excluding"controrand"shift").
Electronic hysteresis for firm"feel". Signal activation time of 1 millisecond. Output via 12 -way edge connector. CMOS compatible with pull-up resistor. Parallel output:active pull-down,direct TTL compatible (one load) open collector type.

System 80 housing High strength GRP moulding in variety of colours. Accepts 128 Nascom 2 CPU board, four 88 expansion boards. £85 incl. frame racking, interconnects and motherboard. Expansion boards* 16K RAM £140.00 32K RAM £200.00
High Resolution Programmable Graphics £90 (kit). High Resolution Colour board £140 (kit).
'Available in kit form. All prices subject to VAT.
AVAILABLE SOON
NASCOM FIRMWARE IN EPROM
NASPEN:£25.00 + VAT + 30p P + P ZEAP 2:£50.00 + VAT + 30p P + P NAS-SYS 1:£25.00 + VAT + 30p P + P
NASCOM HARDWARE
Motherboard:£5.50 + VAT + 50p P + P Mini Motherboard:£2.90 + VAT + 50p P + P

Microprocessor board* (Nascom 2) 4MHz Z80 CPU; TV or Video « 1200 baud Kansas City * Serial RS 232 printer Interfaces; Keyboard; 128 character ASCII p)gs 128 Graphics in 2 x 2K ROM; free I.6 -way parallel port; 8K BASIC; NAS SYS operating monitor. £280 built and tested. Firmware & MOS !Cs Zeap Assembler (4, 1Kx8 EPROMS) £50 Nas Pen text editor (2, 1Kx8 EPROMS) £30 NAS-DIS disassembler (3,1 KX8 EPROMS) £37.50 2708 £9.50 2716 £26 MK 4118N4 £12.75 MK 4116N4£55 for 8
NASCOM SOFTWARE ON TAPE
8K BAS1C:£15.00 + VAT ZEAP 1:£30.00 + VAT + 50p P + P ZEAP 2:£30.00 + VAT + 50p P + P
3 amp PSU:£29.50 + VAT + £1.50 P + P VERO DIP board:£10.50 + VAT + 50p P + P FRAME:£32.50 + VAT + £2.00 P + P

NASCOM IMP PLAIN PAPER PRINTER

MICRO MART

IC SOCKETS 8pin 14 pin 16 pin
20 pin 24 pin
28 pin 40 pin

10p each 12p each 13p each 25p each 30p each 35p each 40p each

ICs EPROMs 2708 EPROMs 2716

£9.00 each £26.00 each

MEMORIES 21L02
4027 4116 2114

£0.80 each £2.75 each £7.50 each £4.00 each

280 DEVICES MK3880 MK3881 (P 10) M K3882 (CTC)

£12.50 each £7.50 each £7.50 each

VOLTAGE REGULATOR

SPECIAL OFFER

LM309K

90p each

Add VAT and 30p P&P to all orders

ORDER FORM

1 Send your orders to: Interface Components Ltd,Oakfield Corner, Sycamore Road,Amersham,Bucks HP6 6SU.
Tel:02403 22307.Telex:837788.

I1 Description

Quantity

II

I111
ll

+ VAT at 15°/0
111

II

+P -FP

II

Total enclosed

NI

PCW/5/80
Price

The Nascom IMP (Impact Matrix Printer) features :
60 lines per minute 80 characters per line Bi-directional printing 10 line print buffer Automatic CR/LF 96 characters ASCII set (includes upper/lower case,$,-/#,£) Accepts 8k" paper (pressure feed) Accepts 91" paper (tractor feed) Tractor/pressure feed Baud rate from 110 to 9600 External signal for optional synchronisation of baud rate
Serial RS232 interface.

VISIT OUR NEW SHOP
We stock PET, TRS 80 ,Sharp MZ-80K,Atari TV games and extensive range of electronic components including ICs, discrete semiconductors. capacitors, resistors, VERO products, tools and accessories for both professional and amateur constructors.

Name Address
Access/ Barclaycard No:
mi -Cheques 8 P/Os made payable to Interface Components Ltd. PCW 153

aEPROMPTa ERASER
SCRUBS UP TO 32 CHIPS IN 15 MINS ON 200-250v A.C. 41 CONTINUOUS 253.7nM BEAM. SAFE &SIMPLE. GUARANTEED
* £39 C.W.O. £40 NETT 30 DAYS ALL INCLUSIVE I *
+ NEW PRODUCTS +
TEX 90 8K 16 -BIT MICROCOMPUTER £99
TMS9980 .'TEXBUG MONITOR .RAM .TIMER.V24 I/O .MANUALS
TEX100 IEEE S100 BUS&POWER UNITS: PAIR £95
RUNS ZBOA+ 64K DRAM +V24 i/O+DISC I/0 MINIFLOPPIES: EXPANDOBUS 4 -SLOT EXPANDABLE MOTHER/EXTENDER £39 COMPACT POWER: +9v8a .+16v6a -16v1a. FROM 240v A.C. £59
TELE-TEX SMART V24 T.V. TYPEWRITER FROM £99
16.64 .256 CHAR. PROGRAMMABLE SOUND &DEVICE CONTROLS TRADE ENQUIRIES INVITED FOR SUBSTANTIAL DISCOUNTS. WE ALSO NEED PARTNERS FOR PRODUCTION INVESTMENT.
ALL ORDERS AND ENQUIRIES POST -FREE TO:
TEX MICROSYSTEMS LTD. FREEPOST. ST.ALBANS. HERTS. A L1 1BR OR PHONE ST. ALBANS 64077 OUTSIDE WORKING HOURS

0

*.*

.*

u

COMPUTER PRODUCTS

11a/corn iipecialirtr

Add-one
lvtem 80

Complete technical aid

Order with confidence

Mail order

CONTROL AND HEX, KEY PADS FOR NASCOM 1 or 2
DUAL MONITOR BOARD
PORT PROBE
NAS-CHESS with graphic options NASCOM 1 or 2
NASCOM 1 GRAPHICS SYSTEM
LARGE S.A.E. FOR DETAILS PLEASE
DEMONSTRATIONS BY APPOINTMENT

18 Rye Garth, Wetherby, West Yorkshire LS22 4UL
0937 63744

Huy it with :Access

0* Professional ASCII Keyboards 'Mar

erfSrTNbrQiTetTredalkiirmNttIP-

oho

MODEL KB 756

FULLY ASSEMBLED & TESTED CASE AVAILABLE

Accessories Available include:-

Edge Connector

KB15P £1.95*

Numeric Key Pad Plastic Case (Black) DC to DC Converter

KB710 KB701 DC512

£7.50* £12.75* £5.00*

* U.K. Orders add 15% VAT on Order total.

FULL DATA SHEET ON REQUEST
Citadel Products Limited.
Dept. PCW 50 High Street, Edgware, Middlesex HA8 7EP. Telephone 01-951 1848
MITER
/KB13041105

154 PCW

fusrmuruQ
wn c3v tss
We offer systems for the smaller business user based on microprocessors by Apple and Microstar and supported by extensive software for a wide variety of applications. We also supply daisywheel printers by Qume, matrix printers by Texas, and a variety of video screens. We sell or lease equipment and guarantee our installations in the field. AND we offer in situ service support via our own engineers. If you have specific requirements for individual items of hardware, come and discuss it with us. We're Access Data Communications ... your flexible friends.
Access Data Communications Ltd., al 1111
228 High Street, Uxbridge, Middx. Tei: 0895 30831/59205

What willyou do with a
12-yearold programmer

when he reaches 16?

Any microcomputer is a major investment for an educational establishment. Many potential users feel that a BASIC only computer is ample for their needs. That may be fine today, but with computer education starting so early you may in a surprisingly short time find you want more than current implementations ofBASIC.
The 380Z is a computer that can grow to match your needs.
In the design of the 380Z our target user is the graduate research scientist. This ensures that the expandability and versatility needed tomorrow has been provided for in the computer you buy now.

approach will allow your students to advance.
380Z BASIC is not frozen in ROM. An enhanced BASIC could be loaded in mid 1980 and a BASIC with structured features sometime later.
On the 380Z the memory used by a BASIC interpreter can also be used for other software.
Does our research -oriented design pay off in classroom hardware?
Our scientific graphics was produced for the professional user. Interest in it for classroom use has been surprising.
The 380Z has the best graphics now available on a microcomputer,

Welcome to PAL Algol uith httgh resolut,oA Araph.gs
freely mix upper and lower case text and diagrams.
Mains noise can cause system crashes which result in loss ofprograms and data. All current 380Zs include a mains filter which significantly reduces the chances of this happening.
Don't buy a 380Z on patriotic grounds.
Please only buy it if you would have bought it anyway. But remember, because it is designed and manufactured here you are bound to have better access to us for influence and help than ifwe were on the other side of an ocean.
Prices range from a 16K cassette 380Z @£897 to a 56K Dual Full Floppy Disk 380Z @£3322.

Might you want to add disc storage in the next few years?
Ifyou do: Given good hardware, software availability completely determines the flexibility and usefulness of your system. There is absolutely no question that a Z80 based micro -computer which uses the industry -standard CP/M* disk operating system has several times more software on the market available to it than non CP/M computers. Today you can purchase a mature CP/M BASIC, FORTRAN, COBOL or Text Processor for the 380Z. Soon there will be CP/M Pascal and Database Management systems. CP/M software is several years ahead of software available for non CP/M family machines. Ifyou don't: Remember that professionals writing packages for your cassette system will themselves often use a disk 380Z, and the power of their tools will influence what they produce. For many people a disk machine is too expensive -but at least the 380Z

allowing multiple resolutions, multiple paging, fading and accurate control over colour. All these features help bring excitement to efforts in computer assisted learning.
Our standard machine comes with low resolution graphics and support for this from BASIC allows you to plot a point directly with a plot command useful for training and teaching.

LOWER COSTS Three things have happened which make it easier to buy a 380Z. ONE: From 1st November 1979
most prices have been reduced. TWO: Schools and some colleges can now get a 5% discount on computer orders. THREE: A new Local Authority quantity discount scheme has been introduced to make it easier for more users to benefit from quantity purchasing. Please contact the Sales Office for
details.

It is worth remembering too that neither our low resolution graphics nor our optional scientific (high resolution) graphics has any limiting effect on your memory usage, and in both you can

RESEARCH MACHINES

RESEARCH MACHINES Ltd,

P.O. Box 75, Mill Street, Oxford, England.

Telephone: Oxford (0865) 49791/2/3.

Please send for full sales information.

Prices do not include shipping costs or

VAT @15%.

* Trademark, Digital Research.

PCW 155

Small Systems
(7-1,71 Engineering
Mil Limited

IEEE-488/PET INTERFACES

Type B

£186

Bidirectional serial interface is fully addressable

and can have split BAUD rates

Type C

£120

Serial interface - output only

PET disk, compatible, RS232 C Handshake

(Printer Busy), switch selectable Baud rates,

Listen Address link selectable.

Type CS

£132

Serial interface output only with switchable

character sets to match the new PET's lower

case Screen mode, otherwise as Type C.

All interfaces are crystal controlled

Type G.P.I. A.P.

£249

Micro -based, bidirectional with buffering.

The General Purpose Interface allows free use

of PET's INPUT # statement without hangup

problems. Software changeable BAUD rates

optional features include: Second Serial

I.O. Port, 20 mA Loop I.O.

Addressable parallel (disc compatible)

for Centronics, Anadex etc.

£106

Non addressable parallel

£45

TV/Video monitor interface

£35

Real Time Audio Spectrum Analyser for

Commodore PET Microcomputer

32 Channels 1/3 Octave Filters, 1K ROM

ROUTINES on board for analysis and

graphical display. USR Functions for linkage to

PET basic operating system

£450

PET MEMORY EXPANSION BOARDS INTERNALLY MOUNTED

24K

£328

32K

£432

S100 BOARDS

Dynamic Memory Boards

IEEE -S100 Specification Timing Transparent on Board Refresh 4Mhz Z80 Operation with no wait states.
Fully tested and Burned In

Bank Select versions available North Star, Cromemco and Alpha Micro

I.O. Port Bank select Bank Size to 64K in 16K increments

Size

Standard

Bank Select

64K

£449

£595

48K

£398

£539

32K

£346

£483

P&T IEEE -488 Interface Provides S100 computers with IEEE -488 £350 Controller, Listener, Talker, Capability

All prices exclude VAT P&P £5.00 (includes Securicor Express Delivery)
62 New Cavendish Street London WI M 7LD Telephone: 01-637 0777 Telex: 8813085 (Abacus)

156 PCW

Explorer/85
Professional Computer Kit

AT
£295 ,VAT

FLEXIBILITY: Real flexibility at LAST The EXPLORER/85 features the Intel 8085 cpu
100% compatible with all 8080A and 8085 software. Runs at 3MHz. Mother Board (Level A) with 2 S-100 pads expandable to 6 (Level Cl.

MEMORY 2K Monitor ROM 4K WORKSPACE/USER RAM
1K Video RAM 8K Microsoft BASIC in ROM

WITH ONBOARD S-100 EXPANSION

INTER FACES STANDALONE FULL ASCII Keyboard Terminal, 32/64 characters per RS-232/20Ma Loop. 4, 8bit: 1, 6 bit 1/0 ports, programmable 14 bit binary counter/timer. Direct interface for any S-100 Board. FULL Buffering decoding for S-100 Bus pads, wait state generator for
slow memory. Each stage has separate 5v 1A regulator for improved isolation and freedom from cross talk. P.S.U. requirements: 8v 6.3v AC. Runs with North Star controller and Floppies/CPM: EXPLORER/85 is expandable to meet your own requirements with easy to obtain S-100
peripherals. EXPLORER/85 can be purchased in individual levels, kit form or wired and tested OR as a package deal as above.

BASE - 2 PRINTER, 80 character unindirectional Hitachi Monitor 9"

£450 £127

16k Dynamic RAM Kit

Expandable to 64K on one S-100 board in 16K increments, designed for

NO wait state operation utilizing the most advanced RAM controller.

16K RAM Kit

£139

16K RAM Expansion Kits each

£89.50

NOW :- EXPLORER/85 with NORTH STAR FLOPPY DISCS

32K

£599

48K

£698

56K

£787

North Star Double Density Disc System, 3 -drive

controller and a Single 5%" Drive with regulator,

180K byte . ..£500

Twin Drive System

£600

PETS CENTRE

LATEST PET's WITH LARGE KEYBOARD

8K

£475

*R RP E795

16K

£575 +VAT for 32K

32K

£675

BASE 2 PRINTER £450 PROGRAMMERS TOOLKIT, £45

Full range of software available.

SEND SAE FOR COMPREHENSIVE BROCHURE
Please add VAT to all prices. Please make cheques and postal orders payable to NEWTRONICS or phone your order quoting BARCLAYCARD, ACCESS number. INe are now open for demonstrations and Sales, Monday -Saturday 9.30am. 6.30pm. Near Highgate Underground, on main Al into London

Afik.,J eallitrirligS
255 ARCHWAY ROAD, LONDON N. 6
TEL: 01-348 3325

Can small computers be more than toys?
You've looked at them all. Most of the small systems are great for playing games...and very little else. And most of the larger systems are designed to run the manufacturer's standard 'applications packages' ...which is fine if you don't mind rebuilding the whole of of your business to suit. It's true: most small computers are just expensive toys whose limited flexibility and expansion is soon outgrown.
When you want to move on to real computing, the right choice is Ohio Scientific.

Real flexibility...
...at a realistic price! Even the smallest Superboard has a realistic 4K of RAM in which to use its Microsoft BASIC; the smallest Challenger 2 has two spare slots in its case for easy expansion; while the Challenger 3 series can be supplied as standard with a 74 -Mb hard disc - probably more on-line memory than all the other 'large' micro -computers put together!
Mutek offer three Ohio Scientific ranges: C1/Superboard from £175 Challenger 2 from £349 Challenger 3 from £2600 (complete system)
C1 is a single -board 'starter' system, complete with keyboard, video display and Microsoft BASIC; it can be expanded to run mini -floppies and most OSI-bus expansion boards. C2 systems start with a versatile two -board computer; expansion can include the full hard -disc and input-output capacity of the C3 series. C3 is the big one! A unique triple -processor CPU and easy expansion up to 300MB hard -disc memory on-line; almost unlimited input/output; can control a sixteen -terminal multi -processing network.
Detailed technical reports for these ranges are available on request.
C3 -OEM 6502, Z-80, 6800 processors 32K RAM, twin 8" discs, 4 spare slots for expansion
Ohio Scientific computers use a simple but versatile 'bus' structure that allows real flexibility and easy expansion. Sensible -sized boards make specialist systems simple to design and implement compared to the complexity and cost of comparable S-100 systems.
For example: CM6 - 48K dynamic RAM - £265 CA -12 - 96 -line parallel I/O (six 6821 PIAs) - £95 MU -116 - multi -function real-time clock, with 6821 PIA
and 8 -channel relay driver - £95
C2 -based 16K 'engineer' system with CA -12 - £595
Ohio Scientific computers are backed by sensible software: OS -65D development package for the 6502 is standard with all disc systems (assembler package on cassette for smaller systems - £20); while OS-DMS Database Management software gives practical database handling for business and other uses, and is compatible with all Ohio Scientific disc systems, floppy or hard -disc.

a superior Superboard...
Mutek offer a variety of options on the C1/Superboard
series. The standard system is fast and flexible, runs its 6502 processor at 1 MHz, and has a nominal 32 X 32 display which is limited in practice, for technical reasons, to about 25 X 25. The Superboard is the unmounted version; the C1 is a cased Superboard complete with power supply. Standard Superboard - £175 Standard Cl - £220
2 MHz conversion - add £5.00 This doubles the speed of operation. The standard BASIC is faster than most; this makes it really fast - more than three times the speed of Tandy's TRS-80®, for example.
True 32X32 display option - add £20 This alters the video circuitry to allow the full 1K of screen memory to be displayed on a standard TV set.
2K display option - add f25 Recommended for special work only, as it is driven by a software 'patch' (supplied on cassette). Gives an effective
50 X 30 display.
All this is backed by the best range of Superboard software available - British and American - and sensibly priced, mostly from f3 to £8. Software catalogue available.
a programmable printer...
Mutek offer the new BASE -2 matrix printer. At first glance it looks a typical medium -duty matrix printer. But there's a lot more to it than anything in its field - a truly flexible printer to match the flexibility of Ohio Scientific computers.
Four interfaces built-in as standard: IEEE -488, Centronics parallel, RS -232 (software -selected baud rate), 20 ma.
bidirectional print at 125 characters per second. two 96 -character sets in ROM (includes APL); space for
two more sets in ROM; user -programmable set in RAM; dot -plotting mode - all as standard. five software -selectable character widths plus double width characters. form, tabs, line -length, line -space all software selectable. uses plain paper up to 81/2" width. friction and adjustable tractor feed both fitted as standard
An amazing specification for an even more amazing price: Base -2 matrix printer - only £395
and full technical support
Our prices are some of the lowest around, but that doesn't imply poor technical support!
We give a full after -sales service that includes much more than 'standard'. As well as the usual service facilities we can offer technical advice on both hardware and software aspects of Ohio Scientific computers and their applications, and can also undertake technical development - hardware and software - for most types of specialist application.
All prices quoted exclude VAT.

Mutek real computing ...for less than you expect
Mutek - the independent OSI specialists - Quarry Hill, Box, Wilts. Telephone: Bath (0225) 743289

PCW 157

'Ever heard of COMAL?

COMAL is an extended and structured form of BASIC

with constructions such as:

REPEAT -UNTIL

WHILE-ENDWHILE

IF -THEN -ELSE

CASE-ENDCASE

and including built-in file system, named procedures

and many other features.

Ever heard of a 100% modular multi-user system running two high-level languages (COMAL and PASCAL) at the same time?

WE'RE IN THE NORTH WEST!
ARE YOU ?
BUSINESS SYSTEMS FOR PROFESSIONAL PEOPLE
All our systems cover the major problem areas encountered in running your business, i.e. Ledgers, Payroll, Stock Control, Word Processing, Personnel Records etc.

Starting at £1995 + VAT for a single -user, ready to run system including the micro with on 51/4" disc drive, VDU, 32K bytes of RAM and COMAL real-time interpreter.
Expanding to an 8 -user system with up to 80 Megabytes of cartridge disc storage - and capable of running
COMAL, Pascal and Assembler at the same time under what must be the most sophisticated operating system on the market.
Phone (01) 727 6668
for more information on the SPC/1 microcomputer system
from
digital data electronics ltd

1. For the
smaller business.
Commodore Pet based system from £2,500

2. For the more ambitious enterprise.
Rostronics Z -Plus from £3,950

3. For the more demanding user.
ACT 800 from £3,950

We are available for consultation, feasability studies and general overviews, etc. We also provide sensible, user orientated service
contracts. For more extensive details of our services and many more
products not listed-write to or telephone
IAN KENDRICK on 051-236 5778.
/ muWe are approved ACT and STAGE ONE Dealers
i ir Microcomputers Limited )

North Western Systems (Microcomputers) Limited
6a Lombard Chambers, Ormond Street. Liverpool 3.
E.Q.A.

Software available for your Apple I I with one disc drive only

TIME - COSTS - INVOICING

DISC ONE DISC TWO DISC THREE DISC FOUR

JOB BOOK TIME SHEET CLIENTS ADDRESS INVOICING

1000 RECORDS 1000 RECORDS 1000 RECORDS 200 RECORDS

SAMPLE PRINTOUTS AND DESCRIPTIONS SENT ON REQUEST. DISCS CAN BE USED SEPARATELY OR TOGETHER. PROGRAMS ARE FULLY INTERACTIVE AND SORTS IN ALL
FIELDS ON DEFINED KEYS ON ALL FILES.
ALL DISCS £200.00 EACH DESIGNERS AID
ALLOWS 200 PREDEFINED OBJECTS TO BE TAKEN FROM DISC IN THREE DIMENSIONS AND PLACED IN A DEFINED ROOM. DISPLAYS AND PRINTS FIVE DRAWINGS. LISTS NAMES OF OBJECTS AND THEIR POSITIONS ON THE DRAWINGS. SAMPLE PRINTOUTS AND DESCRIPTIONS SENT ON REQUEST.
This program is for an APPLE II with one disc drive and plotter £500.00 EACH
ALL ENQUIRIES TO:- ENGINEERING GRAPHIC APPLICATIONS LIMITED. 52 SUTHERLAND SQUARE LONDON S.E.17 3EL. TEL No. 01-670 6293
158 PCW

r:Bor,rrn
computer centre limited
109 QUEENS ROAD LEICESTER LE2 ITT TEL:0533 708483

LEICESTER'S
*PPM
Sales and Service centre

Apple 11 Europhss 16K Mu drive with controller Dine chive lean controller 16K add on memory Pascal language system Hitachi monitor Eurocolor card Serial card Communications card Parallel printer card Mahn filter - plug -In ttnit
Printers line 80
Paper Tiger Paper Tiger with Graphics Tams Omni 810

E695 E349 E299 £69 E299 £127 E69 £113 E130 E104 £18.50
E499 E585 E699 E1450

Service - Apple atended warranty

E 150

Software

I/W.1c for Instant Ftrusncial planning

E95

Cashier store management

£165

Stock control

E120

Apple Writer - turn your Apple Into a

word processor for only

E42

Db.

£33.40 (10)

Paper rolls (OKI) stngle ply

£2.50

double ply

£3.00

Plain listing (14 x 11)

E 11.66 (2000 sheets)

We are agents for the Computes Accounting Pack

Sales, Purchases, General Ledger

£295.00 per unit

All items available to personal callers or by
mail order (Post and Packing extra).

Erase Eproms
in 8 minutes
for under £100
£97 delivered in U.K. + V.A.T.

laxw*"oo)
4 N44,0 '7'7
The high speed, high capacity model UV8 sets new performance and price standards.

Cuts typical erasure times by a factor of 5 8 MINUTE SOLID STATE TIMER Capacity up to 14 EPgaMS 2708 type erased in 4 to 7 minutes High intensity 254 NM UV source Safety interlock automatically starts timing sequence
Audio tone signals erasure cycle complete
Internal switch to extend erase time.

MICRODATA Computers Ltd, Belvedere Works, B Iton Way, Pump Lane Industrial Estate, Hayes Middlesex.

Telephone (01) 848 9871 (6 lines)

Telex 934110

?uT ERicyoq

O

PRESENT
COMPUCOLOR II

A# I

ENGINEERING

STATISTICS 1 (16K)

EDUCATIONAL

STATISTICS 2 (16K)

HANGMAN MATH TUTOR BASIC LANGUAGE VOL. I
GAMES FORMATTED TWIN PACK

arioN ap....iiRE.D 1
te
a
0 3 0.4.

STATISTICS 3 (16K)
SYSTEMS/UTILITY

0

ASSEMBLER (16K)

TEXT EDITOR (16K)

PERSONAL DATA BASE (16K)

SAMPLER OTHELLO

S

J =....

BASIC EDITING (16K) MONITOR (16K)

CHESS (16K) STAR TREK BLACKJACK CUBIC TIC TAC TOE (16K)

ifiifi#'1''"' 'ft lilt )7'1 I. tir

SCREEN EDITOR (16K, 117 -KEY KYBD)
1 I 441 ))) \ FORMATTER
DEBUGGER (16K)
WI\ PILOT (16K)

SHARKS

FORTRAN (32K)

AIR RAID STAR TRADER (16K) SWARMS (16K) LUNAR
SHOOT

* 13" Colour Monitor for Colour Graphics etc.

* Built in Minifloppy Drive 51.2K per side

8K USER RAM £ 895.00

* Impressive Extended Basic on 16K ROM * High Resolution Graphics 128 x 128 * RS232C port simplifies Printer or Modem atch.

16K USER RAM £ 998.00 32K USER RAM £1100.00

TELEX: 83147 - REFER

THE PRIORY, GREAT MILTON, OXON 0X9 7BP. TELEPHONE: 086446 729

'CMPA'

PCW 159

26 ALB ROAD RA7Y40L8E9IGH ESSEX

OP 17 EEL. la] RAYLEIGHANY (0268) 7

(12am-8pm)

(Personal callers by appointment only) **************************************************************

PETS 'N BITS: NEW BK £450 : 16K £625 : 32K £715 COMPUTHINK 400K £755 : BOOK £995
CASSETTE DRIVE with Audio Monitor & Tape Counter ! £55

'GREEN SCREEN' or 'BLUE SCREEN' £5.50 (also for MZ80k) 4K - 8K CONVERSIONS £79 : BK - 32K from £210

APPLE & ITT: 16K EUROAPPLE £649 : 2020 COLOUR 16K £699 16K UPGRADE £68 : DISK DRIVES £339 : CONTROLLER CARD £48

COMPUCOLOR: FULL COLOUR BUILT IN MONITOR & DISK DRIVE 16K USER RAM £998

ACT: 808 £3050. 824 £4950'

VIDEO GENIE: SPECIAL INTRODUCTORY PRICE 1BK RAM 12K ROM £349

SHARP MZBOK ALL MODELS AT LIST PRICE BUT ONLY (EQUIVALENT) HALF RATE V.A.T. :
PRINTERS: ANADEX £560 : LA34 £939 : EPSON TX -80 £495
PR40 (With PET interface) £215 others available
ODDS & ENDS: VERBATIM (PET/APPLE) DISKS £23 PER TEN CURVED HEAD DEMAGNETISER £4 : CASSETTE CLEANING KIT E1.50 Both above HALF PRICE with any new computek pukchcaed PETSOFT:GEMSOFT:LANDSLER:DATABANK p/Lognamei TAX + CARR. FREE TELETEXT CONVERTOR (with hemote) INSTANT CEEFAX/ORACLE f199.95

CURRENT SECONDHAND BARGAINS: EX -DEMO 32K (UPGRADE) PET £600 : 8K PET (OLD ROM) £425 C2 -4P DISK (IMMACULATE) 24K £825 WITH MONITOR (LIST APP.£1200) EX -DEMO ELF II - IMMACULATE, HEAPS OF EXTRAS, FULLY BUILT TESTED FOR LESS THAN KIT PRICE £325 OLIVETTI TE300 TELETYPE WITH.P/T PUNCH. UNKNOWN COND. £55

MOST MAKES SOLD/BOUGHT/EXCHANGED/CONSTRUCTED
WANTED -YOUR OLD 'PETS' (EVEN DECEASED PETS FOR VIVISECTION !) "TELETEXT CONVERTOR FREE WITH ACT 808/824 + PRINTER
ALL PRICES EXCLUpE V.A.T. & CARRIAGE (EXCEPT WHERE STATED OTHERWISE). CARRIAGE CHARGED AT COST.

BIRMINGHAM
Computer Centre

NEW HIGH SPEED

MATRIX

PRINTER

NOW WITH PET GRAPHICS

Due to expansion we are pleased to announce the opening of our new Computer Shop in Edgware.

111111111111111111111111

s4.i#t)L 1=11E11111=1

Call in and see these systems: -
Word Processing. Stock Control/Invoicing. Incomplete Records. Purchase Accounting. Information
retrieval Payroll. Games. Programming Tutorials and many others. If you don't see what you want we will
probably be able to get it for you.

We specialise in this system.

Pet prices start from £495.00

We also stock the QUME Sprint 5 Daisy Wheel printer

for the best quality word processing. Also call us for

the latest second hand equipment supplies.

+ 4)

Open Mon -Sat
9 - 5.30
Easy parking at rear of shoPEntrance 4Vhitchurch Lane

Davin6c5i HCiogmhpsuttreeertShop

DaVir169ce

Edgware Tel. 952 0526

.401.10EAND

160 PCW

Full ASC II 96 Character Set plus Graphics plus 750CH Buffer 2K. Extra Buffer available UNI - or Bi-Directional
IEEE or Parallel Interface Plugs direct into PET.
No Interface needed £525
COMMODORS 3022 PRINTER
* NEW LOW PRICE * Tractor Feed - Genuine C.B.M.
Camden Electronics First Floor
462 Coventry Road Small Heath, Birmingham B10 OUG
Phone: 021-773 8240

Now Available Orders being taken by Sole Distributors.

VIEWDATA
ACCESS VIA PHONE NETWORK

El BE [Computers] Limited
The Consuitenis for the forth West
SUITE 1. 124 NEWPORT STREET, BOLTON. TELEPHONE: 26644.

UHF T.V.
AERIAL

AERIAL INPUT TO T.V.
A

TELETEXT RECEPTION

TABLE TOP VERSION ILLUSTRATED
RACK MOUNTING AVAILABLE

EXPAND WITH RAM/PROM UP TO 64K
HARD COPY
MAINFRAME COMPUTER
E.G. PDPII INTERFACE
TELETEXT LINE INSERTER
THE SYSTEM IS FULLY EXPANDABLE VIA THE TECS BUS STRUCTURE UP TO 64K; WILL SUPPORT ALL STANDARD PERIPHERALS.
Send for further details to above address.

TELETEXT PAGE SELECT
FULL VIEWDATA EDITING KEYBOARD
DISC DRIVE

CASSETTE I/O

PERIPHERAL I/O
Dealer enquiries invited.

PCW 161

Floppy Disk Systems

AT LOW COST

..111.

ti 4

gel

SINGLE DISK UNITS 40 Tracks £250 77 Tracks £345
DUAL DISK UNITS 40 Tracks £440 77 Tracks C645
*from CUMANA LTD*
The high quality and very reliable TEA C 40 track FD -50A and 77 track FD -50C 5% inch Mini Floppy Disk Drives packaged in single Disk and Dual Disk configurations with integral mains power supply unit.
* Both FD -50A and FD -50C are Shugart SA400 interface compatible. * FD -50A has 40 tracks giving 125K Bytes unformatted capacity. * FD -50C has 77 tracks giving 240K Bytes unformatted capacity. * Both models can be used in double density recording mode. * Daisy Chain up to 4 drives on your computer system. * Directly compatible with TRS 80, SWTP, Heathkit, Superbrain, Video Genie, etc. etc. * Japanese quality and reliability. * 220-240v 50 HZ mains power unit. * Warranty and service back up from Cumana.
DEALER ENQUIRIES WELCOMED
Please add VAT to all prices. Delivery at cost will be advised at time of order. Cheques payable to: CUMANA LTD.,
35 WALNUT TREE CLOSE, GUILDFORD, SURREY. GU1 4UN TEL: (0483) 503121 TELEX: 859680 (INPUT G)

ADVERTISERS INDEX

Abacus

69

Access Data

Communications

154

Acorn Computers

65

Aculab

142

ACT

70

Almarc Data Systems

23

Appleware

120

Barnes Consultants

148

B&B

161

Bits and Pc's

154

BNR & ES

152

Business & Leisure

Microcomputers

140

Butterworths

44

Camden Electronics 97,160

Carter Keyboards

154

Comart

99,115

Commodore

38,42

Computerama

137

Computer Centre

141

Computer Consultancy 150

Computerist/Dair

146

Computermania

159

Computopia

108

CRA

163

Crystal Electronics

152

Cumana

162

Currah Comp Shop

150 164,IBC

Datron

27

Davinci

160

Digital Data Electronics 158

Direct Data Marketing

8

D.D.P.

40

Display Electronics

145

E.G.A.

158

Electronic Brokers

95

Ensign Equinox Farmplan

139 35/46 22,108

Feldon Audio

91

Gata Microsystems

148

Great Northern

26

GW Computers

143

Happy Memories

138

A J Harding (Molimerx) 20

Heath Henry's HB Computers

119 136 69,142

Hitech Electronics

138

Intelligent Artefacts 142

Interactive Data

144

Interface Components 153

Intex Datalog

136

L&J Computers

138

Leicester Computers 159

Lifeboat Associates 82,83

Lion Microcomputers 13

Little Genius

140

Liveport Data Products 25

Logitek

66,76

London Computer Store 26

LP Enterprises

10,11

Mendip

144

Microcentre

IFC

Microcircuit

136

Microcontrol

90

Microdata

159

Microdigital

9

Microsolve

34

Microtrend 103,105,107

Mighty Micro

56

Mike Rose Micros

109

Mutek

157

Newbear

62,149

Newtroniks

156

NIC

144

North West

158

On-line Conferences

33

Optelco

160

Orchard

152

Petalect

140

Personal Computers OBC

Petsoft

116

PHL

146

PIPS

46

Q-Com Electronics

144

Research Machines

155

Rostronics

8

Science of Cambridge 14,15

Sintrom Microshop

6

Sirton Products

147

Slough Microshop

163

Small Systems

12,156

Softwarehouse

7

Stack

3,16

Strumech (SEED)

100

Sun

21

Tandy

4,5

Tangerine

18,19

Teq Data

17

Tex

154

Texas Instruments

34

Theydon Computer

32

Transam

112

TVJ Microcomputers

2

Vlasak

24

Xitan

151

PCW would like to apologise to

SIRTON PRODUCTS for the mis-

take we made in their telephone

number last issue. This should

have been 01-668 0761

4

SUPPORT MEMBERS OF THE COMPUTER RETAILERS ASSOCIATION.. .

THEY WILL SUPPORT YOU.
For further details on the associations aims, membership, code of conduct etc.
Please contact: Mrs H. Gibbons, C.R.A., Owles Hall, Buntingford, Hertfordshire. (0763) 71209.

MICROCOMPUTER
SHOPPING MADE SIMPLE
The Slough Microshop is the Thames Valley Specialist in microcomputer systems - for
business, professional or personal use. Our services include:
TAILORMADE OR PACKAGED SOFTWARE COMPLETE HARDWARE MAINTENANCE
SERVICE FULL DEMONSTRATION EQUIPMENT We are the officially approved stockist for
COMMODORE PET EXIDY SORCERER NORTH STAR HORIZON
APPLE II IMS 5000/8000 EQUINOX 300 Ask for a demonstration. Phone or call into the Slough Microshop showroom - where microcomputer shopping is made simple.
THE SLOUGH
MICROSHOP 120 High Street Slough Berkshire Telephone: Slough 72470 or 22855

_.)8M Hz Super Quality Modulators £4.90

6MHz Standard Modulators

£2.90

C12 Computer Grade Cassettes 10 for E4.00

Super Multi -rail P.S.U. +5 -5 + 12v E29.50

ETI Breakout Game - Chip and PCB £9.90

S100 Expansion Motherboard for Nascom I

£39.00

Anadex Printer Paper - 2000 sheets £25.00

Floppy Disks 51/4" Hard &Soft Sectored £3.50

Floppy Disk Library Case 5 1/4 "

£3.50

Eprom Boards 8K Static Ram Boards - S100

£63.00 £110.00

Cartridges for Grandstand George Risk Ascii Keyboard
Cartridges for Atari - Full Range in Stock

£11.99 £39.00
£13.90

Interface PET IEEE - Centronics Parallel

Not decoded £49.00

Decoded £77.00

Interface to Centronics parallel for

TRS80

£75.00

Verocases for Nascom 1 Er 2 etc E22.50

Keyboard Cases

£9.90

Electric Pencil for TRS80

£29.00

40." GET YOURSELF A

,..4?(0"001?

PRINTER FOR

''s Co YOUR PET AND SAVE

A FORTUNE

only £399 VAT
Full Pet Graphics including to. cables. Ready to go.
EX -STOCK.

HITACHI PROFESSIONAL
MONITORS
9" -£129
12" - £199
Reliability Solid state circuitry using an IC and silicon transistors ensures high reliability. 500 lines horizontal resolution Horizontal resolution in excess of 500 lines is achieved in picture center. Stable picture Even played back pictures of VTR can be displayed without jittering. Looping video input Video input can be looped through with built-in termination switch. External sync operation (available as option for U and C types) Compact construction Two monitors are mountable side by side in a
standard 19 -inch rack.

only £356 , VAT

LEVEL 2 16K

Fully converted to UK T.V. Standard. Comes complete with

easy to follow manuals. UK Power Supply - Cassette Leads

- Sample tapes. Special box to enable you to plug into your

own TV. Recommended for first time -buyers. Just plug in

and go.

Full Range of Software Available

Model with numeric key pad £389 + VAT

4K Level I - machine only £251 + VAT

-Vonly £295 VA I

TRS80

Expand your TRS80 by ril EXPANSION

32K. 32K Memory on board `N-

INTERFACE

Centronics parallel port.

Disk controller card. Real

time clock. Requires Level

II Basic. Interface for 2

cassette decks. complete

with power supply,

RRP £540

only £499
- VAT

VNEW REDUCED
PRICES
8K £449

16K £549

32K £649

RRP £795 for 32K

The PEDIGREE PETS

Very popular for home Et business use. 8K Microsoft Basic in ROM 8K Pet 32K Et 16K with new improved keyboard
All with green screen. -"Extra cassette deck 1155 Full range of software available (1;

32K
£690
VA1

48K
£790
VA

EXIDY

SORCERER

RRP £859

For Personal or Business Use.

for 32K

32K or 48K memory. 8K Microsoft Basic in ROM. Dual

Cassette I/O, RS232 I/O. Parallel I/O (Centronics).

Expansion available through optional extra 5100 Motherboard. 69 Key keyboard including 16 key

numeric pad.

S100 EXPANSION - £199

ANADEX
DP8000
Super Quality - Low cost printer. Tractor Feed with full 96 ASCII character set. Accepts RS232C at band rates between
100 and 9600 and Parallel Bit data. Attaches either directly or through interfaces to Pet, Apple,
TRS80, Sorcerer, Nascom, Compukit etc.
video 100
12" BLACK Et WHITE LOW COST VIDEO
MONITOR
RRP £79
only £69 VAT
Ideal for home, personal and business computer systems 12" diagonal video monitor Composite video input Composite video input Compatible with many computer systems Solid-state circuitry for a stable Et sharp picture Video bandwidth - 12MHz + 3DB Input impedance -75 Ohms Resolution - 650 lines Minimum In
80%. Central 80% of CRT; 550 Lines Minimum beyond central
NASCOM-2 MICROCOMPUTER
only £295
VAT

NASCOM IMP PLAIN PAPER PRINTER
Fully built and housed in a
stylish enclosure for just E325 plus VAT. Interfaces with all micro computers.
The Nascom IMP (Impact Matrix Printer) features are listed below:
60 fines per minute. 80 characters per line. Bidirectional printing. 10 line print buffer. Automatic CR/LF. 96 character ASCII set (including upper/lower case, 8, 4 , £1. Accepts 8 1/2" paper (pressure feed). Accepts 91" paper (tractor feed). Tractor/pressure feed. Baud rate from 110 to 9600. External signal for optional synchronisation of baud rate. Serial RS232
interface with parallel option available soon.

Your choice of freebies with every Nascom 2 purchased from us
either FREE POWER SUPPLY OR FREE GRAPHICS ROM OR FREE VERO CASE TO TAKE NASCOM 2

-VA PROFESSIONAL WORD PROCESSING SYSTEM AND IT'S A COMPUTER AS WELL.
ALL FOR ONLY £3250 VAT
including Word Pro and Cables

£790
VAT
PET 32K - This is the standard 32K Pet from Commodore. Reverse video and graphics allow the WordPro Package to give simple clear and easy to read displays.
2040 Disk Drives Twin disk drives allow large high speed storage for your letters, or paragraphs. Plugs in the back of the
PET.
NEC Spinwriter NEC's high quality printer uses a print '"tthimble" that has less diameter and inertia than a daisy wheel,

£1750 VAT
RRP £2200

giving a quieter, faster, more reliable printer that can cope with
plotting and printing (128 ASCII characters) with up to five copies, friction or tractor fed. The ribbon and thimble can be changed in seconds.
55 characters per second bidirectional printing - with red/ black, bold, subscript, superscript, proportional spacing, tabbing, and much, much more.

WordPro II The heart of the system - consists of a ROM and

diskette. The ROM is inserted into a space socket inside the

Pet. One of the most versatile Word Processing Packages

around.

All items sold separately.

Microprocessors Z80A. 8 bit CPU. This will run at 4MHz but is selectable between 1/2/4 MHz. This CPU has now been generally accepted as the most powerful, 8 bit processor on the market.
INTERFACE Keyboard New expanded 57 key Licon solid state keyboard especially built for Nascom. Uses standard Nascom, monitor controlled, decoding. T.V. The Iv peak to peak video signal can drive a monitor directly and is also fed to the on -board modulator to drive the domestic T.V.
I.O. On -board UART lint.64021 which provides serial handling for the on -board cassette interface or the RS232/20mA teletype interface.
The cassette interface is Kansas City standard at either 300 or 1200 baud. This is a link option on the NASCOM-2. The RS232 and 20mA loop connector will interface directly
into any standard teletype. The input and output sides of the UART are independently switchable between any of the options -
i.e. it is possible to house input on the cassette and output on the printer. PIO There is also a totally uncommitted Parallel I/O IMK3881 I giving 16, programmable, I/O lines. These are addressable as 2 x 8 bit ports with complete handshake controls. Documentation Full construction article is provided for those who buy a kit and an extensive software manual is provided for the monitor and Basic. Basic The Nascom 2 contains a full 8K Microsoft Basic in one ROM chip with additional features like DEEK, DOKE ,
SET, RESET for simple programming.
With free 16K RAM board.

COMPUKIT UK101

EUROPE'S FASTEST SELLING ONE BOARD COMPUTER

* 6502 based system - best value for money on the market. * Powerful 8K Basic - Fastest around * Full Qwerty Keyboard * 4K RAM Expandable to 8K on board. * Power supply and RF Modulator on
board. * No Extras needed - Plug-in and go. * Kansas City Tape
Interface on board. * Free Sampler Tape including powerful Dissassembler and Monitor with each Kit. * If you want to learn about Micros, but
didn't know which machine to buy then this is the machine for you.

NEW MONITOR FOR
COMPUKIT UK101 In 2K Eprom 2716
Allows screen editing Saves data on tape Flashing cursor Text scrolls down E22.00 + VAT

Build, Understand and Program your own Computer for only a small outlay.

KIT ONLY £199

-

NO EXTRAS NEEDED

AVAILABLE READY ASSEMBLED & TESTED READY TO GO FOR £249 VAT

Specially designed case for Compu it orange/black With room for accessories £29.50 - VAT

6502 Assembler/Editor for Compukit £1490

The Compukit UK101 comes in kit form with all the parts necessary to be up and working, supplied. No extras are needed. Ater plugging in just press the reset keys and the whole world of computing is at your fingertips. Should you wish to work in the machine code of the 6502 then just press the M key and the machine will be ready to execute your
commands and programs. By pressing the C key the world of Basic is open to you.
This machine is ideal to the computing student or Maths student, ideal to teach your children arithmetic, and is also great fun to use.
Because of the enormous volume of users of this kit we are able to offer a new reduced price of E199 + VAT

THE NEW TRS80 SURPRISE Fast and expandable!
- MODEL II Model II operates at twice TRS-80's high speed.
In addition to either 32 or 64 thousand characters (bytes) of internal Random Access Memory, one built-in 8" floppy disk stores an additional one-half million bytes, including the Disk' Operating System. And you can easily expand up to a four -disk system for up to two -million bytes of storage.
Model II features upper and lower case letters. Its built-in 12" high -resolution video monitor displays 24 lines of 80 normal characters. The profesional 76 -key keyboard (with "calculator" keypad) includes advanced functions such as Control, Escape, Caps, Hold, Repeat. The keyboard is detachable and moveable for convenient data entry.
You get the enhanced Level III version of TRS-80's already -famous Level II BASIC language and "TRSDOS" operating system, automatically loaded in memory when you "power up." (About 24K of RAM is used by this software.)
Each time you power up, Model II thoroughly tests itself to insure proper operation. Your chosen program can appear immediately, without any intermediate steps or questions to answer.
Versatility ... plug-in expandability
Built-in input/output capabilities include two RS -232C channels, and one Centronics parallel port. Future expansion is provided for through four plug-in slots for optional PC boards.
64K 1 -Disk Model II £2250.00 - VAT
1 DISK EXPANSION Room for 3
500K per Drive gives total
of 1.5M Byte - 1 Drive plus Cabinet £799 VAT

Why do people buy more from COMPSHOP than anywhere else?
* LARGER STOCKS we hardly ever run out * GOOD SERVICE - we give extended warranties on all our products. * EXCELLENT REPAIR SERVICE - Through Compucare we repair and maintain most
makes of personal computers. LAST YEAR WE SUPPLIED TO THE PUBLIC - LARGE Er SMALL
16,000 Television Games Et 7,000 Computer Systems
41 OS* TV GAME BREAK OUT
Has ggot to be one of the world's greatest TV games. You really get hooked. As featured in ETI. Has also 4 other pinball games and lots of options. Good kit for up -grading old amusement games. MINI KIT - PCB, sound Et vision modulator, memory chip
and de -code chip. Very simple to construct. £14.90 + VAT ills) OR PCB £2.90 MAIN LSI £11.50 Both plus VAT

THE ATARI VIDEO

£99.00

COMPUTER SYSTEM

-i- VA I

Atari's Video Computer System now offers more than 1300 different game variations and options in twenty great Game

ProgramT NA cartridges!

Have fun while you sharpen your mental and physical coordination. You can play rousing, challenging, sophisticated video games, the
games that made Atari famous. You'll have thrill after thrill, whether you're in the thick of a dogfight, screeching around a racetrack, or dodging asteroids in an alien galaxy. With crisp bright colour (on colour TV) and incredible, true-tolife sound effects. With special circuits to protect your TV.

Cartridges now available All at E13.90 each + VAT

Basic Maths, Airsea Battle, Black Jack, Breakout, Surround, Spacewar, Video Olympics, Outlaw, Basketball, Hunt Et Score*,
Space War, Sky Diver, Air Sea Battle Codebreaker*, Miniature Golf.

Extra Paddle Controllers - £14.90 + VAT

'Keyboard Controllers - E16.80 + VAT

L, L
"Europes Largest Discount --- Personal Computer Store"

Please add VAT to all prices - Delivery a cost, will be advised at time of purchase. Please make

cheques and postal orders payable to COMPSHOP LTD., or phone your order quoting

BARCLAYCARD, ACCESS, DINERS CLUB or AMERICAN EXPRESS number.

CREDIT FACILITIES ARRANGED - send S.A.E. for application form.

14 Station Road, New Barnet, Hertfordshire, EN5 10W Telex: 298755 TELCOM G

Telephone: 01-441 2922 (Sales) 01-449 6596

OPEN - 10 am 7 pm - Monday to Saturday Close to New Barnet BR Station - Moorgate Line.

COMPUTER
COMP COMPONENTS

NOW in IRELAND at: 80 Marlborough St., Dublin 1. Tel: Dublin 749933 Part of the Compshop Ltd. Group)

"My best Apple programs
are on long-term deposit i the City...
it pays rather well !"

We brought the first five Apples into the U.K in November '77, with every penny we had. In November '79, we find several thousand throughout the country. THANK YOU Apple owners. Now we'd like to help you re -coup your investment by cataloguing and supporting the best Apple programs in the U.K The Apple Software Bank is more like an old penny bank than a major clearing bank, but we know you'll help it grow. Telephone Stephen Derrick on 01-626-8121 to discuss your investment. ATTENTION ALL Estate Agents, Employment Agencies, Yacht Brokers, Antique Dealers and Motor Traders.
Find out about FINDER SOFTWARE'
SOME BLUE CHIPS TESKIM. This ROM will simulate the Tektronix 4010 family of graphics terminals. It's rather good! UPPER LOWER CASE ADAPTOR A chip for the chap considering word processing.
NEW ISSUES We are continually trying to bring the latest add-ons for your Apples Please phone for the latest product information and
data sheets.
NEW PRODUCTS
8" SHUGART DISKS giving 1.2 Megabytes A twin drive (with room for a third.) disk system with controller and software,
give tremendous commercial possibilities. £2350 Excl.
V A T
WORD PROCESSOR. Ask about our Apple II Plus word processor package Complete System with Diablo 1650 Daisy -Wheel Printer. £4250 Excl V A T PERSONAL COMPUTER PRINTERS. Sensational 40 & 80 Character printer (graphics options) from £243 Excl. V A T Interfaces for Apple, Pet & TRS 80 High quality silent printers It's your choice' A/D BOARD At last we have either an 8 bit or 12 bit A/D card for Apple. Excellent spec from £125 Excl. V A T
APP/ E PASCAL £296

Per8onal oiroutcr6
Linlitcd
194-200 Bishopsgate, London EC2M 4NR
Let us advise you about COLOUR DISPLAY on your Apple Contact Technical Services

24 HOUR 'NEAREST DEALER SERVICE'
01 283 3391
TECHNICAL SERVICES
01.623 7970 MAIN OFFICE 01.626 821
6 lines 404