SEE YOU AT THE SHOW!

PDF PCW-1979-11-S-OCR
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US S2.00/FF8:80/LIRE 1700/DM 380/FL 4.00/BF 55 DKr 10.75/SKr 7.65/NKr 10.50/A Sch 28/S Fr 3.50/Pts 135

World NOVEMBER 1979 50p

SEE YOU AT THE SHOW!
The 2nd Personal Computer World show- preview issue

cromemco experts

Sample catalogue prices:

'System Two computer 1995

'System Three computer 3293

'Z -2H computer

4998

Extra 64K memory

893

3101 visual display unit 1147

3355 daisywheel printer 2297

HDD 11-mbytes hard

disc

4022

ANSI Cobol compiler

55

ANSI Fortran IV compiler 55

16K extended Basic

55

Word processing system 5

Database management 5

Macro relocating

assembler

55

Prices exclude VAT and delivery

MicroCentre also supply peripherals, applications sofware, and multi -use timesharing systems; a PROM programmer; analogue -digital interface; an much more. On site maintenance can be arranged throughout the UK.
*Computer systems include fast 4MHz Z80A micro, S-100 bus (21 slots), 64 memory, dual floppy discs, peripheral interfaces, etc. CP/M compatible
operating system CDOS free with software.

With our in-depth experience and total commitment to the reliable Cromemco range we are Cromemco's leading UK distributor. Rely on us, as many others do, for expert support with your routine or special micro -computer applications.
Photo features Cromemco System 3 computer. 3101 VDU. and 3355 daisywheel printer

Micro Centre
Complete Micro Systems Ltd. 132 St. Stephen Street, Edinburgh EH3 5AA. Tel: 031-225 2022.
Look out for us at Compec '79, stand no. 756

CONTENTS

40 NEWSPRINT (now featuring What's New) assembled and compiled by Guy Kewney.
AR BENCHTEST
Spotlight this month on the Challenger C3.
mA PREVIEW of the
"" 2nd Personal Com-
puter World Show.. .
an see you there! COMPUTER ANSWERS Readers pose the problems, Sheridan Williams - plus
consultants - finds the solutions.
A2 SHAKESPEARE,
"BASIC and the
C.I.A. Now the micro art of detecting forgeries in literature.
67REVAEDYEHReSlp SuUs wRi-th the questions - and may-
be win a Sharp MZ-80K!
71 BUZZWORDS
an Peter Reynolds is back with us again with his 'computing dictionary'.
743 THE COMPLETE
PASCAL Sue Eisenbach & Chris Sadler continue their series with
Part 3 - loops.
78 INTERRUPT A clear indication of PCW's new, broader base is the respect being gained by this reader forum.
80 SYSTEMS Mike Knight and David Tebbutt present an overture to our new business software evaluation feature.
fit"'" BUGGING THE `" 6800 John Moore outlines a monitor program for the 77:86 system.
tac CALCULATOR
4.," CORNER This month Dick Pountain looks at the Casio FA -1 cradle, the Master Pack software package and the Sharp EL -5100.

89 ON THE LINE David Hebditch unveils his Personal Computer Network.
92 HARD TIMES
David Broad of Comart presents some security solutions for the Winchester disc drive.
BOOKFARE
' Malcolm Peltu
grabs 'The Systems Monster' by the throat.
97 DIRECT ACCESS PCW rationalises its information output by evolving this new department. It includes: In Store, User Group Index, Fax, Transaction File and Diary Data.
10c COMPETITIONS *my ROUND -UP A
short resume of results outstanding.

Founder Angelo Zgorelec Editor Bruce Sawford Technical Editor David Tebbutt Regular Contributors Guy Kewney, Sheridan Williams, John Coll, Sue Eisenbach, Malcolm Peltu. Mike Knight, Dick Pountain Consultants John Coll, Mike Dennis, Charles Sweeten, Patrick Sutton, Michael James, R.W.Davy, David Hebditch, Sheridan Williams, Dr. Stephen Castell, Dr. D.J.Hanc Advertising Manager Stephen England
Group Advertising Manager Richard Howell
Production Manager Dick Pountain Art Director Paul Carpenter Art Assistants Jimmy Egerton, Julia Davies

106 COMMUNICATION Your letters, in double the amount of space.
wa YOUNG COM*" PUTER WORLD John Coll introduces another chapter from PCW's younger readers.

110

PROGRAMS The usual assortment

of interesting listings,

including REVAS plus

Blunders, for errors that

have crept through in

past issues.

117

LEISURE LINES JJ Clessa turns

his obsessions towards

palindromic mileometers.

Cover Illustration Hunt Emerson Typesetter Jane Hamnell Published by Sportscene Publishers (PCW) Ltd., 14 Rathbone Place, London W1P 1DE, England. Tel: 01-637 7991/2/3. Telex: 8954139 A/B 'Bunch' G. London Copyright notice Personal Computer World is published by Sportscene Publishers (PCW) Ltd. © 1979 Felden Productions. No

SEE YOU AT THE SHOW!
The 2nd Personal Computer World show

1-3 November 1979
West Centre Hotel Lillie Road London

material may be reproduced in whole or part without written consent from the copyright holders.
Printed 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 are 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, though independent viewpoint. Finally, before submitting an article, please check it through thoroughly for legibility and accuracy.
Subscription rates: Britain £8.00 for 12 issues, USA $20 for 12 issues (surface mail), 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.
Dr. Chris' Evans, psychologist and computer scientist, died of cancer early in October following a period of indifferent health. Although having been at the forefront of computer science for many years, it's doubly tragic that this should have happened at a time when Chris' was due to attract far wider recognition with the television serialisation of his best-selling book, "The Mighty Micro". With his interests firmly centered around the man/machine interface, his flair and energy are sure to be greatly missed. The staff of Personal Computer World extend their sympathy and condolences to his family.

PCW 1

Rostronics present the
Z- Plus
Dual Floppy Microsystem
Price 63750 plus VAT

Features:

Over One Megabyte Disk Storage 4 MHz Z-80 Processor 64k Memory Two Serial and Two Parallel I/O Ports

An alphanumeric keyboard with 95 keys and numeric pad,character display (24 lines of 80
characters per line) on a 15 inch screen

Including System Desk

1
2 PCW

ill Hr."

I! I .1

11111

I

1

1111111i

LIMITED

115-117 WANDSWORTH HIGH STREET, LONDON SW18 4JP

Telephone: 01-870 4805

Telex: 8813089 INTPRM G

Please mention PCW when replying to advertisers - it identifies you.

DPS-1 MAINFRAME
Introducing the DPS-1 the full IEEE S100 bus computer system from Ithaca Intersyst ems - the S100 experts. FOR EDUCATION, INDUSTRY, RESEARCH and all professional uses. including hardware and software development. low cost OEM systems. teaching applications
etc
A MINI COMPUTER using MICRO technology at a ridiculous MICRO Price!!! The front panel with a backplane and power supply accepts 5100 bus boards from many manufacturers.

Llifece' V2/elm*
Just look at these professional features! * FRONT PANEL (we won't ask you to debug our hardware. but we will give you
the tools to debug yours!) Has lights and switches to allow inspection and control of addresses and data. Other features include programmed input switches. and output lights. Examine. Examine next. deposit. deposit next. single or slow step (0.1 to 1000 IPS). hardware breakpoint on any data or address byte, repeat instruction and many other hardware diagnostic facilities.
* 30 Amp. 8V power supply. 5 Amps on ± 16v rails (all rails are seperately fused) * 20 slot IEEE S100 Motherboard with active termination and shielding between
bus lines
* Guaranteed operation at 4MHz.
The DPS1 comes as a mainframe with front panel. Motherboard. power supply and 4MHz Z80A cpu board. The system is truly modular allowing the user to build up the system he requires in his own time. S100 boards from a number of manufacturers will plug into the DPS1 IEEE S100 bus. Just add S100 Memory Boards - S100 disk controller boards - S100 I/0 boards S100 video and/or graphics boards - S100 EPROM boards All Ithaca Intersystems OEM products including K2 disk operating system and PASCALIZ on 8" floppy drives will run in the DPS-1.
£695 DPS-1 with S100 4MHZ Z80 cup board Fully assembled and tested

SOFTWARE
for your S100 system
PASCAL/Z The new language for Micros
CPIM Version £165.00 (51/4" or 8") K2 Version £131.25 (8")
Runs under K2 operating system. * Compiler that produces Z80 macro assembler code - NO NEED for slow run time P -code interpreter. *
Macro assember. * Produces binary object modules - small and fast. * Modules are re-entrant and can be put into ROM. * IMBED. TRACE and ERROR debug facilities. * Recursion
K2 OPERATING SYSTEM £56.25
8" disk based operating system - distributed on Shugart compatible 8" floppy disk * TED - 52 command character orientated text editor with macros. * PIP - File and directory handler. * ASMBLE - full Z80 2 pass assembler. * HDT - Hex debug tool, * OCI - Utility overlay/command decoder. * SYSGEN - System builder. * COPY - disk to disk file copier. * DUP - disk duplicator.

OEM 5100 boards

from the experts! Assembled

and tested

8K Static RAM board 1450ns)

£123.75

8K Static RAM board (250ns)

£146.25

16K Static RAM board (450ns)

£216.00

16K Static RAM board (250ns)

£234.00

64K Dynamic RAM board (250ns) £540.00

Z80 cpu board (2MHz)

£131.25

New
products from Ithaca audio!

Assembled and tested

Disk controller (up to 4 single

or double sided drives)

£131.25

I/O board (4 parallel and 2 serial

ports) with interrupts

£210.00

I/O board (4 parallel and 2 serial

ports) less interrupts

£180.00

S100 front panel (as used

in DPS1)

£245.00

Analogue I/O board

£295.00

Z80 cpu board (4MHz) 2708/2716 EPROM board Prototype board (bare board) Video display board (64x16. 128U/L Ascii)

£153.75 £63.75 £18.75
£108.75

AVAILABLE SOON: ZBC-1 Single board computer for OEM market. Available in basic through to fully expanded. 4MHz Z80A. 64K RAM. memory mapped 4K screen buffer. composite video. up to 16K power on EPROM monitor. 4 parallel ports. 2 serial ports. 4 channel
counter timer. 1 off £895 - please
phone for a quote for your needs. (quantity discounts available)

ALL MANUALS AVAILABLE SEPERATELY £2.50 each

PASCAL MICRO DEVELOPMENT SYSTEM
,,clite you dillwait6tyfrt owe

ITHACA Utke[1°2072[20 HAVE JUST ANNOUNCED AN IEEE S100 SYSTEM WITH A
TRUE PASCAL COMPILER
FOR RESEARCH and DEVELOPMENT LABORATORIES and TEACHING APPLICATIONS

The PASCAL System

*kik

DPS1 Mainframe with hardware front panel. Z80A 4MHZ Microprocessor.
64K Static RAM.
8" Shugart or DRI
Floppy Disc Drive, Power Supply and Controller.
K2 DOS Operating
System.
Pascal Compiler and Macro Assembler.
I/O Board with 2 RS232 ports and 4 parallel ports

ofitei , ahe

awed

it, toe a/1,e

CONTACT THESE UK DEALERS

All prices quoted are exclusive of VAT

NEWBEAR COMPUTING STORE (Newbury) (0635) 30505 Telex: 848507 SIRTON PRODUCTS (Surrey) 01-660 5617
DATAVIEW LTD. (Colchester) (0206) 78811 TRANSAM (C.London) 01-402 8137 Telex: 444198 CODIFIED COMPUTER SYSTEMS (North London) 01-226 1319 MICRONEX (Bristol) (027589) 3042 DATA SYSTEMS ENGINEERING (Fife, Scotland) (03374) 469 NORTEK SYSTEMS (Merseyside) (0704) 67375
MICROPEOPLE (Nottingham) (06076) 69117 ENERTECH (E. Sussex) (0323) 870814

ITHACA ader2g0(ennoo
(formerly ITHACA AUDIO of New Yorkl

EUROPEAN SUBSIDIARY 58 Crouch Hall Road, London N8 8HG. England.
Telephone: 01-341 2447 Telex: 895 4665 - Ref: ITHACA}

Please mention PCW when replying to advertisers - it identifies you.

PCW 3

_lh
NO1 FOR
`IR SRI

OUR NEW EXTENDED RANGE OF PROFESSIONAL GRADE SYSTEMS

SYSTEM MZ Z80 4MHZ CPU, 48K Ram, 630K bytes disc storage, Serial port & two parallel ports, prom rad board with monitor, 18 slot motherboard (S100), MDOS operating system, Z80 assembler, Basic interpereter

£2300.00

SYSTEM B As MZ plus Vector mindless terminal, 24x80 flashdriter board, MZOS North Star compatable DOS.
CP/M configured by Almarc:

£2850.00

SYSTEM BG As System B plus 240x256 graphics board, 8K memory
10" monitor.

£3240.00

SYSTEM BF
As System B plus Fast Fortran 80 compiler with hardwired floating point system which includes board and interface
software for Fortran. This system uses the A.M.D. chip and provides breathtakingly fast floating point manipulation

£3595.00

SYSTEM BFG Combines BG & BF plus 'Glib' graphics package for use with Fast Fortran 80 and 240x256 graphics board

£4190.00

We also sell a wide range of s100 boards and C/PM cornpatable software.
WE ARE THE SPECIALISTS When you spend £2000.00+ on a microcomputer system you're entitled to support from people who understand the equipment and your problems. At ALMARC we don't
sell systems from many different manufactuers, we specialise in Vector Graphic systems and supporting hardware & software. So if you want to just buy different makes of hardware then don't cometo us, but when you decide that Vector Graphic
is for you then contact ALMA RC.

4 PCW

ALMARC DATA SYSTEMS LTD., 29 CHESTERFIELD DRIVE, BURTON JOYCE, NOTTINGHAM. Telephone: 0602 248565

art SPECIALISTS IN MICROCOMPUTERS

Woouuerr cfnaaacrmetoearybo.onAuifttt.ewrhaaltl

leaves it's got

The next time you want

rpcstearoyloikmsadetbepulameucttlsmeosroais-ckn,rsdoafilnctodgowpislmephkyapcstaudywrtisdseetkrepmust in-

our boxes.
A Comart Computer

Catalogue

will

show you.

Write to
comart

Comart Ltd., P.O. Box 2, St. Neots, HOurntetinlegpdhoonn,eC(a0m48b0s). 215005.

Please mention PCW when replying to advertisers - it identifies you.

PCW 5

Macronoppy
goes twice the distance

Micropolis is rapidly becoming the industry standard in 51/4" floppy disc drives; they have been shipping double density drives for over 2 years, thus proving their outstanding reliability and performance.
By completely reassessing the engineering involved in 51/4" floppy disc drives, and using the most modern technology available, Micropolis achieve a formatted density of 315K bytes per single sided unit.

Starter system
The 1041 / 1 Macrofloppy system includes a 143K byte double density drive with S100 controller card, MDOS and BASIC with a comprehensive manual.
This unit will successfully add on-line disc storage to a wide range of S100 computers at an unbeatable price per byte.
Add to your Cromemco, North Star, Vector Graphic, Sol, Poly 88, Sorcerer, etc.
Fully assembled, tested and burnt -in unit £439.00
Optional regulator for S100 raw power £14.00

\\\\\\\ \\\\\\\\

Also available
A full range of hardware and software including:
Mains powered add-on 143K bytes (Also suitable for Tandy expansion interface) £399.00
Single drive 315K byte system £663.00
Twin drive 630K byte system £1159.00
CPM
£100.00
North Star compatible operating system
£35.00

Dealer enquiries welcome Ring Reading 85464 for further details
SINTROM MICROSHOP
14 Arkwright Road, Reading, Berks RG2 OLS Tel: Reading (0734) 85464
TELEX: 847395 CABLES: SINTROM READING

6 PCW

Please mention PCW when replying to advertisers - it identifies you.

PET Z80/CPM
6800

SOFTWARE
This is how your business appears on the screen. Approx 60 entries update require only 1-2 hours weekly and
your entire business is under control.

*PROGRAMS ARE INTEGRATED
1 = ENTER NEW NAMES ADDRESSES IN LINE! 2 = *ENTER/PRINT INVOICES 3 = *ENTER PURCHASES 4= *ENTER A/C RECEIVABLES 5 = *ENTER A/C PAYABLES 6 = ENTER/UPDATE STOCKS REC'D 7 = ENTER ORDERS REC'D 8 = EXAMINE/UPDATE BANK BALANCE 9 = EXAMINE SALES LEDGER 10= EXAMINE PURCHASE LEDGER 11 = EXAMINE INCOMPLETE RECORDS 12 = EXAMINE PRODUCE SALES
WHICH ONE (ENTER 1 TO 24)

SELECT FUNCTION BY NUMBER
13 = PRINT CUSTOMER STATEMENTS 14 = PRINT SUPPLIER STATEMENTS 15 = PRINT AGENTS STATEMENTS 16 = PRINT QUARTERLEY TAX STATEMENTS 17 = PRINT WEEK/MONTH SALES 18 = PRINT WEEK/MONTH PURCHASE 19 = PRINT YEAR AUDIT 20 = PRINT PROFIT/LOSS ACCOUNT 21 = UPDATE ENDMONTH FILES 22 = PRINT CASHFLOW ANALYSIS 23 = ENTER PAYROLL

EACH PROGRAM GOES IN DEPTH TO FURTHER EXPRESS YOUR REQUIREMENTS. FOR EXAMPLE (9) ALLOWS: a. list all sales; b. monitor sales by stock code; c. invoice search; d. amend ledger files; e. total all sales

BUSINESS PROGRAM VERSION £275 (VERBOSE SIMPLE LANGUAGE AND UNITARY FILE HANDLING)

BUSINESS PROGRAM VERSION 3 £475 (SPACE SAVING AND MULTI MODE AND FUNCTION PROGRAMS)

BUSINESS PROGRAM VERSION 2 £375 (MORE INPENETRABLE VALIDATIONS AND PROTECTION)

BUSINESS PROGRAM VERSION £575 (INCLUDING PAYROLL, YEAR AUDIT PRO LOSS CASHFLOW)

MULTIMODE + MULTI -FUNCTION

HANDLER 12 STRING

£50

MULTI -MODE 2 MULTI -FUNCTION, 12 STRING HANDLER & NUMERIC COMBINER £100

HARDWARE

PEETT 2001 SERIES PET Computer 2001 32K PET Printer 3022 Tractor Feed PET Floppy Disks 2040 PET IEEE Cables

£795 £645
£795
£ 45

TERMINALS HAZELTINE 1510 Interlube Video Terminal Soroc IQ120

£895 £595 £695

PRINTERS Teletype 43 Printer Centronics 779 Printer

£895 £950

COMPUTERS Intertec Superbrain Dual Z -80A Vector Interrupt, 64 RAM pws 1K 2708 PROM Bootstrap, Two Double -Density Sin Floppy Disks
£1,950

Industrial Micro Systems Z-80 System

48K Expands to 594K; Twin D/D Disk

included. Expands to 10 Meg and pro-

grams are CPM compatible

£2,500

Smoke Signal 6800 System 32 K Expandable + twin D/S
Discs

£2,500

Please telephone for appointment - Tony Winter 01-636 8210 G.W. Computers Ltd., 89 Bedford Court Mansions, Bedford Avenue, London WC 1 See us on the Ensign stand (No. 51-52) at the PCW Show.

PCW 7

For Business, Scientific and Educational Uses.

PROFESSIONAL HARDWARE
Use of the North Star Horizon for a short period will enable you to appreciate the professionalism in the product. There's a solid well-built chassis, a good power supply, a quiet fan and an attractive wooden case. There's a Z80A processor running at 4MHz with the 250ns static RAM boards.
There are dual integral Shugart minifloppy drives (capacity of about 360 KB on line, with an option for a further two drives), enabling easy and quick handling and copying of programs and data files.
And of course, there's the 12 slot S-100 bus which enables you to plug in many types of peripheral boards, including a hardware floating point board for increased "number crunching" performance.
PROFESSIONAL SOFTWARE
North Star Computers built their professional reputation around their powerful, but simple, Disc Operating System and Disc Extended BASIC Interpreter.
The latter contains, in addition to the usual BASIC commands, random and sequential access disc files, strings, string operators, multiple dimensioned arrays, formatted output, machine language CALL, memory EXAMine and FILL, line editor, program chaining and more.

The CP/M operating system is also available as an option and provides access to a Macro Assembler, C BASIC Compiler and FORTRAN -80 and COBOL -80 Compilers. A standard UCSD PASCAL has now been implemented.

TYPICAL APPLICATIONS SOFTWARE

Financial
Mathematical
Statistical
Educational Games Sales Ledger

Purchase Ledger Stock Control
Payroll
General Ledger
Estate Agents Package
Incomplete Records
Employment Agents

HORIZON with dual drives, 32K RAM, 2 serial + 1 parallel ports:- Dynamic RANI- £1545, Static RAM - £1905.

COMPLETE HORIZON BUSINESS SYSTEMS (hardware) with 32K RAM, dual mini -floppy drives, VDU and 8" printer - £3295; 48K RAM, dual mini -floppy drives, VDU and 150cps printer £4658.
Prices exclude VAT and carriage.
Dealer, OEM and Educational Discounts available.

UIN
COMPUTER SYSTEMS LTD. "KLEEMAN HOUSE"
16 ANNING STREET, NEW INN YARD,
LONDON EC2A 3HB.
Tel: 01-739 2387/9 01-729 4460

8 PCW

Please mention PCW when replying to advertisers - it identifies you.

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 in numerable 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.
It

UON

u2a

IOUSE

LION MICRO -COMPUTERS

=: SMALL COMPUTERS -TO MAKE YOUR BUSINESS BIGGER

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

London W1 (First Floor). Telephone: 01-637 1601.

Telex:28394 Lion G.
Open 9 to 6, Monday to Saturday (Thursday to 7). 1E31

cD 4'41E(PflS

Tottenham Court Road
7- -1 fFIL_
Je

r77:771

PCW 9

NEW BIG DISTRIBUTOR

NASCOM-2+FREE16K RAM
Here's an offer you can't refuse: Because of the lack of availability of MK 4118
RAMs, Nascom Microcomputers is supplying its Nascom 2 without the 8 spare 4118s but with a FREE
16K dynamic RAM board. When the 4118s become
available, Nascom 2 purchasers can have them
at the special price of £80 + VAT for the 8K.
So, for £295 plus VAT
this is what you get:

MEMORY

16K RAM board

(expandable to 32K). 8K Microsoft BASIC.

2K NAS-SYS 1 monitor.

(101 (0 Nailno£ovt1wBaom6Nirl5pyoiaatorrabspieucilclneuerso'sslfomoauVwbfvllA1i£niygnT1ihgsgc7)o.oe5nounsovpstswelisturnrmssuagucaVhfptolAeolprsdTtltiysehf(soodketlierdtBrymipeodUrruiiiiIccnsLutegTolo!sisrutoilloslnltoy-nly 1K paces. 1MTu2shonO"yiepismsxTnSrtTteicsh8oeohatme"mdnriespuPu4e,ascMovClKmaobtinidBPtcloomee-ekUnrbcdyeoeosoatimfvspa,drieinrarldiotyesdxhcceripaeenlykouilvncgaaisdisutanygtei5atnngeagiraLnndgfssaanSgdsaccadIia1gla1enlMKrE5ns8ddf8PseOou03ZedRrs8S3t8eU0tOte0TorpHcMTaRwotoFhLrdheAoteiMcero.h.lpeetkyrapageti.ng

1K Video RAM. 1K Workspace/
User RAM.
Main board sockets

for the 8x4118s or

MICROPROCESSOR

2708 EPROMS.

Z80A which will run at 4MHz but is selectable between 1/2/4 MHz.

HARDWARE

Industrial standard 12" x 8" PCB, through hole plated, masked

and screen printed. All bus lines are fully buffered on -board.

INTERFACES 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 corn plete with construction article

and extensive software manual for the monitor and BASIC.

NASCOM HARDWARE
Motherboard: £5.50 + VAT + 50p P+P Mini Motherboard: £2.90 + VAT + 50p P+P 3 amp PSU: £29.50 + VAT + £1.50 P+P VERO DIP board: £10.50 + VAT + 50p P+P

NASBUG T2: £12.50 + VAT + 30p P+P
NASCOM NASCOM SOFTWARE ,sliASBUG T4: £25.00 + VAT + 30p P+P FIRMWARE AS-SYS 1: £25.00 + VAT + 30p P+P 8K BASIC tape: £15.00 + VAT

0 P( 1t

Please mention PCW when replying to advertisers - it identifies you.

-Carr

NASCOM IMP PLAIN
PAPER PRINTER
Fully built and housed in a stylish enclosure for just £325 plus VAT. Interfaces with all micro computers.
Deliveries start November.

['he Nascom IMP (Impact Matrix Printer) features are:

D 60 lines per minute.

96 character ASCII set

D 80 characters per line. (includes upper/lower case, $ # £).

Bi-directional printing. Automatic CR/LF.

10 line print buffer.

Accepts 81" paper.

Optional tractor feed. Baud rate from 110 to 9600. External signal for optional synchronisation of baud
rate. Serial RS232 interface with parallel option
available soon.

EVOLUTIONARY TOUCH 1CTIVATED KEYBOARD.

/ ILWP

10ilmlI -

L=-1M4M11/01iiiilLEI I El

Olik0E firiiLIi(ildLlaiiil

IASA MODEL 55

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 ndestructible.
Totally flat and measuring just 0.325" thick, the

TASA has full 128 position

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:

ORDER FORM

II Built-in electronic shift lock. Two -key rollover to prevent accidental two -key operation I
(excluding "control" and "shift"). Electronic hysteresis for firm "feel". Signal activation time of 1 millisecond.

Send your orders to: Interface Components Ltd, Oakfield Corner, Sycamore Road, Amersham, Bucks HP6 6SU.
Tel: 02403 5076. Telex: 837788.

Standard 6 -position dual readout male card edge

Description

Quantity

connector. CMOS compatible with pull-up resistor

Parallel output: active pull -down, direct TTL compatible

(one load) open collector type.

PCW 11/79
Price

MICRO MART MEMORIES £1.20 each

IC SOCKETS
3 pin

4027 10p each 4116

£2 75 each £7.50 each

14 pin

12p each 2114

£4.00 each

16 pin

13p each Z80 DEVICES

20 pin

25p each MK3880

£12.50 each

24 pin

30p each MK3881 (PIO) .... £7.50 each

28 pin

35p each MK3882 (CTC)... £7.50 each

40 pin

40p each

ICs

EPROMs 2708 ... £9.00 each

EPROMs 2716 .E32.00 each

VOLTAGE REGULATOR

SPECIAL OFFER

LM309K

90p each

Add VAT and 30p P+ P to

VISIT OUR NEW SHOP

all orders

OPEN TO CALLERS DECEMBER 1979

Name Address

+ VAT at 15% P+P
Total enclosed

Access/Barclaycard No:
*Cheques & P/Os made payable to Interface Components Ltd.

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P('.V 1 1

Take your first bite at
computers with Apple

WHY APPLE? APPLE II Plus will change the way you think about computers. That's because it is specifically designed to handle the day-to-day activities of business, financial planning, scientific calculation, education, and even entertainment. It makes learning to use computers enjoyable and creative, by bringing to the user a new level of simplicity through design sophistication. Apple Computer Inc. has produced a total system based upon the incomparable APPLE II Plus Computer, which has an unequalled range of accessories with superbly produced documentation.
APPLE FEATURES The basic APPLE H Plus can be used on its own (with your TV) or as the basis of a most comprehensive business computer system by adding such items as floppy disc drives and printers. Professionally written programs are available for a wide variety of tasks.
APPLE II Plus is easily programmed in BASIC but now has available for the first time-PASCAL, probably the most exciting new computer language around.
APPLE II Plus also has some futuristic accessories available today such as-programmed speech output-speech recognition-a superb music synthesiser that even displays the musical stave as it plays-a graphics input tablet-all this and high and low resolution colour graphics too!
Apple brings professional standards to personal computing. It gives you the features, appearance and "feel" for ease of use. The Apple name is your guarantee of satisfaction.
SOLE U.K. DISTRIBUTOR
microsense comppters
Finway Road, Hemel Hempstead, Herts HP2 7PS Hemel Hempstead (0442) 41191(3 lines)
and 48151 (3 lines) 24 hour answering service
Telex: 825554 DATEFF G

Starter System only
£750*
Typical Business System
£2500*

APPLE RELIABILITY Apple backs its quality with a solid warranty and
the Microsense Computers national network of Dealers who can advise and help you in choosing the System and accessories to suit your particular needs whether for Business, Education or in the Home.
APPLE IN BUSINESS Apple is ideal for the small company run by forward looking Management. The Apple Computer System can, for example, help you run the company Payroll or handle the Stock Control for a Retail Store. Specialist applications include those for managing an Estate Agents records.
APPLE IN EDUCATION Computer literacy is rapidly becoming an essential part of the world in which we live. Real "hands-on" experience with the Apple allows teachers to be more effective in preparing their students for business, commerce and the professions where computers will soon be as common as typewriters.
APPLE IN THE HOME The computer can help you give your children a head start in understanding this modern business and scientific tool. Its very nature encourages
learning and increases computer awareness. For the householder there are the advantages of easily handling home finance.

TRADE ENQUIRIES WELCOME-Please telephone (0442) 63561 Ext 52 or 57.

'Prices exclusive of VAT and correct at time of going to press.

I want to know more about how the Apple Computer can help me:

In my Business
ri In Science

In Education
In the Home El

Name

Address

®Apple is a trade mark of Apple Computer Inc- Cupertino. CA, USA.

Postcode

Telephone

Please complete and send to Microsense Computers, FREEPOST, Hemel Hempstead, Herts. HP2 4BR. (No stamp required).

12 PCW

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TRAINAM COMPUTER PRODUCTS

SINGLE BOARD
TRITON PERSONAL COMPUTER

THREE NEW EXCITING EXPANDABLE SYSTEMS DESIGNED FOR EASE OF CONSTRUCTION AND FLEXIBILITY. KITS COME COMPLETE WITH CASE, POWER SUPPLY, FULL KEYBOARD, PCB. ALL COMPONENTS AVAILABLE SEPARATELY SEE CATALOGUE. FULL HARDWARE AND PROGRAMMING MANUAL AVAILABLE. THE SYSTEM IS EASY TO EXPAND AND IS WELL SUPPORTED. FEATURES 2, 2.5 OR 7K BASIC IN EPROM (SEE CATALOGUE).

SINGLE BOARD HOLDS UP TO 8K MEMORY VHF OR VIDEO OUTPUT CASSETTE INTERFACE

THREE FIRMWARE OPTIONS BASIC IN EPROM 64 GRAPHICS CHARACTERS PLUS IN EXPANSION BOARDS

Personal Computer Sr! -h V A T

BI-DIRECTIONAL MATRIX PRINTER

V595 t VAT

THE B080 IS A LOW-COST, 80 -COLUMN LINE PRINTER

WITH MICROPROCESSOR CONTROL TO PROVIDE

EXCELLENT AVAILABILITY AND PERFORMANCE.

5 /7 Dot Matrix Full ASCII Char Set Selt Test

10 Char per inch 010 Lines/sec Paper Advance

6 Lines/inch

112 Cnar ./sec

Fully Cased

400 Char. Buffer 82 Lines per mule

A
UNIQUE PRINTER
FAST AND RELIABLE

SWITCH SELECTABLE BAUD RATE FROM 110 TO 9,600 ON A STANDARD V24 AND RS232 INTERFACE SEND SAE FOR FUR1 HER DETAILS IDEAL PRINTER FOR TRITON OR ANY SYSTEM REQUIRING HIGH-SPEED. RELIABLE HARD COPY. WE CAN SUPPLY CONSUMABLES

COMPONENTS 74LSXX

501/45SOON SN7455010 SN7455020 SN7455030 SN7455040 SN745505N 94741.5080 SN74LS09N SN7455100 SN7455110 SA/7415512N S07455130 5987415146 05745515N 94745520N 50,1745.5210 SN7455220 SN74552601 SN741.5270 SN7455213N 55745530N SN74LS32N SN7455330 SN74552714 SN74LS38N SN74LS4ON SN7455429 SN7455470 SN74LS48N 9(741549N

18 18 20 18 20 26 20 22 18 26 25 55 89 25 20 26 26 29 35 35 25 27 39 29 29 25 79 95 95 I 09

SN7455504 947415556
9,1741.5630 SN74LS73N SN741 S740
SN74( 57519 SN7455760 9E745578N
5074683AR SN7455850 50745586N S07415900 SN74L591 N 91744592N SN74559380 86741.895AN SN74559604 SNI4L51070 90415109N SN74551120 SN74LS113N SN74551140 SN7455122N SN745S123N 0674<61249 SN7455125t4 SN741S1260 5017455132N SN74LS133N SN745513601

21
121
50 35 40 46 35 35 1 15 1 10 40 65 99 90 65 1 20 1 75 39 39 39 44 44 79 90 50 65 65 75 39 40

SA/455130N /5 94741.5139N 75 904(5145N I 20 SW/415148N 1 75 947455151N 85 S074551530 60 567451549 60 SN7455155,4 1 25 5017455156N 125 SN74551570 60 SA74551580 99 5074551600 15 507455161N 15 SN7455162N 15 S5741.5163N 90 SN74151640 50 5017465165N 70
S5741.516601 75
557461680 95
514741. $1690 95 5017001709 50 SN74LS17314 20 SN74LS174N 15 9474501756 05 S074551810 75 0974551900 1 75 SA74551910 1 75 S074551920 1.45
307451930 1 75 SN7455194AN1 89

5N/415105AR 85 SW4151960 20
1
SN7455197A4 1 20 SA1741.52210 1 25 5574052405 2 20 947415241N 190 SN74LS242N 1 90 50745524314 1 95
S574552455 2 60 9474552475 25 50174552485 95 SN74552495 30 51974552515 45 SN74LS253N 25 SN74LS257N 40 9474502585 95 SN74552595 45 SA1745526001 39 904(5261N 50 067410266N 39 St4741 5273N 85 SN74LS279N 79 SN7455280N 75 9705283N 1 80 S57455290N 1.80 S074552930 1 BO SW4152950 2 20 56745529801 2.20 5017053204 1 80

6N74552256 SN74553201 SN74LS3270
501741.5252N S074553530 917455365N
50746366N 91741.53670 SW45536804
SN74LS373N
90455370
S074153750 507455377N 507455378N 50705379N

2 55 2 55 2 55 1 35 1 50
65 65 65 65 1 75 1 70 72 1 75 1 32 40
1

SN745538601 SW45539001 SN7455393N S074553950 507455396N
SW746539801 SN74LS399N SI4746420 5147455445N SN74LS447N 9474(3490N SN74LS668N 947455669N SN7455670N

57 98 50 80 70 75 60 50 25 25 95 95 95 2 70

TRITON DOCUMENTATION

available separately as follows, prices include p&p

Triton manual - detailed circuit description and constructional details user documentation on level 4.1 monitor & basic
L4.1 listing - listing of 1K monitor & 2K tiny basic

f5.70 £4.20

1_5.1 user documentation on level 5.1 firmware

£1.20

L5.1 listing - listing 011.5K monitor & 2 51( basic

£5.20

L6.1 user documentation on 7K basic interpreter Motherboard, 8K RAM & 8K EPROM constructional details

£1.80 £5.00

User group newsletter subscription £4 per annum Triton software - Send SAE for list of programs available for Triton

THAN AM

EXPANSION MOTHERBOARD

TRITON. Expand your Triton simply

and easily with our new 8 -slot motherboard; complete with its own P S U. takes 8 plug-in Euro cards. Plug-in 8K

- - £50

RAM card.

A=A --A A A A

VAT

AND EPROM CARDS NOW AVAILABLE. KIT COMPLETE WITH PSU-1 SET CONNECTORS

8K RAM CARD

TRITON 8K STATIC

RAM CARD KIT USES cC, 2114 LOW -POWER 4V STATIC RAMS ON -BOARD REGULATION. NEW

COMPLETE KIT
£97

JUMP SELECT

PC8 ONLY £5, RAMS £5.50

VAT

KIT LESS RAMS £31 INCL SKIS COMPONENTS

8K EPROM CARD

TRITON 8K EPROM CARD

KIT DESIGNED TO TAKE UP TO 8,2708 EPROMS (1K A) AS RAM CARD

PC8 ONLY £15 KIT LESS EPROMS £31 EPROMS (BLANK) £9

PLUS VAT

COMPLETE KIT

£97
VAT

S100 BOARDS

80 Static RAM hoard 1450,1 £123.75

8K Static RAM board1250ns1 E146.25

080 cpu board 12M1-121 Z80 cpu board14MHA)

0131.25 £153.75

2708/27 16 EPROM board

E63. 75

Prototype board (bare board)

Video display board 164016,

1 28U/ L Asc./

0108.75

Disk controller board

£131.25

K2 disk operating system

E56.25

ASSEMBLE /Z Macro Assrd

037.50

YOUR

ITHACA
PASCAL/Z 19041 your own

LONDON DEALER!

Pascal Micro

Development

system. IE E E
0100 bus systern 011oo Dos! mainIrame. Supports K2. ASSEMBLE/Z and
PASCAL/Z on 8" disk.

WE STOCK THE FULL RANGE OF ITHACA PRODUCTS

PCB CONNECTORS

EDGE CONNECTORS GOLD CONTACT

DOUBLE- SIDED PCB CONNECTORS

1 in PRICE .156,n. PRICE

22/44 25/50
28/56 30/60 35/70 36/72
40/10 43/86 50/100

£3.20

6/12

£3.60

10/20

£3.90

12/24

f4.15

15/30

£4.60

18/36

£4.75

22/44

£5 00

28/56

£5.50

36/67

£5.805100 43/82

£1.25 £1.50 £2.00 £2 20 E2.30 £2.65 £3.30 £3.90
£4.60 o VAT

TRAPI Triton Resident Assembly
Language Package Links via the L6.1 monitor and new
entitle basic to make Triton a stand done development system. Trap 45 an 8K package in EPROM and resides on our EPROM card. Set 01 802708 only £80 deluding document.

EDITOR ASSEMBLER DISASSEMBLER SYMBOL TABLE CREATE

BREAKPOINT
SINGLE STEP TRACE PROGRAMME LOAD MONITOR

SEE CATALOGUE FOR FURTHER DETAILS

MEMORY AND SUPPORT CHIPS

SUPPORT 8212 8215 0221 8226 8228 8238 8245 8246 8251 8253 8255 8257 8259 8292
682015 682IP 6850P 6852E AY 5 2376 m614411 M51109
M51I60 M57161 iMS601 I 815595 815596 81(097 815598

RAMS

e 20 2101

2 20 21025 4

2 80 2111

20 2112

20 6810

20 8154

00 2114

00 21025,3
1
00 740920

1 00 710921 00 74C929

1 00

027

50 4044

I 00 4045

50 4060

50 2107

60 4116

50 4118

1 50 1 00 1 43

280P10 2800T0 280010

00 mom 1 00 280ACTC
1

,,,q

1702

"" 520K 30lE 2708

30 2M

16x21141 only £791 894116 only E581

2 32 1 20 2 22
2 46 4 08
8 18 5 50 1 60 11 00 11 00 11 00 11 00 14 70 9 15 7 00 7 80 0 gg
20 00 10.00 10 00 14 00 14 00
6 00 8.00 9.00 28 00 22.00

tikes tkClUDE vnt

ROIAS 745287 745472 74570
745473 745474

3 7U 12 00 8 00 12 4b 12 48

1,O 2513 96364 14412

7 50 10 95 12 90

LINEAFIS
1.M301AH LAA301AN-8 LM (MINI MP, LAA308 N LAA309K LAATO3 LAA311H
LIA1318H 5A43231(
LM324N LM339N
5M5550,1 LAA5560
LM709CN LM723CH L M723CN LAA733CN LM739CN LAA741C0-14 LAA741CN 8 5017470N-14

U 39
0 30 0 99
1 45 1 29 2 25 6 00 0 79 0.64 0 30 0 75 0 37 0 58
043
1 30 1 30 0 33
025
0 79

5M 74 Ad LM748CN L M748CH 041458H 5M14580 1M14880
M14890 5M1489140 M14994,14 1M33020 5M3401N 5M3403t4 I M3900N 11080CP 51081CP TL082CP 110830N 0.084CN
VOLT PEGS 7805 7812 7815 7824 78050 78120 78150 78240 7905 7912 7915
7924 79050

19
I
0 15 0 46 0 72 0 48
0 85 0 85 1 25 0 99 0 65 0 65 1 25 0 54 1 49 0 69 1 29
65 I 69
0 90 0 90 0 90 0 90 1 50 150 1 50 1 50
I 10 1 10 1.10 1 10 1 80

/9126 79150 79240
Olt SIOS
80,
14011 16211
18011
20011 A4011
28511 4801
CRYSTALS
1000 2006 1 MHZ 1008A 18436 2MHZ 24576 32764 3MHZ 4MHZ 4 43M 5MHZ 6MHZ 7MHZ 7 168M 8MHZ 10MH2
107M

1 50 1 50 I 80
014
0 15
017
0 24 0 27 0.30 0 36 0 50
00 70 3 60 3 51 3 00 1 50 3 05 2 70 3 05 2 10 100 2 70 2 70
2 5/0
2 so 2 70 2 70 2 70

ISM 48M

z 90 2 90

CMOS C040/1 C04040 451411124o
MISCLE 2513 TAA56011 MC14411 MC14412 96364

0.15 0 79
i 50 5 00 12 00 12 90 10 95

CPU's

8080 6800 80 804 8085 6502
SDP 6

6 33 10.00
8 00
15 00 12 95
80
10 00

6802 9900

13 95 30 00

WWRAP5010

801L

0 20

14011

16015 18015

0 42 0 60

24015 28015 40015

0 52 0 74 0 95

HOME COMPUTING CATALOGUE

If you're in town, visit our showroom in Chapel Street, next to Edgware Road tube station. We have Tritons on display plus a
comprehensive range of components and accessories, specifically for personal com-
puter users. Books, mags, tapes, data,

NEW
A4 SIZE CATALOGUE FILLED WITH OUR LATEST PRODUCTS
40p+SAE

cables plus much more. Showroom open 6 days a week. (Half day Thurs from 1.30 pm)

4,4,4 4,

1;12

ALL PRICES EXCLUDE VAT

VAT ALL PRICES

TRANSAM COMPONENTS LTD. 12 CHAPEL STREET, LONDON, NW1

EXCLUDE VAT TEL: 402 8137

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PCW 13

c..i\POoe

ct

co

Q13 AUG

I-4-

MicMroaciloOmrpduetrer

1'31'3
A

W40 II

All your microcomputer requirements can be bought with confidence by mail order from MICRODIGITAL, one of the largest and longest
established computer stores.
Most orders are despatched same day as receipt, if not a note explaining what the supply situation is. If we cannot supply within 30 days we will, on request, make an immediate cash refund.
Access and Barclaycard orders are welcome
either in writing or over the phone. Your account will not be charged until the goods are despatched.
Official orders of over Et 0 are also welcome.
With normal 30 days trade credit extended to bona fide commercial and government organisations.
If you do not have our brochures, write or phone today for free copies by return.

MICRODIGITAL
MICRODIGITAL LIMITED REEPOST (No stamp required) LIVERPOOL L2 2AB TEL: 051-236 0707 (MAIL ORDER 24 HOURS A DAY)
TEL: 051-227 2535

OPENING SEPTEMBERSEPTEMBER
HOME + BUSINESS COMPUTERS
"PET SHOP" FOR THE HOME AND SMALL BUSINESS MAN 8K -16K -32K
"THE QUICKNESS OF THE CHIP DECEIVES THE EYE" WITH SORCERER 32K OF MAGIC. THE IDEAL SYSTEM FOR THE MORE AMBITIOUS HOME USER
- AND THE BUSINESS MAN - FLOPPY DISKS PRINTERS WORD PROCESSING
BOOKS, MAGS, TAPES GALORE! Add a little colour to your life with APPLE/ITT 2020
what better use for your colour T.V.!!
WE ARE HERE

Ilford k
Nth. Cnc. Rd.

Manor Park Stn.

Stratford c7

High Sr North 445

E

East Ham Stn. Woolwich Ferry

445, HHiigghh Street North, Manor Park, London E12. Phone 01-472 5107 (24 Hr Ansaphone)

11 Megabyte Hard Disk for the Apple 2

The Corvus 11A hard disk system for the Apple II is made by Corvus Systems Inc. and is imported exclusively by Keen Computers Ltd.
It has been specifically designed to work with the Apple Disk Operating System and plugs directly into anyone of
the Apple's I/O ports, maintaining total compatibility with existing hardware and software.
The system consists of the IMI 7710 "Winchester" disk drive with Corvus intelligent controller, a complete
power supply and an intelligent module for the Apple, consisting of an interface card and its associated software.
FEATURES: *11 megabytes unformatted storage
*Z80 controller and 16K RAM *All Software in ROM
*Complete compatibility with existing systems *50K bytes/sec transfer rate *Winchester heads
Prices:
Hard Disk and Controller £3500 - Slave Disk £2500

cut out and post today
Please send me more information on the Corvus hard disk
Name Company Address
pcwoct
ft keen computer5 ltd
5b The Poultry Nottingham NG1 2HW
Tel: 0602 583254

14 PCW

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ERE'S TREMENDOUS WILK'

FROM COMPUTER CENTRE

MINI KIT

MEGABYTE

MINI FLOPPY

The lowest priced CP/M Z80 Micro in U.K. Add your power and
terminal. Minifloppy 16KB, RAM, Z80, CTC, Serial + Parallel I/O, S100 motherboard, connectors,

MEGABYTE MICRO KIT CP/M disc based micro in kit form!
Just add power and a terminal.
Kit includes: Drive, 8in double sided double

Double/single density hard or soft

sector used for TRS80 d-'tN

North Star etc.

-000,0700-r,s

40044'
irk 4

manuals CP/M system FREE BASIC density, Z80, CTC, Serial and

and ALGOL. Optional two drive Parallel I/O, 16K ram (expandable

case illustrated and power supply
£149

to 64K), CP/M systems, connectors,

manuals. Case and power supply

extra £149. Assembled and Dual Drive versions available.

8 INCH DRIVE

DRI 7100 (Shugart Compatible)

single/dual density. British Made

Assembled + Guaranteed. Double

sided version. £375

!I4..0.1dt

SDS 100

Z80,12" VDU, 1M. Byte,twin drives,

Serial + Parallel outputs, numeric CP/M Operating system + 6

8K Static Ram Kit

pad, CP/M system

4MHz has run in Northstar, £79

Cromenco, etc.

ass. £94

manuals + Basic - E

£64

Extensive User group

f4.50

Library includes Basic 8" DISC

compilers/interpretors Algol -60,

64K Dynamic Ram Kit

Pilot, Stoic, utilities and games.

4MHz runs with 8080, Z80, uses

10 copies £35

16kbit chips £449 ass. £499

Proprietory software:

SBC 100 Single board Z80 S100, Z80, CTC, USART 1K RAM, 4 ROM, Serial and Parallel I/O.
£155 ass. £215

Microsoft Basic £180 Fortran £280

All
advertised

CIS Cobol £380

items generally

UCSD
Pascal 1150

in stock. Cash with order ensures same

Eprom Programmer Kit for 2708, or 2716 Eproms S100, Eprom sockets rack ass. £145

day despatch. Add 2%
/postage and 15% VAT to
advertised prices.
Send: El Ca talogue(please tick)

Also S100 16K Econoram IV 4MHz
8080A with vector interrupt 104 2 Serial/Parallel
Tarbell disc controller
Versafloppy disc controller

kit ass.
175 199
69 104 89 124 125 160
99 140

16K bytes upgrade kits -

/end

these are the IC's that even work in

the 48 k expansion. Excellent

instructions, screw driver and

common sense extra!

I enclose cheque for £

Name
/Address

VDB 80x24 Video

185 245

Motherboard (11 slot) 19

Prototype board

18

COMPUTER (ENTRE I THE DISCOUNT COMPUTER STORE

9 De la Beche Street, Swansea, SA1 3EX. Tel: 0792 460023 Telex: 48638

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PCW 15

(0176) 62506 (12)For Hardware, Software, Peripherals, Consultancy and Competitive Prices.

MIPCERTOCOMPUTERS ETr. TRS BO Cr commodore

RegetenA lateness

(0272) 422061 (O86°5) 721461

Pet 2001

MODEL II

IN%%firs* From £515

is coming...

NEW PET 2001 with large keyboard. From £ 630.00

with up to 64 K RAM

PET 2001-16N (16K RAM and New Large Keyboard)

£630.00

PET 2001-32N (32K RAM and New Large Keyboard)

£750.00

PET 2001-8 (Standard PET with 8K memory)

£515.00

CBM 3040 (Dual Drive mini -floppy 343K User Storage) £745.00

CBM 3022 (80 col. Printer with PET graphics -tractor feed) £605.00

IEEE/RS232 Serial Interface 'A' Output only

£106.00

IEEE/RS232 Serial Interface 'B' Input/output

£186.00

I EE E-488/Centronics type parallel Interface

£45.00

PET C2N External Cassette Deck

£53.00

Interface to S100 (4 slot motherboard)

£112.00

IEEE to Pet Cable /IEEE to IEEE Cable

(Resp. £19/24

COMPUTHINK dual drive up to 800K storage from

£795

Sorceror

Now with the
S100 Bus Expansion Interface and Dual Drive mini -floppy Disk

Authorised Dealers

Sorceror 16K RAM (inc.UHF Modulator) Sorceror 32K RAM (including UHF Modulator) Exidy Video Monitor (High Resolution) Exidy Dual Drive mini -floppy Disk (630K storage) Exidy S100 Bus with Interface+Motherboard+PSU
Exidy Mini -floppy Disk Drive (143K Storage) CP/M for Sorceror on Disk
Ikapplcioomputar

£740.00 £840.00 £240.00 £1195.00 £200.00
£495.00 £145.00

and 2.0MB Disk Storage!

TRS 80, 4K Level 1 (Keyboard with 4K memory+

VDU+Cassette drive+240v PSU)

£365.00

TRS 80, 4K Level II (as above but with Level II basic)

£425.00

TRS 80, 16K Level II (as above but with 16K memory) £499.00

TRS 80, Expansion Interface with 16K RAM

£275.00

TRS 80, Expansion Interface with 32K RAM

£360.00

Shugart Mini -floppy Disk Drive (including Pal)

£315.00

Micropolis Mini -floppy Disk Drive (including PSU)

£315.00

Percom FD200 Mini -floppy Disk Drive (inc. PSU) 110v. £299.00

Micropolis Dual Drive (394K) (including PSU)

£1195.00

TVJ 232T Serial Interface for TRS 80 TRS 80 Screen Printer (text+graphics) (110V)

£45.00 £445.00

Centronics Parallel Printer Interface for TRS 80

£45.00

TRS 80 Voice Synthesizer

£345.00

TRS 80 Numeric Key Pad supplied & fitted

£69.00

New Radio Shack Micro Printer

£245.00

Radio Shack Phone Modem

£160.00

NEWDOS Super -enhanced TRSDOS

£49.00

Level la Super -enhanced BASIC

£34.00

RSM Assemble/Monitor on Disk

£19.95

MICROCHESS or SARGON CHESS Cassette/Disk

£14.00

UHF Modulators (encased with leads for 625 lines)

£20.00

RAM upgrade 14-16K, 16-32K, 32-48K) supplied and fitted

at our premises (Kit £80)

£ 85.00

Computer with PALSOFT in ROM (16K RAM) B/W Computer with PALSOFT in ROM (16K RAM) Colour Apple mini -floppy Drive (116K storage) inc. Controller Parallel Printer Interface Card
High Speed Serial (RS232C) Card RAM Upgrade (16-32K, 32-48K) ITT 2020 & EUROAPPLE Authorised Dealers

£750 £819
£398 £110.00 £110 00
£69

'Electric Pencil' text/word processing package (on cassette) £65.00

'Electric Pencil' text/word processing package (disk version)£109.00

'Electric Pencil' keyboard mod. to give lower

case with text/word processing package.

£28.00

S100 Interface for TRS 80 (6 slots)

£375.00

'Library 100' - 100 progs for TRS 80 on cassette (Level II) £39.00

Advanced Systems
Altair, Equinox, Billings, Heath, Rair, Horizon. Installations to include hard disk, and multi tasking

NOW AVAILABLE
P. 0. A. Compucolor II CE

Terminals (Most Brands)
Pentland V1, 80 char./24 lines 2 page memory

£580

Ansaback 'Phonemate' Telephone Answering Machine, voice

operated twin cassette

£190.00

Computer with colour Monitor,

Keyboard and Integral Disk Drive

From only

£1058.00

t ..V

Second Disk Drive

£316.00

_

Programmed Diskette albums available from

4', , £9.00

Software

Personal 41F

Petsoll COMPOSETTES Software we GEMSOFT

Printers
Teletype 43 KSR Serial Printer Teletype 33 KSR Serial (110 Baud) Reconditioned

Lifeboat Associates(Authorised Dealerships, Send for Catalogues) Centronics 779 parallel (friction feed)

PILOT (for TRS 80) text orientated language

£18.00 Centronics 779 parallel printer (tractor feed)

COMAC III Suite- Computerised Accounting for TRS 80

£75 Anadex DP 8000 serial/parallel printer

£825.00 £550.00 £750.00 £825.00

STOCK CONTROL (TRS 80) Inventory, P/0 & Invoicing £125.00 (112c p s.bi-directional tractor feed)

£575.00

CP/M for TRS 80

£95.00 Centronics Micro printer (20, 40, 80 columns selectable) £395.00

CBASIC for TRS 80 & Sorceror

£75.00 Black Box Printer (80 col.)

special offer £299

Estate/Employment Agency Systems,Fortran 80, Cobol 80, Pascal HEATH VVH 14 serial (80, 96, 132 cols. selectable)

£510.00

Etc.
Diskettes 5% (blank) boxed (min. order 10) each

TR EN DCOM 100 (40 c.p.s. bi-directional, thermal) from £3.00 QUME or DIABLO daisy wheel serial printers

£243.00 P.O.A.

C12 Cassettes (Min. order 10) each

£0.45

Computalker Speech Synthesis for S100

£350.00

Books - Large range of Microcomputer related books & magazines.

If ou don't see it - ask if we have it.

PRICES EXCLUDE VAT FREIGHT & HANDLING SEND OR 'PHONE FOR PRICE LIST & BROCHURES
IAll prices correct at time of compilationl
Directors' Dr. R.V. King. BA, WEE. 5.G Johnson, BSc. Mons.) T.S. Johnson, ABIBA, ACMB, F BSC, MBIM A.S. Bartora ACII, ABIBA, CdipAF.

W:11
LiS4

T & V JOHNSON (MICROCOMPUTERS ETC) LTD. Member of the TV Johnson Group of Companies 165 London Road, Camberley, Surrey GU15 3JS
48 Gloucester Road, Bristol BS7 8BH
148 Cowley Road, Oxford OX41JJ.
Branches at: Birmingham, Bristol, Edinburgh, Leeds, London, Louth, Newmarket, Nottingham, Oxford, Byfleet, Wokingham.

(07116) 62506
(ilici) 422061

+ Ansaback eves and w/ends.

z"1461 OXFORD .91
(0865)

Telex 858893

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

16 P('W

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/o - Everything you always wanted

to plug into your PET,

APPLE or TRS-80* TRS-80
HARDWARE

TRS-80 SOFTWARE

DOUBLE DENSITY DISK STORAGE

FOR THE TRS-80 (220% capacity of Radio Shack's)
TRS-80 owners can now increase their on-line mass storage
capacity to 200K bytes. How? By using the 77 track
Micropolis model 1033-11 dual drives. Cost: only £1195 for two drives, to give 394K on-line.

DATA MANAGEMENT/REPORT GENERATOR - easily

formats disk files, allows entry, edit, delete & list of

records; and retrieves data for display or calculation on

screen or printer

£200.

ELECTRIC PENCIL - powerful word processor allows full

cursor movement, insert/delete, string search, block move-

How does it work? By writing on 77 tracks (instead of the ment, adjustable line length, justification (on cassette) .£65.

conventional 35) with precision head positioning.

LOWER CASE MOD KIT FOR ABOVE

£28

How do I use it? TVJ Microcomputers Etc. provides you DISK BASED WORD PROCESSING PACKAGE. . £124.95

with a special program to let your TRS-80 DOS know there RSM-2D DISK MONITOR - powerful system manipulates

are extra tracks. This program was written especially disk data, has Z-80 breakpoint routine

£25

by Randy Cook, author of TRS-80 DOS.

ESP -1 EDITOR/ASSEMBLER

£29.95

Will the double density disk work with my Radio Shack

RSM-IS MACH, LANGUAGE MONITOR tape base £23.95 DCV DISK CONVERSION UTILITY - use with TAPE -

drives? Yes, except of course for copying an entire 77 track DISK utility to save system tapes on disk (i.e.) Pencil .£9.95

disk to a 35 track drive.

UTILITY PACK 1 - a) Libloader merges from tapes

NEW

b) Renumber (spec. mem. size); Statement analysis for

Radio Shack Voice Synthesizer for TRS 80 provides the debussing £9.95 ea. all 3 for £24.95

ability to speak in English and limited foreign languages. SARGON CHESS - 16K Iv II - the 1978 champ . . . £14

Capable of producing 62 phonemes (sound units) that are MICROCHESS 1.5 by Jennings - 4K any lev

£14

the building blocks of spoken language. Includes audio LIBRARY 100 - an assortment of 100 programs for . £39

amplifier and speaker

£345. MAZE - random maze on the TRS-80 graphics. . . . £14

TRS 80 Printer Interface Cable - allows you to connect a' FORTRAN IV FOR THE TRS-80! Finally, for high speed

parallel printer (e.g. Centronics 700 series) directly to your calculations on your micro, MICROSOFT's FORTRAN can

Level II Keyboard, i.e. Expansion Interface not required. speed up those computation -bound programs. Complete

£54. package includes compiler, .relocatable assembler, text

TRS 80 Numeric Keypad Mod. - Calculator Style Numeric editor, and linking loader.

£244.

Key pad which sits to the right of the standard keypad; has CP/M + CBASIC for TRS-80

£170.

keys for 0 tog, decimal point and ENTER. Both Keyboards NEW DOS - TRSDOS with corrections& enhancements£25

active at the same time

£69. NEW DOS+ -As above but with further facilities:- KBF IX,

Radio Shack Microprinter for TRS 80, 40 column 21/2" RENUM, Screen to Printer one step, DOS commands from

electro-static Printer, switch selectable RS232 Centronics BASIC, Level I in II, SUPERZAP, Disassembler, Open 'E'

Parallel and TRS 80 BUS Interfaces

£245.to end of sequential file, Load and Save faster, List

TRENDCOM Printers for TRS 80, PET or APPLE. 40 cps, variables

£49.

40 column Thermal Printer

£243.

PET

TRS 80 Interface for Trendcom Printer
PET/APPLE Interface for Trendcom Printer APPLE
SPEECH LAB - provides voice control for the your Apple to understand and act upon the

f£4299:JOYST1CK PACKAGE -complete with connector,

ware, instructiond

£39.95 single,

£59.95

Asppopklee.nTwraoinrdMAICSRTORCOHLEOSGSY2/.N0AbTy AJeLnPniAngCsKAGE - sophisticated

softdual.
£14
chart

(inc. microphone)

£165.00 computation with PET graphics

£14.95

REAL TIME CLOCK - 1/1000 sec. to 388 days with SUBS - best graphics yet - drop depth charges on the subs

interrupt;

below you and rack up points. Complete adjustability for

Software controllable, Rechargeable Battery back-up when many same variations

£19.95

A/C power off

£165.00 SUPER MAZE - 2 games in 1: Tunnel vision lets you travel

GRAPHICS LIGHT PEN

£165.00 through the maze in perspective with graphics, also Kat'n'

PASCAL CARD - Powerful new language for the Business mouse chase

£19.95

User with PASCAL, PALSOFT & Intertur basic . . . £296. 74 COMMON BASIC PROGRAMS on 1 tape COMMUNICATIONS CARD, allows APPLE to exchange PETACT BUSINESS SYSTEMS

£15 P O.A.

data with a remote computer over ordinary telephone lines

through a modem

£140.00

AC line controller - allows APPLE to monitor and control

AC devices remotely

£270.00

T & V JOHNSON (MICROCOMPUTERS ETC) LTD. Member of the TV Johnson Group of Companies
165 London Road, Camberley, Surrey GU15 3JS 48 Gloucester Road, Bristol BS7 8BH
11111111111111111111=1111

Branches at: Birmingham, Bristol, Edinburgh, Leeds, London, Louth, Newmarket, Nottingham, Oxford, Byfleet, Wokingham.

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PCW 1'1

Upgrade your PET...

with thePETSOFT

PROFESSIONAL DISK SYST

A complete stand-alone system for the Commodore Ph . allowing up to 800,000 bytes of mass storage online.
Designed by Compu/Think for business use, this
powerful double density system offers complete randon. or sequential file access and support.
The Disk Operating System is in a ROM which plugs directly into 16K and 32K (new ROM) PETs, or via Expandqmem memory expansion board for 8K PETs. The Disk Operating System adds 16 extra easy -to -use commands to PETs BASIC. The Disk unit comes wit complete set of utility programs and a comprehenE-manual.
Supported by PETACT Business Softwale: Sales Accounting, Invoicing, Purchase Arttn, ing, and soon Stock Control and Payroll
'? More memory power for your money
Reliable and easy to use
Languages supported include BASIC, 651)
Assembler, FORTH, FIFTH, PLM. PILOT. CE and soon FORTRAN and PASCAL

gook optg/remii
800K £1,095 Dual headed double density dual disk for 16K and 32K (new ROM) PETs
400K Double density dual disk for 16K and £840 32K (new ROM) PETs
400K £79J Double density dual disk for 8K (old ROM) PETs. Requires Expandamem
24K £320 Expandamem internal expansict, memory board Prices exclude VAT. PET is the trademark of Commodore who recommend PETACI Business Systems.

Wide range of PETSOFT programs including
Payroll £50 + Stock Control £25
ci Supports the Pagemate Database £299

Try the ACT PETSOFT Professional Disk System and software at your. PET dealer or write to us for full details and the name of your nearest stockist.

Prices exclude VAT

(--

GT

eisoft Radclyffe House, 66-68 Hagley Road, Edgbaston, Birmingharni B16 8PF. Telephone: 021-455 8686 Telex: 339396

Please send me details of the PETSOFT PROFESSIONAL
DISK SYSTEM

My name is I live at
I have a new/old ROM PET

Postcode
J

18 PCW

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The complete range of North Star computer products in both kit and assembled form is offered by Comart: The Horizon computer, the Microdisk System, memory and floating point arithmetic board. And, Comart being S100 specialists, other items from our computer catalogue may be easily added to meet your requirements.
Teaching, Research, Engineering and Commerce .... each field has applications where this state-ofthe-art technology provides cost effective processing of immediate benefit.
Comart quality. Each assembled module is final -tested by our own engineers. Take delivery of a computer system - plug in a wide variety of peripherals and use it.

Attractive prices, good delivery and a choice of Comart's factory repair or on -site service with a Computer Field Maintenance contract make the acquisition of a Comart computer a safe decision.
Find out more - ask us for the Comart catalogue of Computers.

The North Star dual drive double density Horizon computer A together with a typical kit product B, the Microdisk system drive C and hardware floating point board D.

Contact us direct or call your nearest Comart dealer

CAMBRIDGE CAMBERLEY ILFORD
LEEDS
LONDON LITTON MANCHESTER
NEWBURY
NEWPORT NOTTINGHAM
SHEFFIELD SOUTHAMPTON

CAMBRIDGE COMPUTER STORE, Cambridge10223168155 MICROBITS, Camberley Surrey (0276? 34044 THE BYTE SHOP, Ilford. Essex 01-554 2177 also at Tottenham Court Road. London 01 636 064 HOLDENE LIMITED, Leeds105321 459459 also at Wilmslow. Cheshire W6251 529486 DIGITUS LIMITED, London WI 01 636 0105 ISHERWOODS, Luton. Bedfordshire (05821424851 MICROCOMPUTERMART, Manchester (061-83212269 also at West Park. Leeds 105327 788466 NEW BEAR COMPUTING STORE, Newbury. Berko 1063513057:, also at Stockport Cheshire (06149112290 MICROMEDIA SYSTEMS, Newport, Gwent (0633) 50528 COMPUTERLAND LIMITED, Nottingham (0602)40576 also at Birmingham (021-62217149
Manchester 061-236 4737
Glasgow 1041332) 2468
HALLAM COMPUTER SYSTEMS, Sheffield 107421663125 XITAN SYSTEMS LIMITED, Southampton (0703)38740

comart specialists in microcomputers
Comart Ltd., P.O. Box 2, St. Neots, Huntingdon, Cambs, PE19 2AF. Tel: (0480) 215005 Telex: 32514

PCW 19

CROMEMCO SYSTEM 3

*new low prices *multi-user *Fortran
*Word Processing

*early delivery *Basic
*Assembler *Mailing lists

*finance available *Cobol *Data -Base management *Labels

SPECIALLY DESIGNED SOFTWARE NEED NOT BE EXPENSIVE

We specialise in producing well designed and constructed software with full documentation, user training and a guarantee.

We can quote on a fixed price or time and materials basis.
1ple require only one third payment on commencement of software projects, one third on delivery and one third AFTER the guarantee period. We can then provide an annual maintenance agreement.
Why buy unsupported, imported packages?
Also Sorcerer, Apple, Horizon systems, Dolphin, Printerm and OK I I printers Elbit and Burnt Hill VDU's plus a vast range of books and all media requirements supplied.

SHOWROOM and OFFICES open Monday - Friday 9 a.m. - 6 Dm.

34B London Road , Blackwater, Camberley, Surrey.

Saturday 10 a.m. -5 p.m.

Telephone:0276 34044. Telex 858893

On Main A30

SEE US AT COMPEC ON STAND 255

20 PCW

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BUY

MICIIICOMM
NOW AND GET A FREE 16K RAM BOARD

The lack of availability of the MK4118 RAMs has seriously delayed the launch of the Nascom 2, so we have decided to relaunch the product with an offer few will be able to refuse. The Nascom 2 will be supplied without the optional user 4118s. Instead, we will supply a 16K dynamic RAM board and the interconnect for the NAS BUS absolutely FREE. This board allows further expansion to 32K. Also, when the 4118s become available, customers taking advantage of this offer can have the 8K for just £80 (plus VAT).
Meanwhile, the empty sockets on the Nascom 2 can be filled with 2708 EPROMs allowing dedicated usage, now with 16, or 32K of extra RAM. All the other features of the Nascom 2 are available and these include :
MICROPROCESSOR
Z80A 8 bit CPU which will run at 4M Hz but is selectable between 1/2/4 MHz.
HARDWARE
12" x 8" PCB through hole plated, masked and screen printed. All bus lines are fully buffered on -board. PSU : +12v, +5v, -12v, -5v.

Z295 PLUS VAT

MEMORY

2K Monitor-NAS SYS 1 (2K ROM) 1K Workspace/User RAM

1K Video RAM

8K Microsoft BASIC (MK 36000 ROM)

INTERFACES

New 57 -key Licon solid state keyboard Monitor/domestic TV On -board UART provides serial handling for Kansas City cassette

interface (300/1200 baud) or the RS232/20mA teletype

interface. Totally uncommitted PIO giving 16 programmable I/O lines.
The Nascom 2 makes extensive use of ROMs for on -board

decoding. This reduces the chip count and allows easy changes for

specialised industrial use of the board. On -board link options

allow reset control to be reassigned to an address other than zero.

The 1K video RAM drives a 2K ROM character generator providing the standard ASCII characters with additions -128

characters in all. There is also a socket for an optional graphics

ROM on -board.

NASCOM DISTRIBUTORS

Henrys Radio (London W2) Microdigital (Liverpool) Interface Components (Amersham) Comp Components (New Barnet) Electrovalue (Egham & Manchester)
Lock Distribution (Manchester) Eley Electronics (Leicester) Target Electronics (Bristol) CC Electronics (Torquay)

Camera Centre (Barrow-in-Furness) Strathand (Glasgow) Byte Shop/Computerland Group Adda Computers (Ealing) Electronic Services (Sheffield) Business & Leisure Microcomputers (Kenilworth) A & G Knight (Aberdeen) P & 0 Computers (Belfast)

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Ell

MI MI Ng

I TO NASCOM MICROCOMPUTERS LTD

I

I

92 BROAD STREET

I

CHESHAM

I BUCKS

I Tel: 02405 75155 Nascom Microcomputers

NM/PCW/1

I Please send me

Nascom 2 kits

I I (complete with construction article and

I extensive software manual for the monitor and

I I BASIC) at £295 plus VAT plus £1.50 p&p.

I And

3A PSUs at £29.50 plus VAT

I I plus £1.00 p&p. And

optional

I graphics ROMs at £15.00 plus VAT.

II II NAME

I II ADDRESS

I I II

III I

I ACCESS/ BARCLAYCARD NO

I

IN Ns mu ow NE mum Nit mum mom= El mum

PCW 21

WE OFFER A COMPLETE SERVICE!

When you buy a computer from us - we don't give you the box and wave goodbye.
We realise this is a major purchase for a Company and take the time to find out your requirements, design your computer system and write the software, or if you prefer to write your own, we will always be available to advise you.

You can buy a wide range of fully -documented packages - Word Processing/Purchase & Sales Ledgers/ Stock Control/Incomplete Records/Medical Systems/Teaching Programs etc.
on Microcomputers such as --

APPLE II from £750
(16K) A complete business system 48K Apple, 2 Disk Drives, VDU & Printer £2,500

MICROSTAR from
£4,950 Multi-user/Multi-task 1.2/2.4 or 4.8 mb. A complete system with 2 VDUs & Printer £7,000

We stock a full range of VDUs, Printers, Computer Stationery, Diskettes, Disk Boxes etc.

all prices ex VAT.
Come and see us to discuss your requirements and have a demonstration.
kilICIOSOLVE
Microsolve Computer Services Ltd. 125 /129 High Street, Edgware, Middlesex. Tel: 01-951 0218

ALPHA MICRO from
£9,950 From 1 to 32 terminals. From 10 mb. to 90 mb. disk storage. 16 -bit processor, Multi-user operating system.
e.g.
LOW COST PRINTERM
matrix printer £695
LEAR SEIGLER
200A matrix printer £1,650
QUME Sprint 5
daisywheel printer £2,115.

M1 junction 4 /20 mins from Central London.

BOOKS

BOOKS

BOOKS

BOOKS Our most popular titles: -
Introduction to Personal and Business Computing. £5.45 Microprocessors Chips to Systems. £7.95 Microprocessors Interfacing Techniques. £8.75 Introduction to Microcomputers Vol 0 - The Beginners Book. £5.95 Vol. 1 - Application Techniques. £6.30 Microcomputer Prime. How they work for beginners. £6.35 Z80 Microcomputer Handbook. £6.95 Z80 Assembly Language Programming. £6.95 Z80 Prog. for Logic Design. £6.30 Illustrating Basic. £2.25 How to Profit from your Personal Computer. £5.50 6502 Applications Book £8.95 Programming the 6502. £7.95 Instant Basic. The fun way to learn. £7.20 Basic Basic. One of the most widely sold. £6.50 Advanced Basic. £6.00 How to Program Micros. Assembly Language for 8080, 6800 Er 6502. £6.95
22 PCW

How to Build a Working Digital Computer. £4.60 How to Build a Computer Controlled Robot. £5.95 Peanut Butter Et Jelly Guide to Micros. £6.45
Small Computer Systems Source Book, for newcomers - practical knowledge. £6.10 Cobol with Style (proverbs) £5.40 Practice Problems in Number Systems, Logic and Boolean Algebra. £4.95 Some Common Basic Programs, 76 programs, finance maths etc. £6.45
Scelbi 6800 Gourmet Guide £7.95 Scelbi 8080 Gourmet Guide £7.95

Scelbi 8080 Standard Editor

£9.95

Scelbi 8080 Standard

Assembler £15.95

Scelbi 8080 Standard Monitor £9.95

I

The Best of Creative Comp Vol. 1 or Vol. 2 £6.95 General Ledger £10.95 Accounts Payable/Receivable £10.95 ITT 2020 Handbook Set £20.00 Cromemco Catalogue £1.00
NEW! Computer Capers. Tales of electronic thievery embezzlement and fraud! £5.95 David Lien. The BASIC Handbook. Virtually an encyclopedia! A Must! £11.50 A Colin Day. Fortran Techniques Spec. ref. to non -numerical applications. £2.25

Murray Laver. Intro to the Uses of Computers. Includes appreciation of problems computers can handle outside purely mathematics £3.50 D. W. Barron. An Introduction to the Study of Programming Language. A comparison. £2.95 Donald M. Monro BASIC. Not to be confused with J. Coan's title. A must! A bargain! £2.00
Martin Whitbread Microprocessor. Applications in Business and Industry. Must for decision makers. £10.00

'Phone in your Access/ Barclaycard No 0742-585490 or complete this
order form
Lt_

Send s.a.e. for full list. Prices correct at going to press. Add 12p insurance on books if required.
Fc Cromemco ITT 2020 appkii
TEXAS INSTRUMENTS no/corn-I

Basic Computer Games £5.50

I Please supply

Computer Quiz Book £5.45

1976 U.S. Computer Chess I Championships £6.25

I enclose:- £ Cheque/Postal Order No.

Starship Simulation £5.45 I Barclaycard/Access No.

Fun with Computers and

Name:

I

Basic £5.45 Intro. to Computers and Basic

I Address:

I

The Best of Byte £8.95

I

Datron Micro Centre, Latham House, 243 London Road,

on -

She-ffiemldoS2m4N-F.mTeisl: s074n2o-585490

ENE

I

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NOW OPEN

=4= COMPUTER WAREHOUSE

MONDAY -SATURDAY 9.30-5.30

HIGH DEFINITION 9" VIDEO MONITOR
This superb ex corn puter video monitor was originally used as an information display

DATA STORAGE MEDIUMS
RACAL CIO "Supergrade" cassettes complete with library cases , 66 p each 10 for f5.45 VERBATIM 50 soft sectored mini disks £3.45 each 10 for E31.63

Itetordnraqtaihsnsuneptsisoprlfaiocsmsykrttmoeeonrdncesotkr,b,wsmeIl,i.nlCptoieceo.wrs'sswot:,Jsee1wturq0osiuo0tstcil'upssahpm,eopcmsefloi,nebemtsarV,e,pr.mgsDofcarnicaoUienrpco'nssetptisossfro,,unorsvbcoiacegafras.isoalsglseuoceersrrnmss,'s.vbk,aletismeeytslboerao+ttoynaprgrtshdee,oss,p,u,isesrainpdhseroafl

OPTO SMASH! TIL 302/MAN 7 7 segment LED readout 4k x 12 RAM static Memory card

HOW TO GET HERE

on large computer systems. It features all silicon electronics,
attractive style,
housed in shatterproof two colour A.B.S. case with controls under flap. 240v opera Lion, 625 lines, 75 or 50 ohm composite video input 50 hz 20 mhz frequency response. Supplied complete in good condition but untested and unguaranteed.

Connect direct to your M.P.U. at only rA 7 .50

Supplied complete with circuit.

L.'" ORO £6.00

common anode direct drove (via resistors) from 7447 f1-10 each TIL 119/0072 Darlington opto isolator 3 for £1-00.
TIL305 0.3 7 x 5 matrix LED
alphanumeric readouts £3.75 each.

PHOTO TRANSISTOR

Fairchild FPT-100 NPN silicon 30v

25ma. 4 for £1.00

I.C. A D

DISPLA

BARGAINS

TRANSISTOR

Complete 4K x 12 bit memory system on one PCB. This ex computer memory card contains

all relevant decoding, read write and control logic for coupling to your M.P.U. or mini

computer system. TTL in and out make interfacing a "cinch". We understand That by reading

the outputs correctly, the memory can be organised as a 6K a 8! Features include fast 250ns

max. access time. Standard 12v, -12,5v power rails compact construction, non volatile

Original cost over £8£030., memory, data remains even when power switched oft! each, supplied complete with full data and circuit manual, at an unbelievable price of

CI .95 P.P.
Cl .75

Note: Memories are removed from working equipment but supplied untested, unguaranteed.

Victoria, London Bridge or Holborn
Viaduct to Thornton Heath.
1 minute from Thornton Heath
Station.

S.C.R.'s

SCOOP OF THE YEAR

MPU EXPERIMENTORS

NEVER CHEAPER

293001 30v 350 ma 1018 22p each 6 for 01.00

All I.C.'s and Transistors by 2M441 50v 8 amps T0220 45p each 10 for £4.00

well known manufacturers and fully

C106D1 400v 5 amps 10202 55p each 10 for f5.00

HAZELTINE H1200

POWER SUPPLY

guaranteed. No fall outs. Comprehensive data on I.C.'s 15p per type. 2N4351 N channel MOS FET.

TRIACS G.E. 12 amp 600v T0220AB 95p each 10 for £8.75 E.C.C. 16 amp 400v 105 38p each 3 for 0160

V.D.U. TERMINAL

Once again we are very pleased to offer this superb Power Supply Unit, and hope to satisfy most of our

2N4352 P channel MOS FET. 60p.each E1.00 per pair. HIGH VOLTAGE NPN POWER

A.E.I. 10 amp 400v ready mounted on 21" s 2+' heatsink f1D0 each 4 for £3.75

Due to a fantastic bulk purchase, we are

previous customers who were disappointed when we sold out due to demand, last time they were
advertised! These units may just have well been

SWITCHING transistors BVcbo 600v BVceo 500v BVebo 15v lc 5 amps Pc 125 watts H FE 60 typ ft 2.5 mhz

LOW PROFILE I.C. SOCKETS 14 O.I.I. 14p each 8 for f 1.00 16 0.1.1. Gold Plated mil. grade 22p each 6 for f 1.00

now able to offer this superb terminal at a price almost below the cost of manufac-

made for your lab., they consist of a semi -enclosed ideal invertors, etc. TO3 E1.60 each

22 D.I.L. 27p each 5 for £1.00

ture!! Features include: 12" screen, 55

chassis measuring 160mm x 120mm x 350mm containing all silicon electronics to give the following fully regulated and short circuit proof outputs of:

4 for £5.40. BF258 NPN 250v @ 200 ma 45p each 3 for £1.08.

240.11 35p each 3 tor f 1.00 OTHER GOODIES
AF279 low noise P.N.P. germanium up to 180MHZ

key TTY keyboard, full ASCII, RS232 interface, adjustable baud rate 75 to 9600,

+ 5v @ 2 amps D.C.

+ 12v @ 800ma D.C.

I.R. BSB01 2.5 amp 100v bridge rec. 32p each 4 for f1.10

12 lines x 80 characters (upgradable to

- 12v @ 800ma D.C. + 24v @ 350ma D.C. and if that's not enough a fully floating 5v output
@ 50ma D.C. which may be seriesed to give a host

P.C. mount long leads 35p each 4 for

2N4304.WN720 F.E.T. transistor 37p each 3 for 01.00

£1.08.

1.14380NISL6051 14 D.I.L. 2 watt Al amp BOp

IN4998 4 amp 100v P.C. mount diodes each 8 for £6.00

24 x 80), cursor control, lower case option, plus many other features.

of other voltages. All outputs are brought out to the front panel via miniature jack sockets and are also duplicated at the rear on short flying leads.
Units accept standard 240v AC mains input. They

long leads 14p each 10 for f1.10. LM309K + 5v 1.2 amp regulator E1.10
each 6 for £5.35. 2N1671 B unjunction 450mw 30v 48p

CA30288 DC. 120 MHZ differentiallcascode amp f 1.00 each 3 for £2.50 CA3011 20 MHZ wideband amp T099 case 65p each 2 for f 1.00

Brand new at only
£250 CAR. + VAT.R

are ex GPO and may have minor scratches on the each 3 for £1.00.

TMS3114 DUAL MOS 128 bit static shift reg. DC

front panels, they are sold untested but in good IN4004 SD4 1 amp 400v diodes 7p

2.5 MHZ £1.50 each 4 for £4.25

FULL Technical Manual available

internal condition. Our original price of £16.50 and each 18 for Cl .00.

NE555 10 for £2.55

the recent VAT increase makes these an absolute I.R. 12 amp BRIDGE RECS. 400 volt 6E424 zero voltage switch, mac SCR relay driver

snip at only f15.50 each + £2.25 P & P. Complete El .25 each.

TO5 can £1.10 each 7 for £6.50

with circuit and component list. HURRY WHILE STOCKS LAST!!

POWER DARLINGTON SCOOP! MJ1000 NPN 60v 90w B amps 103 95p each

FSA2719 8 independent diodes 154148, 15914 type in 16 O.I.L. pack 38p each 3 for f 1.00

POWER SUPPLY UNITS

HY GRADE SMOOTHING CAPS

MULLA RD - PLESSEY - MALLORY -SPRAGUE

1500mf 3300mf

100v 60p* 3300mf

40v 50p

63v 70p' lmf 600v MYLAR 28p

10,000mf 15v el T 22,000mf 16v E1.10T

100mf

250v 45p 2100mf 200v 12.501-

Ex equipment tested 1

t P.P. 40p

SEMICONDUCTOR

296385 PNP 80v 100w 10 amps T03 f 1.25 each 14.14030 NPN 60v 150w 16 amps T03 £2.25 each

FP03725 4 NPN 50v 500ma transistors in 14 D.I.L. pack 70p each 2 for f 1.00

PLESSEY EDGE STACKABLE DECADE THUMBWHEEL SWITCHES. Gold plated contacts dimensions 2" x 2" x 85p each 8 for £5.35. 28 way 0.156" double sided edge connector, easily cut £1.25 each.
AMPHENOL 51311 BNC plug 50p. 5012 BNC plug right angled 60p. C90 Audio Cassettes screw type construction 45p each 3 for E1.00. Bulbs 24v 14 watt white frosted S.B.C. 8 for f 1.00. 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

5 VOLT 2.5 AMP T.T.L. P.S.U.

Made for T.T.L. this compact ex computer systems

unit features a 10 amp transformer with D.C.

outputs of 5 volts @ 2.5 amps and 7.5 volts @

5 amps. The 5 volt output is fully regulated and

smoothed and has electronic current limiting. May

be easily moded for 5 volts @ 7.8 amps, believed

working but untested

240v A C input

£8.25 P.P. Complete with circuit

£1.60

'GRAB BAGS'
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 - BAG £2.95 100 + BAGS £5.15

round hole, ideal disco displays, scoreboards, etc. 4 for £1.10.
Xtal filters S.E. 1 QC1 1211/ B miniature low insertion loss P.C. mount. C.F. 10.7mhz with B.W. of 7.5khz 20000 imp in -out. Brand new @ £7.99.
Heavy Duty Flat Insulated Earth Braid 100-200 amp braided tinned copper in heavy clear PVC sheath 50p per metre. £6 for 15 metres + PP Cl per 15 metres.
BULGIN miniature 6 way male chassis mount socket and matching free plug 60p each, 2 for fl .10.
Red L.E.D.'s full spec. 0.2" 14p each. 10 for El .25. Dynamic Stick Mics 6000 with built in on/off switch complete with lead and min. jack plug El .15 each. 10 for E10.00.

KEYBOARD

-111

-

11111111111111111111111111

1111111111111111111111111

ideal equipment cooling etc.
tested, ex -equipment. 240v 50-60 HZ E6.15 + p. p. 45p 110v50-60 HZ E5.05 + p.p. 45p

ELECTRONIC COMPONENTS
0 EQUIPMENT

66% 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 all 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 14Ib £ 7.95

28Ib £13.75

561b £22.00

PLEASE ADD P + P £1.25

TO5 HEATSINKS"Thermaloy" black anodised press on aluminium finned type 18p each. 8 for £1.00.

HARDWARE PACK Don't be stuck for the right nut and bolt for the job. Pack contains B.A. Metric, Unified, Self Tap, etc. Nuts, Bolts, Screws, Washers, etc. in Brass Bronze and Steel. All steel items plated. Average contents 400-600 pieces.
£2 65 Sold by weight,
2Ib bag.

A special bulk purchase enables us to offer the above keyboard at a lowest ever price. 49 coded keys encoded into a direct TTL compatible
bit output Fiatures such as delayed strobe, 5 volt O.C. single rail operation and rollover protection make this an absolute must for the MPU constructor! Supplied complete with connection diagram and edge
"no connector, at atsiemconedhtaond test' E20 .00 + P.P. £1.60
price of only

SUPER CASED VERSION Same as above spec. but housed

1 ONLY DEC PDP8M
16k memory, auto restart, vk8 video set, serial/ parallel, printer interface etc. Perfect order. E850.00 + VAT + carriage.

'925 CVSIcrat HC6IU REQ01-V

00 1152

4*H11Z

b'C4f e'50

k33

{235
2.2:h50

in attractive two tone moulded, free standing case. Unit also includes an all TTL parallel to serial convertor Ino details)
.etc. £27.50 +P.P. £1.85
Note, super cased version matches 9 video monitor

TELETYPES KSR33 20ma loop from £150.00 ASR33 20ma loop from £275.00

'act 'Ai

,-cgtuuu

33 339 MHZ AO KHZ. ox 114.

SAE for

C1 g

12

UNIVERSAL TOROID

TRANSFORMER

Just what you have been waiting tor, made for a major electronics co.

this miniature toroidal transformer accepts 240v AC input and gives AC

as

outputs of 0)10v @ 16 amps and 2 x 0-20v @ 750ma. Intended for an

MPU supply of r-5 and and - 12s. its small physical size of only 21" x

111" and negligible hum field make it a snip at only E4.25 ' pp 60p.

ISOLATED 240v 4 AMP Et 10 AMP
SOLID STATE RELAYS
Interface your MPU etc, with the outside world made by the famous "Astralux" Co. They consist of a miniature plastic module with mounting holes containing a reed relay for isolation, choke and trim. 12-20 volts D.C. at a few milliamps enable on/off control of A.G. loads up to 10 amps) The 10 amp version should be mounted on a heatsink. 100's of uses including power control, lighting, etc, etc. Dimensions:4 amp, 11: x x;". 10 amp, 11" x x 4 amp £1.45 10 amp £2.10 complete with circuit

ELECTRONICS
Dept. P.C.W., 64-66 Melfort Road, Thornton Heath, Surrey
Telephone: 01-689 7702
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 30p per order. Bona Fide account orders minimum 110.00. Export and trade enquiries welcome. Orders despatched same day where possible. Access and Barclaycard Visa welcome.

EFFICIENCY SMITHS

RADIAL BLOWERS

Are your hot parts sweltering? Then keep them cool

with our high efficiency radial snail type blowers. Made

by Smghs, designed for continuous use in expensive

electrdhic equipment very powerful and quiet, gives

" massive air flow to prolong component life and

reliability. Easily mounted, air apertu

2;' x Ideal linears etc.
Please state 240v or 110v operation. 50hz only.

t311 AND 14
.55

P.P. £1-1(),

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ENTERPRISES
MAIL ORDER & SHOWROOM

Room PW
8/11 Cambridge House Cambridge Road Barking, Essex, UK IG11 8NT 01-591-6511

EUROPE'S LARGEST SELECTION OF MICROCOMPUTER BOOKS, MAGAZINES AND SOFTWARE FOR THE HOBBYIST, EDUCATIONALIST, PROFESSIONAL AND RETAILER.

BOOKS

SUMMER HOLIDAY BONUS: for the purchase of 3 books or more, and paying by cheque, P.O. or cash, give yourself a 10% DISCOUNT!

Introduction to Microcomputers: by Osborne
Vo 0: Beginners Book Vo 1: Basic Concepts
Vo 2: Some Real Microprocessors (without binder) Vo 2: Some Real Microprocessors (with binder) Vo 3: Some Real Support Devices (without binder) Vo 3: Some Real Support Devices (with binder) Updating subscription (6 issues) for Vol 2 Updating subscription (6 issues( for Vol 3 Updating subscriptions for Vol 2 & 3
1 Updating issue (specify for Vol 2 or 3) 1 Binder (Specify for Vol 2 or 31

£5.95 £6.30 f18.95 E24.70 £11.95
E17.70 E18.95 E18.95 £30.00 £4.00
5.75

Microprocessors from Chips to Systems Microprocessor Interfacing Techniques Z80 Microcomputer Handbook TV Typewriter Cookbook Cheap Video Cookbook
CMOS Cookbook
IC OP -AMP Cookbook RTL Cookbook TTL Cookbook
IC Timer Cookbook
Ciarcias Circuit Cellar
First Book of KIM

£7.00 £8.75 £7.50 £7.50 £4.30
£7.50
£8.95
E4.25
£7.50
£7.50
£5.50
£7.00

6800 Programming for Logic Design
8080 Programming for Logic Design Z80 Programming for Logic Design

f6.30 £6.30 £6.30

More BASIC Computer Games
BASIC Computer Games (also see software section) What To Do After You Hit Return 8080 Galaxy Game
SUPER-WUMPUS -A game in 6800 Assembler code 6- BASIC Computer Music Computer Rage (A Board Game) Artist and Computer Games with a Pocket Calculator Games, Tricks & Puzzles for a Hand Calculator
Introduction to TRS-80 graphics
Take My Computer Please... (light hearted fiction)

£5.50 £5.00 £8.95 £6.95
£4.25
£6.75 £6.95
E3.95 £1.75 £2.49
£5.75
£3.25

Introduction to Personal and Business Computing Getting Involved with your Own Computer Buyer's Guide to Microoftware 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 plus audio cassette

£4.95 £4.75 £2.40 E5.50 £1.75 £3.95 f3.95 £6.95
£8.75

Instant BASIC
Basic BASIC
Advanced BASIC My Computer Likes Me

When I Speak in BASIC

Calculating with BASIC

Users Guide to North Star BASIC

Introduction to PASCAL

£6.95 £6.50 £6.00 £2.75 £4.95
£10.00 £3.95

Z80 Instruction Handbook 8080 Programmers Pocket Guide 8080 Hex Code Card 8080 Octal Code Card
Best of BYTE Scelbi BYTE Primer Best of Creative Computing Vol 1 Best of Creative Computing Vol 2 Best of MICRO (Issues 1-6 of Micro Magazine)
Z80 Assembly Language Programming 6502 Assembly Language Programming Microcomputer Programming 6502 6502 Applications Book 8080A/8085 Assembly Language Programming 6800 Assembly Language Programming 8080 Software Gourmet Guide and Cookbook 6800 Software Gourmet Guide and Cookbook 8080/8085 Software Design 6800 Tracer -- An aid to 6800 Programme Debugging Program Design Programming Techniques: Simulation
PIMS -A Database Management System Scelbal High Level Language + Supplements for the 8080 Basex -A Simple Language + Compiler for the 8080

E2.95
1.95
E1.95 £1.95
£8.95 £8.95 f6.95 E6.95 £5.50
£6.45 £6.45 £7.95 £7.95 £6.45 £6.45 £6.95 £6.95 £6.75 £3.95 £4.25 £4.25
£5.95 (15.00
£5.50

Accounts Payable and Accounts Receivable Payroll with Cost Accounting General Ledger
Basic Software Library. 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: ChessiMedbil/Wdproc Programs
Some Common BASIC Programs Computer Programs that Work lin BASIC) 32 BASIC Programs for the PET
8080 Standard Monitor 8080 Standard Editor 8080 Standard Assembler Special Package: 8080 Assembler, Editor, Monitor Bar Code Loader for 6800, 8080, Z80 and 6502 Tiny Assembler for 6800 Systems, Version 3.1 RA 6800 ML - An M600 Relocatable Macro Assembler LINK 68 -- An M6800 Linking Loader MONDEB -An advanced M6800 Monitor Debugger

MAGAZINES

SUMMER HOLIDAY BONUS: For the purchase of 3 Magazine back issues or more, and paying by cheque, P.O. or cash, give yourself a 10% DISCOUNT!

Magazine Subscriptions:
Subscriptions start within 3 weeks MICRO -6502 Journal 112 issues) Personal Computing (12 issues) Interface Age (12 issues) Dr Dobbs Journal (10 issues) Computer Music Journal 14 issues) Recreational Computing (6 issues) BYTE (12 issues) Creative Computing (12 issues) Kilobaud (12 issues) On Computing (6 issues)

UK Overseas

Price

Price

£12.50 £17.00 £25.00 £13.50 £11.00
£8.50 £24.50 £16.50 £21.00
£6.60

£12.50
£17.00 £25.00 £13.50 £11.00
£8.50 £24.50 £16.50
£21.00
£6.60

Magazine Beck Issues. Micro -6502 Journal Personal Computing Interface Age ROM Dr Dobbs Journal Computer Music Journal
People's Computers/Recreational Computing
BYTE
Creative Computing Calculators and Computers Kilobaud (reprints only)
73
Magazine Storage Box (Holds 121

£10.95 £10.95 £10.95
£17.50 £17.50 £26.95
£7.95 £7.95 f 32.50 E26.95
£6.30 £255 E10.10
£9.95 £9.95 f9.95 E20.00 £2.25 £6.75 £15.95 £5.50 £3.50
£1 .50
£1.95 12.95
.95 E3.75 £1.95 £2.95 £1.95 £1.95 P.O.A. £2.25 £1.25

SOFTWARE

SUMMER HOLIDAY BONUS: For the purchase of 2 or more software packages, and paying by cheque, P.O. or cash, give yourself a 10% DISCOUNT!

Computers Plus Inc., Computer Services
CP/M User Library Creative Computing Cassettes:

FMS -80 (File Management System) Demo Pack (includes manual Et demo disc) £35.00

Bidirectional driver for Diablo Hytype printers

for use on CP/M, CDOS Et IMDOS systems.

BI -DIRECT Complete System Manual only

£65.00 £15.00

40 Volumes (8" only)

£4.00 each

Pet CS -1001 Logic Games - 1 CS -1002 Number Games - 1 CS -1003 Logic Games - 2 CS -1004 Graphic Games - 1 CS -1005 Graphic Games - 2 CS -1006 Conversational Games - 1 CS -1007 Board Games - 1 CS -1008 Sport Games - 2 CS -1201 Simulations - 1

Apple II CS -4001 Space Games - 1 CS -4002 Sports Games - 1 CS -4003 Strategy Games - 1 CS -4201 CAI Programs - 1 CS -4301 Know Yourself

Exidy Sorcerer CS -5001 Graphics Games - 2

OSI Challenger 1P Et Superboard II CS -6001 Graphics Games - 3

SOL-20

Coming Soon

TRS-80

CS -2001 Games - 1 (level 1)

CS -3001 Board Games 1

CS -3002 Space Games - 3

Each of these are £6.50

CS -3033 Adventure

f12.50

CS -3201 Ecology Simulations - 1

£19.50

Creative Computing Discs:

for CP/M CS -9001 BASIC Games, Volume 1, disc 1 CS -9002 BASIC Games, Volume 1, disc 2 CS -9000 Both discs purchased together
These cost £12 each, or £20 if purchased together.

Digital Research

Operating Systems: Name

On 5" Discs

On 8" Discs

CP/M for North Star CP/M for MDS-800
CP/M on Cromemco SID MAC
TEX
DESPOOL CP/ M Manuals only TEX Manual only SID Manual only MAC Manual only DESPOOL Manual only CP/M Disc only SID Disc only MAC Disc only TEX Disc only DESPOOL Disc only

£105.00
N/A
N/A
£55.00 £55.00 £45.00 £30.00

N/A
£65 .00 £65.00 £45.00 £55.00 £45.00 £30.00

£15.00

£10.00

£10.00

£10.00

£2.00

£85.00

£45.00

£40.00

£40.00

£50.00

£50.00

£40.00

£40.00

£29.00

£29.00

Information Unlimited Inc., L.P Enterprises Micah Michael Shrayer Micropro
Northshare

WHATSIT for North Star Horizon APPLE 2, 48K APPLE 2;32K CP/M

£59.00
£72.00 £59.00 £75.00

Diablo Driver runs 300/1200 baud with autoload

For CDOS

£25.00

For CP/M

£25.00

CP/M for CDOS Users Program to Expand CP/M system to be compatable with Cromemco CDOS S /W.

£59.00

Electric Pencil A) SS II for TTY etc., b) DS II for a DIABLO
c) TRS-80 Cassette dl TRS-80 disc (on cassette)

£175.00 £215.00 £60.00 £130.00

WORD MASTER manual only TEX-WRITER Manual only WORD -STAR Manual only

£90.00 £25.00 £45.00 £15.00
£260.00 £2.00

SUPER -SORT Version 1 Version 2 Version 3 Manual only

£130.00 £106.00
£75.00
£20.00

"A Multi -User system for Northstar User's £24.00

Disc only

£22.00

Manual only

£5.00

Osborne associates Software Systems Software Works

Some Common Basic Programs for PET on cassette with book
CBASIC Disc Et Manual CBASIC Disc Only CBASIC Manual Only
On North Star Discs Inventory - 1 Inventory - 2 Mail Room Housekeeper Preventative Maintenance

f10.00 £15.00 £65.00 £70.00 £15.00
£50.00 £75.00 £50.00 f35.00 £75.00

Structured Systems Software

Manuals Only

£10.00

Accounts Receivable (Sales Ledger) Disc Er 772 Page Manual

£395.00

Accounts Payable (Purchase Ledger) Disc Et 177 Page Manual

£395.00

General Ledger (Nominal Ledger) Disc Et 150 Page Manual Inventory (Stock Control)

£480.00 T.B.A

NAD (Name Et Address System)

£50.00

QSORT (Sort Utility)

£50.00

Demo disc for SL, PL, NL, OSORT, NAD) £25.00

STOP PRESS, To be announced soon a MultiUser, Multi lashing operating System for use on Z8O Systems with a minimum RAM of 64K; maximum of 16M RAM STOP PRESS More Coming
HOW TO ORDER For Software please add £1.50 for postage and insurance (not the cassettes) plus 15% VAT.

THIS LIST CANCELS ALL PREVIOUS PRICE LISTS EFFECTIVE JULY 1979 DUE TO FL UC ruATIONS OF THE DOLLAR, PRICES SUBJECT TO CHANGE WITHOUT NO TICE

Send to address on other page Indicate Payment Method; and underline items required.

All Orders must be Prepaid Total Enclosed E

My cheque, P.O., I.M.O. is enclosed in Sterling on U.K. Bank

Charge to Barclaycard/Visa/Access/Diners/American Express

Please not our book and magazine prices include postage and packing, but not insurance, if wanted add 12p for every f 10. of books ordered. Make cheques, PO's etc. payable to:L.P.Enterprises. CREDIT CARDS accepted BARCLAYCARD VISA/ACCESS/DINERS CLUB/ AMERICAN EXPRESS Phone: 01-553 1001 for Credit Card orders (24 hr answering service)

Credit Card No Name Address
Signature

Expiry Date POSTCODE

All publications are published in U.S.A. and shipped into Britain air -freight by L.P. Enterprises. In unusual cases, processing may exceed 30 days. Prices subject to change without notice
TRADE ENQUIRIES WELCOME, CALLERS WELCOME

Great news from Heath.

WH-89 All -In -One computer. The new All -In -One computer from Heath has the power, versatility, and built-in peripherals needed to meet the demands of the business user. Intelligent' video terminal *2x Z80 microprocessors. *floppy disk storage system. *basic 16K RAM (expandable). Easy to program. Simple to operate. It is capable of a multitude of high-speed functions and speaks the language of today's most popular software.
Heath data systems

WH-14 serial printer. With a compact table -top configuration, the WH-14 is designed for a broad variety of uses in both the personal and business computing field. *5 x 7 dot matrix impact printing 096 character ASCII ''upper and lower case characters*microprocessorbased electronics. It combines speed, flexibility and ease of use with any computer providing standard RS -232 C or 20mA current loop interface connections. For complete specifications of these and all Heath Data System products contact:
Heath (Gloucester) Limited, Dept. ( ), Bristol Road, Gloucester, GL2 6EE. Telephone: (0452) 29451.

New Low -Cost ASCII Keyboards

Ex Stock Delivery BALLMIRATELVIDEOMONITOR

DIGITRONICS PAPER TAPE PUNCH

ALL THE ABOVE KEYBOARDS

ARE FULLY TTL-COMPATIBLE PROVIDING THE FULL 128 ASCII CHARACTER SET, AND REQUIRING +5V -12V POWER SUPPLY. FULL TECHNICAL

DATA AND CIRCUIT DIAGRAMS SUPPLIED.

K6771 71 Keystations

Mail Optional Extras:

incorporating

Order KB15P Edge

separate numeric/

Total Connector

£3.25

cursor control pad

KB701 Plastic

and installed in a

Enclosure

£12.50

custom built steel

KB702 Steel Enclosure £25.00

enclosure

£95.00 £115.00 KB710 Numeric Pad £8.00

KB756 56.keystations,

KB2376 Spare ROM

mounted on PCB

£49.50 £58.65 Encoder

£12.50

KB756MF, as above,

DC -5I2 DC/DC

fitted with metal

Converter

£7.50

mounting frame for

25 -Way D -Type

extra rigidity

£55.00 £64.98 connector for KB771 £4.25

£4.31
£15.24 £30.48
£9.78
£14.95
£9.20
£5.46

All equipment is refurbished second -user equipment unless otherwise stated. All prices subject to carriage & VAT. Trading conditions supplied on request.

9in. diagonal P4 phosphor tube. Bandwidth 12MHz (-3dB). Input voltage 220V 50/60Hz 24W. Output voltage + 1 SV DC (short circuit protected) + 12kV DC; 12.6V r.m.s. Separate horizontal & vertical sync. Supplied complete with high & low voltage power supplies, amplifier, and attractive moulded plastic housing including space for keyboard. Full technical manual provided.
PRICE: £95.00
(total including carriage and VAT £123.00) NEW SHUGART FLOPPY DISC DRIVES
SA400 Minifloppy - 110KB capacity, 35 tracks, transfer rate 125Kbits/sec AV access time, S50msec. Power requirements 1- 5VDC +12VDC
PRICE: £195.00
(price including carriage & VAT £235.00) SA800 Floppy - 400KB capacity. 77 tracks, transfer rate 250Kbits/sec. AV access time 260msec. Power requirements + 24DC
5VDC -5VDC
PRICE: £395.00
(price including carriage & VAT £468.00)

Solenoid -actuated unit capable of punching 5 to 8 channel tapes asynchronously. Basic punch contains 8 data, 1 sprocket and 2 transport solenoids plus end -of -tape switch. Pulse amplitude 27VDC. Very compact unit measuring only 6in. X 8in. x 5'z in , weight
£75.00 9l'2 lbs.
Model P120120 cps) (price including carriage & VAT £92.00)
£95.00 Model P135 (35 cps)
price including carriage & VAT £115.00)
RAYTHEON COSSOR UNITEL 11 VDUs BRAND NEW SURPLUS Teletype -compatible display, 15in. diagonal green phosphor tube providing 15 lines of 80 characters (upper case ASCII character set). 6 switch -selectable baud rates (110-2400). Full/half Duplex and buffered mode. Detachable keyboard, Printer port. Dual interface enabling user to select either V.24 (RS232) or 20mA current loop connections. Supplied with operator's handbook and full technical manual.
PRICE:
£295.00
(price including carriage & VAT £356.001

IBM

ELECTRONIC BROKERS LIMITED
49-53 Pancras Road, London NW I 2QB.
Telephone: 01-837 7781 Telex: 298694. Our showroom is open MON/FRI 9-1, 2-5 (2 mins. Kings Cross underground)

26 PCW

Please mention PCW when replying to advertisers - it identifies you.

Graham Knott & Jeff Orr have
now moved.... T

to new premises due to expansion to accomodate larger stock and
workshop facilities for the

A

Microcomputer user.

Our new number is

OMAP933 5511

ring us at any time for your requirements

COMPUTE SERVICES LTDR

625 TV NafiedEladWpgtoVrarapfsho£tirlc2ysP5,eceitmox. cmpHerppoatlnvieoedtnldeeaslppluricestvueVrreAs.eT

PET

Pet 8k

£550

Pet 16k

£675

Pet 32k

£795

2nd Cassette

£55

Disk Units

Computhink 400k Random and

Sequential complete. to fit 8k Pet (via

expandamem)

£795

to fit 16/32n Pet (direct fitting)

£840

Memory Expansion

24k Exandamem for Pet Interfaces

£320

Uni-direc I-EEE to RS232

£89

Bi-direc I-EEE to RS232

£140

Bi-direc 2 ported I-EEE to RS232 £175

A/D Convertors

AIM 161 16 channel A/D convertor for

Apple, Aim, Nascom etc

£130

Petset 1, AIM 161 including all interfacing

requirements for Pet, complete £166

Stack Peripherals

Stack Joystick a balanced, calibrated

unit supplied with software and

examples of use, complete

£25

New 625 Video Adaptor a vastly

improved 625 video convertor for Pet,

works extremely well

£25

Stack Page Printer Interface copies

screen contents onto 20m.a. loop

complete with software

£25

APPLE

Apple II (colour) 16k

£985

Apple -plus (b&w) 16k

£830

ITT 2020 (colour) 16k

£950

16k RAM upgrade

£85

Printer Card

£110

Communication Card

£140

High Speed Serial Card

£110

Disk Drive with DOS

£425

Extra Disk Drive

£375

Diskettes (10's)

£30

SORCEROR

Sorceror 16k

£760

Sorceror 32k

£859

AIM 65

£249.45

NASCOM

£165

KIM I

£99.95

MANUALS New Pet user manual £5

6500 Programming manual

£5

6500 Hardware manual

£5

PRINTERS Teletype 43 pinfeed RS232
friction RS232
pin and friction RS232 Anadex DP8000

£860 £885 £920 £575

Perkins Elmer Pussycat

CRT copier

£839

Also Centronics Range, Texas

Instruments, Lear Siegler

Ring us for a quote on individual models

Consumables

(All paper add £5 carriage per box)

Anadex DP8000 paper (2000 sheets) 9.5".

x 11" drop

£15

Teletype 43 pinfeed paper (2000 sheets)

12" x 11" drop

£15

8.5 inch friction roll Box 'A' quality (12 x

3.5" diam rolls)

£20

Box 'B' quality (12 x 3.5" diam rolls) £15

Box 'A' quality (6 x 5" diam rolls) £20

Box 'B' quality (6 x 5" diam rolls) £15

Cassettes

C15 cassettes, high quality tape, 5 screw

cassette cases. per 10

£4.40

Disks & Diskettes

We supply 8" and 5.25" diskettes for all

disk drives. Please state your machine

and we can give you a quotation.

e.g. Pet 2040

£30 per 10

Computhink

£30 per 10

Apple

£30 per 10

Horizon Sorceror

£30 per 10 £30 per 10

Many others in stock, both hard and soft

sectored.
Connectors

Pet User Port/I-EEE Port £1.10 each

Pet 2nd cassette Port

85p each

Hoods for User/I-EEE connectors £2.25

D.25 RS232 Connectors (State Male or

Female) D.25 Hoods
Demagnetiser

£3.00 £2.25

Curved head

£4.00

If any requirements are not listed please

ring us as we may have them in stock.

All prices are +VAT at 15% and include carriage (unless otherwise stated). Please make chemise payable to Stack Computer Services Ltd.

Stack Computer Services Ltd

290-298 DerbyRd, Bootle Liverpool 20

Please mention PCW when replying to advertisers - it identifies you.

PCW 27

NEWBEAR MAIL ORDER: 40 Bartholomew Street, Newbury, Berks. Tel: 0635 30505

NORTHERN SHOWROOM: 220-222 Stockport Road, Cheadle Heath, Stockport Tel: 061 491 2290

NEW BOOKS

Microprocessors & Microcomputers Huggins . .

£ 4.95

Computers & Commonsense . . Hunt & Shelley . £ 3.50

Business Data Systems .

. . . Clifton

.

.

. £ 5.75

Finance for the Small Business

R. Ragan . . . £ 7.20

The Best of Computer Faires Vol. 3

£ 9 50

Reducing COBOL Complexity

through Structured Programming McClure

£11.30

C Microprocessor and Microcomputer

Systems

Rao .

. £19.85

Encyclopedia of Computer Science Ralston

£48.60

Computer Approach to

Introductory College Maths. . Scalzo

/11.30

Microcomputer Handbook . . . Sippl .

. £16.15

Data Communications Dictionary . Sippl . Handbook of APL Programming . Weidmann

£16.15
£6.50

Computer Output Design . . . Wooldridge Computer Input Design . . . Wooldridge

1 9.70
£8.85

INTRODUCTORY BOOKS
Vol. 0 The Beginners Book
Vol. 1 Basic Concepts . . Vol. II Some Real Products Vol. III Some Real Support
Devices . . .
A Consumers Guide to Personal Computing

A. Osbourne A. Osbourne A. Osbourne
A. Osbourne

5.95 5.95 . £18.95
. £11.95
5 65

BASIC

Basic Basic

J. S. Coan

Advanced Basic

J. S. Coan

Illustrated Basic

D. Alcock

1 Basic with Business Applications The Users Guide to North Star Basic Rogers

Basic and the Personal Computer . Dwyer

5.00
I 5.50 £ 2.25 £ 5 56
£10.00 £10.36

MISCELLANEOUS

Microprocessors C201 . .

R. Zaks

Interfacing Techniques C207

R. Zaks

Best of Byte

Scelbi Byte Primer

A Dictionary of Microcomputing . P. Burton .

Small Computer Systems Handbook

The Cheap Video Cookbook

Lancaster .

TV Typewriter Cookbook .

Lancaster .

Active Filter Cookbook .

Lancaster .

. £ 7.50

.

7.50

£ 8 50

£ 9 95

£10.00

£ 5 10

. £ 5.10

. 1 7.50

. £ 7.50

PROGRAMMING

Top -Down Structured Programming Techniques

Assembly Level Programming

for Small Computers . . . Weller . .

How to Programme Microcomputers Barden .

6800 Programming for Logic Design A. Osbourne

8080 Programming for Logic Design A. Osbourne

8080 Assembly Language

Programming

A. Osbourne

6800 Assembly Language

Programming

A. Osbourne

GAMES 32 Basic Programs for the Pet
Chess & Computer Chess Skill in Man & Machine Basic Computer Games . . Game Playing with Computers Game Playing with Basic . .

D. Levy . P. Frey .
AHL D. Spencer D. Spencer

£12.76
£12.76 £ 6.95 £ 5.95 . £ 5.95
6.95
6.95
9 95
£ 7.16 £11.84
5.50 . £10.20
£ 4.10

M'LLT1 : ALL BOOKS ADVERTISED ARE IN STOCK AT TIME OF PRINTING. OFFICIAL ORDERS (MIN £10), ACCESS & BARCLAYCARD WELCOME.
SEND FOR COMPLETE BOOK & MAGAZINE LIST.

MicroftFacilities Hampton Hill 127 High Street 01-979 4546 Middlesex TW12 1NJ 01-9411197

MIDDLESEX &SW LONDON

As dealers for North Star Horizon and Commodore PET Microcomputers we provide a fully comprehensive service for all types of user:
* Personal * Business * Education * Industry * Scientific
We offer both a large range of software and the choice of supporting peripherals.

Software Packages
Sales Ledger Purchase Ledger General Ledger Stock Control Incomplete Records Loan Accounting Mail Order Payroll Job Costing Text Processing CP/M
Systems & Programming
A professionally experienced team of consultant analysts and programmers offer you a complete service for specifying, designing, writing and testing programs to your exact requirements. Our packages can be tailored to your needs at

very low cost. Our programmers can write in BASIC, COBOL, RPG, or FORTRAN.
Financing
In addition to purchasing, we offer you the choice of Rental, Leasing or H.P. (subject to references). Furthermore if you already have a micro system then why not ask us about part exchange. Commodore PET computers are available for hire from £4.75 per day, disks interfaces and printers are extra.

NORT STAR HORIZON
1011/0 driarlIZ
11111111111111111111111111111110111111111111111111111111111
COMMODORE PET

If you have a computer problem then ask Micro -Facilities for the solution.

Association of Independent Computer Specialists

28 PCW

Please mention PCW when replying to advertisers - it identifies you.

SEfiES I BUSINESS COMPUTER

Up to 4 Megabytes of disc -storage
64 Kilobytes of read/write memory
Choice of dot matrix or NEC correspondence quality Spinwriter printers Choice of three different VDUs.

Software
In addition to CP/M, FORTRAN, BASIC, COBOL and PASCAL we offer the uniquellnsta' software which enables tailor-made applications packages to be configured in a very short time by the computer itself! 'Insta' applications programs can be altered to suit your changing requirements at any time by operators with no knowledge of computer programming but who know what they want it to do.
If you have not seen 'Insta' software, ask for a demonstration. We promise you that you will have never seen anything that even comes close to matching it in business applications.

ptirscoia:E

14-15 BERNERS STREET, LONDON VV1R 30E
Please mention PCW when replying to advertisers - it identifies you.

Telephone 01-6361392 (4 lines)
PCW 29

32K PET

1:11=11=111M

The professional version ... some power!! Full size keyboard, easy -on -the -eye green display. Now at reduced price ...
only £725!

16., £625!

I EXIDY SORCERER Icy

User -definable graphics. Plug-in interpreter ROMs. (Basic supplied). Sophisticated Z80 system! Plug into own TV or monitor and cassette.

£790! 32K now only

16K £690!

APPLE IC
Best 6502 system! Up to 48K RAM on -board .... Plug into own colour or B/W TV & cassette.
48K only
£1130!
16K
£985!
Memory expansions, discs and printers for all above from stock.

OHIO CHALLENGER
2P
Sophisticated 6502 system!! Plug into own TV or monitor! 20K RAM. Interpreter Basic! Ex -stock, with single mini -floppy
only £1200!
with dual mini -floppies, save at
£1530!

Computerama, Department P.C. W.2., Harpers Kensington Showrooms, London Road, Bath, Avon.
Telephone (0225) 28819.

Send for free list.
Add £6 Securicor carriage and 15% VAT to above prices

Access and Barclaycard orders accepted by phone or letter, just quote number and print name and address.

WORD PROCESSOR
complete with printer for
£1195

4110
-4111111111116iP

Based on TRS-80 Level II, 12" screen, 64 characters (A4)

wide, upper/lower case, superb electric pencil software,

Anadex 8000 DOT Matrix Printer or Qume Daisy Wheel

Printer (option)

General business Software also available. To run on the

above system.

Complete with Anadex Printer, 16K

£1195

As above with Expansion Box & 48K

£1445

Qume Daisy Printer in Lieu Anadex

£995

Dual Floppy Disc Drives

f575

All orrce e< /AT

Write or phone for further details or dernonstrat,on

LONDON COMPUTER STORE
43 GRAFTON WAY Off Tottenham Crt. Rd., London W.1. 01-388 5721 OPEN 11-7 Mon -Fri 11-4 Sats.

HEAVY DUTY PRINTER
FOR
PET SWTP HORIZON APPLE
SORCERER CROMEMCO TRS-80
ANADEX D.P. 8000
80 COL. FAST 112 CPS BIDIRECTIONAL PRINTING. VERY GOOD PRINT QUALITY UPPER/LOWER CASE. £ SIGN.

COMPLETE WITH PLUGS, CABLES & 500 SHEETS OF PAPER

READY TO GO

£550 + VAT

FOR PETS, ALL ABOVE + INTERFACE

DELIVERY

EX. STOCK

Also available:

COMPLETE BUSINESS SYSTEMS £2700

DIABLO HYTERM 1620

£1800

Write or phone for further details or demonstration

LONDON COMPUTER STORE
43 GRAFTON WAY Off Tottenham Crt. Rd., London W.1. 01-388 5721 OPEN 11-7 Mon -Fri 11-4 Sats.

u P

'lease mention PCW when replying to advertisers - it identifies you.

MoI MINE OF INFORMATION LTD MoI
1 FRANCIS AVENUE, ST ALBANS AL3 6BL ENGLAND PHONE 0727 52801 TELEX 925859

RENMORE C D

1979

120pp

0 85969 292 2

OSBORNE Adam 1979 20099 0 931988 28 4

EVANS Chris

1979

256pp

() 575 02708 8

BARRON ICURNOW

1979

244pp

0 903804 42 5

0 335 00268 4

BOTHWELL IZEGVELD

NYP

198pp

0 903804 55 7

£2.50 3.50 5.50
10.00 4.00 B.50

SYBEX INC
1977
0 89588 002 4

Scientific American

1977

145pp

0 7167 0066 2

LIPPIATT Arthur

1978

192pp

0 13 044750 1

LEWIS T

1978

144pp

0 8104 5112 3

OSBORNE Adam

1979

30OPP

0 931988 26 8

OSBORNE Adam

1977

350pp

0 931988 02 0

WHITE James 1977 235pp 0 918398 22 3
WILLIS Jerry 1978 207pp 0 918398 54 4

ZAK S Rodney

1977

420pp

0 89588 001 8

2.50 1.00 4.20 4.80 5.40 5.90 5.90 8.30 6.90

LANCASTER Don

1978

256pp

0 672 21524 1

LOOFBOURROW Tod

1978

132pp

0 8104 5681 8

PEATMAN J,B

1979

544pp

0 07 085554 4

LANCASTER Don

1976

336pp

0 672 21035 5

LANCASTER Don

1977

412pp

0 672 21398 2

LESEA /ZAKS

1978

420pp

0 89588 003 2

LEVENTHAL Lance

1979

640pp

0 13 487876 0

HUNTER R P

1978

412pp

0 13 054302 3

GARRETT Patrick 1978 248pp 0 87909 035 9
KLINGMAN Edwin 1977 480pp 0 13 581413 8

OSBORNE et at 1978 1373pp 0 931988 15 2 0 931988 16 0

OSBORNE et al 1978 652pp 0 931988 18 7 0 931988 19 5

OSBORNE el al 1978/1979 Subscription
OSBORNE et al 1979/1980 Subscription

4.40
4.90
5.90
7.00
7.50
7.90
9.50
11.90
14.80
18.50
14.00 3.50 11.00 3.50 19.00 19.00 32.00 19.00 19.00 32.00

SOCIAL IMPACT
Silicon Chips and You A new British book
Running Wild: The Nest Industrial Revolution An insider's view of the future
The Mighty Micro Detailed analysis of the Computer Revolution published in conjunction with TV series The Future with Microelectronics A seminal research study sponsored by the British Government Paperback edition (not yet published) Technical Change and Employment A European study from the Science Policy Research Unit
START HERE
X1 Microprocessor Lexicon Comprehensive glossary of buzzwords
Microelectronics' A broad semi -technical introduction
Architecture of Small Computer Systems Appendices on Nova, PDP-11, M6800
Mind Appliance Home computer applications
Introduction to Microcomputers Vol 0 The Beginner's Book - second edition Minor amendments since first edition
Introduction to Microcomputers Volume 1 Basic Concepts Free Mel list of pedantic corrections Your Home Computer American introduction and market guide
Peanut Butter & Jelly Guide to Computers Despite the icky title this Is quite a reasonable introduction over a wide area C201 Microprocessors: from Chips to Systems Good starter book for electronic engineers
SYSTEMS DESIGN
Cheep Video Cookbook Design based on KIM -1
How to Build a Computer -Controlled Robot 'Mike' based on a KIM -1
Microcomputer -based Design International student edition
TTL Cookbook
CMOS Cookbook
C207 Microprocessors: Interlacing Techniques Circuits and ideas Introduction to Microprocessors Student edition Concentrates on the 8080 and 6800 Automated Process Control Systems: Concepts and hardware
Analog Systems for Microprocessors & Minicomputers Data acquisition & process control
Microprocessor Systems Design A thorough grounding and examples with ten different micros
Introduction to Microcomputers Vol 2 Some Real Microprocessors Full details & independent opinions Binder for above Holds looseleaf book & its updates
Introduction to Microcomputers Vol 3 Some Real Support Devices Full details & Independent opinions Binder for above Holds looseleaf book & its updates
Looseleal updates (8 issues) for Vol. 2 looseleal updates (6 Issues) for Vol 3 Joint updates (12 issues) for both volumes
looseleal updates (6 Issues) for Vol 2 Looseleel updates (B issues) for Vol 3 Joint updates 112 Issues) for both volumes

ALCOCK Donekl

1979

134pp

0 521 21704 0

DOERR Christine

1979

177pp

0 8104 5113 1

REVISOR John
1978 151pp 0 201 05247 4

BOSWORTH INAGEL

1977

224pp

0 574 21090 3

LIEN David
1979 360pp 0 932760 00 7

DWYER /CRITCHFIELD

1978

d38pp

0 201 01589 7

2.30 4.90 5.40 6.90 11.00 11.90

BASIC
illustrating BASIC Still the best book for beginners Spiral -bound to lie flat
Microcomputers in the Three R's A Teacher's Guide Educational use of microcomputers
Little Book of BASIC Style How to write a program you can read Reprinting
Programming in BASIC for Business A good practical introduction Irorn SRA
Basic Handbook An encyclopedia of dialects of BASIC
BASIC and the Personal Computer Well -written with plenty of examples

LEE /BEECH /LEE

1978

100pp

0 905104 03 X

AHL David (Ed)

1978

18599

0 89480 052 3

AHL David (Ed)

1979

185pp

0 916688 09 7

POOLE /BORCHERS

1978

193pp

0 931988 06 3

OSBORNE el al
1979 0 931988 25 X

POOLE/BORCHERS NYP 375pp 0 931988 24 1

POOLE Lon NYP 375pp 0 931988 23 3

OSBORNE Adam 1976 30000 0 931988 04 7
LEVENTHAL Lance 1978 400pp 0 931988 10 1
BARDEN William 1978 256pp 0 672 21549 8
°ODIN Carol Anne 1978 224pp 0 13 580985 1
LARSEN IRONY /TITUS 1979 304pp 0 672 21541 1
McCRACK EN Daniel 1978 262pp 0 201 04575 3

3.00 5.50 5.50 8.50 8.05 8.50 9.50
5.90 8.30 8.50 8.80 8.70

BASIC PROGRAMS Computer Programs that Work!
Twenty our school science programs
Basic Computer Games Over 100 popular games. Microsoft BASIC
More Computer Games Successor to 'BASIC Computer Games'
Some Common BASIC Programs Seventy six tested programs in finance, maths and statistics Some Common BASIC Programs PET Cassette
General Ledger-CBASIC Business package to run under CP/M
Accounts Payable & Accounts Receivable Written in CBASIC Business package to run under CPI M
8080 8080 Programming for Logic Design Recommended for electronics engineers
8080A /8085 Assembly Language Programming Instruction set. hints, examples and algorithms
How to Program Microcomputers Compares 8080 vs 6800 vs 6502
Microcomputer Design 8080 -oriented
8080/8085 Software Design

8.50

Guide to PL /M Programming

for Microcomputer Applications

Using the Intellec MDS

OSBORNE et al

5.90

1978 372pp

0 931988 11 X

LEVENTHAL Lance

8.90

1979 630pp

0 931988 21 7

BARDEN William

8.90

1978

304pp

0 672 21500 4

SPRACKLEN Dan & Kettle 9.50

1978

114pp

0 8104 5155 7

ZILOG CORPORATION 1979 350pp Z 03 30550 01

11.90

Z80/58000
Z80 Programming for Logic Design Reference book for engineers
Z80 Assembly Language Programming The latest in this series, packed with facts, examples and algorithms Z80 Microcomputer Handbook Recommended for those new to the 280
Sargon: A Computer Chess Program In TDL macro assembler, fully documented
58000 PLZ/ ASM Assembly Language Programming Manual Loose-leaf 3 -hole Includes Z8000 overview & full instruction set

OSBORNE Adam 1977 300pp 0 931988 05 5
LEVENTHAL Lance 1978 400pp 0 931988 12 8

6800

5.90

8800 Programming for Logic Design

Reference book for electronics engineers

6.30

6800 Assembly Language Programming

Recommended course material

Please mention PCW when replying to advertisers - it identifies you.

PCW 31

Packaged nformation recessing ystems
We offer a variety of turnkey systems based on APPLE II, CROMEMCO and ZENTEC. 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 suite of programs for a ready written package from another famous software house, such as CAP -MICROSOFT or COMPUTECH.
We can also supply three excellent DEVELOPMENT SYSTEMS, namely NASCOM, ACORN and AIM65.

All the above equipment, along with a range of peripherals, will beon display in our NEW OFFICES and SHOWROOM
P.I.P.S. Computer Services (0632) 482359. Trade enquiries welcomed. See us on Stand 16 at the PCW SHOW.

DATA BANK

(SOFTWARE SERVICES)

PROGRAMS GALORE!!

GAMES: -

EDUCATIONAL: -

Lost in Space Star Trek -1 Star Trek -2 Drag Racer Noughts & crosses
Hangman Take your poison Battleships -1 N im Spook Card Dealer Ticktactoe
Craps Space wars Pontoon 121's)
Jet flight -1 Dice thrower -1 Oil tanker Bridge hand dealer Numbers battle One armed bandit
Spies Racing car Lunar lender Mastermind -1 Spook

£8 Elementary Maths

£5

£6 Advanced Maths

£7

£8 Ele. Statistics

£5

£4 Adv. Statistics

£7

£6 Ele. Physics

£5

£4 Adv. Physics

£7

£5 Ele. Chemistry

£6

£7 Hyperbolics

£4

£4 Ele. Electronics

£5

£4 Adv. Electronics

£7

£3 Ele, Geometry

£5

£4 Adv. Geometry

£7

£5 Ele. Integration

£6

£8 Vector analysis

£6

£5

BUSINESS: -

£5 Payroll

£20

£4 Sales & Purch. Led.

£20

£6 Stock Control

£25

£4 Std. letter printer

£15

£4 Sim/Compound Int.

£10

£4 Tax depreciation

£10

£5 Bank account tally

£6

£5

MISCELLANEOUS: -

£5 Ca lender pr inter

£5

£5 Primes generator

£5

£4 Racing analysis

£25

EXIDY SORCERER, COMMODORE PEI-, APPLE II, TRS-80 and NASCOM II
S.A.E. now: for catalogue with details of over 100 programs.

Prices include Post and Package.

Cheques/Postal orders to

DATABANK
66, QUEENS ROAD, LOUGHBOROUGH LEICESTERSHIRE. LE11 1DH (Mail order only).

PRODUCTIVITY UNLIMITED
DATA PROCESSING SERVICES The Downs Austenwood Lane Gerrards Cross Bucks SL9 9DA
Telephone (02813/ 83626 Telex 847777 DELRAY G attn MANCON
MEET US AT THE PERSONAL COMPUTER WORLD SHOW
Together, on Stand 47, we'll be demonstrating the MICROSTAR 45 PLUS Multi-user, Multi -task computer system in operation with QUME and Texas printers
and TeleVideo VDU's.
COMPLETE SYSTEMS ARE AVAILABLE
FROM £7000

MEI MINI INN

-esc

--mmuniccions

32 PCW

Please mention PCW when replying to advertisers - it identifies you.

>STAN SYSTEM

The South's Premier Microcomputer Supplier.
WE SUPPLY SYSTEMS - LOOK AT THESE TYPICAL CONFIGURATIONS!

System A

32K Commodore PET + Commodore model 2040

Dual floppy drives and cable

£1610

System B

NORTH STAR HORIZON, 32K Ram, dual double

density drives, 2 serial, 1 parallel port, DOS and

BASIC, High quality Brand Name 24 x 80 char

VDU

£2155

System C
CROMEMCO System 2, 4MHz Z80, 64K Ram,
dual minifloppies, 21 connectors, 1 serial, 1 parallel printer port, CDOS 1.07 and Extended Disk Basic, High quality Brand Name VDU etc.
£2655

System D

CROMEMCO Z-2, 4MHz, 1 MEGABYTE floppy

disk storage, 64K Ram, 3 serial ports, 2 parallel

ports, CDOS 1.07 and Basic, High quality 24 x 80

char VDU

£4600

System E

CROME MCO System 3 (the "Rolls ROYCE")

64K Ram, 4MHz, 1 MEGABYTE floppy disk

storage, 1 serial and 1 parallel printer port, High

quality Brand Name 24 x 80 char VDU etc, includ-

ing CDOS and BASIC

£5130

We supply Centronics, Teletype 43 and Diablo Printers, plus the normal range of ancilliary equipment. CP/M for Cromemco and Horizon systems is available from us,
as well as Microsoft Fortran, Tex etc.
23 Cumberland Place, Southampton SO1 2BB Tel: (0703) 38740 Tues - Sats.

Please mention PCW when replying to advertisers - it identifies you.

PCW 33

AUTHORISED PET COMMODORE DEALERS
Birmingham Camden Electronics 021-773-8240
CPS (Data Systems) Ltd 021-707-3866
Taylor Wilson Systems Ltd Knowle 05645-6192
Bolton B & B Consultants 0204-26644
Bournemouth Stage One Computers 0202-23570
Bradford Ackroyd Typewriter & Adding Machine Co 0274-31835
Brentwood Direct Data Marketing Ltd 0277-229379
Bristol Bristol Computer Centre 0272-23430
Sumlock Tabdown Ltd 0272-26685
Cambridge Cambridge Computer Store 0223-68155
Cardiff Sigma Systems Ltd 0222-21515
Colchester Dataview Ltd 0206-78811
Derby Davidson Richards (Int) Ltd 0332-366803
Durham Dyson Instruments 0385-66937
Edinburgh Micro Centre 031-225-2022
Exeter A.C. Systems 0392-71718
Grimsby Allen Computers 0472-40568
Hemel Hempstead Data Efficiency Ltd 0442-57137
Hove Ainplicon Electronics 0273-720716
Leeds TIoldene Ltd 0532-459459
Liverpool Aughton Automation 051-548-6060
Cortex Computer Centre 051.263-5783
Dams Office Equipment 051-227-3301
London E2 Ragnarok Electronic Systems 01-981-2748
London EC1 Sumlock Bondain Ltd Ill 253 2447

Britain's nol micro -computer
from
commodore systems
the complete system full range of peripherals
nation-wide dealer sales and service

AUTHORISED PET COMMODORE DEALERS
London N14 Micro Computation 01-882-5104
London NW4 Da Vinci Computers 01-202-9630
London SW14 Micro Computer Centre 01-876-6609
London W5 Adda Computers 01-579-5845
London WC1 Euro Cale Ltd 01-405-3113
London WC2 TLC World Trading Ltd 01-839-3893
Manchester Cytek (UK) Ltd 061-832-7604
Executive Reprographic 061-228-1637
Sumlock Electronic Services 061-834-4233
Matlock Lowe Electronics 0629-2817
Morley, W. Yorks Yorkshire Electronic Services 0532-522181
Norwich Sumlock Bondain 0603-26259
Nottingham Betas (Systems) Lid 0602-48106
Oxford Orchard Electronic 0491-35529
Plymouth IAD Integrated Services 0752-62616
Preston Preston Computer Centre 0772.57684
Reading CSE Computers 0734-61492
Southampton Business Electronics 0703.738248
Symtec Ltd 0703-37731
Xitan Systems 1)703-38740
Sunderland Tripont Associated Systems 0783-73310
Woking PPM. Ltd Brookwood 04867801 I I
Betalect Ltd 04862-69032
Yeovil Computerbits 0935-26522
North Scotland Thistle Computers Kirkwall 0856-3140
Northern Ireland Medical & Scientific Lisburn 08462-77531

In case of difficulty contact COMMODORE SYSTEMS DIVISION 360 Euston Road, London. Tel: 01-388-5702

34 PCW

Please mention PCW when replying to advertisers - it identifies you.

MICRO COMPUTER CENTRE, 314 Upper Richmond Road West,
East Sheen, S.W.14 876 6609.
Business Specialists/Authorised Dealers for
PET

Corn puters

Standard PET with integral cassette and

calculator type keyboard. 8K bytes of memory £550.00

PET with 16K bytes of memory and large

keyboard. External cassette optional

£695.00

PET with 32K bytes of memory and large keyboard.

External cassette optional

£795.00

Printers

Whymark 201 - 20 columns complete with interface £400.00

Datac BD80 - 80 columns

£750.00

1 -way Interface

£106.00

Teletype 43 - 132 columns - Upper and

Lower Case Keyboard

£900.00

2 -way Interface

£186.00

Memories 16K Memory Extension for 2001 - 8K 24K Memory Extension for 2001 - 8K

£276.00 £337.00

Disc Drives

Compu/Think Twin Floppy Disc Drive - double

sided discs - 100K per side

£833.00

Pet Twin Floppy Disc Dual Drive including cable £815.00

Cassette Recorder

£55.00

The above prices are exclusive of VAT. All the above items are IN STOCK at time of going to press.

We stock all PET accessories and handbooks PETSOFT and PETACT Programs.

CAMBRIDGE COMPUTER STORE
We can help you select the right system for your application. Here in Cambridge your choice won't be limited we'll demonstrate as comprehensive a range of microcomputers as you'll find anywhere in the U.K.:
CROMEMCO TANDY TRS-80 COMMODORE PET
APPLE II N -S HORIZON
SORCERER
ACOR N
NASCOM-1
Stop press - dramatic reduction now in prices of TRS-8-, APPLE II and HORIZON systems. Where possible we deliver off -the -shelf to any location.
The store is open 6 days a week from 9-5.30 with demonstration systems always in operation. We offer a professional standard of advice and after -sales support and we're ready to discuss your application any time.
CAMBRIDGE COMPUTER STORE
1 Emmanuel Street, Cambridge (0223) 68155

umunifintruliff
$tevu:.:12
OUR PET PICTURE
IS NOT HERE
A Pet in the middle will galvanise this 'Computhink' disk drive and 'Anadex' printer into the finest micro based business system we know. Especially if our COMPFER software is on it! 'Hardwearing' Software. As we write quality software for many applications we look for the best in hardware. So we are: OFFICIAL PET DEALERS AREA ANADEX DISTRIBUTORS COMPUTHINK DISK DEALERS and deal in other quality equipment such as NASCOM & SWTPC.
Prices?
Well - the new adjustable Anadex printer, 80 lines per minute, 80 characters full width with self testing facility and optional plug-in PROMS for special character and mode production is now supplied by us complete with parallel interface for a new reduced price of £610. Just plug into your Pet and go! We sell the KIM at £99.95 with a purpose built sturdy and reliable power supply for £24. Seen it before? The text printed on the printer above is one of the facilities of our stock control package as seen on B.B.C's 'Look North'. We are rapidly achieving a reputation as standard setters in micro application software. Still not impressed? We have designed our own A/D converter with Fourier analysis software now in use internationally, we have a large stock of books and magazines and we have Pet interfacing to Oertling balances with software for Department of Trade standard quality regulations. IEEEEEE? Our IEEE parallel divider gives you two arms to your Pet IEEE port for £12.50 Pet Life begins at PR -40 Hard copy for £250! Using ordinary till roll paper, prints results and program listings for your Pet.
Preston Computer Centre
6 Victoria Buildings, Fishergate, Preston. Tel: 0772- 57684
All the above prices are exclusive of V.A.T. Access and Barclaycard accepted.

Please mention PCW when replying to advertisers - it identifies you.

PCW 35

U. K. Micro Supplies -SCOT LAND 03374-795

F LOPPY DISCS MICROPOLIS

1041-1 315K drive + controller Cable + BASIC, ASSEMBLER,
+ EDITOR only 1015-11 315K drive - add-on other products on application

£595.00 £395.00

DS525-10 Pack of 10 5%in. floppy disk £30.00

V. D.U.s LIER SIEGLER
ADM 3A Introductory Offer

£560.00

S100 BOARDS

SD Sales 32K Ram 375 ns Assm.+tested

£355

JADE Z80 2 mhz Assm.+tested

£140

MIKOS 15 slot Mother Board Assm.+tested £110

MIKOS 2 Parallel/2 Serial Assm. +tested

£130

MIKOS 16K Erom (No 2708's) Assm.+tested £110

MIKOS Extender Board Assm.+tested

£47

MIKOS Real time clock 2 interrupt Assm. +tested £120
\ DSEL P.S.U. Kit+8v ±16v 4A Assm.+tested £175

SOFTWARE

rCP/M for Micropolis MACRO for above
`TAILORED Software for all applications

£907 £60

PRI NTERS CENTRONICS

SYSTEMS

Centronics 779 Centronics 701 Centronics 703

£785.00 £1210.00 £1894.00

DISTRIBUTOR for SDS-200 (SD Sales) also HORIZON, CROMEMCO, DATA SYSTEM 800, 801

FULL SERVICE & BACK-UP FACILITIES AVAILABLE

Telephone for all Non -Listed items OEM & DISCOUNTS on Application

ACCESS

BARCLAYCARD

Delivery at cost - Prices exclude VAT

DATA SYSTEMS SUPPLIES LTD.
SHORE HEAD ROAD, INDUSTRIAL ESTATE, NEWBURGH, FIFE, SCOTLAND.

03374-795

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Available from Adda, Nascom-2 the mighty micro kit based on cL) E El >

the powerful Z80A 4MHZ CPU and with the industry standard MICROSOFT basic in ROM. Nascom-2's 20K of on -board memory has 8K of user RAM, a 2K monitor, IK Video RAM, IK of work

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space RAM and the 8K basic ROM. To order send a completed coupon with your remittance or
phone an order quoting your Barclaycard or Access number.

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II Personal callers are of course welcome. Open 9.00 am -6.00 pm Monday -Friday. 10.00 am - 4.00 pm Saturday.
17/19 The Broadway, Ealing, London

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36 PCW

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4101C01111
PLAIN
PAPER
PRINTER

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FOR

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FEATURES

Serial RS232 interface 80 characters wide Bidirectional printing 60 lines per minute 10 line print buffer
96 character ASCII set (includes upper/lower
case, $1t f)

Automatic CR/LF 81" paper Optional tractor feed
Baud rate from 110 to 9600 External signal for optional
synchronisation of baud rate

The Nascom IMP plugs straight into a Nascom 1 /2 but is usable with all other micro systems. Parallel option will be
available shortly.

ml r mum aimulo mom Emu Elm= m

. TO NASCOM MICROCOMPUTERS LTD
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PCW 37

DATRON of SHEFFIELD
for
Cromemco the ultimate name in micros

DATRON import direct from Cromemco, California. DATRON can supply Nationwide. `DATRON can provide maintenance nationally
by C.F.M. DATRON can give you the realistic prices. DATRON have in stock: -
System 2 46K £1995 System 3 32K £2995 System 3 64K £3292 DATRON have Z -2H Hard Disc coming soon. DATRONt can supply Systems 2 and 3 and Hard Disc with;Multi-User facility. DATRON easily accessible - in the centre of
the country.
Write or telephone for FREE colour brochure on System 3 or Z -2H. We use Cromemco for our own business,why not call in for a demonstration.

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38 PCW

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Volume 1 No. 2 June 1978 PCW review Research Machines 380Z/Computer in the classroom/The debut of E78 - The Europa Bus.

Volume 1 No. 3 July 1978
Buzzwords - The first A to Zzzz of computer terms/ Pattern recognition/Johann Sebastin Byte.

wor
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Volume 1 No. 6 October 1978 Minotaur - a new computer game/Computing in the Primary School/Time Tabling for schools.
Volume 1 No. 8 December 1978 Computers and Art/3-D Noughts and Crosses/Meet Mick ie the micro with the bedside manner.
Volume 1 No. 9 January 1979 Super Scamps VDU/Hexadecimal Conversion/TRS-80 Level II Basic/8-Bit Analogue input - putting your pet to work.
Volume 1 No. 11 March 1979 Turning the Tables - a program for the T157/Motorola on sixteen cylinders/The SYM 1 - Computer on a board/Unravelling the Pet Bus.
Volume 1 No. 12 April 1979 Breaking the Software Barrier with Nascom 1/A program for the Z80/Vector MZ review/The Learn Machine.

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Volume 2 No. 2 June 1979

Please send me the next 12 issues of PCW

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PCW 39

NEWSPRINT
Newsprint (now incorporating What's New) is where Guy Kewney reports the happenings of the micro world. Product news, rumours, gossip, prediction and speculation. . .read Newsprint and stay ahead of events.

A quack one?

interesting points of the boring detail. The designer

Memory aid ation Road, Burslem, Stoke-
on-Trent, Tel: Stoke 813631.

It sounds like one of those also provides preliminary

It will be visible at Compec,

old-fashioned quack cure-alls information on a similar level the Wembley show, in a Pelco

that relieves constipation,

about software and memory displayed Aim 65 system.

removes tar from teeth,

mapping.

Thank you, Vic.

dissolves kidney stones and

The really interesting bit is,

cleans your spectacles. It's how does he do it? From the

Sybextraining a £200 kit that uses either the fact that he recommends
Zilog Z80, or the Texas 9980 buying two forty -pin central

system micro, and you can pull out processor sockets, both
one chip and replace it with `multiple insertion' types at

the other, whenever you like. £7.00 extra, you can safely

My attitude is if it's true, deduce that he does not

I want one. There are few

expect to plug the chips into

enough opportunities to get a the same socket. Just as well;

cheap computer based on the it wouldn't work!

TI chip family; the least

Yet, even allowing for the

expensive I know of is a

fact that the 9980 has a

board made by a Birmingham restricted data bus only 8 bits

firm Brandauer, based on the wide, rather than the full 16 -

9900, a chip which has a full bit bus of its big brother the

16 -bit data and address bus. 9900, there are fundamental

It's really meant for the

differences between the Zilog

system builder, not the

and the Texas central

amateur (by this I mean you processors.

need an expensive terminal to For example, Texas

get anything into or out of it). provides an on -chip communi-

At the same time, there are so cations register unit which

few Texas users that I'd be gives direct serial communi-

nervous of buying a computer cations to outside teletype-

that used only that chip.. . writer devices. Can a system

where would I go for help which is built round the Z80's

when things got stuck? And need for universal asynchron-

so, the option of the much ous receiver/transmitters

more common Z80 attracts (UARTs) also accommodate

me.

a chip with a CRU output?

So much for attitude, but But hold it, you say: why

what is it we're talking about? are these questions appearing

According to the preliminary in print?. . .don't they know

specification it's a big board, the answers?

a "double double Eurocard", No, not yet. The designer

with the processor section on is one B.B. Leather of 1

one side, and the TV scanning Willow Way, Loudwater, High

circuit and keyboard interface Wycombe, Bucks HP11 1JR.

which together provide input He has no traceable telephone,

and output, on the other.

and our letter pleading for a

You can cut this side off, and chat had not reached him at

put the processor side in a press time.

standard Eurocard slot, says

By the time you read this,

the designer.

the mystery will have been

If you don't cut it off, this resolved. Watch this space!

side provides a display on a

From America, the publishing company Sybex has 'published' a computer. It costs $300, and from that you can safely deduce that in the UK it will cost quite a bit more than £150.
Making this computer, (which uses the 6502 microprocessor) different from any other 6502 micro, is the fact that it is sold as a self study training system. Packaged with the machine - it looks astonishingly like a Sym I are two books and two
cassette tapes. One book is Programming the 6502, published by Sybex, and my friend Robin Bradbeer of the North London Poly tells me it is a good book. The other is
a 6502 Applications book, also published by Sybex. On one tape, there is software, and on the other, a voice (probably human) giving instructions on how to use the board.
I'm afraid, on the basis of this information, I can't tell you why you should buy this package, rather than getting hold of the books separately, and buying a £75 Acorn which can be built up into a Eurocard system. If I hear of reasons, I'll print them. Sybex is at 2020 Milvia Street, Berkeley, California 94704.

Intel's 2118S
A memory chip from Intel just another 16K RAM, it would seem - is in fact being offered as a boon for the memory designer. The part is called the 2118, and it contains 16K bits, each addressable separately and singly. That means you need eight chips to make a useable memory for a machine with an 8 -bit data bus, and you get a minimum of 16K bytes.
What makes it special, says Intel, is "It is the first 16K by 1 (ie singly selectable bits) RAM to operate with a single 5V power supply and to offer very low levels of power with 150 mW drawn in operation and 11 mW on standby". It is voltage and pin compatible with future 64K bit RAMs , so boards designed with this will carry four times the memory - that is, at least 64K bytes - when the 64s are out. But not this year. Intel also says that this chip is designed to work with its 8202 dynamic RAM controller, which makes it as easy to use as static RAM.

standard TV, and reads from

As you were a standard typewriter qwerty
keyboard. On the TV side, it

gives 16 lines of 64 characters, with a modulator described
as 'on -board channel 36 wide band UHF'.
Data is stored on/or retrieved from an audio tape
recorder. The designer has modified the Kansas City computer users' tape standard (CUTS) to transmit in 64 byte blocks, with error checking. This is very important, although it does kill the possibility of compatibility
on software or data from other systems.

We described the Philips
MDCR as a diskette in the September issue. It is, of course, a cassette - a mini -
cassette, in fact, as Philips rep Vic Drayton has been quick to tell me. He also points out that the bare device includes only read-write and motion control circuitry; software is needed for search ability, and a bit of logic for phase enco-
ding; It is now available from two distributors: Swift Sasco
of Gatwick Road, Crawley,
tel: Crawley 28700; and

So much for the more

Tekdata Electronics of Feder-

COMPUTEACHER-
olM1(
o m p re wen -Ai
THE COMPLETE SELF -STUDY SYSTEM
NI P. LP 'V II A C. 64 W Sybex training system

40 PCW

NEWSPRINT

Tandy trick
Cramming 117,740 bytes onto a Tandy diskette with capacity for 89,600 is a trick done by software from AJ Harding (Molimerx) by the simple expedient of deciding that all the information on a Tandy diskette is BASIC (and therefore is not truly eight bit hexadecimal code, but upper case ASCII - which can all be stored in six bit codes, not eight). Together with this new product, a new word: "as with the regular system this buffer can be configurated as you wish". One can only offer sympathisement. Details from Bexhill (0424) 220391.
Floppy Power
Power supplies for floppy drives are not included in the average computer kit. You can make up one, or you can buy one, now, from HAL computers of Weybridge tel: Byfleet (09323) 45421.
Floppy PSUs
Owl's lisp
A new language? LISP is that, and costing £40 from Owl Computers it's probably a worthwhile experiment. Devotees claim that it's not so much a high level language as an assembly language for a high level machine, plus software to make your computer imitate that high level machine. Owl's version runs on the Apple II; it is supplied on disc or cassette, occupying 6K bytes of code, with a 44 page manual for a 16K byte or larger computer. Two demonstration programs are included.
It is aimed at "hobbyists who want hands on experience of the fundamental language of artificial intelligence research", amongst others. Owl is in Bishops Stortford, on 0279 52682.

Mass erase
You may never need to erase 104 programmable memory chips under ultra -violet - in fact statistics seem to show that most users of this form of read-only storage do just that - read only. Nonetheless, it may be worth your while knowing somebody who can cope with 104 at a time, because you may want to erase a u -v -e PROM that is soldered to a large board. That board will fit inside the big 100T PROM eraser now marketed by Microsystem Services. It's a fair bet that anybody who shells out the cost of a 100T will welcome the chance to recoup a bit by
running an erasing service occasionally so if we hear of a sale - to a careless manufacturer of big EPROM systems who has to call back several thousand faulty boards, - we'll let you know. Meanwhile, back to the sunray lamp and guesswork
timing...
Friends of Pascal
People take languages very seriously, and nobody likes to hear his mother tongue insulted. Not surprisingly, then, the language Pascal found itself amply provided with friends when a slightly negative comment was made by Abacus, about the package as supplied by the University of California at San Diego. (UCSD).
Oddly, Derek Rowe of Abacus was not attacking Pascal; he was announcing that it was available on a system he sells - the TEI system. Rowe's original comment was apparently designed to please Pascal freaks: he said that in the UK the demand for Pascal is very tentative, and that he found this reluctance rather disappointing.
He then blotted his copy book by warning the unwary that UCSD Pascal is not really suited for the amateur until it has been processed from its raw state into a purpose built package for a particular machine. Some exception has been taken! Those who `speak Pascal' already, long to

see others doing so too, and longer is data storage restricted

get very annoyed at anyone by the limitations of cassettes

who seems to doubt their

or small floppy disks; the

missionary zeal.

CTSS user can have many

Yet the warning is worth megabytes of online data

repeating. What Rowe was storage for instant access."

trying to say was simple: if

All of which is very largely

the inexperienced, BASIC - true. Exactly what it proves

only programmer gets hold of about the price of hobbyist

the UCSD package, he won't systems in this country is

have a clue how to select and probably unprintable. Until

tailor those portions that are things change, CTSS is on

dependant on the logical

01-590 1155.

shape of your own computer.

"Most people who are

Switch to bits looking to Pascal to give them
a step up from BASIC are not

systems programmers." Rowe A sub -miniature rotary

said, "and if they were, they encoder switch which will

wouldn't be looking to Pascal, convert its ten positions into

but to assembler. I think all a four -bit binary code from 0

serious programming should to 10 - or rather, from 0000

be done in assembler."

to 1010 - has been produced

UCSD has now handed by Impectron. You could use

over the marketing of its

it as a monitor select switch,

Pascal to Sofach, a US

or as the simplest form of

software corporation which is direct input to a system.

not required to be a non-

Alternatively you can set it so

profit outfit (UCSD was

that when it points to 5, it

having tax problems over the gives out 1100

success of Pascal, it seems). It so introduces a whole new

remains to be seen what

series of bugs! Details on

shape the product will take in 01-992 5388.

their hands, given a stronger

marketing drive. Meanwhile,

Solderless Abacus is at 62 New Cavendish
Street London W1M 7LD.

Experimenters who do not

rate their abilities as soldering

Off peak

operatives very highly will be pleased to see three `solderless

cheek?

Breadboard units' from Lektrokit: two terminal strips,

The whole basis of the micro and one distribution strip.

revolution has been the fact They have an adhesive on the

that you can have your own back, or can be screwed down

microcomputer for less

if you prefer. Details:

money than the cost of a

Reading (0734) 669116.

share in a large computer. So

it takes a special kind of

Connections nerve for a London bureau to
announce an 'off peak' time

sharing service - for hobby- Having brought Lektrokit's

ists. The bureau, Computer solderless breadboard, you

Time Sharing Services (CTSS), can also buy a kit of wires to

is prepared to let you use its connect components together.

machine for about a pound Each kit has 350 wires, comes

per hour. Quote from George in a neat box, and has fourteen

Hertz, manager of CTSS:

different lengths, insulated,

"At these prices, many

bent over, and ready to push

computer hobbyists will find into the holes.

time sharing more economi-

cal: all a user needs to get on

to our system is a terminal with an RS -232C or V24

Photo -save

interface, a modem or

Your computer has just out-

acoustic coupler, plus his

put a screen full of data onto

telephone. All this can be

a television. You know that

rented, or it can be purchased if you write it down, you will

for less cost than most hobby- acquire at least one error, and

ist computers. Yet it gives you can't afford any kind of

access to a system that is very printer. What do you do?

much more sophisticated. No Well it may seem obvious...

PCW 41

NEWSPRINT

you take a camera and photo- Hidden extras are on the posi-

graph the screen. A special tive side too: the Acorn

Polaroid camera costs £128, board can also give you a

and the supplier, John David- light pen facility.

son of GDS Ltd, will sell you

a special hood to cut out

Quest reflections, for around £150
- or he will give you free

micropad designs and let you build
your own hood. Phone Cam-

bridge (0223) 51645 for

For computer users who can't

details.

type, a hand -writing reader in

the form of an intelligent

writing pad has been announ-

Star bores?
American software for Apple
II computers is sold with a certain lack of style that makes it irresistible. Virginia
company, Soft -One, has
announced a two -volume package at $15 for each, with over a dozen programs on each volume.
But do we need things like `Clock - turn your $1200 computer into a $5 clock with this program' and 'Story Teller tells simple stories; you supply the characters and the subject matter. Each one different' and `Starwars put the computer away Luke,
and let the force be with you' and stuff? Yes? Somebody import it, then!

ced by Quest. Originally the
Datapad was a large minicomputer hidden under the table, watching the position and direction of movement of a pen on a pad. It was good, but the minicomputer cost several thousand pounds, and it didn't do anything with the information; it just turned it into the sort of output you would normally get from a keyboard.
Not surprisingly, the original Datapad did not take the world by storm. Its little brother may do. It has a microprocessor built into the pressure sensitive pad - the micro is the Texas 9900. It's a lot cheaper, and, says the
Quest subsidiary which makes it, every bit as good.

Micropad recognises the

Coloured

full English alphabet, with alpha, numeric and special

acorns

characters 'allowing for a wide tolerance in style and

A colour computer for under shape'. You need not interpret

£200 can now be put together this as implying that it will

from Acorn parts. Some may cope with a scrawl, because it

think it almost impudent of won't; there is a little display

Acorn's Chris Curry to

to show you what it thinks

announce a colour video dis- you have written, and that

play board for his £65 kit

display isn't there just for

(£75 built) and apologise for show. It makes the occasional

for the fact that it costs £88. mistake even then. The

Veterans of the hobby busi- Micropad also recognises

ness may recall, somewhat where on the form you are

wryly, that it was the PAL filling in, you have entered

colour output board which data: so if the computer is

Apple told us, here in Europe properly programmed, you

was responsible for its high can enter (say) '33' under

price compared with the US Age, '38 Bloggs Drive' under

price. (PAL is the system of address, and the machine will

colour television we have, and interpret this correctly.

it is much better than the US

system, which is NTSC -

Kits and bits that's all you need to know
to enjoy the fight).

Acorn is 'cheating' a little Kits and bits will be on show

by using the Mullard teletext at the 'kits and bits' show,

chip for colour characters and Breadboard '79 this Christ-

graphics, and there is a

mas. Last year, the first Bread-

hidden extra: £12 for a UHF board attracted several micro-

modulator board to provide computer companies despite

a signal that the aerial socket fears that it would prove to

will be able to tune in to. It's be the normal concoction of

not a lot of money, though. metal detectors and bad

42 PCW

CPS
DATA SYSTEMS
The Midlands
Micro
Sales Centre
Established by CPS to ensure that you buy the micro best suited to your particular need. During your visit you can see, and try at leisure a whole range of microcomputers.
Expert advice is always on hand to guide you through our hardware, software and back-up services.
We're Authorised Dealers for Pet, Apple, Rair and Transdata microcomputers;
Decision Data and Datac printers; and Lear Siegler terminals -all available off -the -shelf;
phone us today, to arrange your visit, or for product information
Telephone: 021-707 3866
CPS
DATA SYSTEMS
Third Floor, Arden House, 1102 Warwick Road. Acocks Green, Birmingham B2 7 6BH
A member of the CPS Group

The 'silicon chip' age is here, now, at your nearest TANDY store. TRS-80, the world's biggest selling microcomputer, is bringing high technology down to earth in shops, factories, offices, schools, laboratories and homes everywhere.
Teaching maths, storing essential information, making calculations for stock control, management accounts, financial analysis, personal finance and performing a -thousand -and -one other functions.
No prior knowledge of computing is required to operate a TRS-80 system using the comprehensive step-by-step 232 pg. users manual. Continuous computer demonstrations are featured at the stores listed below.

* TRS-80 is fully wired and tested - NOT a Kit.
* Designed and manufactured by TANDY CORPORATION.
* 'Level' refers to version of BASIC programming language offered by a particular system.
* 'K' factor relates to size of Random Access Memory and degree of program and data storage a particular system offers.
* TRS-80 is a modular system capable of expansion to suit your needs exactly. Get details of 'expansion interfaces', 'upgrades' and system capabilities from your local TANDY store.

LEVI! LOU

REGULAR PRICE
£596.85 Inc. VAT

OTT PLUS
VAT

£431.25 PLUS
VAT

REGULAR P ICE
Inc VAT

INCLUDING FREE GENERAL LEDGER PROGRAMME

SYSTEM INCLUDES

26 1162 26 1161 26 9503 26 1006 26 1141

DISK DRIVE (0) DISK DRIVE (1) DISK CONNECTOR 16k LEVEL II 16k RAM EXPANSION

INTERFACE
26 1401 LINE PRINTER

26 1301
26 1302 26 1403 26 1152 26 1103 26 310 26 2104

CONNECTOR SYSTEM DESK LINE PRINTER STAND INTERFOLD PAPER TRACTOR FEED PAPER NUMERIC KEY PAD DOS DISKETTE DISK BASIC MANUAL BLANK DISKETTES (10)

FREE WORTH £69.95 Inc VAT 26 1552 GENERAL LEDGER

REGULAR PRICE
£3,333.85 Inc VAT

Continuous computer demonstration stores
WEDNESBURY Bilston Road, (off Hollyhead Road):
021-556 6429
BRISTOL 5 Badminton Road, Downend;
0272 560234
SOUTHAMPTON Shopping centre, 3 East Street;
LEEDS 72 Merrion Centre;
0532 42520
LEICESTER Able Jack, Abbotsford Road, Humberstone Park; 0533 58011
HENDON 21 Sentinel Square, Brent Street, N.W. 1; 01-202 7331
WIMBLEDON 124-126 The Broadway, S.W. 19; 01-542 6389
SALE 13-15 The Mall Shopping Centre; 061-973 0371

TANDY
DEALER

Most items also available at Tandy Dealers. Look for this sign in your area.

Prices may vary at individual >to( es Offers subiect to availability

=PP°

Instant credit available in most cases. Access, Barclaycard and Trustcard welcome. Check your telephone directory for your nearest store.

KNOWN AS RADIO SHACK IN U.S.A. MAKERS OF THE WORLD'S BIGGEST SELLING MICROCOMPUTER TRS-80.
DY

BRINGING HIGH TECHNOLOGY DOWN TO EARTH

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NEWSPRINT

amplifiers, loved by electron- metal oxide silicon technolo-

ics experimenters. This year gy. This takes very little

the organisers, Trident

current, and makes it possible

Exhibitions, say over 90

to run quite large systems off

exhibition stands will feature a dry cell battery. It's also

"microcomputer systems,

noteworthy for having an

analysers, logic test accessor- assembler language which

ies, hi fi amplifier kits,

makes Motorola and Intel

modulators, etc, as well as a assemblers look like voice

variety of exciting construc- recognition. The advantage of

tion. .. ." (oh well, what do its fiddly assembler has always

you expect...) "kits and TV been that frighteningly effic-

games...visitors can construct ient programs could be

their own lie detectors."

written, using only a little

Trident, you should be memory.

warned, is a company with an In the days when nobody

uncanny knack of turning an could afford Cmos memory

exhibition into an astonishing to go with the Cmos proces-

success. The last one I know sor, that was an important

of was Compec (now owned advantage, and a Pascal

by IPC).

system that needed 20K bytes

At this stage, the alpha- of memory would have been

betical list shows Acorn,

meaningless for most

Commodore, Compshop,

amateurs. Now, however,

Crofton, Henry's Radio,

Cmos is much cheaper,

Lektrokit, Lotus Sound, A and even more important,

Marshall, Microdigital,

standard dynamic memory

Newbear, Transam and Vero chips are being sold that use

as the more obviously compu- as little power. All this is

ting exhibitors. The dates are good news for users of the

December 4 to 8, Tuesday to cheap Elf system, and event-

Saturday; and the location is ually, the availability of

Royal Horticultural Halls, Pascal will be reassuring to

Elverton Street, Westminster. them. Golden River is on

Bicester 44551.

Better BASIC
structure
An 'extremely advanced' version of the BASIC language, called Structured Basic, is
available from the big S100 specialist distributor, Comart. The company introduced this new software tool as a way of allowing programmers to write structured (good) programs, rather than unstructured (bad) programs. Commands such as REPEAT, WHILE, IF...THEN...ELSE..., and PROCEDURE are believed to make clear program design easier: they do not make it inevitable, however, and you can write as badly structured a program as anybody - even using Structured
Basic!

Elf prices down
Most of the items in the Elf II range have now been reduced in price. The Giant Board is £37.80, the 4K Static RAM board is £75.60, the ASCII Keyboard, £54.63 and the Kluge Prototype Board, £13.82. A video graphics board will be available soon, as will text editor, assembler and disassembler on cassette. Enquiries to HL Audio Ltd., 138 Kingsland Road, London E2 8BY (01-739 1582).

Pascal for Elf
An unusual microprocessor,
the RCA Cosmac 1802, has
acquired a Pascal system through the Bicester firm, Golden River, which special-
ises in this device. The micro is extraordinary
in many ways: chiefly there's
its use of complementary

ELF II

DIY fibre optics
Do-it-yourself fibre optics for experimenters has been announced by Burr -Brown, the analogue to digital company in Watford. Two packages are available, each with sufficient parts to form a complete link with the addition of a power supply and TTL level signals. The difference between them is speed. Details on 0923 338337.
Look alike
Could Japan have struck.at the hardest nut of all, the TRS-80? Being the most common computer in the world, a Japanese imitation makes sense, and a Matlock based company, Lowe Electronics, may have found one. They call it Genie and expect to sell it for £500 without video monitor. Supposedly, it runs all TRS-80 software.
Danish soft
Denmark's personal computer industry has software for us. From a company called Lisco Micro Data in Kolding, comes a package of languages including Focal, Tiny BASIC, and some applications, aimed at users of the 6502 microprocessor.
Gunnar List claims that his Tiny BASIC will run in 4K byte systems on Kim -1 and Sym-1 from Commodore and Synertek, with a version for the Rockwell Aim 65 due out soon. Cost is £12.30 including

tape and manuals. Focal costs more - £13.20
for the standard language interpreter, £17.60 for the extended interpreter, £4.70 for a mini manual and £9.40 for a 'user manual'. My typewriter won't cope with the subtleties of the Danish spelling, but as near as I can manage is: Lisco, Aprilvaenget 6, 6000 Kolding. The phone number is (05) 56 86 82.
From the
Centre
A British system builder has joined the long list of American names offering systems based on the standard S100 layout. This is a £3,000 machine, so isn't for the user at home unless the user happens to have a generous employer.
The company, Computer Centre, is well known for the low prices it charges (especially on components such as memory boards) so it isn't surprising that boss Peter Norman has offered a 'basic kit form version for the scientific builder' at under £1,000.
The big machine is the OEM 2, with dual diskettes storing 2 million characters of data, a full 64K bytes of internal memory, and built-in software including the well respected CP/M operating system. This will allow the user to expand his external storage to 128 million characters without confusing the computer.
The basic kit version has only one diskette drive. Computer Centre is now in Swansea, at 9 De La Beche Street, Tel: 0792 460023.
Tape basic
Very probably, most people who move from tape cassettes to diskettes could manage quite well on tape, if only the data loaded into the computer or stored out onto tape, were less liable to be wrong.
Nascom software expert Tony Rundle, now with his own company, Starbase, has added an error checking system to the way that computer handles mag tape. It comes with the new version

44 PCW

NEWSPRINT

of BASIC for the Nascom 1. . . . only the Nascom 2, when it is available, will have BASIC as standard on the board. Rundle says that he was virtually forced to design a checksum cassette handling system because there was no other way of loading an 8K byte program.
Tape Basic costs £30 from Nascom itself; Tony Rundle is prepared to help and advise from his address at Waxhouse Gate, 15 High Street, St. Albans, Herts AL3 4EH.
From Japan
Diskettes from Japan are to be marketed in this country by a new company: DRG Business Machines of Weston super -Mare. Both five inch minifloppies and full 8 -inch floppy drives are offered, data compatible on 8 -inch with IBM drives. Details of these and a controller for the 8 -inch, on 0934 415398.
Please help
Ian Litterick was astonished to find that when he was first infected with the desire to become a computer owner, there was nobody to ask about pros and cons of different systems. Ian, a consumerist by nature and by training, instantly wrote off to MPs and civil servants suggesting that here was a hole that needed to be plugged.
"If you want information on big computers," he noticed, "you go to the National Computing Centre and pay for it. But if you want information on a micro, the sort of money the NCC wants for giving help can be almost as much as the micro."
His idea is a national Micro computing Centre; and by dint of being a lot more energetic than the rest of us, he has bullied the NCC into studying the idea, and providing money for the study. The Department of Industry provides half the cost.
Litterick is compiling the informed opinions of people with informed opinions...he has even asked me, for example. That can't be good enough. So, readers, please help with advice. What has

been most lacking when you second micro to control data

were making your purchase coming in from the outside

decision? Would it help if the storage (two floppy disks)

NMCC existed and put out a thereby speeding up the whole

`preferred specification'

process.

against which you could match your requirements,
and compare prices? Send
your opinions to PCW, or, if what you have to say is too harsh for our ears, to the NCC, which is at Oxford Road, Manchester MI 7ED.

The basic system is pretty big with a full quota of memory (64K bytes) and a wide variety of output methods. It will talk to standard computer terminals
using the V24 protocol, and will drive an ordinary S100

bus from its S100 output

port. Software includes the

Pet

standard CP/M operating system, so the whole CP/M

sophistication user library should be accessible to the user. The supplier,

Pet owners usually go for the Computrade, is on Leather -

Pet in the first place because head (03723) 77374.

it has BASIC: after a while,

they start wanting to do more

sophisticated programming.

The Pet Machine Language

Guide, from Abacus Software

in Michigan (not to be

confused with Abacus

Computers in the UK) is

ANIONIPIMP tin

aimed at these ambitious

people. Cost of the guide to Superbrain 2XZ80 us Britons is $8.95.

Included are sections on

using the Pet's input and output routines, clocks and

Comma to you

timers, floating point, fixed point, ASCII number conversion routines, and other complex arithmetic functions. Payments by Visa card is
accepted; Abacus is at PO Box 7211, Grand Rapids, Mich 49510.

Comma Computers is now officially the name of Computer Marketing, the company which got itself known as a terminal supplier, and moved into micros by
selling American ICS micro
courses. News of micros with

the Comma label has been

given in the past, and the

Cash in hand

company felt that to have the same name for computer and

It's competition time, and company would 'give a clearboth Peterborough and the er, crisper image to the

National Research Develop- combined operation'. It all

ment Corporation have

arises out of Computer

thousands of pounds ready to Marketing's takeover of Micro

give away to those with bright Software systems in July; the

micro ideas. Peterborough Companies Registrar is

has a total of about £40,000 blamed for the delay in chan-

(that includes a free factory ging names.

for a year in Peterborough).

Comma managing director

There are lots of details,

George Macfarlane has

musts and must-nots, all

astounded his competitors in

available from the organisers the terminal market with

at Peterborough Council, and his willingness to stick his

at the NCC respectively.

neck out; they speak of him

in hushed tones because of

his willingness to trust Dec -

Superbrain

writer's delivery promises; no doubt they will also shake

2x Z80

their heads over his decision to sell the new Alpha Micro

Causing some interest amongst 16 -bit system.

enthusiasts with £3,000 to

He says he plans to shift

spare, is a computer that uses more than £7 million worth

two Z80 micros. The Super - of micros and terminals in

brain, as it is called, uses the just over a year, "and we are

celebrating the new name by announcing a novel microcomputer system called the Comma Copywriter". We look forward to seeing it, George, when can you bring it round?
Supermicros,
but when?
The supermicros, computers that would give us 'all the power of a middle sized minicomputer like Digital's PDP11/34, on one chip', are knocking on the door.
The most encouraging news is of Motorola's big chip, the 68000, now 'available' on an evaluation board costing £1400, The word 'available' is a wild exaggeration, of course, with around a dozen of these boards so far sold, and with the UK micro people proudly displaying chip number 1065. Obviously the machine is not yet available to just anybody, so when will it be?
The best bet, from the point of the private buyer, is that it will remain a rare beast for at least another year, maybe two. Again, from the private buyer's viewpoint, this doesn't matter a lot. The biggest restraint on any private system is not the power of the processor. It is a question of how much memory it can control - both internal, and external. The Motorola 68000 will be able to control some 24M bytes of semiconductor memory. ..that's more internal storage than most private systems have disc storage. Couple a machine of that power, with its full quota of memory - or even a quarter of it - to a big, 50M byte disc, and it will eat anything on the market for £30,000 today.
But the same could be said of the humble Intel 8080, if one were to spend a little time and ingenuity giving it memory management; with a 50M byte disc, and a virtual disc storage system, to give the appearance of having more than the maximum 64K bytes internal storage (a neat trick, and an old, well proven one), it too could eat most small business systems. The problem is not the speed at which the processor can process data, but the slowness

PCW 45

46 PCW

Strumech Engineering Electronic Developments Limited Portland House, Coppice Side, Brownhills,Walsall, West Midlands.Telephone (279)4321
Please mention PCW when replying to advertisers - it identifies you.

NEWSPRINT

with which data gets into it. A big, fast disc makes many times the difference of a big, fast processor.
That said, the signs are that inside two years, Motorola, Zilog and Intel will be able to offer chips (and support chips) with 16 -bit architectures that will be attractive to private users. Motorola's is agreed to be the biggest and best; many, however, have disagreed as to whether it was not overambitious, with its 68,000 transistors on an area of silicon measuring 246 by 281 mills. Is it just too small for today's semiconductor expertise?
The most convincing argument that says 'yes, it can be built' has just been produced by Rockwell. Rockwell had a design for a supermicro of its own; it was going to be a descendant of the 6502, and it was going to be called the Super 65. Rockwell has abandoned Super 65 in favour of taking on the 68000. In exchange for the design, it will give Motorola its bubble memory designs.
Rockwell's decision tells us two things. First, it is convinced that it can make the 68000, and so the prospect of Motorola making it itself becomes that much more tenable. (Ones and twos don't count; hundreds per day would barely be convincing.) Second, it tells us that Rockwell is equally sure that it has time to learn the recipe for the 68000 before Motorola has got it down to a fine art and can make them for $10 each.
Courses
A new micro consultancy which wishes itself to be known by personal computing enthusiasts is Microsystems Consultants...for the reason that they run courses based on the Rockwell Aim 65. The courses are approved by Rockwell agent, Pelco, in the
UK. Managing director Markus
Moser says he would like to help companies "with little or no knowledge of microprocessor applications", to get them to take the plunge and .develop ideas and projects. Moser says he is an engineer with a degree in communi-

cations, and has worked for
large companies like SCM, IBM and Data General on
mini and micro projects. For details of the courses,
ring Camberley 27417, and to take the plunge, contact Fleet 29627.

IBM on the

move

"If there were any serious

point to personal computing,

then IBM would make a per-

sonal computer." Next time

some computer industry

know-all tries to put down personal computing as some-

Sprint 5

thing for excessively open minded people - along with astrology and roulette systems - the comeback is a number: the 5105.
This machine will be announced by Christmas, and available at under £2,500 by Spring - in America at least.
So says the California market research group Creative
Strategies International (CSI) in a report costing some £500.
According to CSI, this will be the specification of the Entry Level System, or 5105
(assuming IBM doesn't change
the name to prove them wrong): that's 500 nanosecond cycle time, BASIC and monitor in read only memory, a minimum of 16K bytes memory, built-in video with 960 or 1920 character

the hobbyist, 5100 bus, although at something of a price disadvantage. Software packages could give it an edge, however, for those needing something more than the IBM badge.
Final goodie: it may have an S100 bus adaptor.
Get it right!
Last issue I said that a British Company, A J Harding (Molimerx), was responsible for Tandy software addition, Infinite Basic. How wrong I was! Freddy Nichols of Optronics (who also handles the product) tells me that in fact it was written in the States by Ron Johnson.

At our show
Showing for the first time and where else but at the 79 PCW Show? - are systems based on the Microstar 1.2 and 2.4 megabyte modules. Access Data are the appointed distributors and the two micro computer packages will have full software backup for both word and data processing. For the stand demonstration, one will
be showing the word processing capabilities of the 55cps Qume daisywheel printer, the other will be programmed for data processing using a Texas 820 dot matrix printer.
Access Data Communica-
tions are at 228 High Street Uxbridge, Middlesex.

screen, mag tape cartridge for

bulk storage and slow printer

built in. Options will include a
language called ACL in firmware, memory extensions to 64K bytes or possibly 96K bytes; diskette storage up to

soffld
Com oute

2M bytes; add on matrix

printers and software, includ-

ing word processing. A later

option may be a 5M byte

Personal Computer World is looking for a hard working

hard disc - probably a mini

Editorial Assistant to join its magazine production team.

Winchester.

For those who got lost

Candidates for the post must:

somewhere in the middle of

*be able to write good English (often in a hurry)

that, it would be a pick up

*understand the jargon/implications of micro computing

and carry home system rather like the Pet, with a printer and a better quality tape drive, possibly a little more powerful, and certainly priced

*be able to work constructively under pressure *be meticulous in his/her work *maintain a sense of humour (most of the time!)
*be keen to learn the ways of magazine journalism

at the top end of the market for what it is. The add-on list would take the price to around £10,000, for a system that would apparently
compete with others based on

Salary is negotiable... please apply by letter to: The Editors
Personal Computer World 14 Rathbone Place London W1P 1DE

PON 47

BENCH
TEST/

CHALLENGER C3 -Si

At about the time that the 6502, 6800 and Z80 were emerging as the "big three" 8 -bit microprocessors Ohio Scientific, Inc. began to advertise its solution to the problem of program portability.
This was the Challenger CHI series -a range of systems centered on a novel MPU board which contained all those microprocessors and which could therefore utilize programs written to run on any
one of the three. In designing this sytem, OSI have proved farsighted by predicting the decline in price of the actual processor chip relative to the accompanying hardware. To become really successful
however, this scheme depends on the premise that people have a large number of assembly language programs which they need to transport from system to system. In the event, the arrival
of BASIC (especially Microsoft's) and fairly widely implemented operating systems may have detracted from the original idea.
The Challenger III series offers a variety of memory sizes, peripherals and software configured around the basic board. Perhaps the most spectacular peripheral is the CD -74 74MB hard disc which comes with
the top of the line system. Also catalogued are a voice I/O board, an A/D and D/A board, a multiplexing parallel board together with more standard serial and memory expansion boards. Also on offer
are a variety of operating systems, starting with a simple DOS and graduating to a (not yet released)
multi-user multiprogramming OS. CP/M is available, as are a Word Processing Package, Data Base
Management System and a small business package. The review machine, the S1 model, was a 56K RAM, twin floppy system with a Hazeltine 1410 terminal.
Operating systems 65D, 65U, CP/M and application packages DMS (Data Base Management System) were provided on floppies together with most of the software documentation.

BY SUE EISENBACH

Hardware
The Challenger III model C3 -S1
is housed in two cases, a light
one containing the computer itself, and the other, heavier one, the disc drives. To open either box
the cover has to be unscrewed. Both boxes are well ventilated. The computer has no fan and the operating instructions state that it should be run in an air-
conditioned room with 6" clearance for ventilation. The fan in the floppy disc drive is small
and noisy; attached to the box,
for some reason it clatters when it is running.
The outstanding feature of any Ohio Scientific C3 computer is its CPU board. Called the model 510, it contains three microprocessors, the 6502A, the 6800 and the Z80. A software switching program is
on the board so that choice of
microprocessor is under program control. The PROM contains the 6502 and 6800 monitors as well
as a floppy disc bootstrap. An RS -232 port, eight parallel lines
and a clock (which supplies 4MHZ, 2MHZ and 1MHZ signals) are provided.
The memory comprises two to four OSI 520 16K static RAM
cards. The fourth is only half populated, giving a maximum of 56K (as in the review machine).
The disc controller is an OSI

during the journey. Inspection

showed that not all of the PC

boards were attached to the back -

plane of the computer. They

could have been securely

screwed down to the base of the

box but this hadn't been done.

After placing the loose boards

back onto the bus and soldering

up a few wires that had broken

off in transit I turned my atten-

tion to the VDU. It failed to

operate and investigation showed

that a board was missing. Even-

tually, once equipped with a new

VDU, the computer powered up

successfully.

I experienced two hardware

faults during testing. Firstly, the

computer didn't always clear the

memory when the reset button

was pressed and secondly, when

booting one of the CP/M discs, a

few messages appeared on the

screen and then the system crash-

470 which can support 1 or 2 single or dual headed 8" floppy
drives with soft sectored, single density recording format. Capacity varies from 230K Bytes to 290K Bytes depending on the operating system used. The disc

ed. This disc was however accessible (via the other CP/M disc) from the other drive.
My overall impression of the
hardware was of a cleverly designed MPU board enclosed in a rather fragile mainframe.

drives are Siemans FDD 120-8. There were problems arrang-

System software

ing the test. The machine came According to the sales literature,

from Computerland in Birming- there are four operating systems

ham and travelled by train and van for the Challenger III. The review

to reach me. It hadn't fared well machine was supplied with three:

48 PCW

BENCH TEST

OS -65D, OS -65U and OS-CP/M.

no documentation was provided

OS-CP/M appeared to be a stand-

for these so I could not evaluate

ard CP/M running on the Z80.

them.

The other two operating sys-

The other OSI operating system

tems were written by OSI and ran

provided, called OS -65U, is a

on the 6502. OSI do not provide

BASIC only system. In most res-

an operating system to run on the

pects it felt like OS -65D with the

6800 as the fourth (a business/

BASIC booted in. The data file

word processing system) also runs

facilities under 65D are not as

on the 6502.

comprehensive as those under

65D is OSI's simplest operating

65U. Both however have random

system. It runs on any Ohio 6502

and sequential files; in addition

disc configuration (including those

65U has indexed sequential files

of the Challenger I and II) and is

and a FIND command.

monitor type software. I was given

The two operating systems are

two versions, one with BASIC

sufficiently similar that it is sur-

and assembler, and one without.

prising that Ohio Scientific deci-

The disc without BASIC was

ded not to write one operating

designed for facilitating the execu-

system with the features of both.

tion of 6502, 6800 and Z80

machine code programs. It contains the operating system, a utilities package, I/O drivers and file handlers. The utility package provides software to use all three microprocessors. These include
switches to the 6800 and 6502

Disc drives unveiled. Notice the large opening in the back and small fan on the cover.
the documentation supplied, I could see no way of accessing disc files using the 6800. (The Z80 can access disc files under CP/M).

Basic
Each operating system came sup -
lied with a BASIC - 65D and
65U BASIC occupy 9K. This includes 8K Microsoft BASIC and 1K
of OSI add-ons (primarily file

monitors (in PROM on the MPU board), a Z80 monitor and Z80 and 6800 memory movers. For the 6800 there is also a MIKBUG simulator and 6800 LOAD and DUMP routines. MIKBUG itself cannot be executed on the C3 as it's not designed for such a large system. OSI explain how to alter MIKBUG programs for use under the OSI 6800 monitor and only provide the simulator for the execution of programs where there is no one available to do the alteration.
The utilities provided do not
shield the user from the intricacies of data or processor transfers. To load 6800 or Z80 programs from disc the 65DOS must be entered, the utilities loaded, the program

The second 65DOS disc supplied booted in BASIC along with the operating system. The BASIC utilities supplied are not provided
with a 'LOAD and GO' facility
and have to be explicitly executed - e.g. to see the disc directory one types RUN "DIR", to create a file RUN 'CREATE'. There are two ways of saving a BASIC program.
The first is to exit from the
BASIC system and then PUT the program onto a specifically named track (overwriting anything that
might be there) and return to
BASIC. The second method is to create a file before typing in any program. When creating the file
its size must be declared and, unlike the previous method, the new file will be placed in free

handling). The CP/M BASIC
occupies 19K and is a slightly
pared down version of 20K (Altair) Microsoft BASIC. Micro-
soft's BASICs are the industry standard and are upwardly com-
patible. Unfortunately OSI's file handling facilities are not the same as those written by Microsoft. The BASICs running under 65D and CP/M have comparable features (using different instructions) while 65U's are more sophisticated. The Data Base
Management is written in 65U BASIC and utilizes its indexing instructions. For those readers with Pet experience 65D and
65U BASIC should seem familiar. In fact PET BASIC is easier to use with its screen editing.

loaded and then the switch to space. The user then types in a 65U BASIC contains a FLAG

the appropriate processor made. program and saves it in the usual command which enables or dis-

To save programs they must first manner. If the program is larger ables a variety of system features,

be moved out of the way of the than the space allocated, nothing primarily error traps. Although

DOS, control switched back to the will be saved. In addition to the there is no PRINT USING state-

6502, 65DOS booted in and BASIC this 65DOS disc had an ment there is money mode out-

finally the program saved. From editor/assembler. Unfortunately put, which rounds to two decimal

TECHNICAL DATA
CPU(S):

6502A 2MHZ, 68B00 2MHZ, (Sic) Z80 4MHZ.

places with either left or right
,justification. File handling comprises: OPEN, CLOSE, PRINT%, INPUT%, INDEX and FIND. The

MEMORY:

32K - 56K STATIC RAM

INDEX is a pointer to a record

KEYBOARD:1 SCREEN: CASSETTE: DISC DRIVES:

HAZELTINE 1410 N/A 2 DRIVES, 1 OR 2 HEADS PER DRIVE,

in an open file which can be
examined and altered. FIND
searches from the current posi-

8" DISCS, SINGLE DENSITY.

tion of INDEX through the rest

PRINTER: BUS: PORTS: SYSTEM SOFTWARE:

N/A OSI 48 -LINE BUS 1 SERIAL, 1 PARALLEL, EXPANDABLE. OS -65D, OS -65U, OS-CP/M, WP -1B

of the file for a given string (which
can include 'don't care' characters). If found, INDEX points to

LANGUAGES:

6502, 6800, Z80 ASSEMBLERS, BASIC,

the string; if not found it is set

EXTENDED BASIC, FORTRAN, COBOL

to 1,000,000,000.

PCW 49

BENCH
TEST/

The CP/M BASIC is a language you would expect to find on a machine in this price range. It has in line editing, PRINT USING statement, IF. . THEN. . ELSE, AUTO line number and RENUM.
I would have preferred more expansive error codes on all three
BASICs ("OM IN LN 100");
fortunately the messages are the same. The tables with the BASIC" reserved words should illustrate the differences between the languages. OSI claim that the 6502 is a superior microprocessor
. . after running the benchmark programs I don't see much between them.
Other software

CP/M BASIC with 65U & D marked U or D, B=Both

Commands: AUTO FILES NEW(B) SAVE

CLEAR LIST(B) NULL(B) SYSTEM

CONT(B) LLIST RENUM TRON

Program Statements:

DEF(B)

DEFDBL DEFINT

DIM(B)

END(B)

ERASE

GOSUB(B) GOTO(B) IF. .THEN(ELSE)

ON.. .ERROR ON...GOSUB ON. . .GOTO(B)

REM(B)

RESUME RETURN(B)

WAIT

Input/Output Statements:

CLOSE(U) DATA(B) FIELD

KILL

LINEINPUT LSET

PRINT(B)

PUT

READ(B)

Arithmetic Functions:

ABS(B)

ATN(B)

CSNG

ERL

INP

INT(B)

POS(B)

RND(B)

SQR(B)

TAB(B)

CDBL ERR LOG(B) SGN(B) USR(B)

DELETE LOAD(B) RESET TROFF

EDIT MERGE RUN(B) WIDTH

DEFSNG ERROR LET OUT STOP(B)

DEFSTR FOR(B) NEXT(B POKE(B)
SWAP PEEK(B)

GET

INPUT

NAME

OPEN(U)

RESTORE(B) RSET

CINT EXP(B) LPOS SIN(B) VARPTR

COS(B) FRE(B) SPC(B)

Because CP/M runs on it, there is a large range of software available

String Functions:

ASC(B)

CHR$(B)

HEXS

INSTR

for the Challenger III. In particu- LEFTS(B)
lar, I was provided with two SPACES

LEN STRINGS

MID (B) STR (B)

OCT$ VAL(B)

RIGHTS(B)

Microsoft compilers. . . one for 8080 Fortran IV and the second

Input/Output Functions:

EOF

LOC

for Cobol -80. As these are LOF

MKD$

MKIS

MKS$

completely standard (and good)

software packages I will not describe them.

Extensions Both

65U

65D

More interestingly, Ohio Scien- IF.. .THEN INDEX

EXIT

tific have written a comprehen- IF.. .GOTO
sive Data Base Management WAIT
System designed to run under 65U 0/S and aimed at the small

PRINT% INPUT% FIND FLAG NN PRINT $R,X

DISK KSTRINd> DISK OPEN <DEVICE>, <STRING> DISK CLOSE, <DEVICE> DISK GET, <RECORD NUMBER> DISK PUT

business -man with no computer

PRINT $L,X

experience. OS-DMS boots in the

DMS menu which is the first of DATA BASE MANAGEMENT several, the whole system being SYSTEM PROGRAMS

Benchmark

menu driven. The utilities, which Create New Master File

As well as running the Kilobaud

can be altered by the programmer, Create New Key File

benchmarks (see summary), I set

are listed in the table below and Edit Master File

up some disc tests.

show how comprehensive this Load Key File From Master

These were run under OS -65U

system is. For security, passwords Edit Key File

as Ohio Scientific state that this

can be placed on any of the pro- Dump Key File

operating system provides the best

grams in the system. Unfortunate- Generate Mailing Labels From

file accessing facilities. All the

ly, the system might cause Master File
difficulties for a person without Master File Merge or Load computer experience as most Diskette Copier

files in these tests are 100 record files with 256 character records. Each record is composed of 8

input is not checked for legality Multi -File Multi -Format Report fields (called A$ - H$ ). Tests 2

before being accepted. It is not Writer

and 4 are designed to test the

difficult (contrary to statements Multi -Conditional Report Writer "randomness" of writing to and

in the documentation) to type with Statistical Functions

reading from files. If tests 2 and

in an answer that seems reason- Multi -Conditional Statistical

4 take substantially longer to run

able - only to get "SN IN LN 75" Package

than 1 and 3 then the operating

with no obi/ious way of getting Sort a File

system is probably using a sequen-

back to the DMS system. Even Master File Record Inserter

tial method for its random access.

when inputs are checked the Master File Record Delete and

Test 1. Fill A$ - H$ with 32

user is just requested to type in Repack

"A"s each. Open a datafile; using

another response - no range of Inventory
acceptable data is offered. Before Order Entry

a FOR -NEXT loop write to
records 0 to 99; close the file.

the non computer user would feel General Ledger

Test 2. As test 1 but writing the

comfortable using this system, Personnel

records to the file starting with

routines are necessary that buffer Payroll the operator from the programs Accounts Receivable

the last record; that is the FOR -
NEXT loop's step is -1.

and a rewrite of the documenta- Accounts Payable

Test 3. Open "Datafile" using a

tion is needed.

Query

FOR -NEXT loop, read each

50 PCW

BENCH TEST

record out of the file, close the

irritating to have three different

file.

BASICs each with its own advan-

Test 4. As test 3 but reading from

tages and disadvantages.

the file starting with the last

Summary

record.

If a user either needs the large

Disc test 1

19.9

disc capacity or wants to run pro-

Disc test 2

21.9

grams on more than one micro-

Disc test 3

83.1

processor, then the Challenger III

Disc test 4

83.1 Inside the computer itself.

has possibilities. If neither of these

Business potential Benchmarks

conditions apply, then the disadvantages inherent in the Challen-

The Challenger III is designed for

CP/M

65U ger III probably outweigh its

use both as an end user system for BM1

2.3

1.7 advantages. I cannot imagine the

running application packages and BM2

7.9

13.1 purchase of this machine for the

as a development system. For BM3

21

21.6 developing or executing of 6800

either use probably its greatest BM4

21

23.7 programs. Ohio Scientific produce

selling point is its hard discs. No BM5

22.5

29.2 a less expensive range of compu-

other personal computer system BM6

37.5

39.6 ters, the Challenger II (6502

on the market offers the possibili- BM7

59.6

58.3

ty of nearly 300M bytes of on BM8

9.9

17.6

line storage. With a Challenger III, software can be designed or pur-

(processor timings in seconds)

chased for a floppy disc system and then run with hard discs as
capacity grows.

America, for an American market where business jargon is different and VAT is unheard of.

based only) for running their
system software and Data Base Management System. There are a wide variety of other machines
on the market that run under
CP/M that are less expensive, more attractive and more robust.

Business application
Looking at the Challenger III as an end user system, one ought to be able to run 6800, 6502 and Z80 packages on it. Unfortunately Ohio Scientific supply virtually no system software for running 6800

Finally, turning to the Z80, the user should experience few pro-
blems. As CP/M runs on this
microprocessor and most disc based British application packages
run under CP/M, the situation is most satisfactory.

Educational potential
I have my doubts whether the
hardware is sufficiently rugged to withstand student users. Also the
large number of cabinet vents might lead to objects, such as

code. So either 6800 system software must be purchased first to

Development System The Challenger III as a develop-

pencils, "falling into the computer". A rack mounted version

run 6800 application programs or those packages purchased must be written in machine code. In either case, as standard 6800 MIKBUG code will not execute under the

ment system follows a similar pattern. Again the lack of sys-
tems software for the 6800
makes it difficult to use. On the other hand, the Z80 under CP/M

would be more secure against such accidents.
I was told that it was a good machine for education because it allows students to use a variety

Ohio Scientific monitor, it is a gives access to a wide variety of of microprocessors. However, for

safe bet that 6800 programs will system software. Translators for the price of a C3 one can purchase

not run without the attention of
a system programmer.

BASIC, FORTRAN, COBOL, PASCAL, Z80 Assembler and

a CP/M system, a PET and a single
board 6800 computer. Although

Moving on to the 6502, Ohio 8080 Assembler are on the market this collection doesn't provide

Scientific have written three appli- together with their corresponding identical facilities, it probably pro-

cation packages. The review debugging aids.

vides those features of the C3 that

machine was only supplied with their Data Base Mangement System. It is a comprehensive package with the nice feature of optional passwords for reading and/or writing protection from unauthorized users. Unfortunately I had no difficulty in crashing (both accidentally and intentionally) DMS so any potential buyer

Looking at Ohio Scientific's own system software for the
6502 the kindest thing I can say
is that it is of uneven quality. I
have my doubts about the reliability of OS -65U. It crashed regularly throughout the period that I used it. Normally I would put this down to faulty hardware,
but the system did not crash

students would utilize, with scope for more "hands on" experience.
On the other hand, programming needs could well be met by the multi-user system with hard discs but again it is debatable, given the small BASIC, whether
several stand alone computers would not provide a more reliable installation for the money.

should expect to experience some under CP/M and on the whole

problems when it is first installed. The other two packages that Ohio

they use the same hardware. (I suppose there could have been

Documentation

Scientific supply are a Word Pro- something wrong with the 6502 The documentation provided by

cessor and a Small Business Pack- chip itself). It has a few nice Ohio Scientific Inc. was of vari-

age. Bearing in mind that Ohio features such as a password system able quality. The OS-CP/M

Scientific's software is of variable and good file handling facilities manuals (System, BASIC, FOR-

quality, I cannot recommend soft- (including indexing) under TRAN, COBOL), written primari-

ware I haven't seen. In any case, OS -65U. On the whole Ohio ly by Microsoft Inc., are thorough,

I have serious doubts about the Scientific's BASICs are less sophis- paginated, indexed and filled with

usefulness of the Small Business ticated than one would expect examples.

Package. It was designed in on a disc based system. It is also The documentation that OSI

PCW 51

BENCH/ TLST/

write themselves is more difficult to praise. Several of the manuals supplied were photocopies of preliminary versions, but even their final efforts are not impres-

market have meant that program-
mers no longer need to learn machine code in order to use a
personal computer. The overwhelming success of Microsoft BASIC,

a rather ragged feel to the package. In particular neither the OS 65D and U system software nor the overall documentation are up
to the standards currently

sive. Pages are only numbered in which the majority of applica- available in systems priced within sections and there are no tions programs are coming to be upwards of £2000. The 74M byte

indices. The manuals are both written, means that the potential hard disc system sounds promising

repetitious and incomplete. There user who wants to fully exploit but experience (with the Super are very few programming exam- the C3 system will have to become boards) leads one to expect an

ples and most of those are full- more involved with the hardware element of delay between product

sized programs that are rather than is necessary with other announcement and eventual

daunting to scan right through comparably priced systems.

availability.

for a single question of syntax. My overall impression of the PCW would like to express its OSI seem to have difficulty system was of a machine with thanks to Computerland in
in finding the appropriate level some very clever ideas. However, Birmingham and the Byte shop for each type of manual. For I have the feeling that it was rush- in Ilford for the loan of equip-

example in the documentation ed into production, thus giving ment used in this test.

for OS-DMS (the Data Management System that is "immediate-

Prices

ly usable for the untrained small businessman") there is a glossary of terms with definitions such
as: "Index - the index is the
virtual field address of an entry field, record or file". In the midst of a technical discussion about

CS -S1 C3 -OEM C3 -A C3 -B
C3 -C
520

the memory, the OSI technical writer, in an outburst of enthusiasm says, "520 memory is by
far the finest semi -conductor memory available in computing, regardless of price, considering

OS -65U OS-CP/M OS-DMS AMCAP
WP -2

32K dual floppy in 2 cases with OS -65D 32K dual floppies in 1 case 48K dual floppies, 16 slot rack OS -65U C3 -A with 74M byte hard disc C3 -A with 29M byte hard disc 16K board Centronics parallel interface board Single user With BASIC, FORTRAN and COBOL Data Base Management System
Small Business Package Word Processing Software

£2998 £2998 £4251 £9985 £7988
£ 385 £ 160 £ 200 £ 600 £ 300 £ 300 £ 300

both its superb reliability and

outstanding speed/power pro-

duct".

On the whole, I feel a little
tentative about reviewing a system whose characteristics risk

FIRST IMPRESSIONS Looks Setting up

being obscured by such documen- Ease of Use

** ** ***

tation.

HIGH LEVEL LANGUAGES

***** excellent **** very good
*** goo ** fair
poor

BASIC (Ohio)

**

Expandability

BASIC (CP/M) COBOL

Probably the largest personal FORTRAN

****
**
****

computer system advertised is the Challenger III. A C3 -S1 can be expanded to a full C3 -B system
with 768K bytes RAM, four
80M byte Winchester hard discs and 16 communication ports. Also announced is a multi-user version of 65U operating system.

PASCAL System Software PACKAGES Business Education Home PERFORMANCE

n/a ***
**** n/a n/a

MEMORY MAP UNDER 65D

DFFF 3178 2300 200 100

Source File Work Space
OS -65D
BASIC or Assembler 6502 Stack 6502 Page Zero

0

Processor

Condusion
When the Challenger III was designed, there was virtually no
software on the market. At that time, people producing software

Cassette Disc Peripherals
EXPANDABILITY Memory

n/a ****
**

MEMORY MAP UNDER CP/M

B200 A900

FDOS CCP

had to program in machine code Cassette

and so had a thorough knowledge Discs

of the operation of their micro- Bus

processor. It was a clever idea to place all the major microproces
sors on one board, so that all
available programs could be run. Unfortunately for the designers of the Challenger III system, software developments in the micro

COMPATIBILITY Hardware Software
DOCUMENTATION
VALUE FOR MONEY

TPA

** 0100 ** 0000

System Parameters & bootstrap

52 PCW

EUR
Simplicity
isthe watchword

EUROC is a new simple to use, fast, powerful microcomputer system for business. It's British, the program tried and tested.
EUROC is already being talked about by bankers, accountants and businessmen. See it on Stand 642 at the International Business Show at the National Exhibition Centre, Birmingham from 23rd October to November 1st, 1979.

at 55 High Holborn, London WC1 and at 224 Tottenham Court Road, London W1.
EUROC looks after your day books (Cash -Sales -Purchase & Nominal). EUROC keeps your ledgers (Sales -Purchase & Nominal). EUROC prints out your Statements and Remittance advices. EUROC produces 8 vital REPORTS at your month end and to ensure you enjoy complete financial control. (I.E. Aged Debtors Report, Aged Creditors Report, Name and Address Report, Sales Analysis Report, VAT Report, Profit and Loss Report, Assets and Liabilities Report, Fund Report).
In addition optional Stock Control and Payroll programs will be available.

There are no hidden extras. EUROC's price of £7,995 ex. VAT includes -

EUROC hardware is manufactured exclusively for

Hardware, Software, Initial Supply of Stationery and Binders - in fact

Euro-Calc Ltd., by Plessey Microsystems Ltd. EUROC

everything you need to computerise your business including the 1st year's Maintenance Contract - nationwide service is undertaken by Plessey

will be on permanent display at Euro-Calc's branches Microsystems Ltd.

For further information and trade -distribution enquiries,talk to Peter Ingoldby, Managing Director, Euro-Calc Ltd., 55, High Holborn, London, W.C.1., telephone 01.405 3223 or Anthony Manton, Sales Director at Tottenham Court Road on 01-636 5560.

THE 2nd

PERSONAL

COMPUTER WORLD

SHOW
1-3 November 1979 West Centre Hotel,

Lillie Road, London SW6

Last year the vote was just about unanimous. . . The
1st Personal Computer World Show stood out above all others as Britain's major micro event of the year.
Now it's 1979 and although this time far bigger guns are being aimed at PCW's position of eminence,
that in a way just makes us all the more determined to hold on to our first place. `Bigger and Better' may be a hackneyed old phrase, but we are certain it will turn out to be an entirely apt description of The 2nd Personal Com-
puter World Show. We are happy to announce
an over 50% increase in
exhibitors this year - a sure sign of the continued growth
of the micro industry.
Indeed, so heavy has been the demand for site applica-
tions, the organisers have been forced to make special arrangements with the hotel to allow late -corners' to spill over into the foyer area.
Chess will again be a major highlight. Ever popular with the forces of the media,

David Levy takes charge of the first European Microcomputer Chess Championship - and what an enthralling contest that promises to be. 'Chess -nut' or not, don't forget to come by for David's commentary of this titanic struggle between rival programs. By the way, the winning owner picks up a cheque for £1,500.
Of special interest, David Hebditch (who's also one of our Conference speakers) will be demonstrating communication between personal computers. The display will stand as the fruition of his `On the Line' series in PCW in which, issue by issue, he has taught the rudiments of this exciting new activity. Will McLuhan's concept of a
`Global Village' be finally
realised?. . . talk to David

co
54 PCW

and see what he thinks. No PCW show could ever
be complete without its accompanying 3 -day Conference and this year's forum, with its carefully structured programme of subject matter, brings together some of the most skilled and knowledgeable speakers in their fields. Essentially the Conference breaks down into three main
areas of interest. Day One caters for the businessman,
Day Two for the industrialist and Day Three, the hobbyist.
Briefly, Day One looks at a businessman's decision to buy a micro, some possible uses for it, some first hand experience from a real user and, finally, an indication of the sort of return one might expect from the investment.
Next, the Conference switches tracks to look at the uses of microprocessors in the industrial environment. . . their place on the production line, their incorporation into the products themselves, the highly work -efficient world of the industrial robot and, to
end, a session dealing with that thorny and emotive subject, the impact of micros
on labour relations. Day Three is 'hobby' day.
First of all there'll be an over-
view of the current micro
market, and that'll be followed by a look at the practicalities of dialling up other
machines. The Conference
then heads its way into the world of exotic peripherals and, to close, it strays across
the Sci-Fi/Real Science border for a close-up investigation of the innards of fun robots.
Whatever else, The 2nd

Personal Computer World
Show is intended to be a
family occasion. Usually that means, 'dad, bring along the kids and show them what it's all about'. . . in this case it probably means, 'kids, bring along your parents and show them what it's all about'!
There'll be machines on show, books and magazines
for sale, packages being demonstrated, consultants consulting, advisers advising; in fact, you name it and - if it's anything to do with
micros - it'll be there. If
you've never ever attended an exhibition like this before, The 2nd Personal Computer World Show is the one you simply cannot afford to miss. . . SEE YOU THERE!
GENERAL INFORMATION Venue: West Centre Hotel, Lillie Road, London SW6 Hours: 10:00-19:00 Thursday 1st November 10:00-19:00 Friday 2nd November. 10:00-17:00 Saturday 3rd November Admission (Show): £1.00 (advance booking), £1.50 at the door. Admission (Conference)
Thursday & Friday - £45
plus VAT
Saturday - £14, VAT inclu-
sive.
(Both the above prices include entry to the show) Access: Underground to either Earls Court or West Brompton (Beware, the latter station is closed on the Saturday). Also
buses - 30, 74 and 74b.

For telephone bookings or enquiries
call the organisersMontbuild Ltd
All exhibition and conference enquiries
to Anne Reynolds
01-486 0067

ACCESS DATA

47

COMMUNICATIONS LTD

& PRODUCTIVITY

UNLIMITED

228 High Street,

Uxbridge, Middx

0296 624887

A hardware supplier and a consultancy have teamed up to provide a complete service to the prospective micro buyer. The companies specialise in Microstar with Qume or Texas printers.

They offer business analysis advice, guidance and software packages which
they will customise if necessary or they
will write a bespoke system. They
provide hardware and software support and are planning training courses.

ACT PETSOFT & PETSOFT SOFTWARE
SUPERMARKET P.O. Box 9 Newbury, Berks 0635 201131

41 & 49

This company specialises in servicing the needs of PET users. They sell a wide variety of software packages including business, games and training. They also
sell PET peripherals and add-ons such as disc drives, memory expansion and plugin programmers tool kit.

On show will be a well -stocked PET SOFT software supermarket, demonstrations of their packages including a non-stop presentation of their PETACT business system. They will be showing their 800K PET disc drive and their new stock control system written for use with this drive.

APPLIED DATA

A9

EDUCATION SERVICES

LIMITED

Suite 504,

Albany House,

24 Regent Street,

London W1R 5AA

01-580 6361

This company specialises in educational packages designed for Apple, PET and Tandy machines.

On show will be their floppy disc based Little Genius self -instruction courses
plus BASIC courses for the various
machines.

B&B CONSULTANTS

A15

124 Newport Street,

Bolton, Lancs

0204 26644

This company sells hardware, software, support and training. They specialise in ITT 2020, Tandy, PET, Computhink and TECS equipment. They can hook up 2M Bytes disc storage to a PET if required. Their own packages include: Stock control, sales ledger, purchase ledger, nominal ledger and invoicing. A personalisation service is offered. Soft-
ware is guaranteed and a hardware
maintenance service can be provided.

At the show they will have their PET and TECS equipment running demonstration programs.

PCW 55

THE BYTE SHOP LTD

21 &

426/428 Cranbrook Rd

22

Ilford, Essex

01-518 1414

This company sells a range of hardware
and software, both off the shelf and tailor made. They sell about 20 different machines. They also provide a
software service through their sister company - Computer Aided Systems which has been in the software business for 10 years.

On show will be a number of their more substantial systems aimed at the businessman. A range of financial and business packages will be demonstrated.

CS MICROCOMPUTERS A16 460 Cowbridge Road East, Cardiff 0222 565012
This company provides hardware and software to your requirements. They cover England and Wales. Their speciality is in the North Star Horizon although they will provide other machines if required. They offer their own packages for collecting agencies, wages, stock control, sales statistics and word proces-
sing.
Meet them at the show, discuss your needs and see their hardware and soft-
ware in action.

COMPELEC ELEC-
TRONICS LTD 14/15 Berners Street, London W1
01-636 1392

31,32, 33,35,
36

This company provides both hardware and software backed up by comprehensive support services. They sell both to end users and OEMs. The packages offered are designed so that the person totally without experience can customise them in a few days. Applications are: sales ledger, nominal ledger, purchase ledger, order processing and invoicing; stock control; payroll; personal records and fixed assets. These all include 3 days training. Special business applications covered are: estate agents, insurance portfolio management and mailing
lists.

They will launch two new products at the show a 1MB,64K, VDU printer system and a word processing package which will also run their application software. They will also be showing Altair 300 systems - multiuser with
10 MB hard discs.

COMPSHOP LTD

C3

14 Station Road,

New Barnet, Herts

441 2922

This company claims to be the largest discount microcomputer store in Europe. They stock Exidy, ITT, Compukit, TRS80 and PET products. They also sell software packages from PETSOFT, A.J. HARDING and APPLE. They have a service company called Compucare.

They will be demonstrating their basic range of machines and selling COMPUKIT UK 101. They will also be demonstrating colour add-on boards for this machine. The Video 100 and Hitachi monitors will be on display.

56 PCW

COMPUTER BOOKSHOP

3

Temple House,

43-48 New Street,

Birmingham B2 4LH

021-643 4577

A wholesaler of microbooks to the
microcomputer industry, Computer
Bookshop sells books from 8 or 9 publishers. They are the sole Sybex
distributor for the UK.

A wide range will be on show including
Sybex's books and cassette courses.
They will also be bringing about 20 new books from Addison-Wesley.

3D DIGITAL DESIGN

8-9

& DEVELOPMENT

43 Grafton Way,

London W1P 5LA

01-387 7388

3D are microprocessor interfacing specialists for industrial, medical and
educational applications. They quote for custom interfacing packages which include both hardware and software.

On show will be their serial and parallel
printer interfaces for the new Sharp MZ-80K, a wide range of industrial
interfaces e.g. Analogue/Digital converters, Relay drivers and Numeric Control
tape preparation packages for PET.

DATAC LIMITED

A13

Tudor Rd, Altrincham,

Cheshire WA14 5TN

061 941 2361

Datac call themselves "The Printer People". Indeed, that is their speciality.
They also sell floppy disc drives.

They will be showing most of their printer range and flexible disc drives.
Printers on display will include: DB80 an 80 column bi-directional sprocket feed matrix impact printer; 310 series, low cost 20 column printer which can be panel mounted or free-standing; and the 240/410 series of 16,20,32 and 40 column printers.

ELECTRONIC BROKERS A5 LIMITED 49/53 Pancras Road, London NW1 2QB 01-837 7781
This company specialises in the sale of secondhand computer equipment. The equipment is fully refurbished and offered with a warranty and full service backup.
They will be showing a range of low cost ASCII keyboards and accessories, floppy disc drives, monitors, papertape
equipment and VDUs.

ENSIGN LTD

51 &

13-19 Milford Street,

52

Swindon, Wilts

0793 42615

Information not available at time of
going to press.

EQUINOX COMPUTER
SYSTEMS Kleeman House, 16 Anning Street, New Inn Yard, London EC2A 3HB 01.739 2387

45 & 46

This company sells systems to scientific, business and educational users. The systems comprise hardware and system software and they offer a country -wide back-up service. They are well used to multi-user, multitasking systems incorporating hard discs.

On show will be their Horizon series 5000 and 8000, CP/M based with 51/4" and 8" floppies, printer and VDUs. Software will include BASIC, FORTRAN, COBOL, PASCAL, ALGOL, Assemblers, Text and Word Processing.

A.J. HARDING

39

(MOLIMERX)

28 Collington Avenue

Bexhill -on -Sea

East Sussex

0424 220391

This company is one of the largest software suppliers for the TRS-80. Most of the packages are business and utility programs although they also sell some games. Their other activities include consultancy and custom design of systems.

They will be selling their more important programs at the show but, most of
all, they will be there to meet their
customers - both existing and prospec-
tive.

HEATH (GLOUCESTER)

4

LIMITED

11B Bristol Road,

Gloucester GL2 6EE

0452 29451

Two years ago in the USA this company introduced 8 -bit computer kits to hobbyists - this led to a lot of business
interest so they moved on to ready built business systems based on the 16
bit DEC 8/11.

Systems on show will be the WH89 -a 16K, 2 x Z80, integral disc plus VDU and the H8 - an 8080A based machine with an H19 intelligent VDU. A lowcost printer, the WH14 will also be on
show.

ITHACA INTERSYSTEMS 34 (UK) LTD 58 Crouch Hall Road, London N8 8HG 01.341 2447
This company provides full technical and marketing support for Ithaca dealers throughout Europe. They sell a full range of IEEE S100 boards to OEM
users.
They will be launching their DPS1 IEEE S100 mainframe computer, a PASCAL/ Z compiler, a single board computer, a
16K static RAM board and an I/O
board. In addition they will be showing a full range of 5100 boards such as Z80 CPU, EPROM, video disc controller etc. . .

KATANNA MANAGE-

54

MENT SERVICES LTD.

22 Roughtons,

Galleywood,

Chelmsford,

Essex CM2 8PF

0245 76127

This company provides complete
computer systems. They will install
packages or tailor-made systems on any equipment although they do specialise in Tandy. They provide staff training and on -going post -sale support. They also sell a number of packages - both business and pleasure.

On show will be a range of software including the Apparat NEWDOS, their own packages and Tandy Business Systems. They will also have on the stand the Modata DSC-2 with 1.14M Bytes of floppy disc storage, a Hazeltine VDU and a choice of printers.

KEEN COMPUTERS

13 -

APPLE DEALERS

18

c/o 5B The Poultry

Nottingham NG1 2HW

0602-583254

This is a network of companies comprising the Apple distributor and six dealers. They all specialise in Apple and its related hardware and software products.

They will have a 'hospitality area' at the show and will be presenting all normal Apple systems plus hard discs, speech recognition and synthesis, A/C controllers, supercolour for home TV, Business
and games software and a hardware
driven PASCAL.

L. P. ENTERPRISES
8-11 Cambridge House,
Cambridge Road, Barking, Essex IG11 8NT 01-591 6511

C10 & C12

This company distributes and retails books, magazines and microcomputer software. The software is supplied on cassette or floppy discs. Emphasis is on system software, applications and
games packages.

On show will be a wide range of products. Specific items on show will be the Wordstar word-processing system and the new Cromemco Series Three operating system. This operating system is multi-user (up to 16), multitasking for any Z80 with 64K RAM and interrupt handling facilities.

LEXICON TRANSLATORS A10 & ELECTRONICS (UK) LTD Stewartson House, 691 Seven Sisters Road, London N15 01-802 7970
This company markets the LK3000 "your personal computer". This can be used as a computer or as a terminal. Different applications are contained on plug-in modules. There are 9 different language translators (with more to come), a calculator module, a computer terminal module, a user -programmable module and information modules.
At the show they will be exhibiting all the modules, including a Winter Olympics information module containing details of previous Olympic records. This also includes a stop watch facility.

LIFEBOATASSOCIATES A3 30-32 Neal Street
London WC2H 9PS
Information not available at time of
going to press.

LONDON COMPUTER

43

STORE

43 Grafton Way

London W1P 5LA

01.388 5721

This company specialises in microcomputer based systems for business users and software houses. They market and distribute the Pegasus - a Z80 based micro built by the National Multiplex Corporation.

On show will be a 10M Byte hard disc, a 2.4M Byte quad density 8" floppy disc drive and a low cost 80 column printer suitable for PET, Apple, TRS-80 etc.. .

LYNX COMPUTERS LTD A19 Rotherglen, Gerrards Cross Road, Stoke Poges, Bucks SL2 4EJ Fulmer 2572
This company serves "software cottages" around the country. They provide Apples to system writers who, in turn, produce systems to their clients requirements. These systems are then publicised and distributed to the other cottages by Lynx. Lynx themselves are also a
consultancy.
On show will be 3 Apples. One with a daisy wheel printer attached for an embryo word processing system, another demonstrating standard commercial packages, the other demonstrating a stereo music synthesiser.

MBM (MICROCOMPUTER 38 BUSINESS MACHINES) 4 Morgan Street London E3 5AB 01-981 3993
This company is a wholesale distributor
of the entire Ohio range. They offer engineering and back-up support. They also offer software - tape and disc
based.
They will be showing the CI, CII and CIII. The CI will be cased and will include an extension board and a floppy disc drive. The CIII will come with a 29MB hard disc plus business and database software.

MEGAPALM LIMITED

Al2

"Downderry"

Halton Road

Nether Kellet,

Carnforth,

Lancs LA6 1EU

0524 73 3801

A small flexible software consultancy who cover the whole spectrum of pre and post implementation activities. They do consultancy work, systems analysis, system design and program writing especially for the first-time user. They hold dealerships in Commodore and Computhink products and software packages. They run short resi-

dential courses in programming and allied topics. They will be exhibiting a small business system at the show.

MICRO COMPUTER

25

CENTRE

314 Upper Richmond West,

London SW14

01-876 6609

This firm offers PET based systems,

either small applications for large businesses or large applications for small businesses. They offer a service from advice to designing and programming complete systems. They also sell standard packages which they are happy to customise. They supply PETs,
Computhink products and any other
PET peripherals.

On the stand they will be meeting
clients, selling their range of hardware and software and demonstrating their business package.

MICRODIGITAL LTD

A22-

25 Brunswick Street

A24

Liverpool L2 OBJ

051-227 2535

From hobbyist kits to full scale business systems they supply hardware, software,
support, books and publications. As well as selling packages they develop their own and are happy to custom build to your requirements. They also offer a hire service - the cost of which
is deducted from purchase price.

At the show will be books, a reed relay controller board for Nascom, some of their smaller systems and maybe even a surprise new computer???

MICROSOLVE COMPUTER 6 SERVICES LTD 125-129 High Street Edgware, Middx 01-951 0218
This company offers a complete service encompassing hardware and software sales. They will conduct business investigations, design systems and produce solutions. They specialise in 3 machine ranges - Apple, Microstar and Alpha Micro - plus, of course, the usual range of add-ons,VDUs, printers etc.
At the show they will be demonstrating some of their business packages.

MIKE ROSE MICROS

42

67 Nova Road,

Croydon,

Surrey CR0 2TN

01-688 6013

This company specialises in consultancy, training and programming services. They think that systems should be matched to a businessman's needs, and to this end they offer business analysis, hardware recommendations, system design, programming, an implementation service, training and full post implementation support. They will also arrange hardware support on behalf of their clients.

Meet them at the show. They will be happy to talk to prospective clients for their consultancy and training
services.

NEWBEAR COMPUTING 11 &

STORE LTD

12

40 Bartholomew Street,

Newbury, Berks RG14 5LL

0635 30505

They concentrate on the following machines: DPS1, Cromemco Series 3,
Apple, North Star Horizon, printers, VDUs etc. Software is available for all
these machines. The publication section boasts one of the biggest selections of books available. The components division sells chips, tools, kits, Jim-paks, UVEPROM erasing lamps etc.

They will exhibit all their machines, a selection of books and any tools, Vero boxes etc. that can be carried away by
visitors.

NEWTONS LABORA-

19 &

TORIES

24

123 Wandsworth High Street,

London SW18 4JB

01-870 4248

The computer division sells micros direct to end users and to OEMs. They sell their own software - order processing, invoicing, sales ledger, purchase
ledger, nominal ledger and payroll. They offer full customer support.

They will be showing a 16 bit alpha micro with dual density dual sided 8"
Shugart drives plus VDUs and a printer. They will also have 10MB and 90111E hard disc systems. They will be demonstrating their packages.

RESEARCH MACHINES

48

LIMITED

Chapel Street,

Oxford

0865 49792

A British microcomputer manufacturer, their product is the 380Z. The product is aimed at specialist markets such as research, education and the larger existing data processing user. They also
supply system software. They offer
systems and hardware support.

They will be showing 380Z based systems with a mixture of peripherals. On display will be a 1MB 8" floppy disc system, VDUs - both memory -mapped and standard, high resolution graphics with the possibility of a new colour board.

ROSTRONICS

7 &

118 Wandsworth High Street A18

London SW18

01-870 4805

They sell the Z Plus system, TRS80 and associated packages. They provide services from the initial investigation to programming plus training and full support.

On show will be their Z -Plus micro with its associated packages: Inventory, payroll, word processing, accounts receivable, and accounts payable. They will be showing the Paper Tiger printer, I/O boards, a double density, double sided disc controller and PASCAL -Z.

PERSONAL COMPUTERS 30 LTD 194/200 Bishopsgate London EC2M 4NR 01-283 3391 01-626 8121
This company is a long-established Apple distributor dealing in Apple and compatible products. These include Teksim, full size floppy disc drives, printers, analogue to digital converters and a wide range of software products.
They will have their full product range on show. Items of particular interest will be their Estate Agents software, their text processing package and the Milliken interactive medical education software.

SOFTPRINT

A8

The Vicarage, Kimpton

Nr. Hitchin, Herts

0438 832094

This company specialises in the production of tape -based magazines for the PET. They have just published issue 1 of their magazine "Lettercette".

On show they will have Softwriter -a new word processor for the PET, with full editing and format facilities.

THE SOFTWAREHOUSE 146 Oxford Streed
London W1 01.637 1587

Al &
A2

PETALECT LTD

5

33-35 Portugal Road,

Woking, Surrey

048-62 69032

Last year they started selling PETS. They specialise in technical interfaces for the PET - electronic balances, spectrophotometers, light pens and so on. . . They produce the software and implementation service to back this up. In fact they are responsible for some very complex total systems.

They sell software, Apples and periphe-
rals. They import, manufacture and distribute the software both wholesale and retail. They sell packages for
almost every popular computer, covering a range of games and business applications.
They will be exhibiting -Be Wary" -a
new game from the USA by Leo
Christopherson. They will be showing other games, including the Creative Computing range. PET, TRS-80 and Apple machines will be on the stand.

See them on the stand where they will have weighing machines hooked up to PETs, lots of laboratory equipment, bar code readers, demonstration packages and a selection of Computhink products.

RAIR LIMITED

10

30-32 Neal Street

London WC2H 9PS

01-836 4663

Information not available at time
going to press.

of

STRUMECH ENGINEER- 1&

ING LIMITED

2

Portland House,

Coppice Side, Brownhills,

West Midlands

05433 4321

This company holds the UK agency for Midwest Scientific Instruments and are European Master Distributors for Smoke Signal Broadcasting and Micro Term International Inc. They offer a wide range of machines for use in educa-

58 PCW

tion, home computing and small businesses.
On show will be a new. multi-user BASIC interpreter and a graphic capability. Many microprocessors and peripheral devices based on the 6800
will be displayed.

TANDY CORPORATION 26 -

(BRANCH) UK

29

Bilston Road,

Holyhead Road,

Wednesbury,

West Midlands

021-556 6101

Tandy are the manufacturers and suppliers of the TRS-80 computer.
They also provide a wide range of
perhipheral equipment. They will shortly open computer -only stores.

On show will be two new line printers, a voice synthesizer, a P2 Quick printer and the new TRS-80 Model II. Other items on the stand will be the TRS-80 model 1, expansion interface, printers, disc drives, system desk, software, voice synthesis peripheral and a range of books.

TRANSAM COMPONENTS A6 &

LTD

A7

12 Chapel Street,

London NW1

01.402 8137

Manufacturers and distributors of the British -designed TRITON system. They also sell firmware packages namely 7K Scientific BASIC and 8K TRAP a system development package. . They sell both wholesale and retail. Other products include components, books, connectors, cables, Ithaca products, Shugart drives and Compucolor.

3 levels of TRITON will be on show as well as Compucolor, Ithaca and Shugart drives. They will be running their home-grown software and
firmware.

V & T ELECTRONICS

23

82 Chester Road

London N19 5DZ

01-263 2735

This company sells chips, cassette play-
ers and a relocatable assembler for Nascom. With its associated software the cassette can perform high speed, bi-directional, searching at data rates of around 5K baud.

On show will be a faster cassette mechanism (30K baud). They plan to
have a cassette based BASIC which will provide the normal disc facilities but for cassette.

VERO ELECTRONICS

40

LIMITED

Industrial Estate,

Chandlers Ford,

Hants

04215 69911

This company produces a range of useful electronic equipment. Products include: Universal prototyping boards;
power supplies - including an S100 sub -rack; card housing systems; interconnection and wiring systems; instru-
ment cases; small enclosures; racks and
cabinets.

They will be displaying a wide range of their products.

13-19 MILFORD STREET, SWINDON Make more time available to

WILTSHIRE

SN1 1DW enhance the quality of your

Tel: (0793) 42615 Telex: 449703 life and improve your business

COMPUTER SALES HARDWARE SOFTWARE CONSULTANCY MEDIA STATIONERY ETC

For less than 25p an hour for just one year you can COMPUTERISE YOUR BUSINESS NOW ! EVERYTHING YOU REQUIRE TO START COMPLETE - READY TO OPERATE.
Incl. VAT, Pkg. & Delivery. Nothing extra to pay:
£2,300

MICROCOMPUTER WITH 48K RAM (Memory) DUAL DISK DRIVES (Storage up to 400K) DOS DISKETTE (Disk Operating System) BOX OF 10 BLANK DISKETTES
PRINTER WITH TRACTOR FEED BOX OF CONTINUOUS STATIONERY/LABELS
± EVERYTHING COMPLETE WITH MANUALS FREE Programs worth over £500 on Diskettes in a Library Case

comprising:

SALES/PURCHASE LEDGERS

QUOTE/ORDER/INVOICE

BANK RECONCILIATION

STOCKS / SHARES ANALYSIS

STOCK CONTROL

MAILING LIST

GAMES PACKAGE

This package illustrates how to solve many of your business problems.

They may or may not be suitable for your type of application but they will

help you develop your own software for virtually any type of business.

Worth over £500 this package is enclosed FREE.

SOFTWARE We are pleased to announce that we have been appointed
Exclusive Distributor for UK, Europe & the World for GRAMA WINTER SOFTWARE
for TRS 80, Apple, ITT 2020. Also dealer for Pet, Z80, SWTP.
Fully integrated suite of 30 complete business programs.
Usual cost of such Quality Programs would be £2500+.
Complete support, updates, NHI/Tax changes etc. Write for details.
Special introductory price ... £575 . inclusive of VAT.
CONSULTANCY Please write or telephone if you require advice on BEGINNING or EXPANDING your computer installation. Software programs customised to your requirements.
OUR BUSINESS EXISTS ON IMPROVING YOUR BUSINESS.

We are continually adding new products to our range and would be pleased to receive your enquiries. Quantity Discounts available.

TRS 80

4K Level 2

(c/w K/bd, VDU, T/Rec)

16K Level 2

(c/w K/bd, VDU, T/Rec)

OK Interface (to add printer & disk drives)

16K Upgrade kits (for k/bd or interface)

Disk Drives, single

(up to 200K)

Disk Drives, dual

(up to 400K)

Disk Drives, dual

(up to 1000K)

Disk Drives, dual

(up to 2000K)

Disk Drives, cable 2 & 4 way from

Anadex Printer, Tractor feed

Printer cable for Anadex/Centronics

ex. VAT 434.78 500.00 195.66
65.22 260.88 608.70 1173.91 1521.74
21.74 434.78
21.74

inc. VAT 500. 575. 225. 75. 300. 700. 1350. 1750. 25. 500. 25.

APPLE II ITT 2020

16K

(c/w Keybd & Palsoft ROM)

16K Upgrade kits

Disk Drive, single with cable

Printer Interface

Anadex Printer, tractor feed

Colour TV ITT 340

608.70 65.22
326.09 108.70 434.78 239.13

700. 75.
375. 125. 500. 275.

COMMODORE PET

2001-32N

(New keyboard & 32K) 673.91

775.

2040 Dual Disk Drive 343K

673.91

775.

3022 Printer with graphics

521.74

600.

Printer interface and cables, each

21.74

25.

MEDIA LIST

51/4 " Verbatim

from (Qty 10) 17.39

20.

51/4" Dysan

from (Qty 10) 26.09

30.

81/2" 3M

from (Qty 10) 30.44

35.

Blank 51/4" & 8%2" 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.

STATIONERY Listing Paper, Continuous Forms, Labels.

Listing paper 11"x 8.4", white/green music ruled, boxed 2000

El 0

Labels 234" x 17/is", white, fanfold, E5 per 1000 ...10,000 for

£40

Post/Packing/Insurance extra. Delivery by Registered Post, Securicor, etc.
Price List correct at time of going to Press, subject to change without notice. E.& O.E. Standard Warranties apply.
Your enquiries assist us in forward purchasing.

Please send Full Details & Price Lists

My requirements are for:

HOME D

HOBBIES D

STUDENT

BUSINESS

Name Street Town County Post Code Telephone Name of Co Position

PO/Chq No (Payment by Barclaycard / Trustcard / Access etc., can be arranged)

Requirements

Description

Microcomputer

Upgrade Kit

Interface

Disk Drive

Printer

Cable/Interface

Cluster System

Colour IV

Media

Stationery

Software

Post/Pkg/Ins :(please tel. for cost)

PC/PCW/L

TOTAL:

inc. VAT

Please mention PCW when replying to advertisers - it identifies you.

PCW 59

Every month in PCW, Sheridan Williams assists readers with their hardware, software and systems difficulties. Some questions he deals with himself, other enquiries are directed towards members of his consultancy panel.

STOCK DISCS I have been told that I should not look at cassette based micros for business purposes. I do not see why, as even a C60 cassette should in my estimation be capable of holding more than 50,000 characters. My application is for stock control, and I would be unlikely to have more than 1000 items on file at any one time. There are many reasons for rejecting cassettes in favour
of discs. 1 Even the 51/4 inch mini floppy discs hold more on each side than the average cassette. I have seen figures from 70K to 350K quoted. This would save you having to change cassettes in order to swap between programs and files. 2 You can hold many (usually up to 40) programs and files on a single disc, and they will be instantly retrievable. 3 Cassettes can generally be read at between 30 and 300 characters per second. Discs can be read at around 10,000 ch/s upwards. To read a 50K file from cassette could take up to 20 minutes, and yet only around 10 seconds from disc. 4 Discs tend to be more reliable...this is because of the nature of the Philips cassette format and the cassette drives used. If digital cassettes with full logic control were used, this statement would not be true and also search times would be significantly improved. 5 Discs are a 'direct access' medium, whereas cassettes are 'serial access'. The advantage of direct access is that any record on a file is available for immediate use; in order to access the 1000th record from tape the previous 999 must be read and discarded. With disc the read/write head can be moved directly to the relevant track.
When discs are used, program packages may be written as a 'suite' of programs - one program calling the other when required. It is preferable to write many small programs rather than one large one as each can be worked on and developed separately.

Even if discs are used in a serial access mode (and there are many applications suited to serial access), they are considerably faster than cassettes.
I suggest that you follow this by reading more on the subject of files. I have only just brushed the surface on one absorbing aspect of programming. Sheridan Williams
GIVE ME PROBLEMS
Is it possible for me to solve anything on my micro that no-one else has solved? I have found that I much prefer to program mathematical routines than ones related to data processing. Can you suggest any programs or ideas that I can look into? You are obviously a person after my own heart. I agree that there is something very absorbing about manipulating numbers and expressions. However, I doubt whether you could do much with your micro as most of the pioneering work is carried out on machines that are a great deal faster. Don't let me put you off though; try and concentrate on finding better algorithms to solve common problems.
For example, to date I think that the highest known prime number is 21'23209-1; it is known as the 26th Mersenne prime. It took 8 hours 40 minutes on a CDC Cyber 174 just to prove that it is prime! That's a good starting point. ..try to do it more quickly with a more efficient algorithm. Don't waste your time in BASIC, however, unless you have a BASIC compiler.
Look through past editions of PCW and find competitions set by myself. These will provide you with ideas on programs. In the meantime how about looking deeper into the Ackermann function. This can be stated very elegantly by the following recursive definition :A 0 n)=n+1 A m.01=A(m-1,1) A(m,n)=A[m-1,A(m,n-1)] Try building up a table for its values, and then try and find

a formula for each row: ie. A(0,n)=n+1, A(1 ,n )=n+2 A(2,n)=2n+3. (You can do this one in BASIC.) Can you define a function recursively in your version of BASIC? In fact, better languages for this would be ALGOL or PASCAL.
You will uncover further reading on the above two problems in Dr. Dobbs Journals of June/July 1979 and August 1979. Good luck, and Write back with your findings. Sheridan Williams
RANDOM CONFUSION What is the point of 'random
access' files? If the files are random, how do you know where each record is stored? I think the reason that you are confused is because of the word random. I prefer the term 'Direct access' to `Random access'; the two terms are synonymous. I can only imagine that the term random access was coined because it does not matter in which order you access the records in the file. I much prefer to think of the file as a direct access file because you can access any record directly without first having to read all the previous records.
Your question about how do you find a record - this is answered fairly simply now. You only need a way of linking the 'key field' in the record to the disc address. This is known as the 'randomising algorithm' (there's that word again). The disc operating system usually takes care of the track and sector numbers, and all you have to do is work out the relative address (relative to the start of the file and record length). An example would be if you had a file of part numbers. For certain goods you could make your part numbers run from 0001 to 9999 say, and hence part number 1234 would be found at record number 1234.
Problems arise where the key field is a name. Where on a file of 26000 people would you place SMITH. Well, if the file is fairly well balanced, one idea is to start each letter of the alphabet at intervals of

1000 records, and each second letter in the name could start at 1000/26 intervals. Hence Smith would be placed at a record calculated by 19x1000+13x38=19494 (S=19th letter, M=13th). This is just one of many ideas, although obviously it can be wasteful of space. Sheridan Williams
WHAT ARE THE PROSPECTS
I read your magazine regularly, and although I don't have my own system, I do intend to join the club one day. My immediate problem is my son. He is approaching 16 and will be leaving school next year with 0 levels (I hope). He expresses an interest in a computer career on the software side. What are his options as far as i) the course he should follow after school and his choice of jobs within computing? And, as a matter of interest, how do the salaries compare? Your son has a great deal to think about, and I would recommend that he talks to people, visits local colleges and libraries, and reads as much as possible.
As far as job choices are concerned, broadly the staff categories within a computer department are Systems Analyst, Programmer and Computer Operator. There are other categories and even subdivisions, but let us leave it at these three. Systems analyst is really only open to those with at least 5 years' experience and the approximate salary starts at £6500. Next comes a programmer; it's often from programming that people progress to systems analysis.
This is probably the best career to aim for; programmers' salaries start at £4500 for a trainee and can be as much as £250 per week for freelance contract work. A computer operator is the next category to aim for and it's worth saying too, that many companies give their operators time off from work to train as programmers. Computer operators often work shifts,

60 PCW

COMPUTER ANSWERS

and as such get shift allowances, but in general their salaries start at £4000.
The question of courses must really be dependent on whether your son wishes to follow a career in scientific computing or data processing. If he desires the former then the best course of action is probably A level computing science followed by a degree. If he seeks the latter then this reduces to a further question . . .degree or not degree (pun intended). You can gain some very valuable experience by stopping at the stage of A level, City & Guilds 746/747, Royal Society of Arts Computers in Data processing, a Threshold scheme, or a British Computer Society award, and getting a job immediately; in the three years that you would have been studying for a degree you could have become very knowledgeable in a purely practical environment. Please seek further advice as there are many points that I have not covered. However, I hope that I have given you a starting point on which to base further questions. Sheridan Williams (We feel that we should mention the almost universal misuse of the term Systems Analyst. Sheridan is quite right when he says that this is often the next step for a programmer - it is, but it often comes as a disappointment. To illustrate why let's pretend that there is another progression for a programmer - to Systems Designer. This job would involve designing a computer system based on a

want. How can I learn to write big programs that work?
The mistake most beginners make is to jump straight into coding a program without designing it first. The problem with BASIC is that it makes coding very easy, but gives you no help at all in designing programs that are likely to do what was intended, or to be easy to test. Worse, beginners are usually taught flowcharting at the same time as BASIC, and though a well drawn flowchart is excellent for telling you which bit of the program is connected to which, it can still leave you clueless about the relationship between the program and the problem it was meant to solve. The art of programming is being able to go from a clear statement of the problem (a game, a calculation, handling a file), through several stages of refinement and definition, to a set of small, intelligible routines executed in the right order.
Many programmers use a structured programming technique to help them analyse a programming problem and record their stages of progress. There are several different forms. Some use pseudocode, a written problem definition language that looks like PL/1 or Pascal; some use a more pictorial technique such as a Warnier-Orr diagram, which brackets successive levels of the problem; some use structured flowcharts. All

methods are based on the same theory - that correct programs have three components: a set of input data, a set of output data, and a process to convert one into the other. If the process is too complex to comprehend in one go, it can be decomposed into simpler processes by applying straight forward rules.
1 There are only three basic processes; sequence - input process output; decision - IF condition THEN sequence A ELSE sequence B; iteration WHILE condition REPEAT sequence. 2 Any sequence block can be decomposed into two sequence blocks, or a decision block, or an iteration block. By using this technique the programmer is able to concentrate his efforts on one area of the program at a time (knowing the relationship with other parts) and push each area in turn towards more detailed definition, until he reaches a level from which he can code the final program. By this stage the design is complete and hopefully, most of the logic bugs have been discovered before a single statement is coded. The design stages have been recorded, so that the functions of the various sections of the program can be understood and tested, and there is a very good chance that the program will perform as intended as soon as the inevitable keying errors are eliminated. If it doesn't, then the design documentation enables you to backtrack and find out why.
There are two very good

000ks for micro users:"Software Design for Microcomputers" by Ogdin (Prentice Hall, 1978); this will help you define program inputs and outputs, and design appropriate control structure for your applications. "Microprocessor Programming for Computer Hobbyists" by Graham (Tab, 1977); this teaches pseudocode, plus a wealth of information on arithmetic, data structures, searching and sorting.
The American hobbyist magazines frequently have articles on program design and documentation:FLOWCHART -Ellis "Use of flowcharts to communicate" Kilobaud, Feb 1979 (for basic use of flowchart symbols). Dunn "Structural Decomposition" Interface Age June 1979 for structured flowcharting (strongly recommended). WARNIER-ORR - Higgins various articles BYTE Oct 77, Dec 77, Jan 78, Mar 79. PROGRAM DESIGN -Hearn "Top -Down Modular Programming" Byte July 1978. Weems "Designing Structured Programs" Byte Aug 1978 Schwartz "Pascal Versus BASIC: An exercise" Byte Aug 1978. And may all your bugs be little ones. L.S. Warner
RAM DECODE
I found Mike Dennis' article "Practising a Little Micro control" most enlightening but I am not sure how to decode RAM. Is is the same as for ROM?

statement of the business

In a nutshell, yes! Remember,

requirements of that system.

any device connected to the

This statement of require-

data bus must only respond

ments would be produced by

to either a specific individual

someone who had studied

address or a specific band of

the existing system in detail

addresses. Address decoding

- usually by thoroughly inter viewing users of that system

achieves this and any device can be decoded to respond to

and documenting the results.

any address. However, since

This would by followed by an

the address bus doesn't always

analysis of the findings in order to establish the precise

contain a valid address, it would be foolish to decode

requirements of the system. You can see that the skills

the device from the address bus alone. For this reason,

required for the two jobs

the CPU provides suitably

described are quite different,

timed control signals that are

yet they are frequently given the same description systems analysis. The first, I imagine, would be a very satisfying next step for a programmer. The second may be extremely successful but, as well as a logical and analytical mind, it would also require a number of interpersonal skills which are not a natural adjunct to programming. Ed.)

present only when the address bus contains a valid address MREQ (Z80) and VMA (6800); These control signals must be gated with each uniquely decoded address to provide the unique Chip Selection that each device needs. Some micros discriminate further with control signals for either I/O or memory operations (IORQ
and MREQ in the Z80).

Other micros (6800 and 6502)

do not and so any I/O port is

BIG AND BEAUTIFUL

simply treated as a specific memory address - all the

My computer has BASIC and it makes a great programmable calculator, but when I try to write large programs I always get tangled and can't get the program to work the way I

devices are said to be "memory -mapped". There is no reason why the Z80 cannot be used in this mode as well. "Sorry. . . but we already have 27 Russian roulette programs. " Mike Dennis

PCW 61

The portable brain
4HARPSHARPSHARPshmi. SHARPSHARPSHARPSHARF SHARPSHARPSHARPSHARF SHARPSHARPSHARPSHARF
SHARP' SHARPSHARPSHARPSHARF
SHARPSHARPSHARPSHA iHARPSHARPSHARP RF 'HARPSHARPSHARPSSHHAARRI
"""s1-1A0DC.14A1:metA*-

Sharp personal computer

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Z-80 based CPU 4K bytes monitor ROM
Internal memory expansion up to 48K bytes of RAM 14K extended BASIC (occupies 14K bytes of RAM) 10 in. video display unit -40 characters x 25 lines

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62 PCW

Please mention PCW when replying to advertisers - it identifies you.

SHAKESPEARE,
BASIC AND THE CIA Fingerprinting sentence structure
A few miles out of Washington, approaching Langley, Virginia, there is a sign over the highway.
It reads 'C.I.A. Turn Right' Shortly after making that turn a security barrier is encountered,
and behind it a chain link fence. Identity documents are painstakingly checked against a list
held by the guard, and your physical details verified with a computer housed in a large complex
of buildings within the compound. This is the first of a series of increasingly stringent
checks that one meets on penetrating the heart of America's Intelligence machinery. And
there, some six stories below ground, is a computer that plays with words. Exactly what this computer does, and indeed its very specification, remains a closely guarded secret. For at least part of
the time, however, it is engaged in some fascinating literary detective work. by Julian Allason.

Literary detection is not a new science. Almost
from the moment that
Shakespeare was laid to rest, scholars have argued about the authenticity of various passages. In 1850 Spedding postulated that Shakespeare's disputed
play, Henry VIII, was
actually the result of a collaboration with Flet-
cher. This year Sped ding's thesis was largely vindicated by Thomas Merriam - and a computer.
It was the Cold War, with its ceaseless propaganda battles, that gener= ated the interest of the 1 Intelligence community in computerised linguist-
ics. Forgeries and plants 4 abounded. They needed
oautothenkntoicw - awnhdatwhwaats
was not. A celebrated case
=I concerned the auto-

biography of Kim Philby,
the Soviet double agent who had reached the top of the British
Secret Intelligence Service. After his defection, a book entitled 'My Silent War' appeared,
complete with foreword by Graham Greene. Phil by claimed it was entirely his own work. SIS, know-
ing that it was a final attempt to smear them
and damage AngloAmerican relations, sent a copy to Langley. There, CIA specialists ran comparisons of 'My
Silent War' with articles that Philby had written whilst operating as a Foreign Correspondent for the Observer. The tests showed that whole chapters had been
written by others. The
book is now regarded as highly suspect.
A similar thing hap-
PCW 63

pened when the memoirs

of the West's top Krem-

lin agent appeared. Using

similar methods, Soviet

specialists swiftly "proved" the "Penkovsky

Utrtarannvi or oar 1-1..r. rtarao...,..--
leaik Sir i mnct }nimbly nrarr you to deliver

Papers" a forgery. Penkovsky was shot and his
book remaindered. All methods of literary
detection involve recognition techniques. The detective uses the compu-
ter to help establish an
author's sub -conscious habits of speech or writing. Most Shakespearian
scholars are capable of
assembling a passable
pastiche of the Bard's
prose. To overcome vulnerability in this area, only very common
"filler" words such as

1, madam.

Kati. In 'Whir': I
got.

tureended to his
_ _ __l_aughter,.-

6

'

*ha.ste Raves, his young

pee

her

===_

10
12 11
11 LT
12. '" - -

-

-

him.
V_

. !::: f...

I ' Hij athve , 14 ------- -.

-st:rvt.; welt

-
Inetition

-.-- -

1..', l. wmom, hat so

_

..- labial y :

,
I' For virtue and true beatify of the soul. le

II A right gry".td husland,' let it.,

I

t sure. those men are harntv that shall have

Set, I.-1,ntetars. A 6"m'4a7in power,

Enter GARDINER, Bishop "

-

Page with a torch 6.

Car. It 's_ostie-6'elock I fear ne will

..etese should be ndicTirlielegv

at for delights ; times to F,nter

..... ..
Te. swarm.. i

Well

rstfov, L TTar:.- ---

Gosx1 hour of night, Sir7t Whit/ -----..,a late?
Came volt -'
.5.

I !as crep tn,'

- -- Suf.

Before he EO to bed.

ri) `Hag crepe et

-

Mr.

"and", or "it is" are tested. This is because use of these words
is a matter of subcon-
scious habit. Furthermore, they occur
throughout written output whatever the mood

et "not 1,0,e,

they are the poorest,

"

,

Tv .........-_ _

This is the ca '4ind pr

they ma, --- - ''''.6'

- -- -

-t

li
i

AIfnkawso.-m- eI-th1in-1g-as

_.,,,, .,....,,,,,.. d to have c!...__

22

srV'"er As they

able means, we h

parted

Ti

U. left

In them a wilder natuie

est in this world,

I 41...
curst cc scuts j.

or occasion. Position in the sentence is also held to be important.
Surprisingly, our syn-

4111
4 28

70U 1.0Sir
king

to
- _ -=. -
wfflar. T Tint

.. __ _ ;ley Stay in "

_

nes,.

asteri wan To steal ftAnd out of all

r.ww

it._ s___Tie counsels a

tactic habits are so ingrained that they show
through even when an
attempt is made to mimic the literary style of

31I in cal horriiiitta 111";t)I;,hiarkrtnega

. ---- _

vwfwki

;.

T

".[t'(,II rtiPt.Y--Viii. -

'

yon

About Of her

his nec 'brit In,

;v. at tilt

another. Usage of certain "filler" words remains fairly constant

PK. Hen.

... ___

Q. Kath. I am soltatetu not' by P,

And those -T true r- '

-old hea nesenewsar lg. And every true

throughout a writer's work.
At the simplest level a literary detection pro-

Arw '

. rl with hti

3P

7rno*

wife to my graissomome

38 a all trev7 .___. _ ,

, ;Man :e*PtAller

I ....

---- Till Cranme. As T wilt 1.,

,t

e . - I ".-u' high

wot11,1 w;,,, --

gram involves a series of
string searches on text
samples of established authorship. The incidence of certain strings,

I
*v on you, m. t__
mar .m110 . t rsi.}. ,

I
r;

':. -.7 _ ,, v. my Ilff. 'Y e al

r --4-- -
*

__.4

-- - - ___--

ilkt:tve no turome gone o t,

___

voice; aannd " tat pa. a me tart=

for example "such a", are noted. A profile of
the author's literary style is then constructed. Similar tests are carried out

sot
deth-appetir;'fiff,-iite
46 ---

Iges. If I a _--t-gties3----whic_h neirh
- -,-....-....
' -- 'sta antsw ulr
of my Pottig,--1 nie .,c rilar _kuri

on suspect text, and

finally both profiles are

4

compared. It should then

be readily apparent

whether or not all the

wct,tews, in the fear

.rt_4(

sn of aatn

iebsC.sne;

samples were written by

the same person.

Although fairly long

samples of text are

required for a definitive

evaluation, it is possible to obtain reasonably

IT 1/611 'frame I And '11r1t1,

en m

sort

,most sa

accurate results from a
short BASIC program.

you a event I litho-

The routine I am working
on for Petsoft uses less than 8K. The following simplified example illu-
strates a string search for

41111 s=.tweate,

tilent
r rk sarrifire if. Olt> )immimmiem

!ley are 111,

I,y

;

vt,e

62

And stickI nein 1,.
- apt

the word "and".

4111 A& The

f it? in n,)

I Free pardon to each mars renat

I

64 PCW

Prom etindit into pac

ttl17144.
have'-
k.

Lord Ch nberIalt,

,Aith SO:.

My lord, yrni '11 hear Iv lire. -vrvvu.rs:
It the cause? '

'

n

arouta ense..,4

No, his eon

-- I

rts:-.1. .N,

Iro 1' a"74...

ruins., na

(self else I

er79101115-

.' ne.,Pr knnw bin.. A...

-., I
ea
.

hearties ryi
ir-

you thi
_

iii.4ir-1-..
- ----

=__114*t4104kii.

ver lost her lustre_ ith
a
(GI, -
rce

' is till an hoer r 1
rI ,C there ? my sz "Oise ___

2."`"rietralWUe Went a ,. ....

r,-.

ffaelidpr70s verendieemed sir, in

- 'I ...-I1N--T--
Ater

_--

ar,

- ( .4 ride to Su i - '''',--to 3re-ikfiist

apt ifils

10....,r 1...

he letter, ns I hi iimi if ml

(1 .. 01,4

MILLS

100 DATA"HANDSOME ANDREW AND HIS WIFE" : REM Text Sample

110 READ T$

: REM Read Sample

120 FOR C=1 TO LEN(T$)

: REM Set counter to no. of

characters in string

130 IF MID$(T$,C,5)=" AND " THEN S=S+1

: REM Tests next five characters

(including spaces)

140 NEXT C

: REM Increments Character Counter

150 PRINT " `AND'APPEARED"S"TIMES"

160 PRINT"IN A STRING OF"LEN(T$)"CHARACTERS"

170 PRINT"ITS INCIDENCE WAS" S/(LEN[T$1)*100 "%"

Note that five spaces are allowed thesis. But it has given the machine

for the string "AND" to avoid translation and literary detection

acceptance of "HANDSOME", specialists a good deal to think

"ANDREW" etc. An additional about.

statement would be required to Computerised linguistics is now

accept "AND" as the first word in finding a much wider, and acade-

a string.

mically more respectable range of

In practice an expanded applications. In 1974 Dr. Andrew

algorithm tests a much longer Morton created a legal precedent

sample of text for the incidence with his evidence that only 7 of

and position of a number of such 11 police statements submitted in

"filler" words and phrases.

a case had been written by the de-

At about the same time as the fendant. The result was an

C.I.A. was trying to catch up on acquittal.

computerised literary detection In a recent book (Literary Detec-

they faced another problem. They tion, Bowker, £10.50) Dr. Morton

needed English translations of all examined the difference between

the scientific and technical informa- Jane Austin and The Other Lady,

tion being published abroad. Their who in 1965 completed the novel

linguists could not keep up. Com- which had lain unfinished since

puters, it was argued, could provide Jane's death. Although in literary

the answer.

terms the imitation is quite good.

Early efforts at machine transla- Morton demonstrated that the pro-

tion met with little success. The bability of Jane Austin having pen-

problem was the inadequacy of ned the 4,000 words that were

available syntactical analysis. Lin- written by The Other Lady to be

guistics, the scientific study of more than one thousand million

language, was still in its infancy. against (see chart).

But in 1957, Professor Chomsky With the continuing evolution of

of the Massachussetts Institute of linguistics and the rapid pace of

Technology, published a book micro -processor development, it is

called 'Syntactic Structures'. In it, reasonable to project not only con-

he argued the existence of underly- siderably more accurate machine

ing or Deep Structures beneath the translation than my pocket Craig

surface structure of the sentence. translator offers, but the prospect

These defined and inter -related all of an infallible literary detective.

the factors determining structural Post script: Having run this article

interpretation.

through my PET, the computer

It is fair to say that not all confirms that it is almost certainly

linguisticians accept Chomsky's not written by Shakespeare. . .

A comparison of Jane _Austen and The Other Lady

Occurrences of the Habit in

Habit
an a + an
a
P.B. such and F.B.I.

Sense and Sensibility
25 172
147 14
253 12

Emma 26
212
186 16
299 14

Sandition Sandition (Jane Austen) (The Other Lady)

11

29

112

112

101

83

8

2

151

154

12

1

Chi
squared (a) (b) 1.40 12.85
0.20 3.92
2.45 6.84

the

270

271 229

221

P.B. on

11

6

8

17

1.58 8.45

F.W.S.

22

26

19

8

0.43 6.34

this

32

39

15

15

this + that

126

144

52

37

0.25 3.64

with

59

74

28

43

with + without 77

84

38

47

5.02 3.71

very

37

68

26

27

P.B. the

4

2

3

7

- 12.7

Notes: 1. The samples are: Sense and Sensibility - Chapters 1, 3, Emma - Chapters 1 2,3. Sandition, Jane Austen - Chapters 1,6. Sandition, The Other Lady Chapters 12,24. 2. The figures for chi squared are for the comparison of the three genuine samples, (a), and then for the comparison of these samples taken together for the comparison with The Other Lady, (b).

PCW 65

If your Accounts
are a problemthe solution could be on your desk.

You could use your telephone to call Comma Computers on Brentwood (0277) 811131.
Or you could use a pen and envelope to complete and return the coupon to us.
Later on, you could have a free copy of our 'no jargon' brochure on your desk from which you could see how Comma Computers have used advanced micro -processor technology to make business computers easy to understand, use and afford!
Still later, but not much later because Comma Computers are quick and simple to install, you

could have a Comma Aquarius, Aries or Leo business system on your desk -a complete system with computer, printer, keyboard, display, installation, 12 months maintenance and software to perform Payroll, Accounts, Invoicing and Credit Control applications and provide instant management information including Profit and Loss Statements and all from less than £6000.
Butchers, bakers, candlestick makers . . . can all, at last, enjoy the benefits brought to business by the silicon chip and increase the efficiency of dealings with customers and suppliers as well as accountants, auditors, HM Collectors of Taxes and Customs and
Excise.

Comma Computers Ltd
West Horndon Industrial Park, West Horndon,

Essex CM13 3XJ

I=

Inn

IMINI

Name

Position

Organisation _

Address _

MEI MI

Postcode _
Telephone
To: Comma Computers Ltd, West Horndon Industrial Park, West Horndon, Essex CM13 3XJ
no

READER SURVEY -AND WHATAGIVEAWAY!

That's torn it - the secret's out. Our Star Prize in PCW's 1979 Reader's Survey is a 10k version of last month's "Mini Benchtest" machine:
THE SHARP MZ-80K
What a surprise for the sender of the first completed questionnaire drawn out of the bag! And that's not all - to each of the first twenty-five names selected goes a year's free subscription to Personal Computer World.
Where appropriate please either write in block capitals or tick relevent box. Please feel free to tick more than one box, if appropriate.
1. Age

STAR PRIZE
THE SHARP MZ 80K

2. Address

3. Age
4. Occupation 5. Married or Single
6. Sex M 0 F
7. Do you? a) own your own home b) rent your home c) live with parents
8. Do you go to the cinema? a) Once a week or more b) More than once a month c) Once a month d) At least every 3

months e) Once a year f) Never

9.

Which ITV channel do you receive?

a) London

b) Southern

c) East of England

d) South West

e) Wales & West

f) Midlands

g) Lancashire

h) Yorkshire

i) North Eastern

j) Scottish/Grampian

10. Do you watch television

on average?

per day

a) More than 3 hours

b) More than 1 hour

per day

O

per day

b) More than 1 hour

c) Less than 1 hour

per day

CI

per day

c) Less than 1 hour

d) At least 3 days per

per day

week

d) At least 3 days

e) At least 1 day per

per week

O

week

e) At least 1 day per

f) Less than 1 day

week

O

per week

f) Less than 1 day per

g) Never

week

g) Never

El 12. Do you smoke

cigarettes?

11. Do you listen to radio on average?

a) Yes b) No

0

a) More than 3 hours

13. Which of the following newspapers do you read?

a) Daily Telegraph

Every day O

b) The Guardian

Every day O

c) Financial Times

Every day O

d) Daily Mail

Every day O

e) Daily Express

Every day O

f) The Star

Every day O

The Sun

Every day O

h) Daily Mirror

Every day O

Local morning

Every day O

Local evening

Every day O

14. a) b) c) d) e) f)

Which of the following The Observer Sunday Telegraph Sunday Express Sunday Mirror The People News of the World

Sunday NewspapEEEEEEervvvvvvseeeeeerrrrrrdyyyyyyowwwwwwyeeeeeeoeeeeeeukkkkkkread000000?

15. Which of the following magazines do you read?

a) Radio Times

Every week

b) TV Times

Every week

c) Melody Maker

Every week

d) Sounds

Every week

e) The Economist

Every week

f) Amateur Gardening

Every week

g) h)

Country Life The Listener

Every week Every week

New Scientist

Every week

Punch

Every week

k) Titbits

Every week

1) Motor Cycle News

Every week

m) Weekend

Every week

n) Shoot

Every week

Computer Talk

Every week

Computer Weekly

Every week

q) Computing

Every week

r) Datalink

Every week

16. Which of the following monthly magazines do you read?

a) Car Mechanics

Every month 0

b) Do It Yourself c) Family Circle

Every month 0 Every month

d) House & Garden

Every month 0

e) Ideal Home

Every month 0

3 times a week 3 times a week 3 times a week 3 times a week 3 times a week 3 times a week 3 times a week 3 times a week 3 times a week 3 times a week

C0000 00000

Once a week Once a week Once a week Once a week Once a week Once a week Once a week Once a week Once a week Once a week

Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes

3 times a month 0 Once a month 0 Sometimes 0

3 times a month 0 Once a month CI Sometimes CI

3 times a month 0 Once a month 0 Sometimes 3 times a month 0 Once a month 0 Sometimes

0

3 times a month 0 Once a month El Sometimes CI

3 times a month CI Once a month CI Sometimes

3 times a month U Once a month U Sometimes
3 times a month Once a month Sometimes 333 tttiiimmmeeesss aaa mmmooonnnttthhh OOOnnnccceee aaa mmmooonnnttthhh SSSooommmeeetttiiimmmeeesss 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes 3 times a month Once a month Sometimes

9 times a year 9 times a year 9 times a year 9 times a year 9 times a year

0 6 times a year 0 3 times a year 0

D0

6 times a year 0 6 times a year 0

3 times a year CI 3 times a year El

CI 6 times a year 0 3 times a year CI

CI 6 times a year 0 3 times a year CI

PCW 67

f) Mayfair

g) Men Only

h) Motor Cycle Mechanics

Penthouse

Practical Motorist

Readers digest

Electronics Today International

m) Wireless World

Director

Investors Chronicle

P) Microprocessors and Microsystems

q)

Which Computer Management Today

Elektor

t) Omni

u) Video World

v) TV & Home Video

w) Practical Electronics

Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month Every month

17. a) b) c)

Which of the following computer magazines do you read?

Personal Computer World Practical Computing Computing Today

Every month
Every month Every month

000

9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year 9 times a year

0000000000000

6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0

3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0

00000

6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0 6 times a year 0

3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0 3 times a year 0

00

6 times a year 0 6 times a year 0

3 times a year 0 3 times a year 0

6 times a year 0 3 times a year 0

18. Please specify the components of the system you own/have access to/are hoping to purchase. In the case of the Micro itself we are after the manufacturer and type, NOT the chip type or number.

Owned

Have Access To

Hope to Buy Within 12 Months

24. What other topics would you like to see included?

Micro

VDU

Cassette Drive 51/4" Floppy Discs

25. What topics would you like to see deleted?

8" Floppy Discs

Hard discs Printer

Other (Please Specify)

19. Please indicate your usage of computer media

1 per month

1-5 per month

Ordinary cassettes Special length cassettes

0

Data cassettes Floppy discs (51/4")

0

0

Floppy discs (8")

20. Please indicate if you purchase the following Continuous stationary Special printed continuous stationary

YES 0 YES 0

5+ per month
00000
NNOO 00

26. What activities would

you like to see PCW sponsor?

Exhibitions

0

Conferences Courses Book publication

00

Software publication Others (please specify)

0

27. Are there any other comments you would like to make?

21. Please indicate the sections of the magazine that interest you most and least

Newsprint Benchtests Computer Answers Transaction File Interrupt Calculator Corner On the Line Diary Data Checkout In Store Bookfare User Group Index Programs Leisure Lines Business Case Studies Hardware Features Software Features Advertisements

M0 ost 000

Least
0

0000

0 00

22. I am interested in the fol-

lowing types of program: -

BASIC Assembler Machine Code

Games

00

Subroutines Business

Calculator Other (please specify)

00

Engineering Education

Home Applications

Other

(please specify)

23. I am interested in the

following Language

software features: descriptions

-0

Programming efficiency techniques

0

Systems design techniques 0

a Descriptions of software products available Others (please specify)

00

Please answer every question as accurately as you can, then post your completed Questionnaire to: PCW Reader Survey, 14 Rathbone Place, London W1P 1DE. The draw for the prizes will take place Monday 10th December, winners to be announced in PCW's February 1980 edition.
The staff of Personal Computer World would like to thank all readers who have taken the time to complete this questionnaire.

68 PCW

Even More! Super software from the world's leading microsoftware supplier.

DIGITAL RESEARCH

Software with /Manual
Manual Alone

H CP/M* FDOS - Diskette Operating System complete with

Text Editor. Assembler, Debugger. File Manager and system

utilities. Available for wide variety of disk systems including

North Star. Helios II. Micropolis, ICOM (all systems) and Altair.

Supports computers such as Sorcerer. Horizon. Sol System III.

Versatile. Altair 8800. COMPAL-80. DYNABYTE DB8/2. and

iCOM Attache Specify desired configuration

£75/CIS

MAC - 8080 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 (see below) CSS/E10

CI SID - 8080 symbolic debugger. Full trace, pass count and

break-point program testing system with back -trace and histo-

gram utilities When used with MAC, provides full symbolic

display of memory labels and equated values

C45/C10

0 TEX - Text formatter to create paginated. page -numbered

and justified copy from source text files, directable to disk or

printer .

C45/C10

DESPOOL - Program to permit simultaneous pnnting of

data from disk while user executes another program from the

console

C30/C1

MICROSOFT

CI Disk Extended BASIC- Version 5, ANSI compatible with

long variable names. WHILE/WEND. chaining, variable length

file records

£155/CIS

BASIC Compiler - Language compatible with Version 5

Microsoft interpreter and 3-10 times faster execution. Pro-

duces standard Microsoft relocatable binary output. Includes

Macro -80 Also linkable to FORTRAN -80 or COBOL -80 code

modules

C19S/CIS

CI FORTRAN -80 - ANSI '66 (except for COMPLEX) plus

many extensions. Includes relocatable object complier, linking

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£205/C15

CI COBOL -80 - ANSI 74 Relocatable object output. Format
same as FORTRAN -80 and MACRO -80 modules. Complete ISAM. interactive ACCEPT DISPLAY. COPY. EXTEND
£325/C15

O MACRO -80 - 8080(Z80 Macro Assembler. Intel and Dog mnemonics supported. Relocatable linkable output. Loader. Library Manager and Cross Reference List utilities included C75/e10

CI EDIT -80 - Very

text editor for text with or

without line numbers. Global and intra-line commands sup-

ported. File compare utility included

£45/£10

XITAN (software requires Z130" CPU)

1=i Z -TEL - Text editing language Expression evaluation itera-

tion and conditional branching abdity. Registers available for

text and commands. Macro command strings can be saved on

disk for re -use

VI0/C12

ASM Macro Assembler - Mnemonics per Intel with Z-80 ex-

tensions. Macro capabilities with absolute Intel hex or relocat-

able linkable output modules. New version 3 with added

features

C40/£12

D LINKER - Link -edits and loads ASM modules C40/C12

O Z -BUG debugger - Trace, break-point tester. Supports dec-

imal, octal and hex modes. Dissassembler to ASM mnemonic

set. Emulation technique permits full tracing and break-ooint

support through ROM

C45/C12

O TOP Text Output Processor - Creates page -numbered. jus-

tified documents from source text files

C40/e12

CI A4 package includes Z -TEL. ASM. LINKER, Z -BUG. TOP £155/C30

EIDOS SYSTEMS

O KISS - Keyed Index Sequential Search. Offers complete

Multi -Keyed Index Sequential and Direct Access file manage-

ment. Includes built-in utility functions for 16 or 32 bit arithme-

tic. string integer conversion and string compare. Delivered as

a relocatable linkable module in Microsoft format for use with

FORTRAN -80 or COBOL -80. etc.

C275/C15

K BASIC - Microsoft Disk Extended BASIC with all KISS

facilities. integrated by implementation of nine additional com-

mands in language. Package includes KISS.REL as described

above and a sample mail list program

£495/e30

MICROPRO

O Super -Sort I - Sort, merge. extract utility as absolute

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, expo-

nential. field justified, etc etc. Even variable number of fields

per record'

C125/C15

CI %per -Sort II - Above available as absolute program only C105/C15

D Super -Sort III - As II without SELECT/EXCLUDE £75/£15

Software with /Manual
Manual Alone

O 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 C75/C15

O Word -Star - Menu driven visual word processing sys-

tem 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. reach write to other text files, block move.

etc. Requires CRT terminal with addressable cursor position-

ing.

f255/C15

GRAFFCOM SYSTEMS

CI PAYROLL - Designed in conjunction with the spec for PAYE routines by HMI Taxes, Processes up to 250 employees on weekly or monthly basis. Can handle cash, cheque or bank transfer payments plus total tracking of all year to date figures. Prints emp
master. payroll log. payslips and bank giros. Requires CBASIC-2 C475/C15

CI COMPANY SALES - Performs sales accounting function.

Controls payments of invoices and prints sales ledger and aged

debtors report. Suitable for any accounting period. Comprehen-

sive VAT control and analysis of all sales invoices. Requires

CBASIC-2

C425/£15

CI COMPANY PURCHASES - Performs purchase accounting

function. Controls invoices, credit & debit notes. Prints purchase

ledger, aged creditors report and payment advices. Comprehen-

sive VAT control and analysis of all purchases. Interfaces with the

NAD system. Requires CBASIC-2

C425/C15

-4

STOCK CONTROL

Maintains stock records, monitors stock levels to ensure optimum

stock holding. Details include stock desc., 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

£325/£15

ORDER ENTRY & INVOICING

Performs order entry and invoicing function. Handles invoices for

services and consumable items, part orders and part quantities.

Sales Analysis report shows sales movements and trends for

user -defined period. Interfaces with Stock Control, NAD and

Company Sales systems. Requires CBASIC-2

£3251£15

NAD-Complete control of all your names & addresses including suppliers, clients, enquiries etc. Assign your own coding system
and select all output via the report generator. Will pnnt anything from mailing labels to directories. Requires CBASIC-2.
£225/C12

SOFTWARE SYSTEMS

CBASIC-2 Disk Extended BASIC - Non -interactive BASIC

with pseudo -code compiler and runtime interpreter. Supports

full file control, chaining. integer and extended precision var-

iables etc

C75/C10

STRUCTURED SYSTEMS GROUP

Cl OSORT - 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. Parameter file may be generated with CP/M assem-

bler utility

e50/£12

GRAHAM-DORIAN SOFTWARE SYSTEMS

CI APARTMENT MANAGEMENT SYSTEM - Financial management system for receipts and security deposits of apartment projects. Captures data on vacancies. revenues.
etc. for annual trend analysis. Daily report shows late rents. vacancy notices. vacancies. income lost through vacancies, etc. Requires CBASIC. Supplied in source code, . C300/C25

CI INVENTORY SYSTEM - Captures stock levels. costs.

sources, sales. ages. turnover. markup. etc. Transaction in-

formation may be entered for reporting by salesman. type of

sale. date of sale. etc. Reports available both for accounting

and decision making. Requires CBASIC. Supplied in source

code.

£300/C25

CI CASH REGISTER - Maintains files on daily sales. Files

data by sales person and item. Tracks sales. overrings, re-

funds. payouts and total net deposits, Requires CBASIC.

Supplied in source code

£300/C25

MICRO FOCUS

Ei CIS COBOL - Version 3 is ANSI 74 subset with extensions which offer powerful interactive screen formatting and built in cursor control. Version 4 additionally offers lull level 1 ANSI for
Nucleus. Table Handling. Sequential Relative and Indexed 1,0.
Inter -Program Communication and Library Version 3. £295/E25 Version 4. t395/£25

El FORMS - Interactive utility to create CIS COBOL source

code to perform CRT screen handling in application programs.

Supports full prompt text. protected fields and input validation

against data type and range expected

C65/C10

When purchased with CIS COBOL

£55/£10

OTHER

Software with /Manual
Manual Alone

1: tiny C - Interactive interpretive system for teaching struc-

tured programming techniques. Manual includes full source

listings

C45/C30

C Compiler - Supports most major features of language, in-

cluding Structures, Arrays. Pointers. recursive function evalu-

ation, linkable with library to 8080 binary output. Lacks data

initialization. long & float type and static & register class speci-

fiers. Documentation includes C" Programming Language

book by Kernighan & Ritchie

C65/C10

El ALGOL 60 Compiler - Powerful block -structured language

featuring economical run time dynamic allocation of memory. Very

compact (24K total RAM) system implementing almost all Algol 60

10 report features plus many powerful extensions including string

handling direct disk address I/O etc. Requires Z80

CPU

£110/e12

CI Z80 Development Package - Consists of: (1) disk file

line editor. with global inter and intra-line facilities, (2) Z80

relocating assembler. Zilog/Mostek mnemonics, conditional

assembly and cross reference table capabilities; (3) linking

loader producing absolute Intel hex disk file for CP/M LOAD.

DDT or SID facilities.

C50/C12

Z80 Debugger -Trace, break and examine registers with

standard Zilog/Mostek mnemonic disassembly displays. Facilities

similar to DDT £20 when ordered with Z80. Development

NP Package

£30/C7

DISTEL - Disk based disassembler to Intel 8080 or TDIJ

Xitan Z80 source code, listing and cross reference files. Intel or

TDLjXitan pseudo ops optional. Runs on 8080. Standard CP/M

and TRS-80 CP/M versions available

£35/e7

DISILOG -
Runs on Z80 only.

TEL to Zilog/Mostek mnemonic files. £35/C7

TEXTWRITER II - Text formatter to justify and paginate

letters and other documents. Special features include insertion

of text during execution from other disk files or console. permit-

ting recipe documents to be created from linked fragments on

other files. Ideal for contracts. manuals. etc.

C4S/C3

WHATSIT? - Interactive data -base system using associative tags to retrieve information by subject. Hashing and random access used for fast response. Requires CBASIC £70/C15

XYBASIC Interactive Process Control BASIC - Full disk

BASIC features plus uniaue commands to handle bytes, rotate

and shift, and to test and set bits. Available in Integer, Ex-

tended and ROMable versions.

Integer Disk or Integer ROMable

C165/C15

Extended Disk or Extended ROMable

£215/C15

Cl SMAL/80 Structured Macro Assembled Language - Package of powerful general purpose text macro processor and SMAL structured language compiler.SMAL is an assembler
awiTTHlLS . LOOP-REPEAT-WHILE,laErGlgELconstructsi

CI Selector II - Data Base Processor to create and maintain

single Key data bases. Prints formatted, sorted reports with

numerical summaries. Available for Microsoft and CBASIC

(state which). Supplied in source code

£105/C12

CI Selector III - Multi (i.e.. up to 24) Key version of Selector II.

Comes with applications programs including Sales Activity, In-

ventory. Payables. Receivables, Check Register. Expenses,

Appointments. and Client Patient. Requires CBASIC Supplied

in source code

VIS5/C12

Enhanced version for CBASIC-2

C185/C12

CPM/374X Utility Package - has full range of functions

to create or re -name an IBM 3741 volume. display directory

rmation and edit the data set contents. Provides full file

transfer facilities between 3741 volume data sets and CP/M

files

£125/E7

Flippy Disk Kit - Template and instructions to modify sin-
dgtleivesisded 51/4" diskettes for use of second side in singled sided£6

Orders must specify disk type and format, e.g. North Star Horizon single density
Add VAT to orders for software (not manuals alone). Add 50p per item postage and packing (minimum £1).
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The sale of each proprietory software package conveys a license for use on one system only
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PCW 69

WALES LEADING SYSTEMS HOUSE

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B zz 0RDS
Each month, Pete Reynolds takes us through the minefield of microcomputer terminology and jargon.

J
Jack Plug A short rod -like connector whereby an electrical device (such as earphones) may be
plugged into a jack.
JCL Job Control Language -
specifying (typically for some mainframe computer) the input/output devices and other environmental variables
before a program or 'job' is
run.
Jitter
Electrical instability, especial-
ly in the pattern of data
displayed on a screen Commonly due to inadequate voltage regulation.
Job
A set of data processing tasks, including running programs, for a specified application for example, "weekly payroll".
Journal (tape) fAorchbraocnkoulopg,icoafl alilsltintgra,nkseapcttions and data entered to a
computer system.
Joystick
A small control device whose knob may be moved in any direction within two dimensions in order, for example,
to move a dot on a screen. Jump To depart from the normal
sequence of program instructions. A jump instruction is often conditional. When a particular condition is satisfied (or not satisfied) the program instructions may be repeated in a loop, operating on each cycle on slightly
modified data, until a predetermined count has been
exhausted. The condition allowing the jump will then cease to obtain and program instructions will be followed sequentially.
Jumper
An electrical wire temporarily
connecting two points on a
circuit.
Justify (1)
To arrange printed (or typewritten) words so that the right-hand margin of each line forms a clear vertical line, as in most books and newspapers. There is usually no

difficulty about achieving Keyboard

justification of the left-hand The group of pushbuttons, as

margin, where each line of in a typewriter or calculator,

ttyhpeesabmegeinesf,fbecutt

to achieve along the

whereby data or instructions may be input to a computer.

right-hand edge of every line requires that words and letters must, to some extent,
be spaced out more than they need be; this calls for
a count of the characters and spaces required in each line and a calculation of the number of extra spacing inserts required and where they can best be placed. This can be a minor computing problem in itself.
Justify (2)

Key-to-disc/tape A system for computer data entry on a commercial scale
which was introduced to obviate the need for punched cards originally selected for data entry by companies already in the punched -card business. In a key -to -disc (or key -to -tape) system the data -entry operators write
their data on the relevant
magnetic media for subsequent processing in batch

To shift numeric characters mode. A limited validation

to fill any spaces in the right- check may be made on the

hand end of an accumulator data at the time of entry.

or other area of computer
storage, before an arithmetic operation.

Keyword

1. Same as key; a group of

characters
an item or

vrce4chiochrd

fidoerndtifaiteas

K

retrieval. 2. Same as password ; a

secret combination of charac-

Kilo (abbreviation) Signifying 1000 as in kilo-
metre or kilocycle. The internal storage of computers is commonly arranged by the manufacturer to hold a quan-
tity of data which is some

ters which identifies an authorised user to a computer and may indicate which specific facilities are to be allowed
or denied - eg to read data
on the computer files but not
to alter them in any way.

power of 2, for example, KHz

4096 characters, bytes or KiloHertz (abbreviation).

words, which is 212. The convention is to refer to this number as 4K. 64K, sixteen
times as great, actually

Kilo Prefix signifying 1000 - but see entry under K.

amounts to 65536 (2 ° ). KiloHertz.

Note that the unit, bits, A frequency of 1000 cycles

bytes or words is unstated. per second.

A `1K chip' probably holds 1K bits: to avoid ambiguity when referring to chips of greater capacity, the word size in bits may be shown

KIPS Kilo Instructions Per Second, describing the rate at which a processor can operate.

after the K. Thus 1K8 means Kit

1024 bytes, 16K1 means A set of parts for assembly by

16384 bits.

the user. It may not include

Kansas City Standard A way of recording binary
data on cassette tapes in which 1 is encoded as 8
cycles of 2400 hertz and 0 as 4 cycles of 1200 hertz.

case, power supply or connecting leads and may be more expensive than equivalent mass -manufactured systems
(if such existing). But for those who enjoy assembly, a kit can be more instructive

Kb

and satisfying and easier to

1. Kilobytes, ie thousand modify to one's personal

bytes.

design.

2. Kiloband, ie cycles per second.

thousand Kludge

3. Kilobits, ie thousand bits. K/c Kilocycle (abbreviation). One thousand cycles per second; now known as KiloHertz
(KHz).

A local modification or patch
in a computer program to
overcome some error or design fault. Such patches make it difficult for others to follow the program or to deal with subsequent problems.

KCS Kansas City Standard.

Knock -Off A device for automatically

inhibiting some machine

Key A pattern of digits used to

activity in certain circumstan-
ces. For example, a paper

identify an item or record. knock -off will stop a printer

when the paper supply is
exhausted.
KSR Keyboard Send Receive. Descriptive of a printing terminal, such as a teletype, having keyboard and printer but no other media (such as magnetic or paper tape) capable of sending or receiving messages without manual intervention (Automatic Send Receive, or
ASR).
KVA Kilo-Volt/Amps (abbreviation). A measure of electrical power, one KVA (or kilowatt) being equivalent, for example, to 4 amps at 250 volts or 5 amps at 200 volts. The consumption of one
KVA for one hour (or 10
KVA for six minutes) is the familiar unit of the electricity
bill.
L
L 1. Symbol for electrical inductance, eg of a coil, usually measured in Henries or Millihenries.
2. Low (state) in some bist-
able device.
Label One or more characters used to identify the location of an instruction (when line numbers are not used) within a program. The process of
compiling such a program will
replace each label with an
absolute address. Lag
Delay between two successive events, such as reading a program instruction and completing its execution. The lag may be measured in clock cycles and knowledge of the interval used to advantage in
advanced programming.
Land
An internal electrical connection, eg. between an LSI chip proper and one of the pins in the package inside which the chip is supported. Language Term used to describe a coding system by which
instructions may be given,
intelligible to a computer; for example, assembly language, BASIC, COBOL.
Large Scale Integration The fabrication on a small
silicon chip of a circuit embodying several hundreds of semiconductor devices (normally between 100 and 10,000)

PCW 71

10 PART PASCAL
SERIES

THE COMPLETE PASCAL
BY SUE EISENBACH AND CHRIS SADLER

CHAPTER 3 CONTROL STRUCTURES:

1. LOOPS

In the last chapter, the procedure was presented as a means of performing the repetitive tasks so often required in computer programming. Thus program WALKING executed in "steps"
LEFT and RIGHT alternately by successive calls to the procedures of those names. Some programs however have to repeat their procedures a large number of times, the precise figure often
depending on conditions arising within the data or during the calculation, and hence not known in advance. In order to deal with these requirements, a programming device known as
the loop exists in almost all languages.

The function of the loop is to cause the execution of certain lines of code (the body) a certain number of times. Different types of loop may be distinguished by the way in which they decide how many repetitions (or iterations) are required. The process of deciding whether to repeat the body of the loop one more time or to continue with the
rest of the program is called a test.
Every loop therefore consists of a body and a test and is known as a control structure because it causes the program
control or "flow" to differ from the normal sequential execution of pro-
gram statements.
The most elementary type of loop is designed to execute the body a predefined number of times. This operation is controlled by an explicit counter variable and the test consists of comparing the value of the counter
with the known finishing value. Depend-
ing on the outcome of the test, the
counter is incremented (or sometimes decremented) and the body is repeated, or else program control passes to the code immediately beyond the loop.
In BASIC this structure is known as a FOR -NEXT loop and PASCAL has an equivalent called the FOR -DO loop. In addition, PASCAL has two loops for executing the body an unknown (or at least uncalculated) number of times. Here the test will depend on conditions arising within the body and a counter, if used at all, is not an explicit part of the loop. In the WHILE -DO loop, the test is made before the body is commenced whereas in the REPEAT -UNTIL loop, the test comes right at the end of the body. In the next few sections each of the above will be described, defined and exemplified in programs.
The body of a loop consists of either a single statement (now expanded to include the compound statement, as in the syntax diagram in Box 1) or in certain cases, a sequence of statements

When laying out a program it is normal to indent the code between every BEGIN -END pair. When the body of a loop does not contain a BEGIN -END pair, however, by convention it is indented anyway, to emphasize that it is controlled within a loop.
The FOR -DO Loop
Program ROLLOVER in Box 2 illustrates a FOR -DO loop in a fairly typical

context. Procedure RESTOFVERSE contains the parts of the song which are repeated in each verse. The loop, set up
in line 11, ensures that the part that
changes (CROWDS) is correct for each verse. This requires the special DOWNTO reserved word to make the counter work backwards. Lines 13 and 14 actually produce each verse and line 15 sends the program control back to line 11 for the next verse - and so on. Line 16 finishes off the song. Lines 12

-OH variable 1-0---1 expression]

CO 0 output

-0-4-

1110-(WRITEL)

-0-4-

+I procedure identifier

compound statement

ENHANCED STATEMENT

BEGIN ---÷-1 statement

END

A

COMPOUND STATEMENT

72 PCW

1 PROGRAM ROLLOVER ;

®

2 VAR CROWDS: INTEGER ;

3 PROCEDURE RESTOFVERSE

4 BEGIN

5

WRITELN(' IN A BED AND THE LITTLE ONE SAID') ;

6

WRITELN("'ROLLOVERr ROLLOVER"') ;

7

WRITELN('SO THEY ALL ROLLED OVER AND ONE FELL OUT.') ;

8

WRITELN

9 END ; (*RESTOFVERSE*)

10 BEGIN (*MAIN PROGRAM*)

11

FOR CROWDS:=10 DOWNTO 2 DO

12

BEGIN

13

WRITE('THERE WERE 'r CROWDS) ;

14

RESTOFVERSE

15

END I

16

WRITELNUTHERE WAS 1 IN THE BED AND HE SAID "GOODNIGHT".')

17 END

- -

-

18 THERE WERE 10 IN A BED AND THE LITTLE ONE SAID

di 19 'ROLLOVER, ROLLOVER'

20 SO THEY ALL ROLLED OVER AND ONE FELL OUT.

21
22 THERE WERE 9 IN A BED AND THE LITTLE ONE SAID

23

...

..

...

54 THERE WAS ONE IN A BED AND HE SAID 'GOODNIGHT'. PROGRAM ROLLOVER

a

Integer variable

expression

FOR -DO LOOP

--lexpression

statenientl--Oo--

to 15 provide an example of a com- is included in PASCAL as a safety mea-

pound statement. Finally, note sure to guard against the tendency of

PASCAL's solution to the problem of some programmers to re -use a loop

printing a ' mark. Since the quote (') counter at a later stage of the program,

is the text delimiter, the PASCAL without assigning a new value to it.

compiler searches for pairs of quotes enclosing text. Two adjacent quotes will indicate that the text is not to be terminated but rather that a single

EXERCISE:
Write a program to print out the song "Ten Green Bottles".

quote is required for output. The syntax diagram in Box 3 shows

The Generalized Loop

the precise structure of the FOR -DO Circumstances can often arise in pro-

loop. The different components appear gramming where the use of a fixed -

as:

limit FOR -DO loop is too restrictive

FOR (test) DO (body)

to allow for a flue -ht program style. As

The counter is a variable (not a REAL) an example consider the problem of

and must therefore, like any other vari- entering a list of numbers from a key-

able, be declared explicitly in the de- board into a program. If you don't want

claration part. The starting and finishing to count how many numbers there are

expressions must be integer expressions. before you start, you need to have a

Because these expressions are evaluated way of telling the program when the

before the loop commences, rather than list has come to an end. This is usually

during each iteration, there is no loss done with a "rogue" value - a number

of efficiency in using quite complex which couldn't possible be a part of the

expressions if required.

list (eg. -9999). When the program

The counter increases or decreases detects the rogue value, this is an indi-

(depending on whether TO or cation that the input list is complete

DOWNTO, respectively, is used) by 1 and further processing can continue.

on each iteration. The restriction of the It would be nice to place the item -

step size creates a loop -test requiring by -item reading of such a list in a loop,

a minimal number of machine -code but if the length of the list is unknown,

instructions. If a different step size is then the only way of doing this with a

required, a "dummy" counter can be FOR -DO loop leads to awkward and

constructed within the body of the error -prone code. Because circumstan-

loop, but on no account should the ces such as this arise quite frequently,

value of the actual counter be changed PASCAL has a more generalized loop

inside the loop (for obvious reasons). form.
The FOR -DO loop test will discon- The distinguishing feature of the

tinue the loop when the value of the generalized loop lies in the nature of its

counter moves beyond the finishing test. Instead of a steady incrementation

value (in the indicated direction). This of a counter, the test checks the validity

ensures not only that the body is exe- of some relationship which is (presum-

cuted the correct number of times, but ably) affected by the body of the loop.

also, if the counter is accidently set up When the relationship holds, one course

to move away from the finishing value, of action is taken and when events

the body of the loop will be skipped within the loop cause the relationship

over entirely.

to change, a different course of action

When the loop has finished the is embarked upon. Quite clearly, only

counter variable loses any value it had two possibilities exist - the relationship

(i.e. it becomes undefined). This feature holds or it doesn't (i.e. it is true or

false). Such a relationship is called a

Boolean expression after the English

mathematician George Boole who first

studied the algebra of such expressions.

The syntax diagram in Box 4 fully

defines the Boolean expression. Note

that <> stands for "is not equal to".

Consider a Boolean expression like

A=B. This expresses the relationship

"A is equal to B" and the = is known

as a relational operator as are all the

other symbols shown in Box 4. Com-

pare this with the assignment state-

ment A:=B which reads "A becomes

equal to B". Here := is an assignment

operator and it is this distinction

which enables one to write X:=X+1 in a

program where it would make no sense

as an equation.

PASCAL provides two versions of

the generalized loop. In the first, the

WHILE -DO loop, the test is made
before the body is commenced, and

iteration occurs as long as the Boolean

expression is true. If the expression is

false when the program first encount-

ers the loop, the entire loop will be

skipped. The syntax diagram in Box 5

defines a WHILE -DO loop. As with

a FOR -DO loop, the body is a single

statement, generally compound.

The program in Box 6 illustrates the

use of a WHILE -DO loop, which runs

from lines 10 to 15, line 10 containing

the test and the rest comprising the

body. While this is not a very practical

sort of guessing game, it does show the

unlimited nature of the loop which will

go on asking for new guesses until the

right number turns up. It also shows the

major danger of the generalized loop -

suppose the test never fails? The pro-

gram will stay in the loop forever. For

instance, suppose TARGET was 16

while CORRECT and GUESS were

REAL instead of INTEGER, and

CORRECT became 3.99999 (as often happens). Any integer value guessed

could never pass the test. This can

happen quite easily especially when

dealing with the mathematical functions

with which rounding errors are associa-

ted. Consequently, it is good program-

ming practice to check explicitly for

realisable loop tests.

Examples of mathematical functions

appear in line 6. SQRT(A) is a REAL

value representing JA while TRUNC(B)

is the largest integer less than B (when

B is positive). In line 6 the above func-

tions are nested so that CORRECT is

the square -root of the largest perfect

square less than TARGET. A list of

all mathematical or standard functions

available Look -Up

in PASCAL appears in the
Table at the end of this

chapter.

The second generalized loop in

PASCAL is the REPEAT -UNTIL

loop defined in Box 7. The test comes

at the end of the body and iteration

occurs as long as the condition is false.

PASCAL has two complementary loops

to allow for a fluent programming style.

Sometimes it will seem more natural

to use a WHILE -DO loop and sometimes

a REPEAT -UNTIL will suggest itself. In

the latter case however, the body will be

executed at least once, whatever state

the Boolean expression is in, because

the test comes after the body. Program

ANOTHERGO in Box 8 illustrates the

use of a REPEAT -UNTIL loop running

from lines 22 to 26. Line 26 contains the test and the body lies above it.

The REPEAT -UNTIL loop has

PCW 73

reserved words which effectively
bracket the body of the loop. This is not the case with the other two loops where the reserved word DO merely leads up to the beginning of the body. The PASCAL compiler needs to know where the loop body stops and the rest of the program begins. It is for this reason that the two DO loops restrict the programmer to a body consisting of a single statement (usually compound). Without the DO keyword possessed by the other loops, the REPEAT UNTIL loop can contain more than one statement in its body (ef. syntax diagrams for the different loops). This means that one tends not to find
BEGIN -END pairs following a REPEAT although the indentation convention is observed nonetheless.
The program from Box 6 has been converted into a procedure for ANOTHERGO. This is a sensible way to develop programs - writing a small,
self-contained section as a separate
program, testing it, and then incor-
porating it as a procedure in some larger program. This theme will be developed
in more detail in the next section. Finally, line 2 introduces a new data type, the character type CHAR which consists of a single letter of the alphabet, digit or normal keyboard punctuation mark. The variable ANSWER can
contain any one of these characters and can be compared with actual characters enclosed in 'quotes' as in line 26 Vari ables therefore can be declared as INTEGER, REAL or CHAR.
Each of the three control structures defined above is an extension of the definition of a statement, since it appears in the action part of a program. Consequently a complete syntax diagram for the statement must incorporate all of these, and this is shown in Box 9.
EXERCISE:
Computers (and calculators) are often tested for accuracy by computing a range of nested mutually inverse functions [eg. exp (ln[ x ]) = x]. Write a program to input a sequence of (positive) numbers (rogue values could be 0 or less), in each case calculating exp (In[x]) and outputting this value, together with x and the difference between them before reading in the next one.
Using Loops
As an everyday application of the use of
loops, consider the construction of a mortgage repayment table. These are normally constructed by actuaries from
formulae which give the monthly payment incurred by a loan assuming a fixed interest rate and where repayment occurs over a fixed time period.
This reputedly boring occupation seems ideally suited for rendering into machine soluble form, releasing the actuary for more valuable tasks (like
estimating the insurance risks on a
personal computer). Instead of employing the actuarial formula, however, the
problem will be used to illustrate a
common programming technique which consists of taking a guess at the likely
value, working out the implications, comparing the results with the required outcome, improving the guess, working out the implications again, and repeating this process until an acceptable

expression

BOOLEAN EXPRESSION

expression k_

CID

Boolean expression

DO

statement

WHILE -DO LOOP

1

PROGRAM PERFECTSQUARE

2 VAR CORRECT. GUESS, TARGET: INTEGER

3

BEGIN

4

WRITE('TYPE IN YOUR TARGET NUMBER:-')

5

READLN(TARGET)

6

CORRECT:=TRUNC(SORT(TARGET))

7

WRITE('NOW GUESS THE LARGEST INTEGER YOU THINK HAS A SQUARE 'r

8

'NOT LARGER THAN ', TARGET,

')

9

READLN(GUESS) i

10

WHILE GUESS<>CORRECT O

11

BEGIN

12

WRITELN('NO THAT GIVES ', GUESS*GUESS)

13

WRITE('SO GUESS AGAIN:- ')

14

READLN(GUESS)

15

END

16

WRITELN('GOOD

GUESS, ' HAS THE LARGEST PERFECT SQUARE 'r

17

' NOT LARGER THAN ', TARGET,'.')

18

END . (*PERFECTSQUARE*)

19

TYPE IN YOUR TARGET NUMBER:- 59

20

NOW GUESS THE LARGEST INTEGER YOU THINK HAS A SQUARE NOT LARGER THAN 59:- 6

21

NO THAT GIVES 36

22

SO GUESS AGAIN:- 7

23

GOOD 7 HAS THE LARGEST PERFECT SQUARE NOT LARGER THAN 59.

PROGRAM PERFECT SQUARE

1

PROGRAM ANOTHERGO

2

VAR ANSWER: CHAR

PROGRAM ANOTHERGO a

3 PROCEDURE PERFECTSQUARE

4 VAR CORRECT, GUESS, TARGET: INTEGER

5

BEGIN

6

WRITE('TYPE IN YOUR TARGET NUMBER:-')

7

READLN(TARGET)

CORRECT:=TRUNC(SQRT(TARGET))

9

WRITE('NOW GUESS THE LARGEST INTEGER YOU THINK HAS A SQUARE 't

10

'NOT LARGER THAN ', TARGET, ':-')

11

READLN(GUESS)

12

WHILE GUESS,,CORRECT DO

13

BEGIN

14

WRITELN('NO THAT GIVES ', GUESS*GUESS)

15

WRITE('SO GUESS AGAIN:- ')

16

READLN(GUESS)

17

END

18

WRITELN('GOOD ', GUESS, ' HAS THE LARGEST PERFECT SQUARE 'r

19

' NOT LARGER THAN ', TARGET,'.')

20

END i (*PERFECTSQUARE*)

21

BEGIN (*MAIN PROGRAM*)

22

REPEAT

23

PERFECTSQUARE

24

WRITE('DO YOU WANT TO TRY ANOTHER TARGET? ')

25

READLN(ANSWER)

26

UNTIL ANSWER.'N'

27

END.

28

TYPE IN YOUR TARGET NUMBER:- 44

29

NOW GUESS THE LARGEST INTEGER YOU THINK HAS A SQUARE NOT LARGER THAN 44:-

30 GOOD 6 HAS THE LARGEST PERFECT SQUARE NOT LARGER THAN 44.

31 DO YOU WANT TO TRY ANOTHER TARGET? N

answer is reached. Clearly, the loop provides a means of programming such an iterative solution - although it's unlikely to tempt any actuaries away
from their formulae! The approach we shall take in pro-
gramming this problem is known as "Top -Down Design". The Top -Down designer begins by explicitly defining the problem, stating what results are expected from what initial information.
The task is then coded by calling several procedures, each a distinct subtask or module which contributes to the solution of the total problem. Any
consideration of the detail of these

Statement (Box 1)
FOR -DO loop (Box 3)
WHILE -DO loop (Box 5)
REPEAT -UNTIL loop (Box 7)
STATEMENT

74 PCW

PROGRAM REPAYMENTS ;

2 VAR MIN, MAX, LOAN. REPAY: INTEGER

3

PROCEDURE GETINPUTS ;

modules is deferred to a later stage of the design. In due course, each module will undergo the same treatment and

4

(*READ IN INTEREST RATE, NUMBER OF YEARS,

5

MINIMUM AND MAXIMUM LOANS*)

PROCEDURE PRINTHEADINGS

thus the problem devolves into a hierarchy of more -or -less independent sub-

(*PRINT JUT INTEREST RATE, NUMBER OF YEARS AND TABLE HEADINGS-I.E.LOAN G REPAYMENTS*)

problems until a level is reached at

9

PROCEDURE CALCULATEREPAY ;

which only elementary programming

10

(*WORK OUT MONTHLY REPAYMENTS*)

11

BEGIN (*MAIN PROGRAM*)

12

GETINPUTS

functions are required. At this point the final coding can be done quickly

13

PRINTHEADING

14

LOAN:SMIN

15

WHILE LOAN<=MAX DO

and accurately, and the result should be a well -structured program.

16

BEpIN

17

CALCULATEREPAY ;

18

WRITELN(LOAN,

., REPAY)

'

Returning to the mortgage table program, the problem definition could

19

LOAN: -LOAN 1500

20

END

be:

21 END. (*REPAYMENTS*) PROGRAM REPAYMENTS - FIRST ATTEMPT

Given the interest rate and a time

period for repayment, create a table

I PROCEDURE CALCULATEREPAY ; 2 VAR TOTALMONTHS: INTEGER ;

showing the monthly payment due over a given range of loans.

3

MONTHLYINTERESTRATE. AMOUNTDUE: REAL ;

4 PROCEDURE TRYREPAY ;

5

(*WORK OUT THE ACTUAL AMOUNT A GIVEN REPAYMENT

The input data required is therefore:
1. interest rate (% p.a.)

6

WILL ACTUALLY PAY OFF*)

7 BEGIN

8 MONTHLYINTERESTRATE:=INTERESTRATE/12

2. repayment period (years) 3. maximum and minimum loans

9 TOTALMONTHS:=I2*YEARS

10 REPAY:=LOAN DIV TOTALMONTHS ;

II REPEAT

12

AMOUNTDUE:=LOAN

13

REPAY:=REPAy

;

required (thousands of pounds).
The output should be a list of loans
from minimum to maximum in steps of

14

TRYREPAY

15 UNTIL AMOUNTDUEs=0

16 END I (*CALCULATEREPAY*)

PROCEDURE CALCULATEREPAY

£1000, showing monthly repayments. The interest rate and repayment period

should also be displayed.

I PROCEDURE TRYREPAY ;

2

(*WORK OUT THE ACTUAL AMOUNT A GIVEN REPAYMENT

3

WILL ACTUALLY PAY OFF*)

@ The next stage is to decide on the W method of solution in order to code the main program. At this level the tasks

4 VAR MONTH:INTEGER ; 5 BEGIN (*CALCULATEREPAY*) 6 FOR MONTH:=I TO TOTALMONTHS DO

that must be accomplished include reading in the user's parameters, printing out

7

AMOUNTDUE:=(AMOUNTDUE-REPAY)*(1 ... MONTHLYINTERESTRATE)

a

8 END 1 (*TRYREPAY*)

PROCEDURE TRYREPAY

the appropriate headings and, for each loan from the minimum to the maxi-

mum requested, calculating and printing

I PROCEDURE GETINPUTS 1

2 CONST IMIN=2 1 IMAX=50 ;

3

YMIN=5 1 YMAX=35 1

4-

LMIN=5 1 LMAX=200 1

g'

the repayment amount. At this stage, the means by which the calculations are

to be performed do not concern us and

5 PROCEDURE GETINTEREST 1

6

(*READS IN INTEREST RATE BETWEEN IMIN AND IMAX AND

7

CONVERTS IT TO A DECIMALS)

neither are we interested in the details of getting the input data or printing

8 PROCEDURE GETYEARS ;

9

(*READS IN DURATION OF LOAN BETWEEN YMIN AND YMAX YEARS*)

10 PROCEDURE GETMIN 1

out the heading. The calculations will have to be performed in a loop which

11

(*READS IN. IN THOUSANDS. THE MINIMUM LOAN VALUE BETWEEN

will stop when the maximum loan value

12

LMIN AND LMAX AND CONVERTS IT TO POUNDS*)

13 PROCEDURE GETMAX ;

14

(*LIKE GETMIN, BUT FOR THE MAXIMAL LOAN VALUES)

is reached. In Box 10, we have called procedures named GETINPUTS and

15 63 BEGIN (*GETINPUTS*) 16 64 GETINTEREST ; 17 65 GETYEARS ;

PRINTHEADINGS to handle the initial part of the problem, and introduced a

10 66

GETMIN .1

19 67 GETMAX

20 68 END ; (*GETINPUTS*)

PROCEDURE GETINPUTS

WHILE -DO loop (lines 15 - 20) to control the calculation and output of the table. Procedure CALCULATERE-

I PROCEDURE GETINTEREST 1

) 2

(*READS IN INTEREST RATE BETWEEN IMIN AND IMAX AND

3

CONVERTS IT TO A DECIMALS)

4 BEGIN

5 WRITELN ('TYPE IN THE RATE OF INTEREST AS A PERCENTAGE..) ;

6 REPEAT

WRITE ('A NUMBER BETWEEN., IMIN. ' AND'. IMAX. .:-.

87

READLN (INTERESTRATE)

1

PAY will actually perform the calculations.
The declaration part of this first
attempt includes all identifiers used in the main program. These include the integer variables MIN, MAX, LOAN

9 UNTIL (INTERESTRATE)=IMIN) AND (INTERESTRATEs=IMAX) ; 0 INTERESTRATE := INTERESTRATE/100 ; (S % -.> DECIMAL *) II END (*GETINTEREST*) ;

and REPAY, together with the procedures GETINPUTS, PRINTHEADINGS

12

:2 PROCEDURE GETYEARS ;

(*READS IN DURATION OF LOAN BETWEEN YMIN AND YMAX YEARS*)

15 BEGIN

16 WRITELN ('TYPE IN NUMBER OF YEARS FOR WHICH MORTGAGE WILL RUN.')

IIP

17

REPEAT

18

WRITE ('A NUMBER BETWEEN', YMIN. ' AND'. YMAX. .:-.) ;

and CALCULATEREPAY. Notice that these procedures have not been fully defined at this stage but merely contain a comment indicating what each will eventually do.

19

READLN (YEARS)

20 UNTIL (YEARS,=YmIN) AND (YEARSs=YMAX)

21 END; (*GETYEARS*)

22

23 PROCEDURE GETMIN ;

24

(*READS IN. IN THOUSANDS. THE MINIMUM LOAN VALUE BETWEEN

25

LMIN AND LMAX AND CONVERTS IT TO POUNDS*)

III EXERCISE: Try re -writing this first attempt with a
FOR -DO loop instead of a WHILE -
DO loop

26 VAR LOANMIN : INTEGER ;

27 BEGIN

28 WRITELN(.TYPE IN THE SMALLEST MORTGAGE YOU ARE INTERESTED IN.',

29

'IN THOUSANDS..) ;

30 REPEAT

WRITE ('A NUMBER BETWEEN', LMIN. . AND', LMAX, .:-.) :

We have now completed the highest level of the program design and are ready to proceed to the next level. The three procedures will be tackled

32

READLN (LOANMIN)

33 UNTIL (LOANMIN>=LMIN) AND (LOANMINs=LMAX);

34 MIN :. LOANMIN*1000

in the same way that the whole pro-
blem REPAYMENTS was approached.

END (*GETMIN*) ;
365
37 PROCEDURE GETMAX ;

The question arises as to which of the three should be dealt with first. We

38

(*LIKE GETMIN. BUT FOR THE MAXIMAL LOAN VALUES)

39 VAR LOANMAX : INTEGER 1

40 BEGIN

- prefer to start with the "Heart" of the

problem

CALCULATEREPAY

41 WRITELN (.TYPE IN THE LARGEST MORTGAGE YOU ARE INTERESTED IN, ' .

42

'IN THOUSANDS..) ;

43 REPEAT

(Box 11). The problem definition of
CALCULATEREPAY could be:

44

WRITE ('A NUMBER BETWEEN', MIN DIV 1000. . AND'. LMAX. .....) ;

45

READLN (LOANMAX)

Work out the monthly repayment as

46 UNTIL (LOANMAX=M1N DIV 1000) AND (LOANMAXs=LMAX) ;

0 47 MAX := LOANMAX*I000 48 END (*GETMAX*) ;

PROCEDURES GETINTEREST ETC.

follows - first guess an obviously low value and calculate how much that

PCW 75

would pay off over the given time
period, taking into account the interest charges. If there is still a debt by the end, the repayment value was not enough, so increase it and try again. Continue until the repayment amount pays off the loan. Input data 1. duration of loan 2. interest rate 3. amount of loan Output data is the calculated monthly repayment amount.
In the declaration part, the variables required in the calculation will have to be declared only if they are local to the
procedure, since the global variables will
already have been declared. Thus a check should be made that the input
and output variables, YEARS, INTERESTRATE, LOAN and REPAY appear in the variable declaration of the main program. Some of these may be missing in a "first attempt" version and so should be incorporated.
To start coding CALCULATERE-
PAY the first step is to generate the working data from the input data. The repayment period, for instance, is in years but is here required in months,
as is the interest rate. Therefore two new (local) variables TOTALMONTHS and MONTHLYINTERESTRATE must be declared and calculated. Next, the initial estimate should be made, in order to start the whole process off. Since repayments will be increased to improve
the "guess", it is important to start
with an estimate below the likely value. A reasonable first estimate would be the amount one would pay back interest free. This is simple enough to code at this stage as can be seen in line 10 of Box 11. (Note that DIV has been used since REPAY is an integer. This program could be changed to give
pounds and pence if the user were willing to trade some speed for such
accuracy). Since the initial estimate must be too low, the next step should
be to add £1 to the repayment and
test whether that will pay off the loan. The process of incrementing the
repayment amount and testing will be repeated until a figure is reached which actually does pay off the loan. This has been coded in the REPEAT -UNTIL loop, lines 11 to 15, Box 11, but, just as this calculation was put off in the main program, so the job of calculating how much a given value of REPAY would actually pay off over the time -period is deferred to procedure TRYREPAY, which is the next problem to be tackled (Box 12).
The problem definition of TRYREPAY could be: Evaluate how much a given value of REPAY would pay off over the given duration of the mortgage using the given interest rate, assuming monthly
payments and the compounding of
interest. Input data 1. monthly interest rate 2. duration of loan (months) 3. value of loan (£) 4. value of repayment (£ per month) Output data - amount of debt remaining when time period has elapsed.
What is owing at the end of one month? Suppose AMOUNTDUE contains the
amount due at the beginning of one month and an amount REPAY is paid

back. At the end of that month, the within which the input data should

amount due will be (AMOUNTDUE.- fall (lines 2 - 4). If one of these should

REPAY) + interest accrued during the later on prove restricting, it will be

month. This figure will become the easy to change the CONST declaration.

AMOUNTDUE for the next month; The four individual input procedures

for N months, this calculation should Box 14) are so similar that only one,

pass through N iterations.

GETINTEREST, need be considered in

This is coded in the FOR -DO loop, detail. Its problem definition could be:

Box 12, lines 6 and 7. The only variable
needed that has not been previously declared is the loop counter, which is
declared locally in line 4. This completes the definition of TRYREPAY which, in turn, completes the definition of pro-
cedure CALCULATEREPAY. Having coded CALCULATERE-
PAY we now know exactly what
information GETINPUTS must obtain. The problem definition could be:

Output a message asking for the rate of interest. Check whether the response is within the range of reasonable values. Keep asking until an acceptable reply is received. Then convert this number from a percentage to a decimal fraction. Input Data IMIN and IMAX - limits of "reasonable" interest rates (as a percentage). Output Data INTERESTRATE - actual required

Read in interest rate, duration of loan interest rate as a decimal fraction.

and maximum and minimum loans
(in thousands of pounds). Convert
interest rate to a decimal (instead of percentage) and loan values to pounds. Output data
1. interest rate (decimal fraction) 2. duration of loan 3. minimum loan 4. maximum loan

A REPEAT -UNTIL loop (lines 6 to 9) is used to accept input. The program remains in the loop until an acceptable
figure is entered.
The other three input procedures
are developed in a similar fashion. Note that in procedure GETMAX, the minimum value for a loan is not LMIN but MIN DIV 1000 - the actual lower

An input procedure should usually check that the data it accepts is reasonable and unlikely to cause the program to crash. For instance, if the repayment period YEARS were zero,

limit obtained from GETMIN (line 34). Finally, PRINTHEADING is tackled
(Box 15). Its problem definition could
be:
Clear the screen, then print out a title

then TOTALMONTHS would also be zero. But we divide by TOTAL MONTHS in CALCULATEREPAY, so

followed by the required interest -rate
and the duration of the loan. Skip several lines and print the headings

that apart from zero being an unrea- MORTGAGE (for the loan) and

sonable figure for years it will also
crash the program.

MONTHLY REPAYMENTS. input Data

Box 13 contains procedure GETINPUTS. In the action part the four procedures GETINTEREST, GETYEARS, GETMIN and GETMAX are called.

1. yearly interest rate (%) 2. duration of loan (years) Output Data - none as this procedure simply produces the headings.

The declaration part lays down limits Cont. on Page 81

I PROCEDURE PRINTHEADINGS I

2

(SPRINT OUT INTEREST RATE. NUMBER OF YEARS AND

(DI

3

TABLE H EADINGS- I . E. LOAN AND REPAYMENTS*)

4 CONST SPACE='

5 BEGIN

6 WRI TELN( SPACE, ***MONTHLY MORTGAGE REPAYMENTS**')

7 WRI TEA( SPACE.

)

I

8

WRI TELN I

9

WRI TELN( INTEREST RATE = 100* INTERESTRATE. 'S OVER

10

YEARS. 'YEARS') I

II

WRI TELN( '

LOAN

REPAYMENTS ' )

12

WRI TELN(

I

13 WRI TELN

19 END I ( *PR INTHEADI NGS*)

PROCEDURE PRINTHEADINGS

Look up table

PASCAL STANDARD FUNCTIONS

Arithmetic: ABS(X) SIN (X) COS (X) ARCTAN (X) EXP (X) LN (X)
SQR (X) SQRT (X)

Absolute Value Trig functions
Exponential Natural Logs Square Square Root

Real or Integer Answer Real
Answer Real Real or Integer Answer Real

Transfer:

TRUNC(X) Truncate

X real, Answer is integer part

ROUND(X) Round to closest

integer

(ROUND(X) = TRUNC(X + 0.5) when X is positive]

COMPUTING JARGON
Control Structure Counter Compound Statement Rogue Value Boolean Expression Relational Operator Module Iteration

PASCAL RESERVED WORDS
FOR DO TO DOWNTO WHILE REPEAT UNTIL CHAR

UCSD Exceptions ATAN(X) instead of ARCTAN(X) Also LOG(X) is log to base 10.
EXERCISE SUMMARY 1. Ten Green Bottles 2. Accuracy Test 3. Mortgage Table

76 PCW

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PCW 77

INTERRUPT
Interrupt is the place in PCW where readers can unburden their grievances and air controversial views. New subjects are always welcome; the 'right of reply' shall be wielded at the discretion of the Editor. Please hold
all contributions to within 800 words.

Future What future? tion and culture, together with the changes in education and parental attimedia and the inadequacy of many wel- tudes, to produce a situation where

fare payments, conspire to make members of society are capable of achie-

the experience as miserable as possible. ving a high degree of personal satisfac-

Those of you familiar with the work tion, regardless of their source of

of Ivan Illich will know that education income.

can logically be considered as prepara- But what about the profit motive,

tion for failure. The fact is that in I hear you scream. Is not man really

national terms, educational institutions driven by greed, his career being merely

are designed to feed the needs of an expression of an overwhelming

society. Thus, in a society where intel- desire to own more than his neighbour?

lectual activities are accorded more How can we distribute wealth in a way

status than manual, but where manual which will satisfy this inner need with-

jobs greatly outnumber those requiring out some kind of capitalist employment

intellect, it is necessary to ensure that structure? Isn't the alternative a totali-

tarian state where nobody is really

satisfied? True, one doesn't have to look

"...it is necessary to far for confirmation of the intrinsic

nastiness of human nature, and it would

ensure that only a I am beginning to have strong suspicions
that our leaders and the media are
small minority of actively conspiring to keep the real
implications of information technology
people finish their from the general public. Having always
held BBC documentaries in high regard,
education feeling I was disturbed to see the recent three
part production "The Right To Work?"
intellectually brilliantly obscuring the most impor-
tant issues.
adequate." There was the predictable argument
regarding the amount of unemployment
which may occur, and how best to minimise it, and a tantalising, albeit
superficial, glance at the role of leisure in utilising the spare man hours. Unfortunately, however, any good intentions there may have been collapsed into a familiar political squabble between Sir Keith Joseph and two TUC representatives. The problem was one of approach.
"The Right To Work?" provided an excellent example of that little known
but highly pervasive phenomenon, best
described as 'temporal chauvinism'.
This is manifest in the inability of
members of a society to envisage any future society without imposing their own contemporary political and economic structures upon it. The best, latterday example, would be the persistent attitude of unions and government alike towards unemployment; they see it as a social evil to be avoided at all
costs.
The real question posed by the
present technological revolution was summed up by Peter Large of the Guardian; "Do we want to work anyway, if our jobs are unsatisfying or unpleasant, if we are there just for the money? Can we rethink the work ethic and find another way, by whatever political means, of distributing wealth?"
In the present social climate,
however, resistance to such ideas is
very powerful (A Nation of Scroungers?
reads the headline). Even aside from the indignant abhorrence of the average man in the street towards 'living off welfare', there are many respectable

only a small minority of people finish their education feeling intellectually adequate. In order to achieve this end, examinations with a minority pass rate are held, and those who do not fall within the top twenty per cent or so are stamped 'failures'. Put simply, education is a subtle and apparently benign means of inducing people to accept their position within society.
Many young adults thus enter both manual and clerical jobs accepting that they are unlikely to be satisfying in any real sense, but nevertheless with an intense fear of the ultimate failure unemployment. The middle class college student, with some sense of intellectual adequacy and personal confidence, will find long periodg of unemployment much more acceptable than the individual whose dignity relies heavily upon
being able to run a car and buy a
round in the pub. Thus we are brought
up to think of our status in society almost entirely in terms of the job we
do. This is even reflected in linguistics;
when asked "what do you do?" the words "for a living" are immediately implied, and one describes a job. If you were jobless you might say "I'm unemployed at present but. . . "; you would be unlikely to say "I look for a job one day a week, play basketball, read science fiction books and newspapers, go for walks and make love to
my wife". Thus although many people are presently unable to accept

be foolish to suggest that this could
change overnight, if at all.
Nevertheless, I cannot accept that mankind is incapable of achieving a higher degree of social awareness, or of maintaining a more egalitarian and humanistic social structure. Social evolution, which has long since superseded
biological evolution as the major instru-
ment of change in man, is difficult enough to understand - let alone
control. The so called 'profit motive' is just one aspect of the complex relationship between the individual and his society which must be understood if we are to survive the hazardous future ahead of us.
I am not alone in the belief that we are entering a period of social change as dramatic and pervasive as the industrial revolution. This change will affect us all whether we choose to have any control over it or not. As individuals we can avoid the issue (and the headaches) by taking the view of Ron Condon (Editor of Data Link) that: ". . . as for the future, well, let it look after itself as it is so unpredictable anyway..."
I am sure, however, that many of you, feeling as I do, both excited and terrified by the social implications of
information technology, will agree that we must at least attempt to direct the course of events if we are to avoid a catastrophic outcome. I am convinced that if we ignore the problems we will face inevitable social collapse and/or totalitarianism.
I have covered only a few of the most obvious points, and clearly there is much ground to be explored before
any realistic plans can be made. Those of us already involved will have to carry
the discussion across to the general public. Social change can only come from the people, since controlling bodies are, by their very nature, concerned only with social maintenance. Do you want your future to remain in their hands? Dick Granby, Fitzrovia, London

academics who would argue that, for unemployment - in the conventional

Grow your own the individual, unemployment causes sense - this is clearly a result of learn-
depression and psychological instability. ing rather than any innate predisposi-

The latter is, of course, bound to be
true in a society where a person's educa-

tion towards "employment" as such. It should therefore be possible, through

From the way microcomputer hardware
is sold these days you'd think that

78 PCW

INTERRUPT

round every corner there were large forests of software trees tended by `green fingered' programmers. In fact there's more likely to be giant sized briar patches tended by Weed Killer
manufacturers. "If we could only find skilled work-
ers we could double our growth rate over the next four years".
"We've been looking for skilled workers for the past two years with no success".
These two comments were made by two exporters during recent televi-
sion programs on the Malaise of British Industry.
It is, I suppose, a small comfort to see that the computer industry makes the same mistakes as the rest of British
Industry. If you read the computer press, almost weekly you will see an
article or letter bemoaning the 'lack of experienced programmers'. In fact, if you look at the job advertisements you see more and more companies offering larger and larger salaries to proportionally fewer and fewer programmers.
On the other hand, one noticeable
omission from the job advertisements is vacancies for trainee programmers. On
those rare occasions when they do appear the response is normally over-
whelming (one company reported 700 replies to one such advertisement).
As you can see our 'big' brothers in the mainframe business have already got a serious staff shortfall, (by the end of 1980 it is predicted that this shortfall
will have reached 70% of the total
requirements).
What are the prospects in micros?
One noticable omission from the job advertisements
is vacancies for
trainee programmers. On the rare occasions
when they do appear,the response
is normally overwhelming.
Let's look at the numbers first: in
1978 the average monthly sales volume of microcomputers was larger than the total worldwide number of all
computers installed before that year. This fact alone seems to indicate that microcomputers are already in a disaster situation. So what can be done about it.
Solutions to the software problem, available now, are to either use standard packages or to custom build.
The package approach is the one

which seems to have been adopted as `standard'. Every month we see in the microcomputer press ever increasing numbers of software houses advertising ever increasing numbers of 'standard' packages. The problems associated with this are: 1. It gets increasingly difficult for small companies to evaluate these products.
Many of the products on offer are
poorly documented and little indication
is given of their scope. 2. No joint standards have been agreed
between software houses. So even if you get a package which meets your functional requirements it will need customising to interface with products
from other software houses. 3. The products on offer are all generalised and in most cases, therefore, demand that you change your business
to meet the requirements of the software rather than changing the software
to meet your business needs. The custom build approach would
seem to be ideal since you will get exactly what you ask for. The problems associated with this approach
are:
1. The obvious problem of the small
number of programmers available:* 2. The high cost of programmers. They
usually cost between £5 and £10 per hour, so a customised system could turn out as much as 6 or 8 times the
cost of the hardware. 3. Programmers know a lot about pro-
gramming but they don't necessarily
know about your business.
In my view the only satisfactory
answer to the growing software problem is to combine both of these approaches. What is needed is industry specialisation. You, the businessman, bring your
knowledge of your industry and its problems; the programmer brings his
knowledge of computers. Together you provide an ideal combination which will lead to a standard package approach, but, since the package is specific to one industry, it is likely to meet the require-
ments of most companies in that
industry. Obviously no two companies are exactly the same so some customisation is always going to be needed, although, only to a small degree. In
addition, the cost of producing an industry standard package is offset by the higher likely demand for that pro-
duct in that particular industry. This all sounds ideal, but some of
you will have noticed the slight flaw in my argument. I started by saying that we have a major shortfall in programming resource; how can this be over-
come?
Well, the answer is in your own hands. It takes two years to develop a
good programmer but programmers can
be productive after six months. The answer then is to train your 'industry'
knowledgeable staff to be programmers. The better software houses usually run training schemes (e.g. 'BASIC' programming courses) usually lasting 3-5 days and costing approximately £50 per day (a lot of this 'expense' can be recouped from your own industry training board). These courses will enable you to provide your own programming, although they

will need some direction. Once again, the better software houses should offer consultancy services so that the initial system design and program specification can be done by computer professionals with the bulk of the programming being done by your own staff. In addition, the same software house would probably undertake the marketing of the finished `industry package' for you.
In conclusion, one thing is certain if you just sit there and do nothing the problem will not go away, it will just get
bigger. Mike Rose, Croydon
Micro -mania revisited
I would like to challenge Mr Smith's view of personal computing in PCW volume 2 Issue 5, Interrupt column.
Mr Smith - I think you missed the whole point of the hobby. I would like you to show us the magazine or newspaper in which such fantastic claims were made for it. Or did you make them up for rhetorical effect? Because there is no hobby which can truthfully profess to fulfil any of your 'claims'.
Are you addicted, bored, dehumanised? Moreover, are you unable to justify . . . etc? Surely you had some reason for buying yours in the first place, some motivation? Or did you get it because it was the latest executive toy? Anyone who buys anything for such a reason
deserves to be bored out of his/her
tiny mind.
I am one of the genuinely poor people who cannot afford even the meanest computer kit. But already I have tens, even hundreds of ideas for
my dream machine. None of them involves commercial equipment or software. The only reason I haven't tried to contribute to PCW is that I have not had the equipment to debug my ideas, and I doubt that the editor would enjoy reading any bug -riddled script, however valuable the core material.
As for your intro, we don't think
of personal computers as liberating us in any sense. However the microprocessor will liberate a large proportion of the
population, for a large proportion of their week, from the drudgery of work - whether in the typing pool or on a production line. Thus liberated there will have to be a cultural and educa-

PCW 79

INTERRUPT

SYSTEMS

tional renaissance, in which personal

computers could play a great part.

The pocket computer you des-

cribe will follow the development

of the plasma screen or else the ultra

miniaturisation of existing LED/LCD

screens. Whether Woolworths will sell

them is a matter of speculation.

The only requirement for the 'men-

tal annihilation' you talk about is a

weak, even sick mind. No such mind

could insinuate its owner into any

position of responsibility. I must agree

that computer art is boring. The reason

is similar to the reason why musicians

disdain 'disco' music, as being more or less speeded up Musak with heavy

drums/bass overlaid. Computer art is

constrained by:

Display and definition and colouring.

Computer speed and memory capacity.

Display medium; most have just a VDU

and/or printer

Character graphics.

Could you produce a piece of art on a

25x40 grid with PET graphics which is
not either totally random (sorry -

psysmeubdoolrica?ndoImf )so

o- r

documentatively
you're a genius!

In any case, judgement of art on any

basis other than technical exactness

has to be subjective. Similarly 'disco'

music is constrained to a dominant

beat surrounded in time by audible -

but -not -too -distractingly -brilliant music.

Lastly to your question about

defence spending. The only way this

could be stopped is by multilateral
agreement, which would in turn be

followed by multilateral distrust, and by

a surge in spending on surveillance

techniques, and secretion techniques.

In any case, suppose some goodly inven-

tion does come from defence research;

that is, an invention which, had it been
sought from any other point on the

`knowledge map', would have had mini-

mal chance of being found without a huge amount of extra expenditure?

The ultimate aim of a scientific explor-

er is not as significant as the route taken

and what he finds on the way. Example:

The whole 'space race' was sparked off

by military interest. Why don't you send for a catalogue of the valuable

spinoffs that produced?

If you ever decide to drop your
machine from your window, inform me beforehand. I'll be there with a butterfly net, and I promise to decapitate the first new enthusiast I see who even nearly imitates your attitude. T. Magee, Bradford.

PCW already has the most authoritative and comprehensive guides in the UK for hardware - namely our Benchtest and In Store
contributions. Now, building on this success, we are pleased to
introduce Systems. The brief for this new, monthly feature will be to take a different business application each issue and to
report on some of the software packages available around it. PCW 's David Tebbutt and Mike Knight of Mike Rose Micros take up the explanation.

Perhaps before looking at the fine for software. For the businessman

detail of our approach for the it could mean his business crashing

future we should examine the down alongside the programs.

reasons for introducing Systems. Okay, enough of the horror

You've probably seen or heard stories, time now to take a look at

business packages described in some constructive action .

glowing terms. They are said to be Each month when we report on

complete, comprehensive or total. a particular application area, the

Sometimes they are not described feature will be divided into the

in any terms at all; sometimes following sections:

they are described in terms which Objectives

only the writer understands. Tasks and volumes

Somehow the prospective buyer Evaluations

must decide from this morass of Comparisons

inadequate information, which New products

packages to consider buying.

Let's look at each of these in turn.

Nor do the problems end there .

Having selected a few possible
packages, the potential buyer

Objectives

- needs to know quite a lot more
before making any final decision. Is it well documented, for
example? We can barely believe some of the apologies produced in the name of documentation. It can
be inadequate in a number of ways. First of all it may simply
not exist. . .not even instructions for operating the machine! Secondly, yes, it may exist, but in such a form as to be totally unintelligible to mere mortals - not to mention the prospective buyer/user. Thirdly, it may exist, but only in parts. The missing sections are usually the ones you need when you're burning the midnight oil and all the 'experts' are fast asleep in bed.
An exaggeration? In many cases we think not, although we have to
point out that some companies do produce quite excellent docu-
mentation.
And here's something else to
think about - bugs. What are
bugs? ...well, in common parlance,
they are errors existing in the
application package which cause it to go wrong from time to time. Of
course, ideally, one would like
any problems resolved on the spot

In this section we shall define the objectives of the application . We shall also describe the application and explain any relationship with other applications. Failure to be very clear about objectives will lead any investigation to likely failure.
Taking 'payroll' as an example, we might describe the overall objective as 'to pay employees the amount due on time and to meet statutory requirements'. Then we might describe the application as follows: 1 Capturing information upon which payment will be based. 2 Using this information to calculate net payment. 3 Maintaining records of payments to each employee. 4 Producing appropriate documentation for company, employee and government records.
Finally, we might define the relationship with other applications as: 'information gathering possibly the product of production hours recording. The payroll application will almost certainly create "transactions" for the accounting function'.

- time, after all, can be expensive.

Here the difficulty may be that the firm from which you bought

Tasks and volumes

the package no longer exists. In this section we shall

Perhaps (more likely) they aren't select, say, three packages and

too interested, or don't have the match them against the tasks

staff to tackle any bugs. Again we to be performed. Staying with

don't want to paint an unduly our payroll example, we

miserable and pessimistic picture, might say something like this:

but these are very serious matters "Not only will this give a guide

and they need to be considered to three particular packages, it will

before any money is exchanged also offer a framework against

80 PCW

SYSTEMS

services offered.

Tasks:

Package A

B

C

User comments. We shall contact

Create employee records

users of each system and summarise

Delete (suspend) leavers Maintain existing records

:

their opinions and experience of the package.

Build up to gross

Gross to nett Print payslips

Comparisons

payroll cash analysis cheques or credit transfers bank reconciliation NI stamp analysis Update employee records Prepare P60s Produce accounting transactions etc.

This section comprises a straightforward comparison chart showing all the packages notified to PCW,
for the application in question.
Each will be evaluated against the criteria discussed in this article. Because we cannot do an in-depth
analysis of every package, this
information will be based on that

Maximum Volume/sizes: Employee records Record size

400 180th

250 360th

600 200ch

made available by the suppliers. If the publicity documentation fails to mention something, we

shall not make assumptions and

which to measure other packages System maintenance. We shall the column shall be marked N/A

of your choosing."

be interested in whether the - not applicable.

system has been designed to be

Evaluations

changed easily. Examples which
spring to mind are tax rates and New products

In this section we shall again focus discount terms. We shall also see if

attention on the selected packages. customisation is easy. Some Finally, and quite separately to

This part of the feature will be packages are written with 'hooks' the above, we shall provide infor-

written as a structured narrative, to enable customised routines to mation on any packages newly

describing each package in turn . be added fairly simply. The notified, for application areas

The main elements are as follows. language used is also important already covered.

Availability

here. Finally, we shall check out

Documentation

who you have to go to to have We're sure that this structured

System content

these changes made.

approach to package evaluation

System maintenance

Costs need little explanation. will help readers in the selection

Costs

We shall give the costs for various of their business software. There

Hardware required

versions of the package and, if are a lot of good and reliable

Support and training

applicable, the cost of any main- suppliers of these products in the

User comments

tenance agreements.

field, all of whom will give sound

Availability covers number of Hardware required. We shall advice . But this series of articles,

suppliers, their distribution and describe the different hardware as much as anything, should help

whether the product is available configurations and relate these to clarify your own thoughts on

`off the shelf'.

the volumes which can be handled what can be a rather tricky subject.

Documentation describes the by each. We shall also give a guide

scope, content and quality of the to the hardware costs.

From time to time, PCW publishes

manuals and guides supplied.

Support and training. If either business case studies. This involves

System content will describe of these areas are neglected, it's spending a few hours with a user

the programs involved in the pack- likely that you'll end up very dis- of a computer and chatting

age, their functions and certain appointed with your new system. through their experiences. Last

aspects of their operation . For Training should, at the very least, month, you will recall, we featured

example, it may be that each pro- teach you how to operate the a betting shop system. If you

gram, on conclusion, automatically system. Support is the on -going would like to tell the world about

loads the next in sequence. On the advice and guidance you will get your system, be it a standard

other hand, there may be a need for a lot of disc or tape changing

from the supplier. It also covers their response to any problem you

package or please get

incusttoomuc-bhui-lt,otthheenr

during the operation. We will try may encounter -a hardware fault, people's successes (and failures)

to give a picture of what will be a software fault or perhaps an may offer invaluable information

involved in the day to day running accident such as over -writing some to businessmen working in similar

of the system.

important files. We shall assess the areas.

PASCAL... continued from P.76 The coding for this procedure appears
in Box 15. The entire program can now be gathered together, incorpora-
ting the extra global variables (INTERESTRATE and YEARS) into the
declaration part of the first attempt (Box 10) and filling out the details of the different procedures as they have
subsequently been designed. EXERCISE: Adapt REPAYMENTS to produce a

table showing the 15 year, 20 year,
25 year and 30 year monthly repayment figures for a given range of loans. The
input should be the interest rate and
range of loans (and not the loan period) and the output should be a table with 5 columns - one for the amount of the loan and one each for each repayment period.
Conclusion
Loops control the repetition of a set of

statements within a program. Every language needs a loop - PASCAL has three, which enriches the language and makes it versatile. Loops can be distinguished by the type and position of the loop test relative to the loop body.
Just as a program can be built up from basic blocks into an ordered structure, so can the data on which the program operates be organised into efficient and powerful data structures. The next chapter will serve as an intro-
duction to these.

PCW 81

BUGGING
THE 6800

This article presents a monitor program developed by John Moore for the 77-68 system (described in PCW vol. 1 issue 1). This is a very flexible computer system sponsored by the Amateur
Computer Club and designed for home construction. It uses the Motorola MC6800 processor for which there is a wealth of readily available cheap and sometimes free software of good quality.
The 77-68 hardware is usually configured with an interrupt driven parallel keyboard, and a memory mapped VDU with a Teletext compatible 24x40 format of upper and lower case characters.
Users of other 6800 systems may also find ideas in this program that could be of use to them

For those unfamiliar with machine code programming and debugging, or the function of monitors, a little explanation may
be in order. A monitor serves three main pur-
poses:
1. It includes routines to give the computer access to the outside world through input/output
devices such as keyboards, VDUs and printers. 2. It is used as the execu-
tive or operating system to allow the user to run his own applications programs . For example it might support a BASIC interpreter which in turn runs user programs written in the BASIC language. Some monitors can support more than one user program simultane-
ously. 3. Used for machine code program development, it
allows the operator to
examine and alter memory contents one by
one, to run sample programs, and generally to get them into working
order. Usually monitors are held in ROM so that they are available and running as
soon as the computer is started. This particular one is unusual in that after switch on it has to be loaded from tape into a hardware determined 1K byte block of memo-
ry (address FC00 FFFF).

Although this is incon- meet changing requirevenient it only takes 5 ments. The 1K byte limiseconds at 2400 Baud, tation meant there had to and it does allow for easy be some compromise program modification to between the three re -

0000
0000_ 0018

00 00
00

00 00
00

00
00
00

00
00
00

00
00
00

00
oo
00

00
00
00

00 00 00 00 00
00 00 00 00 00
00 00 00 00 00

0024 00 00 00 00 00 00 00 00 00 00 00 00

0030 00 00 00 00 00 00 00 00 00 00 00 00

0030 00 00 00 00 00 00 00 00 00 00 00 00

'104$ 00 00 00 00 00 00 00 00 00 00 00 00

n054 00 00 00 00 00 00 00 00 00 00 00 00

--0 00 00 00 00 00 00 00 00

00A0 00 00 110 00 00 00 00 00 00

0

0078 8E FO SO 4F 06 5F--36 55 81 03 7E FE

on84 85 36 86 04 4A 26 FD 32 39 On 00 00

0090 00 00 00 00 00 00 00 00 00 00 00 'JO

0090 00 00 00 00 00 00 00 00 00 00 00 00

00A8 00 00 00 00 00 00 00 00 00 00 00 00

00E14 00 00 00 00 00 00 00 00 On 00 00 00

0000

000t

00E4

!!

!!

!!

!!

!!

OO

00
110

'30 0O 1j0 00 00 011 1j0 OO 00 00

()UFO

00FC 0108 oo

Oo

:13
00

:1:1
oo

:00
00

iDolpo

00 22

I

0000 00

00

00

oo oo

1. Example of the display while using the Edit function.
The simple program shown is as follows:

0078 8E 007B 4F
007C 06 007D 5F
007E 86 0080 8D 0082 7E 0085 36
0086 86 0088 4A 0089 26 008B 32
008C 39

F080
55 03
FE85
04
FD

DELAY S1

LDS £$F080 CLRA
TAP
CLRB LDAA £$55 BSR DELAY JMP CONTROL
PSHA LDAA £04 DECA BNE $1 PULA
RTS

The pointer is at location 007E.

quirements outlined above so, if anything, the emphasis was in favour of program development capabilities. In particular MIKBUG, the original standard Motorola 512 byte monitor, and similar related variations do not support modern I/O systems and have only slow and limited debugging facilities.

MIKBUGTM

Compatibility

The monitor described
here retains a good num-

ber of MIKBUG compati-

ble subroutines and although their coding and

locations are different

they do achieve the same end results. The follow-

ing are included: 1. CONTROL, the nor-

mal re-entry point.

2. Output to VDU:

OUT2H,

OUTHL,

OUTHR,

OUT4HS,

OUT2HS, OUTS, and OUTEEE. (Note that PDATA could not be squeezed in, but commer-

cially available software usually has it built in).

3. Input:

BADDR,

BYTE, INHEX, INEEE.

All these operate from

keyboard or tape, so that a MIKBUG format tape can be loaded, if neces-
sary, by use of a short

routine relying heavily on the monitor.

Input/Output
Looking at the program

82 PCW

listing, the section from
FEF8 to FFDD is the

The following are avail- pointed to may be overable in this monitor: written simply by typing

to a new area starting
at ZZZZ. It is not neces-

VDU driver. As most of
it has been described

G XXXX Go to

the new value. Bytes can
user be removed by typing

sary for the user to calculate the length of the

before in the ACC news program at address "R" or inserted by typ- block in advance. If de-

it will not be covered XXXX. The user pro- ing "I" followed by the sired, the effect of the

again in detail. The rea- gram runs in a stack new value.

move can be checked

son for it being so long (230 bytes) is that the

whose pointer is extrac- In both cases, the sucted from TGTSTK ceeding memory contents

afterwards, with the Edit command. This routine

24x40 format is not (FOFA in the scratchpad close up or move out as (FDEA-FE04) is short

simply divisible by binary RAM). After a system necessary up to the end and fast because it uses

numbers, and therefore reset the stack will be address (initially YYYY). the stack pointer as a

some calculation is neces- from FOEO down to The new end address is data counter in the

sary. The HOME routine FODA, but after escap- displayed for reference at absence of a second

can be used at any time,
even when a user pro-

ing from a user program the bottom of the screen. this value could be inde- This system allows fast

index register on the MC6800. You cannot, of

gram is running, because terminate. It is thus good and easy interactive edit- course, move a block for-

it is called by a keyboard practice to make sure ing of machine code in wards to a new area

interrupt (see FED01 and that your own programs small or large chunks. In which overlaps the old

and it is transparent, i.e. set their stack pointer at the process it does away one. . . it will overwrite

it saves and restores all an early stage.

with the need for a num- itself. In this case you

registers that it uses so as Continue from an ber of separate com- have to move it first to

not to disturb the user escaped point in a mands to manipulate a spare area and then to

program.

program. This will only memory contents. The its destination.

The selections from work properly if the tar- edit routine runs from

FEB9 to FEBD and get stack has been initiali- FC5B to FCE1; it uses T WWWW XXXX YYYY

FEF4 to FEF7 handle sed to some area not used the MEMPRINT subrou- ZZZZ This is a software

the keyboard input. Its by the monitor (try LDS tine at FC20 to FC5A to single step and trace rou-

simplicity shows one of £$F080 for example). print the display. It tine that provides a

the advantages of using

should be exited by typ- powerful debugging tool.

an interrupt driven key- L XXXX Loads a binary ing a non -hex character, It traces a target program

board. FEC8 to FEF3 tape into memory from such as a space.

WWWW to XXXX, start-

handles the non-maskable address XXXX. In this

ing at instruction address

interrupt itself, having mode the test of the M XXXX YYYY ZZZZ ZZZZ. It needs a spare

been called by the vector data register switches at Block move of memory block of memory which

at FFFC. The ability to FEB9 is bypassed and from XXXX to YYYY you define to start at

break into a user program their position is imma-

and escape from it (e.g. terial. When the tape has if stuck in a loop) is the finished it is necessary to
other advantage of an use the Escape key to
interrupt driven system. return to CONTROL. The rather fiddly bit from FED9 to FEEB (19 D XXXX YYYY Dump bytes) is necessary to a binary tape from cater for the situation address XXXX to address where a user program has YYYY. This routine can stopped at a WAI instruc- be used to dump any area tion, to await a key- of memory including the board input. Press the monitor itself. The pro-

den
00711
007C 007D 007E 007F
0081
0086 0087
0089

8E F080 F9 FF FF FFFF FOSO

4F

F4 FF 00 FFFF F080

06

CO FF 00 FFFF F080

5F

C4 00 00 FFFF F080

30

C4 00 00 F081 F080

86 55 CO 00 55 F081 F080

8D 03 CO 00 55 F081 F07E

36

CO 00 55 F081 FO7D

86 04 CO 00 04 F081 FO7D

4A

CO 00 03 F081 FO7D

Home key; after homing gram starts at FE13 by 008A 26 FD CO 00 03 F081 FO7D

the screen, it re-establish- calling INADDS, a useful 0089 4A

CO 00 02 F081 FO7D

es the WAI condition, subroutine to get a pair (without that the user of addresses from the

program would press on keyboard. When the

regardless).

dump is finished it

returns to CONTROL.

Commands

E XXXX YYYY Edit a

To use the monitor for block of memory from

program development, XXXX to YYYY. This
commands are entered at routine is one of the the keyboard and decod- central features of the

008A
0089 008A 0089 008A 008C 008D
40083

26 FD CO 00 02 F081 FO7D

4A

CO 00 01 F081 FO7D

26 ED CO 00 01 F081 FO7D

4A
26 FD 32
39

C4 00 00 F081 FO7D
C4 00 00 F081 FO7D C4 00 55 F081 FOIE C4 00 55 F081 F080

7E FE85

ed by FE8F to FEA5. monitor. It displays on

In this case, the use of a the screen the first 276 2. An extra byte (30=TSX) has been inserted at 007E and

keyed jump table is more bytes of memory conten- then the program run in the single step and trace mode. The

efficient than successive ts starting from XXXX. order of the columns is: address, opcode, operand if any,

comparison with a list of characters. It also allows easy modification and expansion; in fact, space
has been left at FFF3 to FFF6 for the inclu-
sion of your own defined

The format is 23 lines
and each contains the
address at the start of line and 12 bytes of
memory. A cursor, which
is initialised to the first byte in the top left hand

condition codes register (CCR), B,A,X,SP. Note the movement of the stack pointer on entering and leaving the subroutine and the further movement when pushing and pulling data onto the stack; also how the Z (=Zero) bit 2 of the CCR is set at 0089 when A has been finally decremented to zero. Details like these of the internal workings of the processor are clearly demonstrated by this sort of display.

command. This could corner, points to one of

even be a prefix to a the locations and may be

whole group of com- moved left, right, up or

mands, contained in down by the keys #-,

another area of memory. t, and C/R. The byte

PCW 83

YYYY and must be of the same length as the target. Any areas of data must be excluded from both and left intact as they are used by both the target program and
the trace routine (or "host" program).
To understand how
this routine works you
should know that manual debugging of a user pro-
gram uses the software interrupt (SWI, opcode 3F) as a breakpoint. The SWI is placed at a strategic point in the target so that, when the program gets to it, it res-
ponds to the artificial interrupt by dumping the processor registers on the stack and jumping to the address contained at FFFA. It is then possible manually to examine the
stack to see what was happening at this point.
There are some problems with this approach: 1. The program may
never get to the SWI.
You can counter this by placing several SWIs in different likely places in the hope of hitting one of them. 2. The process of substituting bytes of target with SWIs, remembering them, and replacing them afterwards is tedious and prone to error.
3. The whole business
takes a long time and a
lot of mental effort. The solution adopted
here is to extend this
method to its logical conclusion by filling the whole of the target program, except for the instruction being executed, with SWIs. Whatever the instruction does it
should now hit an SWI next. If it should jump
right out of the target
program this will be
obvious from the dis-
play, so you will at least have located the problem instruction.
The trace, starting at FDOF, sets its own SP at FOCF, and the target's at FOB8 (to allow the target to run in an independent stack right from the start, and both
target and host to be
independent of the monitor stack). As soon as (or if) the target sets its own SP, this is used from
then on. At FD32 the
host calls the Transfer

routine to save a copy of
the target in the area
from YYY Y, and to fill the original with SWIs. At FD37 it starts a line by line print by displaying the first instruction address. From FD48 to FD74 it measures the length of the instruction
(1, 2 or 3 bytes), then
displays it. At FDA7 the program waits for the single step command from the keyboard (->) and at FDB2 it executes the one instruction. Usually an SWI will be encountered next which will vector to FDB9 and fill the rest of the display
line with the resulting
register contents for your
information. At FDE1
Transfer again prepares
the target area and the
program then loops
round to the start again and waits for the next
single step command.
The result is a line by line trace of the program flow that shows exactly what happens at each step. Apart from its diagnostic use this is a first rate educational tool for showing the internal workings of the micro-
processor.
If the target gets into a long loop (e.g. a timing loop) you can skip to the
end as follows:
1. Press the Escape key
once. Do not press it
again while you are temporarily out of the trace routine. 2. Knowing from the display where the target SP is, use the Edit command
to examine the 7 bytes
below it. These correspond to the CCR, B, A, X, and PC registers. You can then modify the CCR, B, A, and X registers (but not the PC) as necessary to shorten the loop. Press the space bar to leave Edit. 3. Alternatively you can modify areas of data in memory in the same way. 4. Press the continue key (t) to return to the Trace routine.
The only types of
program that cannot be handled by the Trace are
those with self modifying code or those with areas of data and program intermingled.
When you have finished, it is necessary to use
the Move command to

shift the program copy sophisticated tape dump

from YYYY back to and load formats with

WWWW.

file names and error

Conclusion

checking before transfer from a buffer to storage,

This monitor has been in unlike MIKBUG which

use for about six months loads each block first and

now and has made it then checks the address

possible to tackle and data to see if it got it

programs like 8K BASIC, right!

study them and modify 5. An even bigger Edit

them to run on the 77-68 display if you have a

without too much bigger VDU format.

difficulty. If you have 6. Software vectoring of

more than 1K available interrupts to allow more

for your monitor I than one interrupt driven

suggest the following peripheral at a time, and

inclusions:

also multi -programming.

1. Automatic return of Finally, may I add that

a traced program to its suggestions for improve-

original location when ment of the existing

finished.

monitor will always be

2. Automatic decoding welcome.

and display of the indivi- Copies of the monitor are

dual CCR flags during available on 2708

Trace.

EPROM at £14.10 +

3. Addition of the VAT. Contact John at

MIKBUG PDATA rou- 1 The Spinney, Fleet,

tine.

Hants. Telephone: 02514

4. Inclusion of more 29553.

Program

FC00 FCO2 FC04 FC06 FC07 FC09 FCOB FCOD FCOF FC11 FC12 FC14 FC15 FC18 FCIA FC1C FC1E FC20 FC23 FC26 FC29 FC2B FC2C FC2F FC31 FC33 FC35 FC38 FC3B FC3D FC3F FC41 FC43 FC45 FC47 FC48 FC4A FC4D FC4E FC4F FC51 FC53 FC55 FC58 FC5A FC58 FC5E FC60 FC61 FC64 FC67 FC69 FC6B FC6C FC6E FC70 FC72 FC73 FC75 FC77 FC79 FC7C FC7E FC81 FC83 FC86 FC88 FC8A FCBC FC8F FC91 FC94 FC96 FC99 FC9B FC9E FCAO FCA2 FCA4 FCA7 FCAA FCAB FCAE

A6 00 8D 05 A6 00 08 20 04 44 44 44 44 84 OF 88 90 19 89 40 19 7E FE F8 80 E6 80 E4 86 20 20 F5 BD FF 1C FE FO Fl FF FO F6 C6 17 37 CE FORS C6 DC 80 CO 80 CB FE FO F6 BC FO EF 26 06 86 50 80 D4 20 02 80 D7 8D B9
50 26 EE FF FO F6 33
541
26 DA 86 3C 80 CO CE FO F3 8D BE 39 BD FE 05 BD CO 3E B6 FO FE FE FO EF 81 50 26 03 08 20 2D 81 5B 26 03 09 20 26 81 OD 26 OF B6 FO FU 8B OC B7 FO FO 24 03 7C FO EF 20 D6 81 5E 26 14 86 FO FO 80 OC B7 FO FO 24 03 70 FO EF 20 C3 FF FO EF 20 BE 81 49 26 19 BD FE 55 FE FO F3 OB FE FO F3 09

OUT2H

LDAA

8SR OUTHL

LDAA

INX

BRA OUTHR

OUTHL

LSRA x 2

LSRA x 2

OUTHR

ANDA £000001111

ADDA

Allison's algorithm - saves 2 bytes

DAA

average of 26 cycles per character

ADCA f$40

DAA

DUTCH OUTOIS

JMP OUTEEE
BSR OMB

OUT280

BSR OUT2H

OUTS

LDAA f'space

BRA DUTCH MEMPRINT JSR HOW

LOX STARTING

STX TEMPO

LDAB f$17

page length

NEWLINE PSHB

LDX fTEMPX

LDAB USOC

line length

B5R OUT2H

BOO OUT2H

Print address

LDX TEMPO

NEWBYTE CPA MEMLOC

I BNE MEM1 ,.LDAA f..e.

Print pointer against the byte

,'fBSR DUTCH

BRA MEM2

MEM1 : BSR OUTS

1EM2

8SR OUT2H

DEC B

BNE NEWBYTE

STX TEMPX

fULB

DEC 8

BNE NEWLINE

LDAA

BSR DUTCH

LDX LENDING

B5R OUT4HS

Print end address

EDIT

RTS
JSR MAUS

End of MEMPRINT

ED6

BSR MEMPRINT

WAI

Get keyboard command

LDAA KBUFF2

LDX MEMLOC CMPA

Cursor right?

BNE EDI

INX

BRA ED2

EDI

CMPA 1.4-

Cursor left?

BNE ED3

DES

BRA ED2

ED3

CMPA

Cursor down?

BNE ED4

LUAA MGMLUL LOW

ADDA 800C

STAA MEMLOC LOW

BCC ED5

INC MEMLOC HIGH

ED5

BRA ED6

ED4

CMPA f'f

Cursor up?

BNE ED7

LDAA MEMLOC LOW

SUBA f$DC

STAR MEMLOC LOW

BCC ED8

DEC MEMLOC HIGH

ED8

BRA ED6

Ern

STX MEMLOC

BRA ED6

E07

CMPA 1.1

Insert?

BNE ED9

JOB BYTE

LDX ENDING

1NX

SIX ENDING

EDlO

DEX

84 PCW

FCAF E6 00FCB1 E7 01

LDAB X STAB 1,X

FCB3 BC FO EF

CP% MEMLOC

FC86 26 F6 FCB8 07 00

BNE ED1O STM X

FCBA FCBB FCBD FCBF FCC1 FCC4 FCC6

08 20 DE 81 52 26 13 FE FO EF E6 01 E7 00

ED9 8012

INX BRA ED2 CMPA l'R BNE 8011 LDX MEMLOC LDAB 1,X STAB X

Remove?

FCC8 08 FCC9 BC FO F3 FCCC 26 F6

INX CPX ENDING BNE ED12

FCCE FCCF FCD2 FCD4

09 FF FO F3 20 80 BO FE 69

ED11

DES STX ENDING BRA ED6 JSR INHEX1

FCD7 BD FE 57 FCDA 87 00

JSR BYTE1 STAA X

FCDC FCDD FCEO FCE2

08 FF FO EF 20 FO FE FO E2

TRANSFER

INX SIX MEMLOC BRA ED6 LOX TGT START

End of Edit routine

FCES FCE8 FCEA FCED FCEF

BE FO EC C6 3F 86 FO FO 84 OF 26 04

TRAN4

LDS M.S.A.

LDAB f$3F

LDAA VDULOW

Used as a flag

ANDA 1%00001111

BNE TRANI

FCF1 A6 00 FCF3 36

LDAA PSHA

Included if flag = 0

FCF4 FCFS FCF7 FCFA FCFC FCFF FD02

31
E7 00 BC FO EA 26 03 BF FO E8 BC FO E4 27 04

TRAM TRAN2

INS STABx CPX 1.A. BNE TRAN2 STS H.I.A. CPA TGT END BEQ TRAN3

Sets Mirror Instruction Address

Fong U8 FOOS 31 1006 20 E2
FMB BE FO CD
FOOB 39 FDOC 7E FE 44 FOOF BE FO CF 1012 CE FO 88 F015 FF FO E6 F018 8D F2 FD1A FF FO E2 FD1D BD ED FD1F FF FO E4 FD22 80 EB FD24 FF FO EC FD27 8D E3 FD29 FF FO EA FD2C FF FO BE FD2F BD FF lC FD32 80 AE FD34 CE FO EA FD37 BD FC 18 FD3A 8D 77 FD3C FE FO E8 FD3F A6 00 FD41 81 3F FD43 26 03 F045 7E FE 82 FD48 81 BC FD4A 27 22 FD4C 81 BE FD4E 27 18 F050 81 CE FD52 27 IA FD54 84 FO

TRAN3 BAD1 TRACE
TRACE1
TRACE2

INX

INS

BRA TRAN4

LDS £HOSTSTK-2 To enable correct RTS

RTS

JPP BADDR

LDS fHOSTSTK Beginning of single step 8 trace routine

LDX ITGTSTK

Trace target stack

STX TEMPSTK

To allow Continue command

BSR BAD1

STX TGT START Start of target program area

BSR BAD1

STX TGT END

End of target program area

BSR BAD1

STX M.S.A.

Mirror program start address

BSR BAD1

STX I.A.

Instruction address

SIX P.C.

Sets P.C. in target stack

JSR HOME

Clear screen

BSR TRANSFER

LDX 81.A.

JSR OUT4HS

Print Instruction Address

BSR OUT51

LDX M.I.A.

LDAA X

CMPA 183F

Is it a SWI?

BNE TRACE2

,114, ESCAPE

If so

CEPA f$8C

Start disassembly of Opcode

BEQ THREE

CMPA UBE

BEQ THREE

CMPA £SCE

BEQ THREE

ANDA 1011110000

FD56 81 50 FD58 22 OC FDSA 81 20

CMPA f$50 8H1 MORE CMPA f$20

FD5C FDSE FD60 F062 FD64 8066 FD68 FD6A FUEL FD6E FD70 fD72 FD75 FD77 FD78 FD7A F070 FD7F FD82 FD83

26 04 C6 02 20 OE C6 01 20 OA 85 10 27 F4 85 20 27 FO C6 03 86 03 B7 FO F5 BO 3F 09 A6 00 FE FO EA A7 00 7A FO F5 5A 27 10

TWO ONE MORE
THREE TRACE3
PREP1

BNE ONE LIMB £2 BRA TRACE3 LDAB £1 BRA TRACE3 BITA f$10 BEQ TWO BITA BED TWO LDAB f3 LDAA f3 STAA CKSM BSR OUT 2/101 DEX LORA X LDX I.A. STAA X DEC CKSM DECB BEQ PREP2

010 9VErf S.x0C\11

.);101 9/. ,BVE al&

8

Length of, Print PI

r

'

kactyt.r. oPPAEw .31.6

Get instruNtArtlAvar ,1 mimic

121J

VIM 819

FD85 08 F086 FF FO EA

INX STX I.A.

F089 FE FO E8 FD8C 08 FD8D.FF FO E8 F090 BD FC 00 FD93 20 E2 FD95 7D FO F5 FD98 27 OB FD9A 80 17 FD9C 8D 15 FD9E 7A FO F5 FDA1 20 F2 FDA3 8D OE FDA5 80 OC FDA7 3E FDA8 B6 FO FE FDAB 81 50 FDAD 26 F8 FDAF BE FO E6 FDB2 36 F083 7E FC IC FDB6 7E FC IA FDB9 BF FO E6 FDBC 8E FO CF FDBF FE FO E6

PREP2
PREP3 PREP,*
OUTS1 OUT2HSI SWINT

LDX M.I.A. INX STX M.I.A. JSR OUT2H BRA PREP1 TOT CKSM BEQ PREP3 BSR OUTS1 BSR OUTS1 DEC CKSM BRA PREP2 BSR OUTS1 BSR OUTS1 WAI LDAA KBUFF2 CMPA BNE PREP4 LDS TEMPSTK RTI Jt4P OUTS MAP OUT2HS STS TEMPSTK LDS MOSTSTK LDX TEMPSTK

Print operand
Get command from keyboard Wait for single step command Run next instruction Start of SW1 service routine

FDC2 FDC3 FDC5 FDC7 FDC9 FDCC FDCE FDCF FDD2 8004 FDD7 FDD8 FDDB FDDE FDE1 FDE4 FDE7 FDEA

08 8D Fl BD EF 13D ED BD FC 18 AE 00 34 BF FO EA AF 00 88 FO CF 08 FF FO F6 CE FO F6 BD FC 18 BD FC E2 BD FE FC 7E FD 34 8D 19

MOVE

INX BSR OUT2HS1 BSR OUT2HS1 BSR OUT2HS1 JSR OUT4HS LDS, X DES STS I.A. STS X LDS IHOSTSTK INX STX TEMP% LOX LUMP% JSR OUT4HS JSR TRANSFER JSR OUTC/R 314P TRACE] BSR INADDS

Print CCR Print 8 Print A Print X Get P.C.41 Correct it Update Instruction Address, and P.C. on target stack.
Correct S.P.
Print corrected S.P. Refill with SW's 8 update M.I.A.
and round again Block Move routine

FDEC 08

INX

'

FRED FF FO F3 FDFO BD 52

FDF2 35

STX ENDING*1 BSR BADDR TXS

FDF3 31

INS

FDF4 FE FO Fl

LDX STARTING

FDF7 A6 00

MOVE1

LDAA X

FDF9 08

INX

FOFA 36

PSHA

FDFB 31 31

INS x 2

FDFD BC FO F3

CPA ENDING -0

FE00 26 F5

BNE MOVE1

FE02 7E FE 85 CONE

JMP CONTROL

FE05 13D 30

INADDS BSR BADDR

Get start 8 end addresses

6E07 FF FO Fl

STX STARTING

8800 FF FO EF
HOD 8D 35

STX MEMLOC
BSR BUM

For MEMPRINT routine

FEOF FF FO F3

SIX ENDING

FE12 39 FE13 8D FO

DUMP

RTS BSR INADDS

To tape in binary thyme

FE15 FE FO FT

LDX STARTING

FE18 FE1A FE1D FEIF

80 14 B6 F4 01 85 02 27 F9

DUMP1

BSR INITZE LDAA ACIA S BHA 1%00000010 Ix busy? 8E0 DUMP1

8E21 A6 00 FE23 B7 F4 00 FE26 BC FO F3

LDAA STAA ALIA D CPX ENDING

Dump a byte

FE29 27 5A

BED CONTROL

FE2B 08

INX

FE2C FE2E FE30

20 EC 86 23 87 F4 01

INITZE

BRA DUMPI LDAA f$23 STM ACIA C

Subroutine to prepare ALIA

FE33 47 FE34 B7 F4 01

ASRA STAA ACIA C

No parity, 2 stop bits

FE37 39 FF38 80 OA

LOAD

RTS BSR BADDR

Load a binary tape until stopped

FE3A 80 F2

BSR INITZE

FE3C BD FE BE LOAD1

JSR STATUS

Get a byte

FE3F A7 00

STAA X

FE41 FE42 FE44

08 20 F8 BD FC IC

BADDR

INX BM LOAD1 JSR OUTS

round again Mikbug routine, from keyboard or tape.

FE47 EID OC

BSR BYTE

FE49 87 FO F6

STAA TEMPX HI

FE4C BD 07 FE4E B7 FO F7

BSR BYTE SEM TEMPX LO

FE51 FE FO F6

LOX TEMPX

FE54 39

RTS

FE55 8D 10

BYTE

BSR INHEX

8E57 48 48

ASIA x 2

FE59 48 48

ASLA x 2

FE58 16

TAB

FESC 130 09

BSR INHEX

FE5E 18

ABA

FESF 16

TAB

FE60 FB 80 85

ODOR CKSM

FE63 F7 FO FS

STAB CKSM

Update Checksum

FE66 39

RTS

FE67 8D 50

INHEX

BSR INEEE

FE69 80 30

INHEX1

SUBA 6930

FE6B 2B 18

BMI CONTROL

FEED 81 09

CMPA £909

FE6F 2F OA

BLE 1NTHG

FE71 81 11

CMPA f$11

FE73 28 10

BMI CONTROL

FE25 81 16

CMPA f$16

8E77 2E OC

BGT CONTROL

fE79 80 07

SUBA £007

1E7B 39

INDIG

RTS

FE7C BE FO DA RESET

LDS ICTRLSTK-7 Initialises target stack if required

FE7F BD FF IC

JSR HOVE

Clears screen

1(82 BF FO FA ESCAPE

STS TGTSTK

1E85 81 FO El CONTROL LDS £CTRLSTK

FE88 BD FE FC

JSR OUTC/R

Carriage return

FE8B 86 2A

LDAA f'.

FEBD 80 69

BSR OUTEEE

FE8F BD 28

BSR INEEE

Get keyboard command

1E91 CE FF DE

LOX £310818

Point at keyed jump table

FE94 E6 00 FE96 Cl 00

CONTI

LDAB X CMPI3 800

Get key End of table?

FF98 27 EB

BEQ CONTROL

If character not recognised

FE9A 11

CBA

FE9B 27 05

BED FOUNDIT

FE90 08 08 08

INX x 3

Point to next key

FEAT 20 F2

BRA CONTI

FEA2 EE 01

FOUNDIT LDX 1,X

FEA4 6E 00

JPP X

Jump to required routine

FEA6 80 9C

GO

BSR BADDR

FEAR FE FO FA

LDX TGTSTK

FEAR B6 FO F6

LDAA TEMP% HI

PEAS A7 06

STM 6,X

FEBO B6 FO F7

LDAA TEMP% LO

FEB3 A7 07

STAA 7,X

FEB BE FO FA CONTINUE LDS TGTSTK

Target P.C. prepared Target S.P. prepared

FEB8 38

RTI

and go

FEB9 136 FO FF INEEE

LDAA SWITCHES Mikbug compatible routine.

FEBC 27 36

BEQ KBD

If parallel input required (sws..0)

FEBE 86 F4 01 STATUS

LOGO ACIA S

If serial input required.

FEC1 44

LSRA

Rx ready?

FEC2 24 FA

BCC STATUS

FEC4 B6 F4 00

LDAA ACIA D

FEC7 39 BEGS B6 FB FF NMI

RTS LDAA KBUFF

NMI handler

FECB FECD FECF FEDO

81 03 27 03 36 81 04

CMPA 0003 BEQ ESCAPE PSHA CMPA 1004

Escape? Home?

FED2 26 1B

BNE NMI]

FED4 FF FO F8

STX TEMPX2

FED7 8D 43

BSR HOW

FED9 30

TSX

FEDA EE 06 FEDC 09

LDX 6,X DEX

Get last byte before NMI occurred.

FEDD A6 00 FEU 81 3E FEE1 26 09

LDAA X CMPA f$3E BNE NMI2

Was it WAI?

FEES 30

TSX

FEE4 6D 07 FEE6 26 02

1ST 7,X BNE NMI3

FEE8 6A 06 FEEA 6A 07

NM13

DEC 6,X DEC 7,X

Re-establish WAI after R11

FEEL FE FO F8 NM12

LDX TEMPX2

FEEF 32

NMII

PULA

FEFO B7 FO FE

STAA KBUFF2

FEF3 3B FEF4 3E

RTI

KBD

WA1

Get keyboard input

FEFS 86 FO FE

FEF8 81 OD

OUTEEE

LDAA KBUFF2 CMPA l'C/R

Mikbug compatible, echoes INEEE

FEFA 26 39 FEFC 37

OUTC/R

BNE PUTVDU PSHB

Entry to print carriage return

FEFD 36

PSHA

FEFE 86 20

LIMA £'space

FF00 F6 FO FC OUT1

LDAB VDU HI

FF03 Cl F8

CMPB f$FB

FF05 27 04

BEQ OUT2

FF07 8D 2C

BSR PUTVDU

Print space

FF09 20 F5

BRA OUT1

FFOB F6 FO FD OUT2

LDAB VDU LO

FFOE 53 FFOF C5 07

COMB BITE f07

End of line?

FF11 27 04 FF13 80 20

BED ENDOUT BSR PUTVDU

Print space

PCW 85

CALCULATOR rL°i/1

;1

Dick Pountain analyses and reports on the micro -associated world of programmable calculators.

GETTING IT TAPED stored on tape and added package, though extracts to existing programs in I have looked at from the

the machine.

manual suggest that it will

I have used the adaptor be far superior to Casio's

with three different recor- own User Manual. The

ders including an 'electro- programs include all of

nic memo -pad' (which Casio's own library pro-

provides great portability) grams ready to load, plus

and found loading and a variety of educational,

saving very easy and reli- games and personal finan-

able on all of them - ce routines and general

provided the output purpose subroutines for

volume is set as high as advanced programmers.

possible.

The pre -production

The FA -1 is also necess- sample contained some

ary for the music synthe- quite sophisticated games

sizing function of the with ingenious use of the

calculator, about which Casio's display formats,

the less said the better. including one which

The world didn't need scrolls a 10 by 10 field,

Rolf Harris and the Stylo- line by line over the dis-

phone; it needs a robot play. Another routine

Rolf Harris even less. provides, via data packing

IN My glowing review of data file is found. the Casio FX501/502P For speed, it is best to

To summarise then, the Casio FX502P with

techniques, the equivalent of 100 independent

last month ("This one will first roughly locate the the FA -1 and a mini memories - each to store

run and run . . ."), I file using tape counter cassette recorder provides a single digit variable. promised a follow up on readings, but if necessary, a pocketable computing The Master Pack will

the FA -1 adaptor. Here it the calculator will search system which is in some be available from dealers

is.

a whole tape - displaying

Tempus of Cambridge each file name as it passes,

ways unrivalled, even by
the £150 plus Hewlett

after the middle of October and I shall report more

kindly supplied the adap- but loading only the de- Packard and Texas machi- fully when a production

tor and also exchanged signated one.

nes, particularly in regard sample is available.

the 501 for a 502 (which, The maximum time of ease of learning.

Look sharp as I suspected, is just like for a LOAD is about 15 As a footnote, I must
the 501, but more so). seconds... corresponding- clarify a wrong impression

The FA -1 is a small ly shorter for smaller pro- my review last month may A new pocket calculator

cradle into which the grams. Therefore a C-60 have given. I said that the from Sharp, the EL -5100,

calculator slips, connec- cassette can hold over 501/502 have only ten has reached me; although

ting via a gold plated, 7 - 200 programs.

labels available for use in it won't interest PCW

pin socket. The cradle As alluded to earlier, programs. Of course, since readers particularly, since

has a lead ending in two program and data are there are ten i.Idependant it is not truly progra-

mini jack plugs which fit stored in separate files, program registers; all ten mmable, nevertheless it

into the microphone and unlike most magnetic labels may be used ten has some clever features

earphone sockets of a card calculators which time over, if the program which may give pointers

standard cassette record- store the whole program is broken down into to the future.

er. Cassette radios, mono and data register contents and stereo cassette decks on one card. The separate

modules (which is a habit the machine rapidly en-

Immaculately presented in the inimitable

and even mini cassette way is of much more use courages). This gives a Sharp fashion, it's dis-

dictation machines will as the same program can potential of 100 labels, tinguished from an ordi-

work. Some hi-fi cassette be used with any number which is quite sufficient. nary scientific calculator

decks will require a 5 -pin of different data sets.

by its unusually large

Master pack DIN plug to be substitu- Also, execution of a pro-
ted for the mini jacks. gram may be halted part-

LCD display. This display is alphanumeric (though

Saving and loading are way through and a fresh Following on from the only a part alphabet is

performed in the same data file loaded (manual- above, I have been in- provided).

manner as on a micro ly, of course) which formed by Premier Publi- When you enter a

computer. The instruc- greatly increases the data cations that they are simple arithmetic calcula-

tion SAVE is followed handling facilities of the launching the Master tion problem, the whole

by a three digit file 502. In addition, the load Pack, a software package calculation is displayed,

number, and is executed instruction will fill all or for the Casios. It takes the e.g. 5.7 + 3.8 x 6.4. On

from the keyboard with any of the ten program form of a cassette con- pressing = the answer is

the recorder running. registers. Therefore seve- taining over 160 programs displayed. But more in-

Loading is by LOAD and ral different programs and a 60 page manual triguing is the Algebraic

the same file number. may be loaded into the which includes an intro- Expression Mode. In this

The calculator searches machine simultaneously duction to programming, mode, algebraic expres-

for the named file and (size permitting), or parts advanced programming, sions of any complexity

displays, say, FP005 of a large program may plus full program docu- may be written in stan-

when a program file is be loaded independently, mentation. At press time

found or F005 when a or subroutines may be I hadn't seen the whole

Cont. on Page 93

86 PCW

Four ofa kind!

This is it., ACIAPH Colissir VDU

Double HeiOt Characters

64 Craphics Charactows:

" ^1-4411. :

1(TV:ow/MIMI

111 MVO, " "1.m' di. yid

11111111111111111
Cursor

Acorn Computers announce with pride the fourth module in the series-a VDU interface on a Eurocard. This unit uses two very powerful devices, the MC 6845 and the SAA5050. The 6845 programmable controller provides all
the signals to drive a 625 line 50 frames per second VDU together with read addresses for the character RAM, the SAA5050 character generator then produces the necessary dot patterns to refresh the VDU. The SAA5050 produces standard teletext characters and graphics and has Red, Green and Blue outputs. This means that the Acorn system will be compatible with CEEFAX, ORACLE and PRESTEL transmissions. The Acorn VDU module in kit form is complete with sockets and is supplied with listings for programs which set up the 6845, a miniature dissassembler which displays 25 hex instructions (double or treble byte) and graphics programs. All these may be loaded and run using the Acorn system 1 monitor. Options include VHF modulator for B W. domestic T.V.and PAL colour encoder for domestic colour TV

40 characters per line 25 lines per page 5 colour graphics and characters Upper and lower ASCII Teletext graphics font Programmable cursor Hardware scroll Light pen facility Memory mapped Transparent access Single 5V supply

Acorn CPU

Acorn System 1

Order form
Send to: Acorn Computers Ltd., 4a Market Hill, Cambridge. Cambs.

PcwU

Acorn 8K Memory

MemoryACORN 0Acorncontroller @£35.00plusVAT5.25

0 Microcomputer @ £65.00 plus VAT 9.75

0 Assembled

Microcomputer @ £79.00 plus VAT 11.85

0 Memory

@ £85.00 plus VAT 14.25

0

assembled @ £100.00 plus VAT 15D0

Name Address

0 V.D.U.

@ E88.00 plus VAT 13.20

Ill V.D.U. assembled @ C98.00 plus VAT 14.70 V.H.F. Modulator to be announced Colour Encoder to be announced

COMPUTER

Acorn Computers Ltd , 4a Market Hill. Cambridge

Telephone 0223 312772

FROM: KINGSTON COMPUTERS LIMITED.

TO:

ALL PET OWNERS.

INFO:

HRSTOT.ABABY.COLCKXOORCOMOWFPMFUIILPTCSUEEORTENESQRSUYSIESPTRMEVEMICNSETS WEGO COMPUTERS

DATE: 15.10.79 REF: KC/PCW/9/1

0536-83922.

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ONCE STOCK CLEARED.

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Please mention PC W when replyinff trs

ON THE LINE
For almost a year now, David Hebditch in his 'On the Line' series has been expounding the basic concepts of using your personal computer to communicate with other systems over the public telephone network.

HIGH-LEVEL PROTOCOLS
By the way of review, we have now explored the basic hardware
and software mechanisms for interfacing personal computers to the public telephone network and for moving blocks of data between processors with a minimal level of error control.
This may well be adequate for most users to be able to establish simple point-to-point 'conversations'. However, in order to determine what to do with this
capability it may be useful to return to base and consider our
original ideas for the practical application of personal computer
networking. Let's forget (for the time being)
the medium -term possibilities of using Prestel, Teletext and tele-

conferencing etc. The most practical (and useful) applications in the short-term are listed below. 1. Conversations: Simply sending messages between systems. The benefits of this are:
a fast (and relatively cheap) way of sending someone a
message - electronic mail?
an effective way of using the
telephone for deaf people. a means of setting -up calls for other purposes (see below) - given the correct data link
control, a basis for emulating
a terminal for linking to
another, larger computer (eg. a time-sharing service or data-
base provider). 2. Program Transfer
a means of swapping programs with another user. -a means of sending the fixes to make the previous version of the program work. It is technically feasible for software companies to use this as a method of distributing programs. Of course, the number of prospective customers with a communications capability needs to be big enough to make the investment on their part worthwhile and it may

be some time before this is achieved. 3. File Transfer is functionally
very similar to program transfer but involves the shifting of data from one processor to another. This is more likely to be of use in a business system than in a domestic environment. For example, details of goods received at a warehouse could be transmitted to the order -processing computer for addition to the
stock -on -hand file. The major difference between program transfer and file transfer is one of data
format and this will be discussed later in the article.
I did consider including a category for interactive game -playing. The protocol required is, however,
a function of the type of game involved. In the case of video
games very little information needs to be sent (eg. the eight -bit
value of a game -control) but it must be sent quickly (to avoid missing the ball!) In view of this and the relatively unimportant nature of the application, the use of a data link control with error handling would probably be too cumbersome. Other games like

rANNOUNCING.. 11E PERSONAL COMPUTER NETWORK'

The number of users with some form of communications capability has now reached a high enough level to justify the introduction of the 'Personal Computer Network'. The network will comprise a directory published in Personal Computer World (and periodically updated). The directory will include an entry for each reader who is interested in linking up to other enthusiasts and will list his name, telephone number, type of system, times available and applications. If you wish to partici-

pate, please complete the form below and send it to Personal Computer World.
During the Personal Computer World show, David Hebditch will be demonstrating data communications on a number of popular systems, including the Apple II, Pet and Nascom I. He will be available to provide assistance and answer any questions you may have about networking in general and the Personal Computer Network in particular.

Please register me as being interested in Personal Computer Networking. Name: Address:
Telephone No:

I have the following type of communi-

cations interface: I can transmit at the

following

Tick
speeds310100bbiitt//ss

1200 bit/s

I have a Post Office modem: I use an acoustic coupler:

0

I can act as an originating station: a receiving station:

0

both:

Other comments:

Computer System: ___

__

I do not yet have a communications interface, but would like to he kept informed of developments:

Tick Date: Signature:

PCW 89

`We stock 20 different
makes of computer.
So our only vested
interest is
customer
satisfaction'
Bill Cannings, Managing Director
Businesses can only improve their efficiency with computers if they buy exactly the right kind of equipment and software for their needs. The problem can be in matching their needs with what the market can supply at any one time.
At the Byte Shop and Computerland we have the widest range of computers available from any single source. We have deep-rooted systems know how going back over 10 years, so you get not only a refreshing breadth of choice, but also high level impartial advice from computer specialists on what to buy.
Our business is computers and only computers, so you will be talking to people who really understand their subject. Once you have taken the decision to visit us, you are already a good way towards choosing the right computer for your needs.

Branches at:

Ilford

Nottingham

426 428 Cranbrook Road,

92a Upper Parliament Street

Gants Hill, Ilford. Essex IG2 6HW Nottingham NG1 6LF

Tel. 01-554 2177

Tel. 0602 40576

London 48 Tottenham Court Road. London W185 4TD Tel. 01-636 0647
Birmingham 94 96 Hurst Street, Birmingham 85 4TD Tel. 021-622 7149

Manchester 11 Gateway House, Piccadilly Station Approach. Manchester Tel. 061-236 4737
Glasgow Magnet House Waterloo Street Glasgow

Glasgow Tel. 041-332 2468

THE I TE sill ILIll

CITIUTTIFNIFITI IT]

90 PCW

iiima-eliniri"masta"r
Please mention PCW when replying to advertisers - it identifies you.

ON THE LINE

chess and simulations could be

handled using the conversational

mode. To cut a long story short, I

don't think that any special pro-

tocol is needed for game -playing.

A major problem with the

three modes identified above is

that of transparency. This is

caused by the transmission of

characters in the text of a mes-

sage which could be mistakenly

identified at the receiving end as

a data -link control character.

For example if you sent ASCII

ETX (3) in a message the receiv-

er will treat this as the last charac-

ter in the transmission and lose

all the subsequent characters. The

same thing could happen with

EOT (4).

"Well", you might ask, "why

do such a silly thing?" But it may

be difficult to avoid. For example,

in conversational mode, the user

may inadvertently type a control -

shift key which generates a proto-

col character. The solution here is

relatively straight -forward; impose

a rule which says that only dis-

playable characters may be inclu-

ded in messages. This means that

your dialogue control program

must 'filter out' any illegal charac-

ters.

But what if you have to transmit

the equivalent of a control charac-

ter in a message? This could

happen during the transmission of

a program in object form, or of a

data file containing integer values,

or of a program in source form

with 'funny' characters between

the quotes in a PRINT statement.

The standard way of solving

this problem is to employ some

form of 'escape logic'. This in-

volves the prefixing of each

dubious character with ASCII

ESC (27). This has to be inserted

by the transmitting program and

tells the receiving software that

the next character is not really

ETX (or whatever). The receiver

will delete the ESC.

Now the smart guys amongst

you are
happens

iaflryeaoduy waasknitngto, "Wsehnadt

`ESC'?" Clearly a spurious ESC

immediately prior to the real

ETX will cause the ETX to be

ignored. More problems. In this

case, a further ESC prefix is also

required and will cause the follow-

ing ESC to be treated as a regular

data character.

Phew! That's enough of escape

logic. Now let's move on to the

high level protocols (HLP) needed

for the three application modes.

Byte No.
0

Name Type

1 - 3

Transmission Number

Action code (Command/ Response)

5 - 9

SPARE

First of all, I have to make a disclaimer; there are no internationally agreed standards for HLP. Indeed there are no national standards, either. Whilst writing this article, I have a three-foot molehill on my desk of working papers from the various standards organizations (BSI, ISO, ECMA, CCITT, ANSI et al) as well as the
manuals for many proprietary
networking standards (IBM's SNA, Digital Equipment's DECNet and
so on). I even have articles from
BYTE and INTERFACE AGE describing the procedures used in the various US personal computer
networks. And I plan to ignore
them all. The reasons are as follows:
1. They are too complicated. 2. Although we are talking about
the establishment of a Personal Computer Network the network we are employing is the plain old telephone system rather than any
sophisticated multi node grid, permanently interconnecting a large number of users. Only two
processors will be connected at
any one time.
3. Implementation of the HLP
should be possible by the average home user. 4. Costs must be kept to a minimum. 5. Speed and reliability concerns are not so serious. 6. Which proposed 'standard' do we choose anyway?
Now having said all that, I would need an ego of enormous proportions to even consider that I might be able to come up with the definitive HLP for all future requirements. But as my ego is only of moderately large proportions (he says modestly) I am only going to suggest a possible protocol and then throw the floor open for discussion. In other words, we need a simple, minimal, easy to implement protocol with which we can play and experiment and

Comments H: Handshake message D: Dialogue P: Program Transfer F: File Transfer etc. Sequential message number (incremented automatically by transmitting program) I: Initial transmission block S: Subsequent transmission block F: Final transmission block etc. (And anything else we can think of).

develop. HLP's are all based upon

the use of a 'header' in each mes-

sage which will contain all the

necessary control information. A

possible format is shown in Figure

1. The header occurs in every mes-

sage of the exchange and compris-

es the following items: (Box 1).

It is now necessary to consider

how this header might be used for

each mode. For example, I would

suggest that the first message sent

by each processor be a handshake

message (Type 'H'). The action

code would be set to 'I' and the

transmission number to '001'. The

data area might consist of:

- User name

(20 bytes)

- Telephone number (15 bytes)

- System type

(e.g. APPLE II 24 K) (20 bytes)

A handshake message must be

received before any further

communications can take place.

At a later stage, a password might

be incorporated in the message.

Immediately handshakes have

been exchanged the system can

enter dialogue mode to facilitate

a conversation between the users.

Subsequently, file or program

transfer can be initiated.

We will look at these in more

detail in another article. In the

meantime, please send me your

ideas and comments c/o The

Editor, Personal Computer World.

-l0 CH:

-VARIABLE --

Soli HEADER sTx DATA\\

E I X L RC

Start]
of Header

Start Text End Text Longiitudinal Redundancy Check (if used)

1-3
t ' -,
Type Transmission I number Action code Spine

-1 5 6 7 8'--9
1s

PCW 91

HARD TIMES
Winchester discs -secure or not?
Comart Ltd. have just announced the Cromemco Z2H microcomputer system, incorporating a Winchester disc drive. David A. Broad, Managing Director and Chairman of Comart, gives a description of the device and presents some solutions to the data security problems imposed by it.

The emergence of high capacity The other aspect is the very stances the heads will come in con-

low-cost disc storage units housed small size of the Winchester disc tact with the media (for example

in the physical space previously drives. They can be inserted in during powering up or powering

occupied by first generation floppy physical replacement of standard down of the disc drive). Secondly,

disc drives has opened up a whole floppy drives and with very similar because of the enclosed environ-

new spectrum of applications for power supply requirements. Indeed ment, the ingress of dust and other

the small computer and intelligent their ability to work from DC foreign bodies is almost totally

controller. The technology of supplies makes them not only very restricted and build-ups of material

"Winchester" drives was first suitable for microcomputer appli- on the head is eliminated.

pioneered by IBM with their cations, but also ideal for inter- Electronic controller design also

Piccolo fixed drive systems; they national use where there may be allows individual surfaces to be

were designed to incorporate high variations in mains frequencies write protected and operating

reliability with high capacity. and voltage. Of course the drives system design further allows

The essence of the concept is a will find applications in the mini- faulty tracks to be interchanged in

disc pack fixed and spinning inside computer industry and other types the event of corruption. So the

a sealed enclosure. Air within this of small computer where low cost problem of disc failures is greatly

enclosure is internally filtered by and compactness are desirable. reduced. Write circuitry in the

convection through a micro filter, But application areas will also controllers is also normally design-

with the effect that the disc drive open up in communications cont- ed for fail safe operation so that

has its own environment.

rollers, word processors and in the incorrect combination of con-

Another aspect of the Winches- other dedicated but intelligent ditioned signals will result in no

ter concept is that the disc heads devices where high capacity is current passing through the disc

and carriage are of very low mass required.

head.

and inertia, allowing them to come

But of course failures can occur

within a very close proximity of the spinning disc surfaces. This

Security aspects

and the MTBF of the drives are commonly quoted at 10 thousand

results in a high sensitivity to flux One of the regular comments made hours or so. To back up these disc

changes which, in turn, enables a on the fixed disc Winchester drives drives several methods are often

high storage capacity. Electronics relates to their use in business proposed by the manufacturers.

are normally mounted outside the applications. Here, the necessity Firstly, individual files or trans-

enclosure itself, to minimise dis- exists for protecting and backing action records can be backed up

sipation and the necessity for up the data in the event of a catas- to floppy discs. Careful systems

access into it.

trophic failure and, indeed, advice design can enable the history of

The concept of the fixed disc is often sought from the suppliers changes to the 10M byte data base

is particularly relevant to the on the best way for a customer to to be recorded in concise form in

microcomputer market. This is a approach this problem.

transaction records. It is not

market where the owner, operator

necessary therefore for the entire

and programmer of a computer

disc to be saved in a back up

system is often one and the same person and the environment that

". . the necessity

procedure - the latest transactions are merely re -run to a different

the system is intended to work in is that of a normal office, work-

exists for protecting

disc file.
Secondly, many suppliers pro-

shop or laboratory. Exchangeable and backing up the pose the attachment of an auxiliary

disc systems should ideally only

cartridge tape system. These sys-

be operated in environments which data in the event of a tems often use high speed slewing

are controlled in terms of the dust and temperature.

catastrophic

of the tape across the head in order to record a very large amount of

The second important benefit relates to one of the prime aspects
of all microcomputer devices

failure.."

data in the shortest possible time. These devices, however, would still
take some 15 minutes or so to

their very low cost. Systems are

back up a drive, and current

being brought to the marketplace Let us first, however, consider deliverable versions of cartridge

now which enclose 11M bytes of the nature of the problem in rela- units average in the order or 4-5

hard disc storage, 64K bytes of tion to the design of the drives. M bytes total capacity. Also, the

main memory processors, and Firstly, because of the light head data rates proposed often exceed

interfaces for a VDU and printer mechanism and loading techniques, the design specifications of the

- all for less than £5,000; it's the consideration of 'head crashes' is cartridge media.

price that the micro user wants to of lesser concern. The media itself The conclusion on tape cartridge

pay.

is lubricated and in certain circum- back-up media may therefore be

92 PCW

that, because of these limitations, these drives possess, it is often would have envisaged with the

it is not the best method of pro- possible to do a complete back up introduction of the floppy disc

tecting valuable data. Indeed, it is of data in a minute or so.

drive that it would become an

the very occasion when you need It's not surprising that back up essential part of the standard

to recover using back up media procedures are often only followed microcomputer system of today.

that the best possible reliability is where the operation is quick and Now, many anticipate that the

required.

easy. Most will be content to wait microcomputer system of to-

A third method of data protec- a minute or two to undertake a morrow will include a Winchester

tion is perhaps more practicable back up, whereas 15 to 30 minutes drive as a standard feature. There

and certainly most reliable. That is
the provision of a second disc

is unpopular and hence often
avoided.

is no doubt that whole new ranges
of applications can be brought

drive which can often be run from

the same controller in a daisy
chain fashion and which may well

Conclusions

within the capabilities of the
microcomputer and that many
who up to now have been using a

have write protect key lock switches for operator protection.

Winchester technology has brought
a new impetus to the micro-

mini, on an OEM basis, are starting to consider the micro as an

With the very high data rates that computer revolution. Few people alternative tool.

Calculated Corner

Cont. from P. 86

longer than the display hand held micro which is But the impossibility of

dard algebraic form, e.g scroll off to the left. The programmed in BASIC! any sort of recursive

A2 + B2 + SIN C2

eleven memories are non- For a user who needs to operation limits its flexi-

up to 88 characters. On volatile and a full set of evaluate many algebraic bility drastically and at a

returning to the Computa- scientific and statistics functions and doesn't price of £69.90, it cannot

tion Mode, the calculator functions are provided. want to trouble to learn compare well with various

asks you for the variable The sophistication of a calculator "language" programmables in this

values (A = ?) and this display is such that, for programmed solu- cost range. Perhaps worse

evaluates the expression! surely soon, once large tions, this calculator will is that it takes away

Editing is via a flashing scale LCD displays are be useful; anyway, it's all the fun of playing

cursor, and expressions available, we will have a certainly a status symbol. computers!

PCW 93

Malcolm Peltu has made his name writing and lecturing about the nature and impact of computer -related technologies.

In the grip of
the systems monster
Why is it that a personal computing "amateur" can produce a multiprogramming operating system, compiler and utilities in a couple of years part-time work, whereas "professional" software suppliers can invest decades of man years to less avail?
"Perhaps it was because I didn't know that some problems existed, so I never encountered them", was the answer given to me by Tom Aschenbrenner who won the 1977 P.Tsonal Computer Fair competition at the US National Computing Conference (he had developed a message switching system for fellow radio hams in the Dallas area). As, another reason he added2 "I did it because I enjoyed it not because I had to, in order to earn a living." Aschenbrenner's comments would fit very pertinently into System antics by John Gall which tries humourously to analyse the behaviour of a beast which seems to run amok through so many aspects of modern life - The System. Written in a sometimes irritating, too -clever -by -half style, Systemantics offers a number of "laws" relating to systems behaviour, often paying homage to folk-lorish inventions like Murphy's Law that "If anything can go wrong, it will go wrong."
The Fundamental Theorem of Systemantics is that "New systems create new problems". According to Gall, one starts with a problem, like getting rid of rubbish. Then a system is set up to organise garbage collection and the main objective of that organisation is to manage the system rather than to solve the original garbage problem. In fact, Gall says, "for the practising systems -manager, the greatest pitfall lies in the realm of problems and problem -solving. Systems can do many things, but one thing they emphatically cannot do is to solve problems. This is because problem -solving is not a systems -function, and

there is no satisfactory systems -approximation to the solution of a problem. A system represents someone's solution to a problem but does not solve a problem.
"Solutions," he continues, "usually come from people who see in the problem only an interesting puzzle and whose qualifications would never satisfy a select committee." There could be no better proof of Gall's pudding than in the exciting tang of the home -brewing personal computer world. Aschenbrenner's remark about not being aware of the problems was true because many of the problems of software development are concerned with the complexities of managing large projects. A programmer in a Data Processing department or large software development team is likely to be less productive and less creative than a hobbyist.
Gall's most biting comments are lashed out at the dangers of trying to control complex systems. "Any large system is going to be operating most of the time in failure mode," he says, putting the boot in further with the Fundamental Failure Theorem that "a system can fail in an infinite number of ways" and that "the mode of failure of a complex system cannot ordinarily be predicted from its structure."
For programmers he has two special axioms: programs never run the first time, and complex programs never run. In a more general context, these axioms are summarised by his belief that complex systems designed from scratch never work; the only complex systems that do work are those which have evolved from successful simple systems.
I believe that computers are ideal models of Gall's system world. Operating systems which hog machine resources in order to sort out machine rather than user problems are perfect examples of how complex systems fail to tackle the problems for which they were initially created. The way in which the personal computing market has focused on the development of more human interfaces, such as colour graphics, has also shown that the computer industry as a whole proves another Gallism, "To those within a system, the outside reality tends to pale and disappear."
At the last National Computing Conference in New York, the hundreds of stands from the traditional computer industry paid lip service to "user needs" but were still essentially displaying evolutions from the grey elephants which form

Illustrations from The Cyberiad

94 PCW

BOOKFARE

their "user base". The personal computing show at the same event was filled with colour graphics, voice synthesisers and other devices that offer a human window to the computer. And the reason is that the personal computer user is also a systems developer who focuses attention to the main goal of using the system.
For larger, established computer companies, the System has other goals, like growing and extending its administrative machine, its sales targets and all those other factors that have little to do with the user.
Systemantics is a book with a serious message and you'll find it if you scratch beneath its glossy, over -jokey veneer. Anyone working a bureaucracy whose purpose is to deal with people in need should, for example, spread the message "The dossier is not the person" which is Gall's extension of a sign he saw in a smallish hospital which said "The chart is not the patient".
The underlying strength of Gall's book is that it is based on a good appreciation of General Systems Theory and cybernetics. With tongue in cheek, Gall does in fact admit that the science of General Systemantics is a spoof of General Systems Theory, an idea inspired by one Ludwig von Bertalanffy (who coined the phrase system to describe the entity concerned with the organisation of a function rather than the function itself).
In An Approach to Cybernetics by Professor Gordon Pask, von Bertalanffy's work is cited as one of the sources that lead to the study of cybernetics. Where Gall provides some glib but perceptive insights into the complexities of Systems thinking, Pask, who is a professor of cybernetics at Brunel University, takes a more scientific and mathematical approach in trying to explain the background and scope of one of the major Systems "sciences".
For example, Gall and Pask both quote Le Chatelier's Principle, derived from chemistry, which states that any natural process tends to set up conditions opposing the further operation of that process; thus equilibrium can be maintained when various forces, such as chemical reactants, are mixed in certain concentrations in a closed vessel.
Gall turns this Principle into a corner stone of General Systemantics, that "Systems get in the way and Systems tend to oppose their own proper functions". He clarifies this by the example of a research worker who is asked to define his aims and objectives to satisfy various organisational Systems needs - like touting for research money.

So he makes up objectives in order to program a poetry those available on the

that look good to the System, machine, one would first have machine at hand. With

such as writing x papers in to repeat the entire Universe microcomputers, the most

a year, even though his real from the beginning..." and widely available language is,

objectives are different. But that is what Trurl does to

of course. BASIC.

he then has to waste time

Universe -shattering effect.

The trouble is each

meeting his Systems -inspired

A trip on Lem's Cyberiad machine has its own restric-

objectives. The System has machine gives a whole new tions and dialects for any

therefore got in the way of perspective to the real world given language. And this is

real objectives.

of machines, people and

the major drawback with

For Pask, Le Chatelier

organisations and helps to

the otherwise excellent The

provides a simplified analy- point to the farcical pimples BASIC Handbook by David

sis of what he regards as the on the bum of the Systems A Lien

crux of organisational

beast.

The Handbook is aptly

Learning Systems study - stability.
"That which is stable can he

described by its subtitle as being an "encyclopedia". It

thelingo described, either as the
organisation itself or some characteristic which the

clearly admits in the introduction, however, that it is not intended to replace the

organisation preserves intact". One day Grace Hopper, one manufacturer's handbook

He writes "The trouble with of the founders of the Cobol which describes the language

cybernetics is that the very programming language, found facilities for that machine.

substance of its study is an herself lost in Tokio. And

Instead it concentrates on

entity as amorphous and

she managed to get back to simple, clear descriptions of

generalised as the words

her hotel merely by speaking the fundamental core words

`organisation' and `systems'." Cobol words such as MOVE that are common to most

Pask, however, makes a and GOTO because, she says, machines using BASIC.

brave attempt at trying to Cobol uses such basic univer-

The aim is to provide some

explain in relatively simple sal commands.

help to those who wish to

terms the unique characteris- It would be nice if a

adapt programs in a magazine

tics of a science which, as

stranger lost in computerland like Personal Computer World

he says, "cuts across the

could rely on a similar simple into suitable forms to run on

entrenched departments of language. (In parentheses it is particular machines. Each

natural science; the sky, the worth noting that Grace

BASIC word discussed starts

earth, the animals, and the Hopper is said to have

at the top of page. They are

plants." The book is well

originated that descriptive

listed alphabetically and an

worth reading as a first step computer jargon word 'bug', indication is clearly given

towards a deeper understand- meaning an error. According whether the word is part of

ing and involvement in a sub- to the story, one of the

the American National

ject which both fascinates early computers with which Standards Institute (ANSI)

and confuses by its general she was working was giving BASIC standard.

applicability to anything - a lot of trouble, until one day Then there is a standard

from running a company to she opened a processor

list of topics dealt with for

developing a computer to

cabinet and a moth flew

each word, such as its word

studying the brain.

out. Hence the 'bug' came

category, general description

A mad and magnificent into being).

and variations that might be

book which puts the whole

Meanwhile, back with the encountered. Test programs

Systems and cybernetics

stranger in computerland, it is for the word and sample

approach into an imaginative necessary to provide him/her runs are also given as well

galactic context is Stanislaw with two forms of route

as some very useful hints,

Lem's The Cyberiad. A

finding assistance - firstly including what to do if your

combination of science

some guidance through the computer does not have a

fantasy, political satire and jargon used to describe the particular word. Used as an

mathematical impishness, The technology, and then help encyclopedia, the Handbook

Cyberiad consists of a

with learning the program- will be exceedingly helpful

number of short fables, most ming languages that get the in a variety of ways.

of them loosely linked by the machines doing something

But, as Lien says, "like

journeys of the 'constructors' useful.

the expanding universe

Trurl and Klapaucius.

The problem with intro- theory, BASIC keeps expand-

The starting point of each ductory books in computing ing; we can only chase it -

fable is often a superbly

is that they tend to be

but never catch it all."

illogical logical idea like a

either too general, and there-

So, although the BASIC

machine that can create any- fore of little use in finding Handbook will shine a guid-

thing that begins with n,

out about one system or else ing light through some

then causes havoc when asked they are far too specific to unknown territory, it will still

to create Nothing. Or the

give a good perspective on the be necessary to get a more

stupidest eight storey thinking intrinsic points of the tech- detailed and updated A to Z

machine in the world which nology.

of any real system you want

terrorises the constructors be- Introduction to Micro-

to use.

cause they challenge its belief processors by G. L. Simons

that 2+2=7. My favourite is Trurl's
Electronic Bard, the poetry machine. In Lem's words "Whenever Trurl felt he just couldn't take another chart or equation, he would switch over to verse, and vice versa. After a while it became clear to him that the construction of the poetry machine itself was child's play in comparison with writing the program. The program found in the head of an average poet, after all, was written by the poet's civilisation, and that civilisation was in turn programmed by the civilisation that preceded it and so on to the very Dawn of Time. Hence,

offers a general overview of the hardware and software technology together with sufficient detail of some popular processors, languages and microcomputers to give the stranger some confidence and sense of direction; however it can in no way be taken as a training or reference book.
In addition to the systems, Simons provides a useful overview of design needs and the range of applications for micros, as well as a summary of some contemporary views on the social consequences of microcomputing.
When it comes to learning a computer language, one's choice is usually limited to

Books discussed in this month's Bookfare have been: Systemantics by John Gall (Fontana, 85p) An Approach to Cybernetics by Professor Gordon Pask (Hutchinson's Radius Books, £1.00) The Cyberiad by Stanislaw Lem (Secker & Warburg, £3.90) Introduction to Microprocessors by G. L. Simons (National Computing Centre, £6.50) The BASIC Handbook by David Lien (Compusoft, available through Rostronics, 118 Wandsworth High Street, London SW18 - .£11.00)

PCW 95

THE ALPHA MICRO COMPUTER
Multi -User, Multi -tasking, Timesharing, Memory Management

Basic 64K RAM, 2 4Mb Floppy Disk System:

£6,496.00

Basic 64K RAM,10Mb Hard Disk System:

£9,965.00

('lerminals & Printers to be added to user specification.)

ALPHA MICRO gives a new meaning to the words "Cost Effective!'
It combines a powerful 16 Bit processor with a proven time-
sharing disk operating system to give you data handling and
software sophistication parallel to that of high performance commercial minicomputers. It can be upgraded from a simple
64K single terminal floppy disk system up to a 24 terminal, multi -printer, system with 2400 Megabytes of disk storage and
1.02 Megabytes of Random Access Memory without any hardware redundancy.

ALPHA MICRO in Business

* Powerful WD16 16 -Bit Processor

A fully integrated Accounting System is available * S100 Bus Compatible

"off the shelf.' It includes Order Processing, Auto- * Expands from 6-24 terminal ports

matic Invoicing, Stock Control, Accounts Receivable, * Multi -Printer Spooler

Accounts Payable, Nominal Ledger, Payroll, and

* Adaptable to most RS232 peripherals

Sales Analysis by Customer Product or Salesman. * Sequential, Index Sequential and Random Access

ALPHA MICRO Word Processing Comprehensive word processing software is

files supported * Comprehensive disk file management system

available which can run simultaneously with the

and utilities

accounting system (or any other program for that * Multi -User structured file system with

matter). It will handle anything from standard letters up to large and voluminous documents with automatic Index/Table of Contents generation.

programmer/project number and password protection * Command file interpreter with parameter

substitution

ALPHA MICRO in Research & Education Since the system can handle up to 24 terminals,

* Multiple level DMA and vectored interrupt system

where each user terminal has its own 32 or 48K

* Multiple pass assembly programming system

memory partition, it is ideal in education or research with linking loader

since each user can do his own application, i.e. one can be running the BASIC Compiler whilst another

* ALPHABASIC Extended compiler and re-entrant runtime package

runs LISP; again another can do programming in

* Index sequential files supported in both

PASCAL or ASSEMBLER etc.

Assembler and ALPHABASIC

ALPHA MICRO Standard Features

* File management system with logical file I/O

* Multi -User, Multi -Tasking, Time-sharing Disk

calls

Operating System

* ALPHAPASCAL, one of the best UCSD

* Memory Management from 64Kb-1. 02Mb

implementations

* Disk storage from 2.4Mb-2400Mb

* ALPHALISP, a textual data manipulation language

rRequest for ALPHA MICRO brochure
THE ALPHA MICRO COMPUTER I Name

nEurrons PO Box 789

Title

123 Wandsworth High StreetI Company

LABORATORIES

London SW18 4JB

Address

Tel: 01-870 4248 Telex: 929222 (SLOTS G)

jostcode

Tel:

PCW 11,

96 PCW

Please mention PCW when replying to advertisers - it identifies you.

REIN STORE reESS #

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) ALPHA MICRO (£5,700)
A(aPiPmLE II

Main Distributor/s (No. of dealers) Alpha Micro Systems UK Ltd: 01-930 1991 (TBA)
Microsense: 0442 63561 (80+)

ATTACHE Moncoland: 01-839

(£4,381)

3661 (5)

CHALLENGER (£350) CHALLENGER C3 (£2,450)

Mutek: 0225 743289 Byte Shop: 01-518 1414. CTS: 0706 79332 (5) As above

COMMA VO3
(£4,200)

Comma: 0277 811131 (n/a)

COMPELEC Compelec: 01-636

SERIES

1392 (n/a)

(£2,400)

COMPUCORP 625
(£6,000)

Compucorp: 01-952 7860 (15)

COMP

Comp Workshop: 01-

WORKSHOP 491 7507 (n/a)

SYSTEM 1

(£1,600)

COMP

As above

WORKSHOP

SYSTEM 2

(£11,000)

COMP

As above

WORKSHOP

SYSTEM 3

(£36,000)

COMPU-

Abacus: 01-580 8841

COLOUR II (6)

(£1,058)

CROMEMCO Comart: 0480-215005. SYSTEM 2 Datron: 0742-585490. (£1,995) Microcentre: 031-225
2022 (20)

CROMEMCO As above SYSTEM 3 (22,995) (64K, £3,293

Hardware

Software

Documen- Miscellaneous tation

64K -16M RAM: W/L 16 bits: multi-user O/S: E

Dual 8" F/D (1.2MB): 6 S/P: BASIC: M/A:

modular

PASCAL: T/E:

U: B/P

Expands to 1200 MB, 32 terminal system: average 10MB H/D system £1,100

16-48K RAM: 6502: 8 I/O O/S: BASIC: S slots: 15"x18"x5": options PASCAL: - single 51/4" F/D (116K), games £425; C, £33; RS232 int, £110; 16K RAM, £110

280x192 high resolution graphics: integer BASIC in 6K ROM

48-64K RAM: 8080: dual 8" ExBASIC: S F/D (616K): 1 S/P, 1 P/P: FORTRAN two units: option - 9", 16x

Interfaces to Centronics 702 printer

64 b&w VDU, £250

4-8K RAM: 6502: RS232 O/S: BASIC:
port: 15"x16"x4": option - games: Ex-

S

dual 51/4" F/D (160K), £550 BASIC: Data

Man: B/P

D/A cony: colour capability: 8K microsoft BASIC in ROM

(limited)

32-56K RAM: 6502, 6800, Z80: dual 8" F/D (1.15MB): 2-16 S/P: 17"x22"x12" 32K RAM: LSI 11: dual 8" F/D (512K): 4 serial DLU11S ports: modular 64K RAM: Z80: dual 8" F/D (512K): 2 RS232 ports, 1 P/P
60K RAM: Z80: dual 51/4" F/D (700K): 9", 16x80 b&w VDU: 40cps printer 1
RS232 port: 20"x28"x10"

0S65U O/S: S&H CP/M BASIC:

COBOL: FORTRAN: Data

Man: B/P

RP11 0/S

H

(£750): BASIC:

COBOL: FOR-

TRAN: B/P

(limited)

CP/M: A:

S

CBASIC:

COBOL: FORTRAN: PAS-

CAL: W/P: B/P

A: BASIC: U: B W/P: B/P

Also C3B & C3P H/D modules: 74MB for about £10,000 Many configs possible: max 20 MB, H/D about £27,000 Also with double den sity F/D, 1MB, £2,900; 1K EPROM
Also available, 655 model with 315K F/D capability & 12", 20x80 VDU - £3,750

32K RAM: dual 51/4" F/D (170K): 9", 16x64 b&w VDU: modular

A: BASIC: E FORTRAN: FLEX: PASCAL: PILOT: B/P

128K RAM: 6809: dual 8" F/D (1.2MB): 3 intelligent 20x80 terminals; 80 col, 125cps printer: daisy wheel Sprint 3 printer

A: BASIC: E FORTRAN: FLEX: PAS CAL; PILOT: B/P

768K RAM: 6809: dual 8" F/D (1.2MB): 64MB H/D: 10 intelligent 20x80 terminals: 2 132 col, 120cps printers: 2 80 col, 125cps printers: 2 daisy wheel Sprint 3 printers: max 16 ports.

A: BASIC:

E

FORTRAN:

FLEX: PAS -

CAL: PILOT:

B/P

8-32K RAM: 8089: 13", 32x64 8 -colour VDU: single 51/4" F/D (51K): RS232 port: 18"x15"x13"

ExBASIC

I

(ROM): A:

personal data

base: games

64K RAM: Z80: dual 51/4" F/D (180K): options - dual 8" F/D (512K), £1370; 11MB H/D, £3495; 22MB H/D, £5999

CDOS: BASIC: E COBOL: FORTRAN (£55): multi-user BASIC

32-64K RAM: Z80: dual 8" CDOS: BASIC: E

F/D (512K): options as above: COBOL: FOR -

extra dual F/D, £1,200

TRAN; multi -

user BASIC

These systems are exam ple configs from a fully compatible modular range As above
As above
16K module, £1,134; 34K, £1,137; maintenance & programming manual available. Expandable to multi user system (2-7 users), £3,455-£6,400 As above

List of Abbreviations A Assembler B BASIC B/P Business package C Cassette

C/P Commercial package E Extensive F/D Floppy disc G/C Graphics card H Hardware H/D Hard disc

I Introductory int Interface I/S Indexed sequential M/A Macro assembler N/P Numeric pad 0/S Operating system

P/P Parallel port

W/L Word length

S Software

W/P Word processor

S/P Serial port

TBA To be announced

T/E Text editor

T/P Text processor

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 97

RGGf-e55

IN STORE

Machine

Main Distributor/s

(Price from) (No. of dealers)

DIGITAL Modata: 0892 39591 MICROSYS- (TBA)

TEM DSC-2 (£5,395)

DURANGO Comp Ancillaries:

(£7,750)

07843 6455 (12)

DYNABYTE Dynabyte UK/Europe

DB8/1

Ltd: 0723 65559 (6)

(£1,500)

EQUINOX Equinox: 01-739 2387

300

(n/a)

(£11,750)

EUROC (£7,995)

Eurocalc Ltd: 01-405 3113 (TBA)

EXIDY

Factor One: 0736

SORCERER 66565 (10)

(£650) (16K,

£760; 32K

£859)

IMS 5000 Equinox: 01-739 (48K desk 2387 (20) top £5,100)

IMSAI VDP Computermart: 0603

42

615089. Corner

(£3,900)

Comp: 03727 41101

(2)

IMSAUI VDP As above 80 (£6,200)

ITT 2020 ITT: 0268 3040 (15) (£867) (32K, £916; 48K, £995)

LUXOR ABC 80 (£790)

CCS Microsales: 01-444 7739 (TBA)

MEGAMICRO (£6,080)

Bytronics: 0252 726814 (5)

MICROENGINE (£2,080)

Pronto: 01-599 3041 (TBA)

MICRONOVA
(£12,000)

Digitus: 01-636 0101 (3)

MICROSTAR 45 PLUS (£4,950)

Data Efficiency: 0442 57137 (TBA)

Hardware

Software

Documen- Miscellaneous tation

64K RAM: Z80: dual 8" F/D (2.28MB): 4 RS232 ports: EIA port: 17"x21"x7"
48K RAM: 8085x3: dual 51/4" F/D (1MB): 9", 16x64 green VDU: 132 col 165cps printer: N/P: options - add F/D £1,753; aux VDU £875 32-64K RAM: Z80: S100 bus; 2 RS232 ports: 1 P/P: 20"x18"x7": option - dual 8" F/D (1MB), £2,000 64-256K RAM: W/L 16 bits: 2MB H/D: 15", 24x80 b&w VDU: 150cps printer: 6 S/P
64K RAM: 8080A: dual 8" F/D (1MB): 15", 25x80 b&w VDU: 132 col, 14Ucps printer

CP/M: BASIC- H E: CBASIC: COBOL: FOR TRAN: PASCAL: CAP B/P O/S: DBASIC: S B/P
CP/M: BASIC: H COBOL: FORTRAN: PASCAL: W/P: B/P O/S: BASIC: S COBOL: M/A: PASCAL: T/P: multi-user: B/P CP/M: CBASIC:S A: account systern: U: B/P

Up to 6 additional F/D units possible
Takes up to 4 workstations: fully integrated system 15"x30"x24" Expands to multi-user system: also DB8/2 with dual 53/4" F/D (400K), £3,000 Up to 1200MB of storage possible (4x300MB, Calcomp Tridents) A year's maintenance and stationary supply inc.

8-32K RAM: Z80: RS232: 1 P/P: 5100 connector: 30x64 VDU I/O: options dual 51/4" F/D (630K), £1,200; 12", 30x64 green VDU, £240; S100 chassis, £210 32-256K RAM: Z80: dual 51/4" F/D (320K): 15", 24x80 b&w VDU: 150cps printer: 2 S/P; 1 P/P: 18"x24"x3"

O/S: ExBASIC I (ROM): W/P: Editor: A: games
CP/M: BASIC: S&H COBOL: FORTRAN: PASCAL: W/P: CAP B/P

High resolution graphics capability. Also available: IMS 8000 (dual 8" F/D); IMB desk top or stand alone models, £6,500

32-64K RAM: 8085: dual 51/4" F/D (400K): 9", 24x80 b&w VDU: 1 S/P: 1 P/P: 18"x27"x12"

IMDOS

H

(CP/M comp):

A: ExBASIC: U:

CBASIC:

COBOL: FOR-

TRAN

Can support 8 additional F/D drives; also available, VDP 44 with F/D (780K), £4,400

32-64K RAM: 8085: dual 8" F/D (1.2MB): 12", 24x80 b&w VDU: 1 S/P: 1 P/P: 25"x15"x25"
16-48K RAM: 2020: 15"x 18"x4": options - single 51/4" F/D (116K), £425, C, £33; 60cps printer, £825; 16K RAM, £110; RS232 port, £110 16-40K RAM: Z80A: C: 12", 16x40 b&w VDU: 4680 bus: IEEE 488: RS232 port: option dual 51/4" F/D (160K, own DOS), £895

IMDOS: A:Ex- H BASIC: U: CBASIC: COBOL: FORTRAN: CAP B/P Monitor: A: B BASIC: DisA: games
DOS: BASIC: S games: W/P: Database: Engineering & construction prog

High resolution graphics capability: Integer BASIC in 6K ROM Graphics loudspeaker with 128 effects: View data compatible.

256K: 8080A: dual 8"

CP/M: U:

H&B

F/D (1MB): 12", 20x80

B/P

b&w VDU: 120cps printer:

2 S/P: 2 P/P: option -

printer stand, £100

64K RAM: MCP 1600: 2 RS232 ports: 2 P/P:
16"x13"x5": options -
dual 53/4" F/D (1MB), £1,500; dual 8" F/D (2MB), £1,200

BASIC: PAS- H&S CAL: File Manager: U

CPU has user written word set: PASCAL uses integral P code: available as board, £1,400

64-1128K RAM: N601: LOMB H/D (5 fix, 5 rem): 12", 24x80 VDU: 132 col 60cps printer: 4 S/P: 1 P/P 64K RAM: 8085: dual 8" F/D (1.2MB): 3 S/P: RS232 port: 17"x26"x8"

DOS: M/A: U: E T/E: I/S: debug: FORTRAN IV:
BASIC: PASCAL: W/P: B/P
STARDOS: E CP/M: BAS IC: COBOL: FORTRAN: UPDATE (database): B/P

Larger configs usual: bus system for multi user; smaller system possible with F/D

98 PCW

IN STORE

.44 ime-gi

Machine (Price from) MSI 6800 (£1,203)
MSI 6800 SYSTEM 1 (£2,175)

Main Distributor/s (No. of dealers) Strumech: 05433 4321 (5)
As above

MSI 6800 As above SYSTEM 2 (£7,500)

NORTH STAR HORIZON (£4,650 for 48K) PET 2001-8 (£550)

Comart: 0480 215005. Comma: 0277 811131. Equinox: 01739 2387 (20) Commodore: 01-388 5702 (150)

PET 2001 - 16/32 As above (£675) (32K, £795)

POWERHOUSE II
(£1,650)

Powerhouse Micros: 0442 48422 (TBA)

RAIR BLACK BOX (£2,300)

Rair: 01-836 4663 (n/a)

RESEARCH Research Machines: MACHINES 0865 49791 (n/a) 380 - Z (£1,048) (56K, £1,654)

SDS 100 (£4,290)

Airamco: 0294 57755 (11)

SEMEL 1 (£2,900)

Strutt Electrical: 0822 5439 (n/a)

SHARP MZ80K (£520-£740) SMOKE SIGNAL CHIEFTAIN 1 (£3,050)

Sharp UK: 01-571 2157 (TBA) Winrush Micro Designs: 069-24 5189 (TBA)

Hardware
16K RAM: 6800: C: (9", 16x64 b&w VDU: 1 SIP: option - PROM prog 32K RAM: 6800: dual 51/4" F/D (160K): 9", 16x24 b&w VDU: 1 RS232 port: option - dual 8" F/D (624K), £1,640 56K RAM: 6800: Single 8" F/D (312K): LOMB H/D: 1 RS232 port: 9", 16x64 b&w VDU: options - dual 8" FYD (624K), £1,640 10MB H/D £4,250 24-56K RAM: Z80A: auai 51/4" F/D (360K): 15", 24x80 b&w VDU: 150cps printer: 2 S/P: 1 P/P
8K RAM: 6502: C: 9", 25x40 VDU: IEEE488 (non standard) port: options - dual 51/4" F/D (353K), £795; 80 col 93cps printer, £645; expand to 32K RAM, £249

Software

Documen- Miscellaneous tation

BASIC: mini A H&S T/E: U

Up to 8 serial or parallel interfaces possible.

DOS, BASIC: H&S U: A: FOR TRAN: T/E

As above

DOS: BASIC: H&S multi-user BASIC: A: B/P

Rack mounted

DOS: BASIC: E CP/M: CO BOL: FOR TRAN: PAS CAL: B/P 0/S: BASIC: I A: FORTH: PILOT: games

Graphics facility: BASIC in 8K ROM: also avail able, dual 51/4" F/D (800K), £995 + £30 for operating ROM

16-32K RAM: 6502: C: 9", 25x40 green VDU: IEEE488 (non standard) port: options - dual 51/4"

0/S: BASIC: I A: FORTH: PILOT: games

F/D (353K), £795; 80 col 93cps printer, £645

16-32K RAM: Z80A: 5", FDOS: BOS: I

27x96 b&w VDU: 1 S/P: 1 P/P: 17"x11"x7": options - IEEE488 int, £95; C, £150; G/C, £250

BASIC: games: C/P: ExBASIC (14K EPROM), £350

32-64K RAM: 8085:

CP/M: BASIC: H

dual 51/4" F/D (160K): 2 RS232 port: 20"x16"x 5": option - dual 51/4" F/D (520K), £1,000

COBOL: FORTRAN: M/A: T/E: B/P

16-56K RAM: Z80A: C: RS232 port: 19"x16"x6": options - dual 51/4" F/D (168K). £895; dual 8" F/D (1MB), £1,695 (fitted in machine)

Tiny BASIC: S games: graphics: A: ExBASIC: CBASIC: COB OL: FOR-

TRAN: AL-

GOL: CP/M:

U

64K RAM: Z80: dual 8" F/D CP/M: A:

E

(1MB): 12", 24x80 VDU: ExBASIC:

S100 bus: RS232 port: N/P: COBOL:

1 P/P

FORTRAN:

CAP B/P

16-64K RAM: Z80: single BASIC:

I

8" F/D (250K): 12",

COBOL:

24x80 b&w VDU: RS232 FORTRAN:

port: options - single 8" B/P

F/D (250K), £500; light pen

6-34K RAM; Z80: C: 10", BASIC: A: B

24x40 b&w VDU

games

As above but disc opera ting ROM included.
16K RAM expansion, £250. Designed for education: high resolution graphics being developed Facility for 8K PROM Supports up to 8 drives Graphics: loudspeaker: BASIC in 14K RAM

3521-/644"KFR/ADM(:166800K0:)d:u1al2",DBDAOSS:IBCA:SIC: E

24x80 VDU: 112cps printer: RBASIC: A:

RS232C port: option - 16K FORTRAN:

RAM expansion, £500

U: T/E: B/P

Also available, Chieftain 3 with dual 8" F/D (1MB), £3,950.

List of Abbreviations A Assembler B BASIC B/P Business package C Cassette

C/P Commercial package E Extensive F/D Floppy disc G/C Graphics card H Hardware H/D Hard disc

I Introductory int Interface I/S Indexed sequential M/A Macro assembler N/P Numeric pad 0/S Operating system

P/P Parallel port

W/L Word length

S Software

W/P Word processor

S/P Serial port

TBA To be announced

T/E Text editor

T/P Text processor

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 99

Pp_o- i,.1..S Machine (Price from)

Main Distributor/s (No. of dealers)

SOLITAIRE/ Solitaire/KPG: 04252

WP

71448 (TBA)

(£6,750)

SOLITAIRE/ As above

BS200

(£7,950)

SOLITAIRE/ As above HBS100 (E9,500)

SORD

Dectrade: 0602

M100 ACE 861774

(£2,650)

(TBA)

SORD M223 (£3,500) SUPERBRAIN (£1,995)

As above Icarus: 0632 29593 (TBA)

TAND-

Tandberg: 0532 35111

BERG EC10 (n/a)

(£5,000)

TANDY TRS Tandy: 021 556 6101 80 LEVEL 1 (200) (£380) TANDY TRS As above 80 LEVEL 2 (£515£1,0051

TECS (£1,600)

Technalogics: 051 724 2695 (TBA)

TEI 208 (£4,400)

Abacus: 01-580 8841 (5)

TEI 212 (£5,067)

As above

VECTOR Almarc: 0602

GRAPHICS 248565

MZ

Sintrom Microshop

(£2,300) 0734 84322 (5)

VECTOR GRAPHICS SYSTEM B (.£2,850) ZENTEC (£5,700)

As above Zigal Dynamics: 0753 71049 (1)

IN STORE

Hardware

Software

Documen- Miscellaneous tation

64K RAM: 8085: dual 5'A" DOS: W/P: S F/D (700K): 14" VDU (with BASIC own CPU): 45cps printer: CPU

All Solitaire systems are compatible: graphics on 11x13 dot matrix

64K RAM: 8085: dual 8" F/D (960K): 14" VDU (with own CPU): 45cps printer: CPU port 64K RAM: 8085: LOMB Fix H/D: 14" VDU (with own CPU): 200cps printer: CPU port: option - up to 40MB H/D

DOS: BASIC: S W/P: specialised B/P

As above

DOS: BASIC: SUp to 8 interface ter-

W/P: speciali-

minals can be used:

sed B/P

also available, HBS200

with 20-80MB H/D.

48K RAM: Z80: single 51/4" O/S: BASIC I F/D (143K): 12", 24x64 colour VDU: RS232 port: option - single 51/4" F/D, £300

With colour graphics: 8K ROM

64K RAM: Z80: single 51/4" O/S: BASIC: I

F/D (350K): 12",24x80

CAP B/P

b&w VDU: S100 bus:

RS232 port: option - extra

F/D, £450

Other configs possible.

64K RAM: 2xZ80: dual 51/4" CP/M: A:

H&S

F/D (320K): 12",25x80

BASIC:

b&w VDU: S100 bus:

COBOL:

RS232: TRS80 port: 21"x23" FORTRAN:

x14": options - dual 51/4" APL: B/P

F/D (320K); dual 8" F/D

(2.4MB); 8-120MB H/D

50K RAM: 8080A: single 8" F/D (250K): 12", 25x

ExBASIC

1-I&S

(24K): multi -

80 b&w VDU: RS232 port user BASIC: A: U: COBOL

Limited graphics: main frame interface available Pascal available next year

4-16K RAM: Z80: C: 12", BASIC: games: I

16x64 b&w VDU

A

BASIC in 4K ROM: up gradable to level 2

4-48K RAM: Z80: C: 12", 16x64 b&w VDU: RS232 int: 1 P/P: option single 51/4" F/D (78K), £478 (max of 4)

BASIC: games: I M/A: FORTRAN: B/P

16-56K RAM: 6800: 8K

BASIC

H

PROM: RS232 port: C int:

option - dual 51/4" F/D

(320K), £800

32-60K RAM: 8080/8085: dual 51/4" F/D 320K: 9", 24x80 green VDU: 3 SIP: 3 P/P: 17"x18"10": option - 150cps printer,

CP/M: BASIC: H&S COBOL: FOR TRAN: PAS CAL: ALGOL: B/P

£1,250

32-60K RAM: 8080/8085: CP/M: BASIC: H&S

dual 8" F/D (1MB): 15",COBOL: FOR -

24x80 green VDU: 3 S/1: TRAN: PAS -

3 P/P: 17"x20"x17":

CAL: ALGOL:

option - 150cps printer,

B/P

£1,250

48K RAM: Z80: dual 51/4" F/D (630K): 1 S/P: 2 P/P:
20"x17"x8"

DOS: BASIC: E A: CP/M: CBASIC: COBOL: FORTRAN: PASCAL:

48K RAM: Z80: dual 51/4" F/D (630K): 12", 24x80 b&w VDU: 1 S/P: 2 P/P:
20"x17"x8"

DOS: BASIC E A: CP/M: CBASIC: COBOL: FORTRAN:PASCAL

32-64K RAM: 2x8080: dual 51/4" F/D (280K); 15", 25x80 b&w VDU: RS232 port: options - dual 51/4" F/D (280K, £600; dual 8" F/D (1MB), £2,100

O/S: A: U: S BASIC: micro COBOL: W/P

RS422 port, £105

16K machines include N/P: 4-16K upgrade, £120; without pad, £85 256 char graphics: Prestel compatible: plugs into standard TV
4K PROM With graphics and N/P User programmable character set

List of Abbreviations A Assembler B BASIC B/P Business package C Cassette

C/P Commercial package E Extensive F/D Floppy disc G/C Graphics card H Hardware H/D Hard disc

I Introductory int Interface I/S Indexed sequential M/A Macro assembler N/P Numeric pad 0/S Operating system

P/P Parallel port

W/L Word length

S Software

W/P Word processor

S/P Serial port

TBA To be announced

T/E Text editor

T/P Text processor

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

100 PCW

Machine (Price from) ZILOG MCZ1/05 (£4,200 portable)

Main Distributor/s (No. of dealers) Micropower: 0256 54121. Memec: 084421 5471 (n/a)

ZILOG MCZ1/35 (£1,200)

As above

Z -PLUS
(£4,000)

Rostronics: 01-874 3665 (TBA)

IN STORE

ERNE"-
Aftc:id

Hardware 64K RAM: Z80: dual 8" F/D (600K): RS232 port 64K RAM: Z80: 10MB H/D (5 fix, 5 rem): RS232 port
32-64K RAM: Z80: dual 8" F/D (1MB): 2 S/P: 2 P/P: 10"x29"x11"

Software

--------------___ 41
Documen- Miscellaneous tation

Rio O/S:

H& S

M/A: U:

T/E: BASIC:

COBOL:

FORTRAN:

PASCAL: B/P

Rio O/S: M/A: H&S U: T/E: BASIC:
COBOL: FORTRAN: PASCAL: B/P

Debug in 3K PROM: also available as desk top unit or R/M model, both £4,800. Internal disc control with own Z80

CP/M: A: U: H&S BASIC: COBOL: FORTRAN: PASCAL: Database: B/P

In response to reader demand PCW will soon be extending In Store to include single board computers.

USER GROUPS INDEX

User Group Index is Britain's major, up-to-date listing of clubs, user groups and societies. The details published here were correct at the time of going to press;
if YOUR group hasn't been included, then please let us have all relevant information. Send it to: PCW, 14 Rath bone Place, London W 1P 1DE. Updates on changes would also be appreciated.

AVON Bristol Computing Club. £3.00 p.a. Meetings 3rd Wednesday monthly. Contact: LeoWallis, 6 Kilbirnie Rd., Bridge Farm Estate,
Bristol, BS14 OHY. Tel: Bristol 832453.
Brunel Technical College Computing Club. The club divides into two sections
..the "skilled" and the "not skilled". They share alternate Wednesdays at the College. Contact S.W. Rabona at 18 Castle Road, Worle,
Weston-Super-Mare, Avon, BS22 9JW (0934 513068).
BEDFORDSHIRE
UK Intel MDS Users Group. Contact: Lewis Hard, 29 Chaucer Rd., Bedford.
Cosmac Users Club (proposed) For People using the RCA 1802, Cosmac ELF, ELFII, Super Elf etc. Those interested contact James Cunningham at 7 Harrowden Court, Harrow den Road, Luton LU2 OSR (enclose sae, please).
The 6502 Users Club. Hoping soon to hold regional and national meetings, they offer "support, encouragement and fellowship". Contact: Walter Wallenborn, 21 Argyll Ave., Luton, Beds LU3 lEG.
BERKSHIRE
77/68 User Group. Quarterly Newsletter. Free membership for 1st year if you buy the 77/68 instruction manual, £1.50 thereafter. Contact: Newbear Computing Store, 40 Bartholomew St., Newbury, Berkshire.
The Thames Valley Amateur Computer Club. Meetings are on the first Thursday of every month and from November on, that will be at "The Southcote", Southcote Lane, off the Bath Road, Reading, Berks. Starting time, 7.00pm. Contact Brian Quarm (Camberley 22186) OR Brian Steer (Slough 20034).

BUCKINGHAMSHIRE
TRS-80 Users Group. Contact: Brian Pain, 40a High St., Stony Stratford, Bucks.
CHESHIRE
Anyone interested in starting a Chester club please contact: Mr. W. Collins, 37 Garden Lane, Chester, Cheshire.
DERBYSHIRE
The Independant PET Users Group. IPUG. Secretary is Mike Lake of 9 Littleover Lane, Derby (Derby 23127).
DEVONSHIRE Exeter and District Amateur
Computer Club. General meetings 2nd Tuesday monthly, specialist meetings 3rd or 4th Tuesday. £5.00 p.a. Contact: Doug Bates, 3 Station Road, Pinhoe, Exeter, Devon. DURHAM Northeast PETS. Contact: Jim Cocallis, 20 Worcester Road, Newton Hall Estate, Durham. The group meets on the 3rd Monday of each month (at 7.30 pm.) in: Room A102, Ellison Bldgs, Newcastle Polytechnic, Newcastle-upon-Tyne.
ESSEX
TRS80 User Club (Chelmsford). Now part of the National TRS80 User Club. Contact Michael Dean, 22 Roughtons, Galleywood, Chelmsford, Essex. Amateur Computer Club. Membership now costs £3.50. Contact D. Ellis (the Membership Secretary), c/o 118 Cambridge Avenue, Gidea Park, Romford, Essex RM2 6RA. The Colchester Microprocessor Group. Meetings held at the University of Essex on the second and fourth Wednesdays of each month 7.30pm start. Membership is open to all, on payment of £5 annual sub for full-time students). Contact the Information Centre at the Univer-

sity on the evening of the meeting.
GLOUCESTERSHIRE
Cheltenham Amateur Computer Club. Meetings, 4th Wednesday monthly, 7.30pm start. Microprocessor workshop starting October 2nd. Contact: Mr. M. Pullin, 45 Merestones Drive, The Park, Cheltenham, GL50 2SU (Cheltenham 25617).
9900 Users Group, TI
9900 Users Group, TIMUG Contact: Chris Cadogan, 21 Thistle Downs, Northway Farm, Tewkesbury, Glos. HAMPSHIRE Southampton Amateur Computer Club. Meetings 1st Wednesday monthly (not July, Aug. or Sept.). Contact: Paul Dorey, Department of Physiology, University of Southampton, Southampton, SO2 3SU or Tel: Paul Maddison on Winchester 4433 Ext. 6955.
HERTFORDSHIRE 'lls Users Group. A sort of
help service only. No meetings no newsletter. Contact: Pete Harris, 119 Carpenter Way, Potters Bar, Herts., EN6 5QB. Tel: 0707 52091 or 01-248 8000 Ext. 7065.
Harpenden Microprocessor Group. They hold meetings every fortnight, cover a wide range of interests and attract members from the area around Luton, St. Albans and Welwyn. Contact: David James, 5 Ox Lane, Harpenden, Herts AL5 4HH (05827 5366).
KENT
Medway Amateur Computer and Robotics Organisation. Contact: Tony Aylward, 194 Balmoral Rd., Gillingham, Kent. Tel: Medway 56830. North Kent Amateur Computer Club. Meetings, the second Tuesday of each month - usually at the

Charles Darwin School, Jail Lane, Biggin Hill, Kent. The sub is £2.50 per annum (21 for students). More members are needed ...contact: Barry Biddies at 3 Acer Road, Biggin Hill, Kent (09594 71742).
LANCASHIRE
Merseyside Microcomputer Group. Several sub -groups
.Contact: J.S. Stout, Department of Architecture, Liverpool Polytechnic, 53 Victoria St., Liverpool Ll 6EY or Tel: 051 236 0598 or STEM Ltd. 19/23 Abercrombie Sq., PO Box 147, Liverpool University, Liverpool L69 3BX. LEICESTERSHIRE The Leicestershire Personal Computer Club. Meetings held the 2nd Monday in each month, at Leicester University and Loughborough University alternately. They start 7pm. Membership is £2 per annum (£1 for under 168). Contact Miss Jill Olorenshaw (Club Secretary) c/o Arden Data Processing, Municipal Buildings. Charles Street. Leicester (0533 22255) OR Mr Dick Foden (Club Chairman) at 11 Gaddesby Lane, Rearsby, Leicester. LINCOLNSHIRE Lincolnshire Microprocessor Society. Various meeting places. For up-to-date information, contact the Hon. Sec., Mr Eric Booth, Senior Common Room, Bishop Grosseteste College, Newport Lincoln.
LONDON
MK14 Club. Bi-monthly magazine called "Complement and Add". Contact: Geoff Phillips, 8 Podsford Rd., London NW9 6HP. Southgate Computer Club. Meetings 1st Wednesday and 3rd Thursday monthly during term time. Newsletter. Contact: Paul Woolley,

PCW 101

Southgate Technical College, High Street, London N14 6BS. Tel: 01-888 6521. UK Pet Users Club. Contact: Commodore Systems Division, 360 Euston Road, London, NW1 3BL. East London Amateur Computer Club. Meetings 3rd Tuesday monthly. £2.50 p.a. (1/2 price to school students). Contact: Jim Turner, 63 Millais Rd., London Ell.
The North London Hobby Computer Club. General meetings held on a Wednesday evening, once a month specialised topics on three evenings each week. Location: The Polytechnic of North London. Contact: Robin Bradbeer (Chairman) at the Dept, of Electronic and Communications Engineering,
P otechnic of N. London,
Holloway, N7 8DB (01-607 2789).
MIDDLESEX Harrow Computer Group. Meetings (term thne) at the
Harrow College of Higher Education and (other time) the "Traveller's Rest" Public House, in Kenton, Middlesex - on alternate Wednesdays at 7pm. Contact: Bazyle Butcher, 16 St. Peter's Close, Bushey Heath, Watford (01-950 7068) or P. Lecker, 23 Moss Lane, Pinner, Middx.
NOTTINGHAMSHIRE
UK Apple Users Group, Contact: Andy Witterick (Keen Computers), 5 The Poultry, Nottingham. Tel: 0602 583254/5/6.

USER GROUPS INDEX

OXFORDSHIRE
Research Machines Ltd . National User Gro up. Inaugural meeting 5th October. Contact: M.D. Fischer, PO Box 76, Oxford, OX4 1EY, for a registration form. Oxfordshire Microcomputer Club. £5.00 p.a. Contact: S. C. Bird, 139 The Moors, Kidlington, Oxford OX5 2AF Tel: Kidlington (08675) 6703 Microsoc, the Oxford University micro group holds shared meetings with the Oxford Microcomputer Club. Contact: M Bourla, St. John's College, Oxford.
STAFFORDSHIRE
Central Program Exchange. Full membership £25 Europe, £40 overseas), provides 30 free programs p.a. Small User Serivce £10 Europe, £20 overseas) provides 10 free programs p.a. Contact: Mrs Judith Brown, The Polytechnic, Wilfruma St., Wolverhampton, WV1 1LY.
SURREY
Exidy Sorcerer Users Group. Newly formed, and a division of the U.S. User Group. Fee is £5 p.a. Write, stating what hardware you own, to: Andy Marshall (Micro44), 44 Arthurs Bridge Road, Woking GU21 4NT (04862 66084). Richmond Computer Club. Held the second Monday of each month at the Richmond Community Centre (20p per meeting), members have the

use of a good range of equipment. Contact: Robert Forster, 18a The Barons, St. Margarets, Twickenham, Middx (01-892 1873).
SUSSEX Independent PET Users Group - South. Free membership - meetings the first Wednesday of every month. £1.50 to receive monthly newsletter. Contact: John C Nuttall, 56 West Street,
Shoreham -by -Sea, Sussex BN4 5WG.
WARWICKSHIRE ACC (Midland) Group. They meet every 3rd Saturday in room P109 at Lanchester College, Coventry. ..no sub, no magazine. Contact: Roy Diamond (Chairman), 27 Loweswater Road, Coventry, Warks (0203 454061). WEST MIDLANDS West Midlands Amateur Corn-
puter Club. Newsletter . ..
meetings 2nd Tuesday monthly. £2 p.a. or £1 if under 18, or a full time student. Contact: John Tracey, 100 Booth Close, Crestwood Park,,Kingswinford, West Mids DY6 8SP. Phone Brierley Hill 70097.
YORKSHIRE
South Yorkshire Personal Computing Group. (Please note, another publication has listed, incorrect)y, a South Yorkshire Amateur Computer Club. It does not exist). For details of the SYPCG, contact Tony Rycroft, 88 Spinneyfield, Moorgate, Rotherham,

S. Yorks, (Tel: Rotherham 74889, eve).
IRELAND
Computer Education Society of Ireland. A voluntary organisation that consists of a national body and an expand ing number of local branches. Their brief is to monitor computer education in Ireland. National CESI (23 p.a.) Diarmuid McCarthy, 7 St. Kevin's Park, Kilmacud, Blackrock, Co. Dublin. Cork branch (21 extra) - Michael Moynihan, Colaiste an Spioraid Naomh, Bishops town, Cork. Dublin branch (21.50 extra) - Jim Walsh, C.B.S. Naas, Co. Kildare. Limerick branch (21 extra) - Sr. Lourda Keane, Convent F.C.J., Laurel Hill, Limerick. Waterford branch (21 extra) - Mr. Hugh Dobbs, Newtown School, Waterford. Kilkenny branch (21 extra) - Sr. Helen Lenehan, Presentation Secondary School, Kilkenny. SCOTLAND Ithaca Audio 5100 bus UK User Group. Contact Dave Weaver, 16 Etive Place, Cumbernauld, Glasgow G67 4JE. Phone 02367 36570. WALES Gwent Amateur Computer Club. Covering the Gwent and Cardiff areas, the club has its own computer room and technical library. Meet ings held once a week, Wednesdays, starting 7.30pm, at Room 149, Civic Centre, Newport. Contact: Peter Hesketh on Shirenewton 696.

FAX

PCW introduces the first of a series of reference sheets with, this month, the 8080 instruction set. We plan to give you similar charts with the op -codes for all the common processors. Other areas we shall cover are standard codes -
ASCII, EBCDIC, BAUDOT etc, hardware interface standards and protocols and anything else which lends itself to this format.

THE 8080 MNEMONICS ARRANGED BY OP CODE

MSB
° LS1E3

1

2

3

4

5

6

7

8

0 NOP

MOV MOV MOV MOV ADD B,B D,B H,B M,B B

1 LXI LXI LXI LXI MOV MOV MOV MOV ADD

B

D

H

SP B,C D,C H,C M,C C

2 STAX STAX SHLD STA MOV MOV MOV MOV ADD

B

D

B,D D,D H,D M,D D

3 INX INX INX INX MOV MOV MOV MOV ADD

B

D

H

SP B,E D,E H,E M,E E

4 INR INR INR INR MOV MOV MOV MOV ADD

B

D

H

M B,H D,H H,H M,H H

5 DCR DCR DCR DCR MOV MOV MOV MOV ADD

B

D

H

M B,L D,L H,L M,L L

6 MVI MVI MVI MVI MOV MOV MOV HALT ADD

B

D

H

M B, M D,M H,M

M

7 RLC RAL DAA STC MOV MOV MOV MOV ADD B,A D,A H,A M,A A

8

MOV MOV MOV MOV ADC

C,B D,B H,B A,B B

9 DAD DAD DAD DAD MOV MOV MOV MOV ADC

B

D

H

SP C,C D,C H,C A,C C

A LDAX LDAX LHLD LDA MOV MOV MOV MOV ADC

B

D

C,D D,D H,D A,D D

B DCX DCX DCX DCX MOV MOV MOV MOV ADC

B

D

H

SP C,E D,E H,E A,E E

C INR INR INR INR MOV MOV MOV MOV ADC

C

E

L

A C,H D,H H,H A,H H

D DCR DCR DCR DCR MOV MOV MOV MOV ADC

C

E

L

A C,L D,L H,L A,L L

E MVI MVI MVI MVI MOV MOV MOV MOV ADC

C

E

L

A C,M D,M H,M A,M M

F RRC RAR CMA CMC MOV MOV MOV MOV ADC C,A D,A H,A A,A A

0

1

2

3

4

5

6

7

8

9A

SUB ANA

B

B

SUB ANA
CC

SUB ANA
DD

SUB ANA EE

SUB ANA HH

SUB ANA
LL

SUB ANA

MM

SUB ANA AA

SBB XRA

BB

SBB XRA

CC

S1113 XRA
DD

SBB XRA
EE

SBB XRA
HH

SBB XRA
LL

SBB XRA
MM

SBB XRA AA

9A

Compiled by John A. Coll.

BC

D

E

F

ORA RNZ RNC

B

ORA POP POP

CB

D

ORA JZ JNC
D

ORA JMP OUT
E

ORA CNZ CNC
H

ORA PUSH PUSH

LB

D

ORA ADI SUI

M

ORA RST RST

A0

10H

CMP RZ RC

B

CMP RET

C

CMP JZ JC
D

CMP

IN

E

CMP CZ CC H

CMP CALL
L

CMP ACI SBI
M

CMP RST RST

A8

18H

BC

D

RPO RP 0

POP POP 1

H

PSW

JPO JP 2

XTHL DI 3

CPO CP 4

PUSH PUSH 5

H

PSW

ANI ORI 6

RST RST 7 20H 30H RPE RM 8

PCHL SPHL 9

JPE JM A

XCHG EI B

CPE CM C

D

XRI CPI E

RST RST F 28H 38H

E

F

102 PCW

TRANSACTION FILE
The "Transaction File" is available for the free use of PCW readers (please, no companies). Buying, selling, exchanging, searching. . .whatever, just post your advertisement to: PCW Transaction File, 14 Rathbone Place, London W 1P 1DE. We'd appreciate a maximum of around 50 words per insert.

For Sale

77:68 CPU board.. .all complete - £20. 77:68 MON 1 Board...all socketed and complete - £20. 77:68 VDU board. . .all socketed and complete - £25. Apply Mr J K Newman, 2 Carlton Drive, Benfleet, Essex. Phone 0702 556891.
Applesoft floating point BASIC card. ..
£80. Phone A Gleeson on Southampton (0703) 557538.

Also, anybody interested in implemen-
tidineags,Pileotct.orCFoonrttahctoMn 6r50D2u?n-niscwlifafep,
19a Hitchin Road, Henlow Camp, Beds. Texas TI58. . . programmable calculator. Little used, too good for me, 240 and
110 volt adaptors - £45. Contact A. Park, Laburnum Cottage, Broomhall,
Nantwich, Cheshire. Phone Crewe (0270) 780608.

Olivetti printer/terminal. . . 10cps with papertape punch/reader (similar to ASR
33), recently reconditioned - £250 o.n.o. Phone 01-455 3888, evenings.
Nascom 1. . . complete, fully socketed and working, with buffer board, cased keyboard, Cannon connectors - £180 o.n.o. PSU available if required. Phone Jon on 021 743 3442 (Solihull) evenings/weekends.

Cromemco Z2. . .computer system, 48K memory, 5" floppy (90K) drive, 16K

Pet 8K. . .new in March 79. Inc sound -
box, software, manuals, etc - £500.

TRS-80 Level 1 4K. . . complete with monitor and cassette unit, plus program

extended BASIC and macro assembler Phone Peter on 01-883 1560.

library - £300 o.n.o.

included - £2200. Plus Hazeltine intelligent VDU 1510 - £800. Contact Paul

System 68 VDU.. .cards A&B, socketed & wired, never used: teleprinter type 28

Olivetti TE 500. . . printer with tape punch/reader, believed good working

Clarke, 32 Upper Mall, London W6 9TA. KSR, 115V: Bunker-Ramo type 103A1 order, but no documentation - hence

Phone 01-748 1176.

VDU, needs new main transformer: £40 o.n.o.

Triton micro. . .full on board RAM, with cassette recorder - £280.
Nascom 1.. .with T2 & B -Bug Monitors,
complete in case with PSU - £150.
Both units fully operational. Phone Ken

high speed Opto. paper tape reader, 8 or 5 holes. Will sell or swop for interesting/ useful bits. Contact Chris Warwick G8DSO, 44 Wellington Road, Birmingham B20 2SB.

Video writer. . . Practical Wireless
design 7 -bit ASCII in video /UHF out - £20 o.n.o. Phone Chelmsford
84732.
Pet 2001-8K. . .6 months old, plus

on Shrewsbury (0743) 56698 (between 3 & 5 pm).

VmDinUe. a. n.dnemedakaeVmDeUa?nCoofmfeeraIndcasene't

assorted games software and BASIC manuals - £475 o.n.o. Phone 01-572

Motorola 6800. . 12K words, cassette interface, ASCII keyboard for TV set,

refuse. Phone 01-794 8419. 16 Dynamic RAM chips. . .4027, 250nS

4215, evenings. Texas SR -56 calculator.

.

.program-

manuals. Offers - phone Ron James on 01-388 1827 (office hours). Verbatim Soft Sector Discs. . .51/4", unopened box of ten - £20. Ten used very briefly - £1.90 each. Contact D. Briers, 53a Newlands, Pershore, Worcs. Nascom 1. . .PSU, B -Bug Monitor, graphics board, all neatly boxed in Vero

- £48. Phone 01-907 9065 any tima. TI59. . . noughts & crosses program on mag card -£1.35. Contact M. Lancaster, 14 Barley Cote Road, Riddlesden, Keighley, W. Yorks. PDP8-L. . .4K mini -computer with TTY interface and full set diagnostics software. Ideal for emulation of Harris

mable, 100 step, with operating manual and various sample programs - £25. Contact F. R. Applewhite, 252c Porchester Road, Nottingham NG3 6HE. Apple II (ITT 2020). . . 32K RAM, cassette recorder, 30 various programs, as new with box and packing - £950
or take good Pet in part exchange.

case, fully tested and working, all docu- HM6100 12 -bit micro. Seen working - Phone Warrington (0925) 811191, after

mentation, 3 months old - £220. Phone £400. Additional 4K memory for above 6pm.

01-722 2039 or 01-249 6764. IBM "Golfball" Typewriter. . .with
punch and reader, box of spares &
accessories & literature, metal case with

fitted and working in BA08 peripheral expander unit - £150. Phone Cobb on Portsmouth (0706) 385589. Printer Mechanism. . .80 -col. impact,

Sorcerer 32K. . . as new and complete with all cables, manuals etc. Also tape deck and technical manual. Save £150 plus by buying mine at £650. Phone

tape holder. Z80 program for linking unused, no logic - £65.

Charles Thompson on 0438 832737 or

IBM printer to Exidy Sorcerer included Star devices. . .touch keyboard - £30. 0438 032321 (Herts).

(will require adaptation for this machine). Works, but needs overhaul to

MK.14 computer.. .extra RAM. manuals, new keyboard - £30.

Sorcerer 16K. . . in excellent condition with all accessories - £615. Also avail-

remove small faults. As is £290. Phone Phone David Pearce on Biggin Hill 73585. able, TV monitor, cassette recorder,

Porthtowan 890688. Pet 2001. . . 8K plus twenty or so pro-
grams (Petsoft etc). - £400 and free
delivery in the London area. Contact Mr Forrester, 24 Connaught Avenue, Plymouth. Phone 0752 29638.
Texas T158. . .with PC100A printer, includes Master & Leisure libraries, electrical program "Pakette", programs & paper. £200 or S100 boards (RAM I/O A/D etc) in exchange. Phone Garelochhead ( 0436 ) 810605 evenings/weekends. Pet 2001-8. . .nearly new, plus many

TRS-80 Level II 16K. . . plus extra 16K chips, sound adapter and software, auto/manual tape control. Also soft-

ware:
T -Bug,

SatnardtrekothIeIIr,s

-X£-W50in0g .

PFihgohtneer,

0480 624286.

Flexowriter. . . electric typewriter with integral 7 -hole paper tape punch and

reader. All solenoid operated, requires 110 volt transformer, includes hand-

book and cct diagram - £40. Card Reader. . .Burroughs, reads 200 80 -col cards per minute, circuits and

maintenance manuals included - £100.

D/A and A/D converter, library of programs and cassettes, technical manual £130. Together - £715. Phone Southport 65787/64809.
7p/e8r"8p"arpeeerlta(pine.clu. de. stop&clpe)a.rC, o£n1t.a5c0t
C. E. Brough, 21 Ashdene Gardens,
Stourbridge, W. Mids DY8 5JQ. Printer/terminal. . . ASR33 teletype (Westrex) with paper tape punch/ reader, RS232 & SWTP MP -S interface
- £300 o.n.o. Phone 01-764 5999.
Nascom 1. . . built and working plus modulator, without PSU - £120. Phone

games and programming aids. Only used
in home - £500 o.n.o. Contact Mr
Hounsell after 7pm on 031 332 8913.

Maintenance manual. . .for IBM Selectric I/O typewriter - £8. Phone 01-449 1690, evenings.

Pete Overall on 0626 68975. Nascom 1. . . built and tested, including PSU, mounted in stylish wooden

MK.14. . .new keyboard, revised moni- PET 2001-32N. . . complete with cabinet, all manuals and programs sup-

tor, cassette interface, single step facili- cassette drive, dustcover and TIS work- plied - £200 o.n.o. Contact T. D.

ty, instruction manual & amendments - £50. Phone K. Hones on Sandown

books 1-6. Commodore 2040 dual disc
drive, just add printer for complete

Botterill, 48 Yardley Drive, Northampton. Phone N 'ton 844338.

(0983) 405256. TRS-80 Level II 16K. . .with lower case,
shift lock and control keys (Electric Pencil use), levels 1/2 and technical
manuals, keyboard cover, video monitor, CTR-41 recorder with audible CLOAD/ CSAVE and AUTO/MANUAL switch for rewind etc., "Electric Pencil" tape, "Tandy Personal Finance Package",
output only RS232 interface, various other tapes - £600. Phone Dave Holloway on Asthall Leish (093 387) 241
(evenings/weekends). Mikbug 6830 L-7 ROM. . .£8 o.n.o.

business system. Plenty of software

iCncolsutdeodv, erbo£t1h70s0till-

under warranty.
open to offers.

Anadex printer. . . DP -8000 80 -col

printer, RS232C and parallel interfaces,

complete with CMC Pet interface for

immediate use with any Pet. Cost over

£700 - open to offers. Phone P. Wright

on Blythburgh (050270) 252.

w77o:6rk8i4nKg -R£A5M0 beoaacrhd.s.Ph. o.tnhereLe,efeudllsy 771681 between 9 and 5.30 or write

to David Thatcher, 2 Halfpenny Lane,

Featherstone, Yorks.

Kilobaud and Byte. . . exchange your unwanted copies - SAE list. Contact Geoff Smith, 84 Edenfield Gardens, Worcester Park, Surrey KT4 7DY.
Superboard II. . . with 8K RAM, fully operational, mounted in custom built and professionally finished metal cabinet. Supplied with all interface cables, diagrams and manuals and program tapes. Also UHF modulator. Needs 5V PSU - £280. Phone Mr A. D. Sellers on 0582 38581, 9am - 6pm. Comp 80. . . fully built and working
Powertran W. W. Comp 80 - £300.

PCW 103

TRANSACTION FILE

Phone 0632 650653 and ask for Geoff. Superboard II. . . with 8K RAM, complete with 5V 5A PSU and UHF modulator - £220 o.n.o. Phone Rod on Watford (0923) 20310, evenings. Ohio Disc System. . . C2 -4P with TV monitor, as illustrated in the American Data adverts, complete with many business and games discs - £950 o.n.o. Phone Lichfield (Staffs) 54515.
SC/MP II. . . in superb Vero case, 1K byte memory mapped VDU including cursor control, 21/2K byte memory expandable to 64K, 5V PSU 10 digit
7-seg LED O/P, cassette I/P & 0/P
interface, 16 -bit I/O port with handshake mode, light touch keyboard, programs and all documentation - £125.

Contact U. Yoltay, 1 Grosvenor Gardens, London N10 (top flat). Triton. . . includes full on board RAM (4K) and the new BASIC and monitor in (4K) of ROM; has sprayed front and
rear panels, also includes cassette
recorder - £400. Phone 01-805 1878, after 6pm.
Colour graphics kit. . . William Stuart Systems, for Nascom 1, complete with instructions, colour modulator and software - £38. Phone 0602 266748, weekends only. Pet. . . new ROM set for 8K Pet. Update your machine for £25, or offer. Phone Sandwich (03046) 7209, even-
ings.
TRS-80 Level 2. . . numeric keypad,

32K interface - £750
Micropolis Dual Drive. .

p. lu3s 94VKAT-.

£950 plus VAT. Only a few months

old. Phone Henfield (Sussex) 3101.

Wanted
Mite printer. . . any condition, any price considered. Contact Mr P. Spooner 6 Ebor Close, West Parley, Dorset
BH22 8LZ.
Software. . . copies of CP/M library programs on 51/4", 16 sector Micropolis quad density. Also programs for the Sorcerer: IN BASIC, machine language, on disc or cassette, or on CP/M format disc. Phone Garelochhead (0436) 810605, evenings/week-
ends.

DIARY DATA

Moscow, Russia

Electronic Devices Production & Control Exhibition, `Expocentre', la Sokolnichesky Val, 107113 Moscow, U.S.S.R.

Budapest, Hungary MIPEL - International Exhibition of Industrial Electronics. Hungarian Foreign Trade for Fairs & Publicity, Electronics, P.O. Box 44,

H-1441, Budapest.

Birmingham, England International Business Show. BETA 109, Kingsway, London WC2B 6PU. Tel: 01-405 6233

Harrogate, England

Management Services & Equipment Exhibition. Peter Mirrington Exhibitions, 1 The Coppice, School Rd., Kelvedon Hatch, Brentwood, Essex. CM15 6DL Tel: 0277 74290

Frankfurt, W. Germany Office Equipment Exhibition. Collins & Endress, 36 Sackville St., London W1X 1DB. Tel: 01-734 0543

London, England

2nd Personal Computer World Show. Montbuild Exhibitions Ltd., 11 Manchester Sq., London W1M 5AB. Tel: 01-486 1951

Cardiff, Wales

BEX - Business Equipment Exhibition. Douglas Temple Studios Ltd., 104B Old Christchurch Rd., Bournemouth, BH1 1LR, Hants Tel: 0202 20533

London, England

COMPEC - Computer Peripheral & Small Computer Systems. Iliffe Promotions Ltd., Dorset House, Stamford St., London SE1 9LU. Tel: 01-261 8000

Dublin, Ireland

ITRON - Irish Electronics Exhibition. SDL Exhibitions Ltd., 68 Fitwilliam Sq., Dublin 2, Ireland. Tel: Dublin 763871

Helsinki, Finland

FINNTEC 79/ELKOM 79 - Electrical Technology & Professional Electronics Fair. ECL Ltd, 11 Manchester Sq., London W1M 5AB. Tel: 01-486 1951

Munich, W. Germany PRODUCTRONICA - International Exhibition for Electronics Production, ECL Ltd, 11 Manchester Square, London W1M 5AB. Tel: 01-486 1951

Dunstable, England The All Business Show. Luton and District Chamber of Commerce and Industry, George Street West, Luton LU1 2BT. Tel: 0582 23456

Hamburg, W. Germany Office Equipment Exhibition. Hamburg Fairs & Congress Co., 238 High St., Poole, Dorset BH15 1DY. Tel: 02013 4450

Madrid, Spain

SIMO - International Office Equipment & Computers Exhibition. CITEMA, Plaza de Conde de Valle Suchil 8, Madrid 15, Spain

Manchester, England Minicomputers, Word Processors & Copying Machines Exhibition. Ground rule Exhibition Co. 7 Market St., Altrincham, Cheshire, WA14 2QW Tel: 061 928 2227

London, England

Electronics '79 Show. Industrial & Trade Fairs Ltd., Radcliffe House Blenheim Court, Solihull B91 2BG. Tel: 021 705 6707

Brussels, Belgium

International Electronics Exhibition. Brussels International Trade Fair, Palais du Centenaire, Parc des Expositions, B 1020 Brussels, Belgium

Tokyo, Japan

Semicon Japan. Golden Gate Enterprises Inc., De Anza Office Center, 1307, So. Mary Ave., Suite 210, Sunnyvale, CA 94087 U.S.A.

Bucharest, Romania SYSTEMTECHNIK - International Electronics Exhibition & Trade Fair. Glahe. International GmbH & Co., Herler Strasse, 91-109, P.O. Box 800349, D-500 Cologne 80. W. Germany

London, England

Breadboard Exhibition (Home Electronics). Trident International Exhibitions Ltd., 23a Plymouth Rd., Tavistock, Devon, PL19 8AU. Tel: 0822 4671

Paris, France

International Electrical Equipment Exhibition. French Trade Exhibitions, 54 Conduit St., London Wl. Tel: 01-439 3964

Birmingham, England TV MEX. Montbuild Ltd., 11 Manchester Sq., London W1M 5AB. Tel: 01-486 1951

Wembley, England Microsystems '80 Exhibition & Conference. Iliffe Promotions Ltd., Dorset House, Stamford St., London SE1 9LU. Tel: 01-261 8000.

Leeds, England

BEX - Business Equipment Exhibition. Douglas Temple Studios Ltd., 104b Old Christchurch Rd., Bournemouth, Dorset. Tel: 0202 20533

Milan, Italy

INTEL - International Electrical & Electronic Technology Exhibition. Intel, Via Luciano Manara 1, 20122 Milan, Italy

Solihull, England

Mini Computers, Word Processors & Copying Machines Exhibition. Groundrule Exhibition Company, 7 Market Street, Altrincham, Cheshire WA14 2QW. Tel: 061 928 2227

Oct 11 - Oct 21 Oct 23 - Oct 28
Oct 23 - Nov 1 Oct 25 - Oct 26
Oct 30 - Nov 2 Nov 1 - Nov 3 Nov 5 - Nov 6
Nov 6 - Nov 8
Nov 6 - Nov 8 Nov 6 - Nov 10
Nov 6 - Nov 10 Nov 13 - Nov 15 Nov 13 - Nov 17 Nov 15 - Nov 23 Nov 20 - Nov 21
Nov 20 - Nov 23 Nov 26 - Dec 1 Nov 28 - Nov 30 Dec 3 - Dec 8
Dec 4 - Dec 8
Dec 10 - Dec 15 Jan 15 - Jan 17 Jan 30 - Feb 1 Feb 6 - Feb 7 Feb 9 - Feb 13 Feb 12 - Feb 13

104 PCW

DIARY DATA

London, England

Business Computing, Word Processing & Information Mgt., Exhibition & Conference. BED Exhibitions Ltd., Bridge House, Restmor Way, Wallington, Surrey. SM6 7BZ. Tel: 01-647 1001

Wembley, England Bournemouth, England

INFO EUROPE - European Information Management Exhibition & Conference. Clapp & Poliak Europe Ltd., 232 Acton Lane, London W4 5DL. Tel: 01-995 4806 BEX - Business Equipment Exhibition. Douglas Temple Studios Ltd., 104b Old Christchurch Rd., Bournemouth, Dorset, Tel: 0202 20533

Swansea, Wales
Dortmund, W, Germany Birmingham, England

OFFEX - Office Equipment Exhibition. Phoenix Exhibitions Ltd., 1st Floor, Burrows Crambers, East Burrows Rd., Swansea. Tel: 0792 460364 HOBBYTRONIC - Electronic Hobby Exhibition. Westfalenhalle GmbH, Postfach 1130, Reinlanddamm 200, 4600, Dortmund, W. Germany IEA - International Instruments, Electronics & Automation Exhibition. Industrial & Trade Fairs Ltd., Radcliffe House, Blenheim Court, Solihull, West Midlands, B91 2BD. Tel: 021 705 6707

Copenhagen, Denmark TECHEX - World Fair of Technology Exchange. Dr Dvorkovitz & Associates, P.O. Box 1748, Ormond Beach, Florida 32074 U.S.A.

Birmingham, England Computermarket '80, Couchmead Ltd, 42 Great Windmill Street, London W1V 7PA. Tel: 01-437 4187

Liverpool, England
London England Sheffield, England

Merseyside Business Efficiency & Office Equipment Exhibition. Gwen Shillaber Design, 81 Whiteladies Rd., Clifton, Bristol BS8 2NT. Tel: 0272 312850 Microforum Europe. Business Equipment Trade Association, 109 Kingsway, London WC2B 6PU. Tel: 01-405 6233 Business Efficiency & Office Equipment Exhibition. Gwen Shillabar Design, 81 Whiteladies Rd., Clifton, Bristol BS8 2NT. Tel: 0272 312850

Manchester, England Computermarket '80. Couchmead Ltd., 42 Great Windmill St., London W1V 7PA. Tel: 01-437 4187

Bahrain, UAE

Middle East Business Equipment Show. Arabian Exhibition Management 11 Manchester Sq., London W1M 5AB. Tel: 01-486 1951

Glasgow, Scotland

Computermarket '80. Couchmead Ltd., 42 Great Windmill St., London W1V 7PA. Tel: 01-437 4187

London, England

Computermarket '80. Couchmead Ltd., 42 Great Windmill St., London W1V 7PA. Tel: 01-437 4187

London, England

Viewdata '80. Online Conferences Ltd., Cleveland Road, Uxbridge, Middx UB8 2DD. Tel: 0895 39262

Paris France

International Exhibition of Electronic Components. French Trade Exhibitions, 54 Conduit Street, London W1R 9SD. Tel: 01-439 3694

Feb 12 - Feb 15
Feb 18 - Feb 21
Feb 20 - Feb 21 Feb 20 - Feb 22 Feb 20 - Feb 24 Feb 25 - Feb 29
Feb 26 - Feb 29 Mar 4 - Mar 6 Mar 4 - Mar 7
Mar 11 - Mar 13 Mar 11 - Mar 13 Mar 11 - Mar 13 Mar 16 - Mar 20
Mar 18 - Mar 20 Mar 25 - Mar 27 March 26 - March 28 Mar 27 - Apr 2

COMPETITIONS ROUND -UP

One of the less appreciated than a round -up of results program. The solution was as

inheritances for the new team at although, through later issues, we follows:

PCW was a collection of hither- hope eventually to publish a much to unresolved competitions. We fuller analysis. believe, after some hours of research, that five (and possibly KNIGHT'S TOUR

13 34 25

36 23

24 14

12 35

reversed

31 43 52 63 42 21 32 41 53

six) sets of results are outstanding The problem was to find a MC=72

MC=126

(! ) - please let us know if you spot others - and of those, at
least two still require their instigators to pass judgement. They are: "Puzzle Dazzle 2", set in the February '79 issue; "Alphametics" set in the May '79 issue. Others, which we can deal with now, are:

complete tour of the chessboard
for a knight, so that the piece visits, in turn, every square on the board once, and once only.
Sheridan had purposely set a difficult competition. . . and yet the entries still came flooding in. Joint winners (£10 each) are

The winner is: Mr 0. M. Dixon
of Alverstoke in Hampshire, who receives £10. A consolation prize
of £5 goes to Mr C. Palmer of
Bradford, Yorkshire who, although not first out of the 'hat', submitted the best entry.

"Magic Squares", set by Sheridan
Williams in the June '79 issue: "Knight's Tour", again set by Sheridan Williams, this time in
the January '79 issue; finally, "Witbit 1" set by David Parkin-

Philip Crane of Romford in Essex and Brian Legg of Bishops Stortford in Hertfordshire. The run times of the two programs were 3.87 seconds and 2.36 seconds, respectively.

WITBIT
The problem set was to write a short subroutine for an editor to execute a "Find string" com-
mand. Solutions were accepted in Z80

son and Graham Trott in the June '79 issue.
It's obviously most unfair that the winners be kept waiting any longer. However, it'll come as no surprise to everyone to learn that the outlining of all these reports
would take up far more space than any one PCW issue could possibly donate (not to mention
the possibility of our readers going down with a nasty bout of `competition overkill').
Therefore, this month we are restricting ourselves to little more

MAGIC SQUARES
The problem here was to find a magic square that satisfies the following conditions: (1) It comprises of 2 -digit numbers (zeroes not allowed) (2) It's a 3x3 square (3) When the digits are reversed, another magic square is produced with none of the original numbers reappearing (4) The sum of the two magic constants is less than
200. A prize was offered for the first
correct entry supported by BASIC

and 6800 code, prizes to be awar-
ded to the winners of each section. Z80. First prize (£10) goes to Mr J. Robertson of East Kilbride, Scotland for his neat solution which uses the minimum
of temporary storage. Second prize (X5) goes to David MedlandSlater of Farnborough in Hampshire. 6800. Only four entries received in this section! Winner (£10) is Martin Bond of Didsbury,
Lancashire and runner-up (£5),
John Phillips of Saltash, Cornwall.

PCW 105

COMMUNICATION

Cryptic clue
Re September Issue 1979, Spaceship FX201-P . I have an entry for your diversions and puzzles page.
With reference to the above article: A Try and figure out how the list of step numbers applies to the program. B Make a list of incorrect function signs. C Fill in the missing line which would give answer 4 your new radial distance.
I would be most grateful if you could send me the same copy that Dick Pountain wrote his review from. E. Fernie, Enfield, Middx Okay, pax. . . Corrections to Spaceship FX201-P in Blunders at the end of our Programs section.
Faith healing
Further to my letter of 1st June, 1979, concerning difficulties I have experienced in obtaining a MPS 6550 memory chip for my Commodore PET. I now have the greatest pleasure to inform you of the remedy... a small shop in the town of Luton, Bedfordshire, called IsherWoods. I rang them and explained my problem and was told that they had the devices in stock. I was invited to take my PET over to them where they could test the device in situ.
Once at the shop I was received by their Wizard, John Rees, who operates in a well -organised (you should see mine) workshop with an air of calm confidence and rather like a slow-motion Magnus Pyke. That he knows what he is doing is evident from the constant flow of people seeking his advice and leaving satisfied. I was invited to participate in the operation (painless) but the best part was enjoying the interesting chat seeded with snippets of valuable information.
The Wizard introduced me to the Vizier, Ian Wade who is their Divisional Controller and obviously knows a lot more about the aspects of hard and software than he is telling! If you wish to discuss the purchase of either he is in an ideal position to give you the "low down" on it. I wonder how many persons in his position can say the same.
Throughout my visit I was impressed with the atmos-

phere of friendly co-operation and enthusiasm and I strongly urge anyone in the vicinity, to drop in and say hello. This really is an unsolicited testimonial; unless Isher-Woods reads your worthy publication they will never know about it. S.R. Somers, Aylesbury Well earned "plugs" we never mind repeating - Ed.
Punter postscript 1
I read with interest "The Programmed Punter" by Dr. M.R.J. Morgan in the July issue of PCW. I was surprised at the low limits on the value of the permutations he could calculate until I realised that he calculated them from three factorials.
This is a very long winded and restricting method as many terms in the fraction always cancel out. To take his example:
8!
3!x5!
8x7x6x5x4x3x2x1 (3x2x1)x(5x4x3x2x1)
8x7x6 3x2x1
The subroutine at line 1000 in the program below calculates the permutations this way cancelling the larger factorial on the bottom into the top.
10 REM BINOMIAL CO-EFFICIENTS **'' 20 INPUT "M, N"; M, N 30 IF M=0 THEN END 40 GOSUB 1000 50 PRINT C 60 (10TO 20 1000 REM $ IS BIN COS 10 1010 IF M -N> -N (10I 0 10:10 1(120 N=M.N 1030 C=M 1040 IF N=1 GOTO 1090 1050 Ml -M+ I 1060 FOR 1=2 TO N 1070 (1-C*041-1111 1080 NEXT 1 1090 RETURN
This program will allow your readers to see how large they can get M and N on their systems. With M=122 I can do all values of N although my RML380Z overflows at about 1038. Hugh Williams (Past Chairman MUSE) West Bridgeford, Nottingham
Punter postscript 2
In Dr Morgan's short article "The Programmed Punter" (July PCW) he used the formula M!/N! (M -N)! which gives the number of combina-

tions of N objects that can be chosen from M unlike objects. ABC and ACB are different permutations of the same combination of letters.
An alternative way of calculating the number of possible combinations, other than evaluating the three factorials as that program does, uses the fact that the coefficients of the binomial expansion (x+y)M, are the number of combinations of 0,1,2,...,M objects from M objects. For example, the coefficients of the terms of (x+y)7 are 1,7,21,35,35,21,7,1 so there are 21 possible combinations of 2 objects from 7 objects.
Successive coefficients are related by:.
InCnimCn-1
= m!/n!(m-n)! x (n-1)!(na-n+1)!/m!
= (m-n+1)/n
7C3/7C2 = 35/21 = 5/3 = (7-3+1)/3
so mCn = mCn_i x (m-n+1)/n

C=C/I*(N-I+1) will enable greater values of M to be
evaluated. Peter Butt, Chadwell Heath, Essex.

MK 14 sound out

In musical or noise generating applications of the Science of
Cambridge SC/MP based Mk.14 microcomputer, a crystal microphone insert may be used as a high impedance loudspeaker, driven directly by the logic levels at the flag outputs of SC/MP. The prototype used an ACOS
type MIC-43 connected as shown below.

FLAG I 32
0v.0

-1
MIC-43

As "0 = 1, the number of combinations can be evaluated by successively multiplying by (M-I+1)/I where I=1,2,
,N. A program, assuming that the data is always correct
being: 10 INPUT M,N
20 C = 1 30 FOR I=1 TO N
40 C= C*(M-I+1)/I 50 NEXT I 60 PRINT C
As mCn= m Cm -n another
line could be added to increase the efficiency of the program

The brief program listed here may be used to generate a sound to test the set up. It operates by incrementing a store, loading the result to the Status (flag) Register, and also using the result as a parameter for a variable delay before jumping back to the start. The program is written in locations OF20 to
OF26 inclusive with OF1F as a store but it is relocatable to any eight contiguous loca-
tions in RAM. The type of output sound may be varied by altering the delay base number in location OF24.

15 IF M -N <N THEN N=

OF1F 00 Store:

M -N
Using this algorithm, our RM 380Z, using DBAS12, can evaluate the number of combinations of N objects from 123 objects to an accuracy of 10 significant figures. Some results for values of M greater than this can be obtained, but the

OF20 A8FE Start: 1LD Store

OF22 07
OF23 8F00 0F25 90F9

CAS DLY
JMP Start

0000

.END

See the Mk.14 User Manual

Music section for more ambi-

tious programs using this

circuit.

T. J. Spriggs, Havant

greater M is, the smaller N has to be. When M= 300,N

can only be 26 or less. Using the formula for the number

Dodgy delays

of combinations directly, the

greatest value of M is 33. The formula for the
number of permutations of N objects chosen from M unlike objects is M!/(M-N)! and a similar method of evaluation can be used that does not involve working out factorials.
As the order in which

The SC/MP micro -processor has a DELAY instruction (opcode 8F) which provides a pause, corresponding to a specified number of micro cycles, with very simple software. (In the 6800 MPU,
we have to write a short subroutine to achieve the same effect).

multiplication and division

In the manual for the

are executed does not matter, Mk.14 (which uses the

it is worth investigating to see SC/MP chip) there are pro-

if the equivalent statement grams (on Pages 65 and 66)

106 PCW

COMMUNICATION

for Serial Data Input and

by taking the mean of the

Serial Data Output. These

upper and lower limits of

programs use the DELAY

the delays found to be satis-

instruction. In a program I factory.

wrote, similar to the Serial

Because of the synchro-

Input program, I found that nising action of the START the constants for the DELAY and STOP bits in the

operation suggested in the

program, there is a certain

Mk. 14 programs, were not range within which opera-

correct. My program worked tion is satisfactory. With

correctly when the constants "8F 07" the program would

were changed to values which work with values stored in

were found after some experi- the accumulator varying from

ments guided by theory.

00 to 44 (in hex).

Page 64 of the manual

In addition to changing

gives a table for delay

the constants for "bit time",

constants based on a frequen- I changed those required

cy of 4 MHz. These constants for "half bit time". To save

are used in the Mk. 14 pro- space, those changes will not

gram for Serial Data Input. be mentioned here. The pur-

But the Mk. 14 works in asso- pose of this letter is to

ciation with a crystal which suggest that values in a table

has a frequency of 4.433618 intended for a frequency of

MHz (this is the value stamp- 4 MHz should not be applied

ed on the casing of the

to an MPU working at

crystal). It would therefore 4.433618 MHz.

seem to be wrong to use the constants in the table.
In my project, I was working at 300 baud, the "bit time" is 3.333 milliseconds. For this condition, the table
suggests
"C4 5E 8F 03" This means "Load 5E into the accumulator and set the displacement in the DELAY instruction to 06". This leads to a delay of n microcycles, where n is given by 13 + 2 x (accumulator) + 2 x displacement + 29 x displacement; i.e.
13 + 2 x 5E + 2 x 6 + 512 x 6. This statement is some-
what confusing in that decimal numbers are mixed with hexadecimal. "5E" in hex means "94" in decimal. Thus n =
13 + 188 + 12 + 3072

Tom Palmer, Kew
We rang Science of Cambridge who confirm your observations. They did point out, however, that since January they have incorpora-
ted a genuine 4MHz crystal. They also mentioned that their manual page numbers have changed following a recent update so you may find Tom's references different to your own. One last thing - they also told us that because the input and output routines use the same byte in memory, spurious data can find its way onto the output line as it is displaced by incoming data. You can work out your own solution to this by either dealing with the content of this byte before a read or by gate'-ing
the output. -Ed.

= 3285 microcycles.

At a frequency of 4 MHz, one microcycle lasts 1 microsecond. The delay is thus 3.285 milliseconds.
We require 3.333 milliseconds. This leaves 48 microcycles for the SC/MP instructions -a reasonable
figure.
However, when SC/MP is working at 4.433618 MHz, the delay corresponding to
3285 microcycles is

3285 x

4 microsecs

4.433618

i.e. 2.9637 milliseconds.

For my project, I found that the program would work with
"C4 22 8F 07" The constants were chosen

Pascal
possibilities
Alex Cawley's letter in your September Issue gives incorrect information concerning the availability of PASCAL Compiler RAM requirements.
Our company has a 3 Pass PASCAL Compiler designed for the RCA 1802 Microprocessor which runs in a 20K RAM System with Floppy Discs. This Compiler, whilst designed for the 1802 family, can be adapted to other microprocessors by alteration of the 2K run time kernel to suit the required instruction set.
The 2K interpreter makes application programs as small as 3K a practical possibility;

the package is designed to appeal to the professional and industrial user looking for minimum read only memory costs. M. J. Dalgleish, Golden River Company, Bicester
Routine
business
I read an aritcle in PCW recently describing Dr. Roger Quy's 380Z system at the National Hospital's Institute of Neurology. In it, Dr. Quy was quoted as saying that he had found PCW to be a useful source of assembler multiplication and division routines. As a fairly recent convert to PCW and a new user of a 380Z, I should like to track down these routines. I wonder if you can quote me chapter and verse? I'd be very grateful. Mrs A M Guenault, Lancaster We rang Dr. Quy and, with his help, tracked down an article by Neil Harrison in volume 1 number 2. It's called 'Four Easy Pieces' and in it, among other things, he describes a multiplication routine. He thinks that his division routines came out of a hardware manual - Ed.
Was istdas?
I would be grateful if you could kindly inform me of any computer that translates German into English, it would also be a great help if you could supply the companies' names and addresses. PS I do take your magazine. H. Thomas, Shirehampton, Bristol. Nice to hear from another discerning reader! The company distributing translators in the UK is Lexicon. Their head office is in Parliament Street, London (Tel: 01-930 3030). They supply to shops all over the country - the nearest one to you is probably Communications Imports in Cheltenham. The phone number there is 0242 41173. It is probably worth noting that the translator has a repertoire of some 1500 words and translates word for word in the present tense, first person singular. Therefore, although it's no replacement for a human interpreter, it does provide a very useful means of communication. One last thing - price; a Lexicon

3000 with one language module of your choice costs £148 + 15% VAT. Each additional module costs £32.95 + 15% VAT. Each module plugs in and allows translation in either direction. Stop Press: Lexicon have just announced that they are selling 'personal program' modules - you can store recipes, 'phone numbers jokes etc. - Ed.
Sorcerer tips
Despite claims to the contrary, there is no GET statement in Sorcerer BASIC. It is, however, possible to simulate a GET statement using a machine code routine that is POKE'd in from BASIC.
The statements are as follows: firstly, FOR X = 1 to 14 READ W POKE 223 + X, W NEXT X DATA 62, 0, 50, 240, 0, 205, 9, 224, 200, 50, 240, 0, 201, 0. then, POKE 260, 224 POKE 261, 0
To use this routine: V = USR (0) : A = PEEK (240) A now has the value of the ASCII code of the last key to be pressed. If no key is pressed then A = 0.
An example is shown below:
10 PRINT "DO YOU WANT TO CONTINUE" 20 V = USR (0) : A - PEEK (240) 30 IF A = 0 THEN 20 40 IF A = ASC ("Y") THEN 80 50 IF A = ASC ("N") THEN 100 60 PRINT "RESPONSE INVALID" 70 GO TO 20 80 REM Do something 90 GO TO 10 100 END
To control a printer from BASIC, rather than from the monitor, USE the output vectors:
7FDO H 32720 D and 7FD1 H 32721 D
The contents of these locations will change depending on the output option selected. To turn on the line printer (Centronics) POKE 32720, 147 and to switch it off again POKE 32720, 240. (A word of warning, we've found that if we mess about in the monitor before executing POKE 32720, 147 we lose our program entirely - some caution is needed). Rob Beynon, Liverpool University.

PCW 107

z t- --9L1[1Q.-J

D

jgg

13 Warwick Road, Cou sdon, Surrey, CR3 2EF Telephone : 01 - 660 5617

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.

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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 £228 MIDAS 1 : Z80 System from £625 (built) MIDAS 2 : Z80 Disc System from f1100 (built)

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 - many also as bare boards

SOFTWARE

Z80 Starter Kit, featuring on board

CP/M on 8" or 5" Floppy Disc

Keyboard, 2K Monitor, 1K RAM, 2x8

C -BASIC 2

bit I/O Ports, Prom Programmer etc. £145. 00 Z80 Disc Based Assembler,

280 CPU, 2 MHz, 1K RAM, up to

Linker & Editor

8K EPROM, Serial/Parallel I/O port,

Microsoft BASIC V.5.

four channel counter timer

XYBASIC - Extended

- SBC 100

£155. 00 FORTRAN 80

Z80 CPU Board 4 MHz,

COBOL 80

jump -on -reset

£116 .00 PASCAL

8080 CPU Board, jump -on -reset

£87 .00 PASCAL/Z

8K RAM Board, low power

DISZ I LOG Z80 Disassembler

450 n Sec (21L02-1)

£79 .00

16K RAM Board, low power

PERIPHERALS

250 n Sec. Static

£195 .00 12" VIDEO MONITOR, green

Dynamic RAM Board for 16-64K

phosphor bonded tube, displays

RAM (4116)

£91. 00 up to 80 ch/24 lines, 50/60 Hz

2708 EPROM 116K) for 2708

operation

or 2716 EPROMS 2708/2716 EPROM Prog. Board,

£63. 75 PRINTER, Bi-Directional Dot Matrix; 112 ch/sec: 96 ch ASCII

2 Textool All sockets

£86. 50 set, 80 ch/line; 900 ch

I/O Board, 2/2, DIP switch selection £95. 00 RS232 or parallel input

I/O Board, 2/4 provision

KEYBOAR

4K RAM/4K ROM

£135 .00 set, 80 ch/line; 900 ch buffer;;

Video Interface, 16 lines, 32 or 64

PERI

ch/line 160 frames)

£91. 00

Video Interface, 16 lines, 64 ch/line

150 frames) A/T

£108.75 PERIPHERALS

Video Display, 80 ch x 24 I,

12" VIDEO MONITOR, green

keyboard interface, 2K RAM,

phosphor bonded tube, displays

256 available chars etc Motherboard 113 slot with four

£192.00 up to 80 ch/24 lines, 50/60 Hz operation

edge connectors) Motherboard 19 slot with four

£48.50 PRINTER, Bi-Directional Dot Matrix; 112 ch/sec: 96 ch ASCII

edge connectors)

£40.00 set, 80 ch/line; 900 ch buffer;

RS232 or parallel input

FLOPPY DISCS

KEYBOARD, 56 -key Tri-mode

SHUGART SA400 Mini Floppy 5%" £190.00 ASCII output, with case & edge

SIEMENS 1208" Disc Drive

£325.00 connector

Disc Controller, 5" or 8"

£98.00 12V DC/DC Convertor

Double -Density Disc Controller

£280.00

£76.00 £74.00 £60.00 £160.00 £220.00 £210.00 £325.00 £145.00 £131.25 £37.00
£215.00
buffer; £595.00
£215.00
£595.00
£68.00 £6.00

HARDWARE
EPROM Eraser )240V) Erases up to 12 EPROMS at a time S100 Edge Connectors, solder tail S100 Edge Connectors, gold plated wire wrap Transformer Pri 110/240V; sec. 8V @ 10 amp & 25V CT @ 2 amp Bridge Rectifier 25 amp @ 50V

£40.00 £2.45
£3.50
£12.75 £3.75

WRITE OR PHONE FOR CATALOGUE

108 PCW

Please mention PCW when replying to advertisers - it identifies you.

YOUNG COMPUTER WORLD
\Young Computer World is the place where, each month, John Coll highlights the thoughts, ideas and contributions of PCW 's younger readers.

Reactions
I can see that the major problem about this page is going to be finding space to print all the good stuff that comes in. We have given some thought to this problem and perhaps there is a place for publishing a whole selection of programs in book form in addition to the regular page in PCW. Anyway that remains to be seen. Also, of course, we are able to "overflow" into the Programs section.
However, I have only had one reply to my request for an idiot proof input subroutine, but I guess that may be because of the misprints which made the idea a little difficult to follow! I will leave that topic open for a while in the hope that others will try.

Calculator programmes
I've been surprised at the number of calculator programs sent in. S.P Tait (17) is an apprentice with Marconi Communications Systems in Chelmsford and he has submitted five programs for the T157. One uses Kirchoff's and Ohm's laws, one plays pontoon. The other three deal with Matrix Multiplication, Number Base Conversion and a version of Mastermind. One of his programs is printed below.

Number base conversion

STO 2 R/S STO 0 R/S STO 5 RCL 2 LBL 1 STO 2
1
STO 3 LBL 6 RCL 5 INV PROD 2 X RCL 2 INV INT INV SUM 2 X RCL 3
SUM 1 RCL 0 PROD 3 RCL 2 X=T GOTO 6 RCL T INV SUM 1 R/S RST

32 2
81
32 0 81 32 5 33 2 86 1 32 2
01
32 3 86 6 33 5 -39 2 55 33 2
-49 -34 2
55
33 3 85 34 1 33 0 39 0 33 2
-66
51 6 33 1 -34 1 81
71

The program converts any integer in any base 1 to 10 to decimal or any decimal integer to any base 1 to 10 To use the program enter the number then R/S. Enter the base of the first number then R/S, then enter the base of the result followed by R/S.
CESIL
Undoubtedly the most interesting letter this month came from Richard Clyne (15) of London SW11. He has written a CESIL interpreter in BASIC. CESIL is a language which makes the computer behave like a very simple machine and

illustrates how an assembler works. Space does not permit a detailed explanation of how to work the program but it's fairly obvious. It was not the length of the program that was impressive but rather the fact that it was so clearly set out and easy to use. Richard's program was written to run on the ILEA RSTS Systime 6000 but it will be easy to alter the file handling for other systems. A fine piece of work.
See you at the show and in the meantime keep sending me useful bits and pieces. My address is Laxton House, Oundle, Peterborough PE8 4AQ. Thanks.

Program listing

CESIL 13:37

13-SEP-79

10 RANDOMIZE

20 PRINT " MODES AVAILABLE :" 30 PRINT TAB( 10)." < I ) INPUTING A PROGRAM" 1:13 PRINT TAB(10)," ( 2) LISTING A PROGRAM" 50 ,PRINT TAB( 10)," (3) EDITING A PROGRAM"

60 PRINT TAB( 10), " (4) RUNNING A PROGRAM" 70 PRINT TAB( 10)." (5) RECALLS A SAVED PROGRAM"

80 PRINT TAB( 10) " (6) INDEX OF ALL SAVED PROGRAMS"

90 PRINT TALI( 10), " ( 7) SAVE A PROGRAM" 100 PRINT TAB( 10)," (8) LIST OF VARIABLES" 110 PRINT TAB( 10), " (9) LIST OF LABELS"

120 PRINT TAB< 10). " (10) DELETING A PROGRAM"

130 DIM CSC 3, 2003.LC 200).L SC 2001, VSC 2003 VC 2001. PSE 1001

131 DIM DC 1001

140 PRINT: INPUT "MODE"; II

150 IF M>10 GOTO 20

160 M= INT CM)

170 IF A9>A6 THEN A6=A9

180 IF M>7 GOTO 1940 190 ON N GOTO 200., 310, 410, 530.1530. 1610.1710. 1950

200 OPEN 'KB: 'FOR INPUT AS FILE 9%

210 A9=1

220 INPUT /9. "1,..c"; CS( 1. A9 )

230 IF CS( 1,A9)="END"GOTO 290 240 INPUT #9. "c"; CS( 2.A9)

245 IF CS( 2,A9)="DATA" GOTO 301 250 INPUT #9,"A<"; CS( 3,A9 )

260 PRINT

270 A9=A9+ 1

230 GOTO 220 290 CLOSE /9

300 GOTO 140 301 INPUT "HOW MANY DATA ITEMS"; D: FOR DI= I TO D: INPUT #9. DC DI): NEXT DI

302 D2=1)

303 GOTO 140

310 I

LISTING PROGRAM ( CES1L )

320 PRINT: PRINT

330 PRINT VCARD NUMBED",

340 PRINT "LABEL", "COMMAND", "LABEL/VARIABLE" 350 A9 = I

360 IF CS< I.A9 )="END" GOTO 140

375 IF CV 2.A9 )="DATA" GOTO 401

377 PRINT A9. 380 PRINT CS( 1,A9),CS( 2.A9),CS( 3.A9)

390- A9=A9,- 1

400 GOTO 360 401 PRINT "Dt.TA", : INT DID); FOF, D= 1 TO D2

402 GOTO 140 410 ! ********-********************************************************

420 A9=1 430 IF 05(1,A9)="END" GOTO 440 ELSE GOTO 460

440 INPUT "ADD tIORE"IY5 450 IF LEFTCYS, 1 )="Y" GOTO 220 ELSE GOTO 140

460 PRINT CS( 1,A9),C$(2.A9).CS(3.A9)

470 INPUT "KEEP" ; ES

450 IF FS="E" GOTO 140 490 IF ES="C" GOTO 500 ELSE A9=A9 +1: GOT0430

500 INPUT CS(1,A9),C5(2,A9),CS(3,A9)

510 A9=A9+1

520 GOTO 430

PCW 109

MICR®MART

530 L=1:0=1

PROGRAMS

540 FOR. A8=1 TO A6-1

550 IF CSC 1, A8 )=""GOT0570

Ai 1 COMMODORE PETS

560 LS(L)=C4(1,A8):LCL)=A8:L=L+1 570 NEXT A8

l

IFree file and record

558900L0<.O1>=L

111

management program with

600 FOR 100=1 TO A6-1

every PET sold (limited period only).
Selection of Printers and Floppy Disks.
Large selection of software + programming service available.
Few secondhand PETS available, e.g. 8K from £400.00 +

,.. 610 1/95 =CSC 2,A8 ) ler 620 IF V9 S="STORE" GOTO 650
eao NEXTA8
0 640 GOTO 680
650 1/9$=LEFT( CS< 3.A8 ). 1 )
660 IF V95."+" OR V95."-" GOTO 630
670 VS( V)=CS( 3.A8 ) : V=V+1: GOTO 630 680 VC 0)=V
690 P.1 700 A=INT(A)

VAT.
Call at: Davinci Computers Ltd., Classic Offices, Rear of Classic Cinema, Hendon

710 XS=CS( 2,P) 720 IF XS="IN" GOTO 890 730 IF XS="OUT" GOTO 920 740 IF XS="HALT" GOTO 950 750 1 F XS."LOAD" GOTO 980

Central, London NW4. Tel:

760 IF XS="JIZ:ERO" GOTO 1090

202 9630.
*** Wanted *** Part Time

770 IF XS."JINEG" GOTO 1120 780 1 F XS."VUMP" GOTO 1140 790 1 F XV="STORE" GOTO 1210

0

Programmers. Call above

BOO IF XS."PRINT" GOTO 1270

address.

810 IF XS="LINE" GOTO 1290 820 IF X$="ADD" GOTO 1310

830 IF XS="SUBTRACT" GOTO 1340

840 IF XS="MULTIPLY" GOTO 1370

INTELLIGENT

850 IF XS="DI VI DE" GOTO 1400 860 IF CS( 2. P)="" GOT0140 870 PRINT CS( 2, P): " IS NOT A LEGAL COMAND

ARTIFACTS

880 PRINT"EDIT IT OUT I ": GOT0140
890 A=DC DJ : D=D+1 900 P=P+1

910 GOTO 700

Sale of 5100 Memory Boards 16K fully static, 2MHz £175 each 4MHz £220 each. Also Z-80 CPU Boards
4 MHz £150 each.

920 PRINT A; 930 P=P+I 940 GOTO 700
950 GOTO 130 960 P=P+ 1

We also sell PETs, Challengers, AIM 65 etc. All imported direct from

970 GOTO 700
''' 980 JS.CS( 3.F)
990 IF LEFT (..1 8, 1 )."+" OR LEFT(,1 S., 1)."-" GOT01060

USA. Lowest prices in UK.

1000 FOR A9=1 TO V( 0)

Send or call for Price List.

1010 IF CSC 3,P)=VSCA9) GOTO 1040

III

Telephone: Arrington (022 020) 689

1020 NEXT A9:P=P+ I

Cambridge Road, Orwell, Nr Royston, Herts.

1030 GOTO 7001NEVER REACHED 1040 A=V(A9)
1050 P=P+1:GOTO 700

1060 A. VALCRIGHT(.1S,LEN(JS)-1))

1070 IF LEFT(JS, 1 )."-" 'NEN A. -IA)

PETS £400

1080 P.P+ Is GOTO 700 1090 IF A=0 GOTO 1140 1100 P. P+1

4K VERSION IN STOCK. 8K £450 etc. ALL PET PRODUCTS WAY

1110 GOTO 700 1120 IF A.:0 GOTO 1140 1130 P=P+1:G0T0 700 1140 FOR A8=1 TO L(0)

UNDER UK PRICES.WE IMPORT

1150 I F Cs( 3, P)=LSC A8) GOTO 1190

1160 NEXT A8

DIRECT FROM USA AND CONVERT TO UK MAINS.

1111 1170 PRINT"LABEL ERROR CAFD"; 1. 1180 GOTO 140
1190 P=1. ( A8 >

0

AIM 65
WITH CASE, POWER SUPPLY AND 4K RAM, BASIC AND ASSEMBLER £400

1200 GOTO 700

n

1210 FOR A7= 1 TO V(0) 1220 IF VS(A7)=CS( 3, P) GOTO 1260

W 1230 NEXT A7

1240 PRINT "VARIABLE ERROR! CARD"; P

1250 GOTO 140

AIM + KIM
EXPANSION CHASSIS AND 16K

1260 V(A7)=A:P=P+1:GOT0700 1270 PRINT CSC 3, P);
0 1280 P.P+1 :GOTO 700
1290 PRINT

MEMORIES. NORTHSTAR BASED

1300 .P=P+ 1: GOTO 700

S100 SYSTEMS FROM £1,200.

1310 80S1113 1430 1320 A=A+T

SEND FOR PRICE LIST INTELLIGENT ARTIFACTS LTD

1330 I...P*1300'0 -CO 1340 GOSUB 1430
1350 A=A -T

CAMBRIDGE RD, ORWELL ROYSTON, HERTS.

1360 P=P+1: GOTO 700 1370 GOSUE 1430 1380 A.A*7

1390 P. P+1: G OT 0 7.00 1400 GOND 1430

QWERTY COMPUTER SERVICES

1410 A=INT(A/T)
0 1420 P=P+1: GOTO 700
1430 US=CS( 3.F)

Q.C. software; best quality budget

1440 IF LEFT (JS,1)="+" OR LEFT (JS,1)."-" GOTO 1500

priced programs:-

1450 FOR A7= 1 TO V(0)

*

FUN

LANGUAGES

1460 I F VS(A7)=JS GOTO 1490

Torpedo Run

Q.Sil

Squash/cricket etc Pilot

1470 NEXT A7 IF 1480 PRI:.7T" VARIAbLE ERROR!! ! ! (MATH FUNCTION) CARD"; P: GOT0140
14907-.1AP:7): RETURN

EDUCATIONAL Graph, plot Remedial Maths/ English, Payroll

BUSINESS Stock ',ontrol Cash glow

Many more, send s.a ' . for listing.

We always require original programs and

interfaces. If you have one send it to us for evaluation. Up to 35% royalty paid.

'.

1500 T.VALC RI GHT(JS.LEN(JS)-1 ) ) 1510 IF LEFT (,15, 1 )="-" THEN T= -( T)

1520 RETURN

1530 INPUT "PROGRAM NAME"; PS

1540 OPEN PS FOR INPUT AS FILE 1t

1550 IT= 1

1560 INPUT #1,05(1,57)

1570 IF CS( 1, V)="END" GOTO 1590

1580 INPUT*1, CS( 2. V): INPUT 01., CSC 3,V): V=V+1: GOTO 1560

1590 CLOSE*1

CI C.Z 20 Worcester Road Newton Hall, Durham. Tel 0385 67045

110 PCW

PROGRAMS

1600 GOT0130 1610 OPEN 'INDEX. FOP. INPUT AS FILE 19 1620 A=INT (RND*6)+7

1630 PRINT TAB( A), "CESIL PROGRAMS" 1640INPUT 01,J 1650 FOR 05 = 1 TO J 1660 INPUT 01, P$ 1670 PRINT PS

1680 NEXT 05

1690 CLOSE 01 1700 GOTO 130

17 14 iNPUT"FROGRA-i Nra-ii',/ PS 1720 OPEN PS FOR OUTPUT AS FILE IR 1730 FOR A7=1 TO A6
1740 .PRINT 01,CS(1,/,7) 1750 PRINT *I, CS( 2, A7) 1760 PRINT 01, CS( 3,A7) 1770 NEXT A7 1780 PRINT #1."END"

1790 CLOSE 01 1800 OPEN ' INDEX . FOR INPUT AS FILE 1S 1810 INPUT #1,J

1820 FOP. A=1 TO ..1 1830 INPUT 01, PS(A)

1840 NEXT A
0 1850 CLOSE Al
1860 PS(J+ I )=PS 1870 OPEN ' INDEX'.FOR OUTPUT AS FILE 15 1880 PRINT #1,J+I

1890 FOR A=1 TO J+1

1900 PRINT 01.PS(A) 1910 ,IFXT ., 1920 CLOSE Id

1930 GOTO 130 1940 ON N-7 GOTO 1950 , 2070, 2110

1950 ! LIST OF VARIABLES 1960 Z.= I

1970 FOR X= I TO V( 0) 1980 FOR Y = 1 TO X-1 1990 IF VS(X)=V99(X) GOTO 2030 2000 NEXT Y 2010 V99(Z)=V9(X):V9(Z)=V(X)

2020 Z=Z+ 1

2030 NEXT X
2040 PRINT "VARIABLE", "CONTENTS" 2050 PRINT V9 S(X), V9(X) FOR X= 1 TO Z-1 2060 GOTO 130

2070 ! LIST OF LABELS 2080 P7INT"CARD", "LABEL" 2090 PRINT L(Z),L$(Z)FOR Z=1 TO L(0)-1 2100 5 OTO 130

2110

I DELETEING A FILE

2120 INPUT"PROGRAM TO 'DELETE"; PS

2130 OPEN' INDEX 'FOR OUTPUT AS FILE 15

2140 INPUT 01,J

2150 FOR X=1 TO J

2160 INPUT 01,PS(X)

2170 IF PS=PS(X) THEN 2210

2180 NEXT X 2190 PRINT"NO SUCH PROGRAM" 2200 GOTO 130 2210 INPUT 01, P$(X)

2220 FOR Y=X+ 1 TO J 2230 .INPUT 01, PS(Y)

2240 NEXT Y

2250 CLOSE 01 2260 KILL ps

2270 OPEN 'INDEX 'FOR OUTPUT AS FILE1%
2280 PRINT #1,J-1 90 FOR X=1 TO J-1
2300 PRINT #1,P$(X)

2310 NEXT X

2320 CLOSE 01 2330 GOTO 1.30 32627 END

BELLS & WHISTLES

Recently PCW has received several cassette handling programs and subroutines. Here are two which should prove particularly useful.'.

READ/WRITE ROUTINES
Thomas Turnbull, PETSOFT consultant presents a method for reading and writing PET data files without error.

This method gives close to 100% reliability. It involves two subroutines to increase the gap between data blocks written to tape, thus allowing the machine to read back all the data without dropping a single block. Remember, if a block that is lost contains an EOT or EOF the computer will crash with hardly any hope of recovery.
My subroutine starts at line 5000 for tape 1 and line 6000 for tape 2.

These subroutines need only be used on PRINT files (not READ files). Before opening a print file to
CASSETTE 1 have the following POKE commands: 10 POKE 244,2:POKE 243,122:open 1,1,1
This is the POKE command for CAS SETTE 2: 20 POKE 244,3:POKE 243, 58:OPEN
3,2,1

MICRON=

COMPUTECH FOR APPLE SYSTEM APPLICATIONS SOFTWARE
Professional business software packages now available are turnkey systems with comprehensive manuals, built-in validity checks, interactive enquiry facilities, user options, satisfying accountancy. Inland Revenue and Customs and Excise requirements on diskette with DOS 3.2 and Space Utility. From £295 ea.
Not adaptations, written specifically as packages for the Apple System.
COMPUTECH SYSTEMS
168 Finchley Road, London, NW3 6HP Tel: 01-794 0202
Dealer enquiries welcome

AZTEC We have a growing selection
of PET SOFTWARE for MANAGEMENT SCIENCE plus books, accessories etc.
Send for free catalogue. We publish good, original programs and books on a royalty basis. Write now
for details. AZTEC 29 Royston Way Slough Berks. SL1 6EP
Burnham (06286) 65408

Vets for Pets
Anita Electronic Services (London) Ltd. are specialists in the repair and service of Commodore Pets. We offer a fast on -site service, or alternatively repairs can be carried -out at our workshops should you wish to bring in your Pet. Pet maintenance contracts are available at very competitive prices. Trade inquiries welcomed.
For further information tel. or write to: -
John Meade Anita Electronic Services, IS Clerkenwell Close, London EC I
01-253 2444
We also specialise in the repair of all makes of office equipment.

RACAL -ZONAL

RACAL -ZONAL C-12 CASSETTES Quality you can rely on Screwed shell, c/w library case 5-E3.20, 10-£5.30, 50 £23.90

TDK HEAD DEMAGNETISER £11.75 RACAL HEAD CLEANER £ 0.40

BOOKS.BOOKS..BOOKSBOOKS

Computer programs that work £ 2.90

Introduction to personal and

business computing (ZAKS) £ 5.00

Microprocessors - f-om chips

to systems (ZAKS)

£ 7.50

Programming the 6502 (ZAKS) £ 8.00

6502 Applications bookIZAKS)£ 9.00

CW0.£2.00min. Post & VAT included

DJM SERVICES 82 Hilden Park Rd Hildenborough KENT. Tel 0732 832815

PCW 111

..., ,
MICROIVIART

BIAS POWER

FOR SYSTEM 64K EXPANSION

BIAS 1 for general micro use

+5 @ 10amps ±12v @ 2a mps

-5 @ 1 amp

KIT £42.50

BIAS 3 for S100 systems

+8v @ 10amps

±18v @ 3.5amps

KIT £40.20

Over Voltage Protection
-optional B1-£12; B3-£9

HEAVY ALLOY CASE 150 x 150 x 200
includes switches, connectors, predrilled £12

Assembled & Guaranteed add £15

Mail order to:

TOOTING COMPUTING

P & p £2.50

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Prices excluding VAT.

Tel: 01-543 1398

50 HZ
SUPERBOARD
£190
(BRITISH STANDARD)
PLUS
OFFICIAL Dealer Support
PLUS
ASS/ED, EX/MON and other software and expansion available
CTS 1 Higher Calderbrook Littleborough, Lancs. OL15 9NL Tel: Littleborough (0706) 79332 anytime

PETS! Pets - new for old, part exchange your faithful Pet for a new model. We stock commodore or computhink discs,
PET printers and teletypes etc.
We also by used Pets and peripherals for cash.
HORIZONS! 32K static memory (the best) 2 double
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High Quality Cassettes! C15 41p C30 55p including VAT
Post 20p Orders over £4.00 free postage
Contact: Richard Mortimore or Chris Phelps at
MICRO - FACILITIES 01 979 4546/941 1197

PROGRAMS

These POKE commands tell the PET which buffer it is to use and make sure that a proper tape header is written. If this is not done you will be unable to open that file for read operations. These POKE commands need only be put before the open statements and

nowhere else in the print file used. To use these subroutines you must
GOSUB 5000 for tape 1 or GOSUB 6000 for tape 2 after every print to the
file.
Here is an example:

40 PRINT*1,A$:GOSUB5000:REM THIS IS FOR TAPE 1
TAPE 1 5000 IF PEEK(625)<180 THEN RETURN:REM LOCATION
625 IS THE TAPE 1 BUFFER COUNTER 5010 POKE59411,53:T=TI:REM POKEING LOCATION
59411 WITH 53 STARTS TAPE 1 MOTOR RUNNING 5020 IF TI -T<6 THEN 5020:REM THIS SETS TAPE
RUNNING FOR 1/10TH SECOND INCREASING GAP 5030 POKE59411,61:RETURN:REM THIS POKE COMMAND
SWITCHES CASSETTE 1 OFF
TAPE 2 6000 IF PEEK(626)<180 THEN RETURN:REM LOCATION
626 IS BUFFER FOR TAPE 2 6010 POKE 59456,207:T=TI:REM THIS STARTS CASSETTE
2 MOTOR 6030 IF TI -T<6 THEN 6030
6040 POKE 59456,223:RETURN

Al PETSOFT programs that use files have this subroutine included and they
are very reliable in use.
The reason that the buffer is made
to check the number 180, and not 191 as you would expect, is because
this keeps the motor running in small

starts until the buffer is finally emptied. Once empty, there is no need for the
tape recorder to build up to writing speed as it will already be at the right speed and the data will be written at
the correct rate.

GLITCH FREE LOADING
by J. Luxford

This is written for NASCOM 1 users but 2 Clean the tape recorder heads.

the principles described may be easily 3 Load as normal, (keep a note of

applied to other micros.

errors). We will call the memory block

Problem:

just loaded block 1.

You have a cassette written on another 4 Copy block 1 to a free memory

recorder which (due to incompatible area. Call this area block 2.

head alignment, speed differences or 5 Re -run the tape, reloading block 1

poor tape quality) will not give error to free memory area. Call this block 3.

free program loading. You do not have 6 Re -run the tape, reloading block 1

listings in order to make manual correc- 7 Execute the corrector program. If

tions and, anyway, even if you did there there are any remaining errors the faulty

may be too many. What to do?

locations will be listed. If none are listed

Solution:

the program is loaded.

1. Load the corrector program in a 8 If errors still exist copy block 1 to

disused location.

block 2, reload block 1. Execute correc-

PROGRAM: Data error corrector for Nascom 1 (Z.80)

CP Machine

Label

Mn

Opl

Op2

Code

Comments

ODOO 21000E 03 DD210016 FD21001E
OB 7E OC DD5600 OF FD5E00 12 BA 13 2812 15 BB
16 280F 18 7A 19 BB 1A 77 1B 280A 1D E5D5 IF CD3202 22 CD4002 25 D1E1 27 23 28 DD23 2A FD23

START NEXT
GOOD

LD LD
LD
LD LD
LD CP JR CP JR LD CP
LD
JR PUSH CALL CALL POP INC INC
INC

HlxL
1Y A D
E
D
Z
E
Z A E
(HL)
Z HL
TBCD3 CRLF DE HL 1X
1Y

: 0E00 it 1600 : 1E00 (HL) (1X+d) (1Y+d)
GOOD
GOOD D
A
GOOD DE
HL

Initialise pointers

to start of mem.

blocks 1,2& 3.

07

l Get the bytes

for comparison

Are blocks 1,2 same ? If so, good Else compare blocks 1,3 If 1,3 same good 1 Else compare
J blocks 2 & 3 Upgrade block 1

If data bad print bad addr. and scroll

Set pointers to next byte

2C 010016 2F B7 30 ED42 32 09 33 CA8602 36 1BD3

LD
OR SBC ADD JP JR

BC
A HL HL Z
NEXT

(:: END1) BLK1+
BC BC PARSE

1 Check to see I if finished
Exit to monitor Else get next byte

112 PCW

PROGRAMS

tor program.

byte first.

9 If errors are still listed repeat step 8. 2 Load block 1. Copy to block 2.

Note: If insufficient memory is available >CE00 1600 7FF NL

to load the whole program in one go, 3. Reload block 1. Copy to block 3.

split the program into segments. When >CE00 1E00 7FF NL

each segment is cleaned up, DUMP on 4. Reload block 1

to scratch tapes, then assemble the 5. Execute corrector program, but

individual good tapes to re-form the because block 1 overlaps page 0 - 1

complete program.

first modify R.SP. to 0C33 to prevent

corruption of block 1. (see PCW March

Example:

1979 letters).

1 The corrector is loaded at ODOO - >MOC3D NL

33 OC. NL

OD37. (This may be relocated as only >E0D00 NL

relative jumps are used). Our program The monitor will now list any remain-

to be loaded resides in 0E00 to 15FF so ing errors. If none, the monitor will

we define block 1 as 0E00 to 15FF, return a prompt (>) and the program is

block 2 as 1600 to 1DFF and block 3 loaded.

to 1E00 to 25FF.

Final note: This represents a very simple

Note: corrector lines ODOO, OD03 and process of choosing any two from three,

OD07 are set to point at the start of more sophisticated combinations may

these blocks and line OD2C is a termina- be used but it is doubtful if more

tor set at [(END OF BLOCK 1) + 11. complex and hence longer programs are

Notice Z80 practice of putting Lo order justified on this application.

FUN & GAMES

APPLE WORMS

by Ray West, freelance programmer

TAPEWORMS: A KEYBOARD VIDEO tions 1 to 4 are converted into the rele-

GAME FOR THE APPLE

vant keystroke equivalent for each

player.

`Tapeworms' is a game for two players SUB 1000 & SUB 1400. This symmewhich uses the keyboard interactively. trical pair of routines reads the key-

Each player has four allocated keys, board. The point of the last statements

which are identified by the keyboard of lines 1000 and 1400 is that the Apple

PEEK function. Two shape tables are seems sometimes to admit a low ASCII

loaded by the program, and these give value. If on A's turn his part of the key-

each 'worm' a different appearance. To board registers an input, its ASCII value

improve the appearance of the display, is saved; and similarly on B's turn. In a the rotation feature of the shape table fast game, only one peek at the key-

is used so that the direction of move- board is allowed.

ment of the worm is matched by the SUB 2110 & SUB 2510. The x or y

rotation of the shape. A game ends coordinate is incremented/decremented

either when a player crosses the rectan- as required, and the direction indicator

gular border of the playing area, or collides with a previously plotted shape;

AD or BD set to correspond. Lines 2145
and 2545 test the new plot. If it is an

the collision counter provides a way of acceptable move, the other person's score

checking for this event. For a detailed is increased by 1 and exit to the end -of -

explanation of the
on...

listing, now read

game routine occurs. The POP instruction removes the subroutine's return

Lines 510-640 are the main program control. There are essentially six subroutines which are called.
SUB 20000. This sets up a shape
table of two shapes. Line 20000 sets up pointers in locations 232 and 233, the low and high bytes respectively. Since 117*256+48=30000, the Apple expects the shapes to start at 30000. This works for a 48K or 32K machine. Line 20001

address from the stack: were this
instruction omitted, after about 24 games the stack would fill up and an
OUT OF MEMORY message appear. The formulae for ROT need to introduce multiples of 16, for which the values differ for the shapes plotted, so that lines 2147 and 2547 use different calculations. The direction is coded as
1 for north, 2 for east, and so on.

tells the machine there are two shapes SUB 25000. This is entered only in

in the table, and lines 20005 and 20010 a slow or medium speed game. It uses

give their addresses, offset from 30000. simple delay loops, which, however,

So shape 1 begins at 30000+256*0+ have diminishing effect as the game pro-

159=30159, for example. The two ceeds. So the tempo accelerates towards

shapes are 'A' and 'V', and were used the end.

because they happened to be available. SUB 26000. This routine displays

If you don't like them, try adjusting the aggregate scores to date, the player

the table!

sitting on the left having his score

SUB 10000. This prints the title shown at the left of the screen and vice

page onto the screen, enabling one of three playing speeds to be selected. In addition, variables are stored just after the program; line 10010 ensures that the coordinates and directions of each `worm' are stored where retrieval time is minimised. Random start points and

versa. The set of games can be terminated in order to change speed, or start afresh, by entering 'N'. Since some characters may remain in the buffer, line 26040 checks for the presence of
an 'N' within it. If the set of games continues, line 26040 loops back to

directions are generated for each player; reset new starting positions and direc-

in line 10220 they are checked to avoid tions, before returning to the program's

starting too close to each other. Direc- main control.

PETFOLIO
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Also Book 2 £1.50 Also a new generation of
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INTENSIVE WEEKEND COURSES IN BASIC
including hands-on mini computer operation.
This short intensive course is intended to instruct from minimal knowledge to an operational capability of computer programming in BASIC high level language. The course is fully residential from Friday evening to Sunday afternoon. Option of non-residential weekend, weekday evening and weekday courses available if required. For further details of dates available, fees, etc:
Phone (0401) 43139, or write to CLEVELAND BUSINESS SERVICES
Cleveland House, ROUTH Beverley, North Humberside
1111.1111M
HIRE A PET MICRO WHY NOT TRY IT BEFORE YOU BUY IT £5 PER DAY OR £25 PER WEEK 2ND HAND MICROS BOUGHT AND SOLD SPECIALISTS AVAILABLE FOR SOFTWARE DEVELOPMENT ESSEX COMPUTER SERVICES TEL: CANVEY ISLAND (037 43) 61663 OR 61926
PCW 113

MICROMART

PROGRAMS

-I P.A.Y.E. + NAT. INS. CONTRIBUTIONS PAYROLL FOR TRS 80 LEVEL 2+ PET COMMODORE (IN BASIC) DOES ALL DEDUCTIONS, REBATE, GROSS + NET PAY. WILL DO ANY PAYROLL IN ONE RUN AND MAY BE REPEATED AS OFTEN AS REQUIRED, THEN PRINTED. PRICE ON CASSETTE WITH A LISTED PROGRAMME £25. LISTED ONLY £15.INVENTORY LEDGER INVOICE, BUSINESS ACCOUNTS, CASH REGISTER, VAT etc. S.A.E. FOR FULL LIST OF BUSINESS PROGRAMMES. JACQUES (ELECTRONICS), 16 MARKET PLACE, HEXHAM. NORTHUMBER LAND, TEL: HEXHAM: 3423.
_41
DEMACAN LTD

We supply complete scientific and business systems based on ITT2020 (Apple II) or Pet Computers:SEE OUR Minicam Modular Data Acquisition and control systems. We can supply ALL ITT2020 system products FROM STOCK - send for details. Pet Machine Language Guide (BASIC Entry Point etc. etc. for old and new Pet). £6.75inc. 5%. inch BASF discettes (10) £32.00exc.
6K bytes RAM (41165s) £65.00exc.
FOR FURTHER INFORMATION PLEASE CONTACT DEMACAN LTD. 2 WEST PRIORY CLOSE WESTURY ON TWIRL BRISTOL 8594130 TEL 0272 621920
7`

TOPMARK
Computers

dedicated to
APPLE II

r

1,....

, c-,,,cgc.,c,.f?,,°,7 is-, 7

Simply the best!

go 0 REM 'TAPEWORMS' GAME (C) RAY WEST MAF.,1 11 GOSUE 20000: GOOSE 10000 510 GOSUE 1000: REM SEE IF A WANTS TO MOVE,
0 520 SOSUE: 2110: REM PLOT A'S NEW POSITION 530 IF PEEK (234) < ) 2 THEN SEX . SEX . 1: GOTO 26000: REM END OF A SAME INDICATED BY COLL ISION COUNTER 548 IF R ( ) 1 THEN GOSUE 25000
610 GOSUE 1400: REM SEE IF P WANTS TO MOVE 620 GOSUB 2510: REM PLOT B'S NEXT SEGMENT 630 IF PEEK (234) ( ) 0 THEN SAX . SAX + I: 60T0 26000: REM END OF A SAME
632 IF R 7 1 THEN 510
635 SOSUB 25000
640 SOTO 510 1000 Z . PEEK ( - 16384): POKE - 16368.0: IF 2 < CTX THEN Z = Z . CTX 1002 IF 2 . WKX OR Z = SKS OR Z . 76% OR Z = AKX THEN ADX . 2: RETURN 1004 IF R = 1 THEN RETURN 1006 Z = PEEK ( - 163841: POKE - 16368.0: IF 7 ( CTX THEN 2 . Z + CTX 1088 IF Z . ABS OR Z = SKX OR Z = ZKX OR Z = AKX THEN ADZ . 2: RETURN
1020 RETURN

-

144:071; Z

OR1:"41!:( X

1P636:ke'l !FKKX(THg gr.ZZ7 41UICRL2

1404 IF R . 1 THEN RETURN

0 1406 Z . PEEK ( - 16384): POKE - 16360,0: IF 2 ( CTX THEN Z = Z + CT% 1408 IF Z . OKX OR 2 . LK% OR 2 = CBS OR 2 = !Oa THEN ET% = Z: RETURN

1510 RETURN

2110 IF ADX = ABS THEN AYX . AY% - C7X:AD = CIX

0 2120 IF ADX = SKX THEN AXX = AXX C7X:AD . C2X 2130 IF ADX . ZKX THEN AYX = AYX + C7X:AD = C3%

2140 IF ADX . AKX THEN AXX . AXX - C7X:AD = C4X

2145 IF AXX ( 2 OR AXX ) 277 OR AYX ( 3 OR AYX ) 152 THEN POP :SEX . SE% + 1: SOTO 26000

2117 ROT= CS% S. (AD - C1X)

2150 ORAN 1 AT AXX,AYX: RETURN

2510 IF BDX = OKX THEN BY% = BOX - C7X:ET = C1X

2520 IF BDX = LKX THEN BOX = BXX + [MET = C2X

As 2538 IF BDX = Cla THEN E:YX = F%% * C7X:ED = C3%

.W 2540 IF BOX = KKX THEN BUS = BOX - C7X:8D = C4X

2545 IF BXX < 2 OR BXX ) 277 OR BY% ( 3 OR BY% ) 152 THEN FTP :SAX = SAX + 1: SOTO 76000

2547 ROT. CS% * (C1X + ET)

,,, 2550 DRAW 2 AT BXX,BYX: RETURN

.."

10000

TEXT :

HOME

: FLASH :

PRINT '44**

TAPEWORMS

****, NORMAL

10010 SOX . 0:AY% = 0:BXX = 0:EYX . 0:ADX = 0:60% . 0

10015 WKX . 215:SKX . 211.2KX = 218:Ala = 193:0KX . 207:LK% = 204:CM% . 172: REM

10016 KKX = 203: REM K.KEY. STORED AT START OF VARIABLE SPACE

10017 CIX = 1:C2X . 2.C3X = 3:C4% = 4:C7% = 7:CS% = 16:CTX = 128

10030 PRINT : PRINT . PRINT 'A GAME FOR 2 PLAYERS': PRINT : PRINT 'PREFERABLY ONE LEFTHANDER!

PRINT PRINT PRINT 'FIRST PLAYER'S WORM CONTROLLED': PRINT 'WITH KEYS W,S,Z.A.'

:

:

10040 PRINT PRINT 'SECOND PLAYER USES 0,L.COMMA.K.' :

10045

PRINT PRINT PRINT 'A RAY WEST SUPERIOR': PRINT 'PROGRAM PRODUCT': PRINT

:

:

10046 INPUT 'SLOW, MEDIUM. OR FAST GANE7'11($

10047 IF LEFT* (KCI) = 'F' THEN R . 1:S . 1.1. . 1: SOTO 10050 10049 IF LEFTS (MI) = 'M' THEN R . 100:S = 50: GOTO 10050 10049 R = 200:S = 150:1 . 158 rousw--rirmr-T-mwr-rfur RETURN TO PLAY': GET Kf 10200 AXX . 7 * INT (I RND (I) * 74 3)):AY% . 7 * INT (1 RND (1) * 17 . 3)):AD =
4 * RND (I))

INT (1 =

10201 IF AD . 1 THEN ADO . 215 10202 IF AD . 2 THEN ADX = 21.1 10203 IF AD = 3 THEN ADX = 218
41 10204 IF AO . 4 THEN ADX = 193 10210 BXX = 7 * INT (( RND (I) * 34 + 3)):BY% . 7 8 INT (( RND (1) * 17 31):130 = INT (1 + 4 * RND (I)) 10211 IF BD = I THEN FOX = 207 10212 IF BD . 2 THEN ETX . 204 10213 IF BD = 3 THEN PDX . 172 10214 IF ET . 4 THEN ET% = 203 10220 IF ABS (AXX - DX%) < 20 AND ACS (AY% - E%%) < 20 THEN 10200 10300 HCOLOR. 3: SCALE 1: MGR

10305 SP . FT 10310 HPIST 3.3 TO 277,3 TO 277.152 TO 1,152 TO 3,7 ,, 10328RETURN ... 20000 POKE 232,48: ETRE 213,117
20001 POKE 10000,2, POKE 30001,0 20005 POKE 30002,159: POKE 30003.0

di 20010 POKE 30004,21: POKE 30005,3: REM V ''' 20015 PONE 30159,146, FTKF 30160,27
20020 POKE 30161,4: POKE 30162.76 20025 POKE 30163,36: POKE 30164,33

2

POKE. 30165,49: POKE 30166,49

20935 FTKE 30167,49: POKE 30160 54 ,

20040 POKE 30169,6: POKE 30170,36

20045 POKE 30171,63: POKE 30172,63

20047 PUKE 30173,0

20050 POKE 30709,146: FTKE 707,0.16

20055 ETRE 70791,39: POKE 30792.60

0 20060 POKE 30793,16! POKE 30794.140 20065 POKE 30795,73: POKE 30796,54

20070 POKE 30797,55: POKE 10790,62

200/5 FTKE 30799,0

20060 RETURN

25000 SP = SP * 1: IF SP ) BO THEN 25040

25010 7E SF' i 10 THEN 25030

25020 FOR I

1 TO R: NEXT

75030 roR I

I TO S. NEXT

25040 TOP I

1 TO 7: NEXT

25050 FTIORN

26000 HOME: FUR 1

1 TO 7: PRINT

CHR4 (7):: NEXT :

LIRE: 23: PRINT

SPC( 111:: INVERSE

'*98* SCORE ****': NORMAL : PRINT SAX: TAR) 41 - LEN ( STR$ (STX)))1SEM

PRINT

26010 INPUT 'HIT RETURN FOR NEXT GAME OR N TO EXIT.:K$

26020 VIRE: 22, CALL - 956 26030 IF K$ . " THEN GOSUE 10200: SOTO 510

,. 26040 L

LEN ,KS): FOP I 1 TO l IF M1D$ ,K$,L,11 '

.N. THEN GOSUE: 10200: SOTO 510

'w 26050 NETT I

26060 END

Full details from Tom Piercy on Huntingdon (0480) 212563 or circle enquiry card.

Here, by popular demand, is the continuation of David Parkinson's Revas.
We apologise for the delay - it disappeared during the recent move.

-

.

.

THE BEST FOR LESS !

HARDWARE FIRMWARE . SOFTWARE BOUGHT SOLD CONSTRUCTED
SHARP PET ITT TANDY ELF COMPUKIT
PETSOFT & GEMSOFT

Examples of prices: -
SHARP MZ8OK 10K: £499 18K: £599 22K: £619 34K: £699 Up to £75 worth free programs with new Pet
Built, tested & cased Compukit £285 Teletext Convertor (with remote) £215
Grandstand Games Computer £115 VAT/Carriage extra
OPTELCO RAYLEIGH (0268) 774089 Up to 8p.m.

Fc24
FC27
0 FC2B

CD 16 FC CD 31 F9 FE 22

FC2E
FC30 FC31 FC32 FC33 FC36 ,.. FC39 UP FC3C FC3C
0 FC3C
FC3C FC3F FC42
FC45 FC45 FC45 FC45 FC46

36 28 23 EB 3F D4 7E F9 DC 57 F9 C3 04 FA
CD 28 FC CD 11 F9 C3 7D F9
F1
CD 7E F9

0680

CALL ST1

; "A"

0681 0683 LD1:

CALL -,14,

CP

$22

H.,,,,1,(

1

;REGPR OR EXTENDED?

0685 0686 0687 0688 0689 0690

LD INC EX CCF CALL CALL

1 FR, ) , ' ( ' Hi,
DE,HL
NC,REGPR C,LD16A

FC2D EB
;REVERSE RESULT OF COMPARE ;(RETURNS WITH NC) ;EXTENDED ADDRESS

0691

JP

NOTIXY

;CLOSE BRACKETS

0692 ;

0693 ; 16 -BIT INDIRECT STORE LD (NNNN),PP 0694 ;

0695 ST16I: 0696 0697

CALL CALL JP

LD1 COMMA REGPR-1

;DO INDIRECT BIT
:"" ;GET OP & PR. REG PAIR

0698 ; 0699 ; 16 -BIT INDIRECT LOAD LD PP,(NNNN) 0700 ;

0701 LD16I: POP AF

0702

CALL REGPR

;GET OPCODE ;PRINT REG PR.

40
0682
40
40
41
0
40
0

...,
114 PCW

FC49 FC4C FC4D FC4F FC4F FC4F FC4F FC4F FC52 FC53 FC54 FC56 FC59 FC5B FC5E FC61 FC64 FC65 FC67 FC69 FC6C FC6D FC6E FC70 FC71 FC72 FC73 FC76 FC79 FC7A FCTB FC7C FC7D FC7E FC7F FC80 FC82 FC84 FC85 FC86 FC89 FC8A FC8B
FC8D FC90 FC91 FC92 FC94 FC96 FC98 FC9B FC9C FC9D FC9E FCA1 FCA4 FCA7 FCA8 FCA9 FCAB FCAB
FCB4
FCC9 FCC9 FCC9 FCC9 FCCB FCCE FCCF FCD1 FCD2 FCD5 FCDS FCDB FCDC

CD 11 F9
A7 lb DE
JA OB 10 A7 F5 28 OB 11 34 10 36 06 CD C4 F9 11 2D 10 CD DB F8 F5 FE 40 38 27 21 A8 FC 07 07 E6 03 47 07 80 CD 2A F9 CD 23 F9 13
13 Fl F5 OF OF OF E6 07
F6 30 12 13 CD 11 F9 Cl
Fl 78 CO
C3 C4 F9 OF OF C6 02 66 OE FE OE CA D6 FD
47 OF 80
21 B4 FC CD 2A F9 CD 23 F9 13
13 18 DE
42 49 54 52 45 53 53 45 54 53 52 4C 52 4C 43 52 52 43 52 4C 20 52 52 20 53 4C 41 53 52
41
CB 57 C2 D6 FD F5 E6 03 07 21 E9 FC CD 2A F9 CD 25 F9
Fl
21 Fl FC

PROGRAMS

0703

CALL COMMA

0704

AND A

;CLEAR CARRY

0705

JR

L01+2

;DO INDIRECT BIT

0706 ; 0707 ; ROTATE/SHIFT/BIT/SET/RESET 0708 ; NB. IF INDEXED THEN OFFSET PRECEDES OPCODE

0709 ;

0710 CB: 0711

LD

A,(HXYFLG)

AND A

;INDEXED?

0712 0713 0714 0715 0716 0717 0718 NOTXY:

PUSH JR LD LD CALL LD CALL

AF

;SAVE FLAG

Z,NOTXY ;NO,SKIP

DE,BUFFER+34;YES,WRITE..

A,6

;...REG. FIRST.

SREG

DE,BUFFER+27;RESET POINTER FOR MNEMONIC.

BYTE

;GET OPCODE

0719 0720 0721 0722 0723 0724

PUSH CP JR LD RLCA RLCA

AF

;SAVE IT

$40

;<$40?

C,ROTATE ;YES,JUMP

HL,BRSTAB-3;LOAD POINTER

;SHIFT OPCODE DOWN

0725 0726 0727

AND 3

LD

B,A

RLCA

;ISOLATE ID ;MAKE 3,6,0R 9

0728 0729 0730 0731 0732 0733

ADD CALL CALL INC INC POP

B
FTADR COPY3 DE DE AF

;FORM ADDRESS ;WRITE MNEMONIC ;SPACE
;GET OPCODE

0734 0735

PUSH AF RRCA

;SAVE AGAIN ;PRINT BIT NUMBER

0736 0737 0738 0739

RRCA

RRCA

AND 7

OR

$30

;ISOLATE BIT ID ;MAKE ASCII

0740

LD

(DE),A

;WRITE IT

0741

INC

0742

CALL

0743 TESTXY: POP

DE COMMA BC

;RECOVER OPCODE

0744 0745

POP AF

LD

A,B

;RECOVER HEY FLAG ;LOAD OPCODE

0746

REr NZ

;YES,RETURN

FC8C

0747

JP

SREG

0748 ROTATE: RRCA

;NO,G0 WRITE. ;SHIFT DOWN

0749

RRCA

0750 0751

ADD 2 AND $E

;ROLL CODING ROUND ;ISOLATE ID

0752 0753

CP

$6

JP

Z,NTVL

;IS IT OE? ;YES,INVALID CODE

0754

LD

B,A

;DO ID*3 AGAIN

0755

RRCA

0756 0757 0758

ADD LD CALL

B

HL,ROTTAB ;LOAD BASE ADDRESS

FTADR

;FORM ADDRESS

0759

CALL COPI3

;WRITE MNEMONIC

0760

INC DE

0761

INC DE

0762

JR TESTXY

;EXIT WRITING REGISTER

0763 ; 0764 BRSTAB: DB

'BITRESSEP

0765 ROTTAB: DB

'SRLRLCRRCRL RR SLASRA'

0766 ;

0767 ; AUTO CP LD IN OUT

0768 ;

0769 AUTO: BIT 2,A

;TEST FOR VALIDITY

0770

JP NZ,NOTVAL ;JUMP IF NOT

0771

PUSH AF

;SAVE OPCODE

0772

AND 3

;ISOLATE OP ID

0773

RLCA

;*2

0774

LD HL,OPTAB ;LOAD BASE ADDRESS

0775

CALL FTADR

;FORM ADDRESS

0776

CALL COPY2

;WRITE PART OF MNEMONIC

0777

POP AF

;RECOVER OPCODE

0778

LD HL,OPTAB+8;LOAD BASE ADDRESS

To be continued

BLUDNERS

Basic Problem You all spotted the Ss coming out as Ss in Bench Test and ESP didn't you? If not, why not!
Puzzle We've decided that Pythagoras was right after all - the area of a right-angled triangle is (once again) V2B x H.

Spaceship
We think that we've had phone calls from every Fx 201-P owner! Just in case we haven't, ÷ came out as-in the following steps: 40,59,74, and 86 (the
second one). Step 98 reads 4 = 7 ÷ K2 + 9 + 4:.

MICRON=
THE NEW uHEX 480 EPROM PROGRAMMER
2704 and 2708 Control programs for Z80, 8080, 6800, 6500. Please state machine. Programs permit programming any length block into the eprom, so even unexpanded machines can now program eproms. Needs only +5v, +12v, -5v. Host computers require a PIO (PIA)
complete kit ONLY £35 or ready
built and tested £5 extra. PIO, PIA INTERFACE PANELS
Available for Z80/8080, 6800/6500 THE uHEX 416 DELUXE EPROM PROGRAMMER Push Button selection for 2704, 2708, 2716. STILL ONLY £65
All prices inclusive. SAE for further information about
these products.
MICRO HEX COMPUTERS 2, Studley Rise, Trowbridge, Wilts.
WiernaildWaWANIWNWINVis
1
SIGMA SYSTEMS
PETS, PERIPHERALS, PETSOFT PROGRAMS
and
A RANGE OF PRINTERS FOR THE PET
including
CENTRONICS, BD80, TELETYPE AND THE AXIOM. THE ONLY PET PRINTER AVAILABLE WITH GRAPHICS £575 cwo
54 PARK PLACE CARDIFF 21515
APPLE AND PET IN DUBLIN
*Come and see these fine computers in our new show room.
*Try them and discuss your requirements.
Sensible Software for Apple
*Sales Ledger, Financial Modelling. *Fourier Analysis Shape Maker *Educational Systems in Maths and
Physics, Geography, Commerce.
Softech Ltd
51 Lower Camden Street Dublin 2 Republic of Ireland Telephone Dublin 976279
--i
SORCERERS APPRENTICE
All kinds of software available for the Sorceror. Send S.A.V. for full details. Full range of
Exidy products.
7 Westbourne Grove Manchester 20
Macclesfield (0625) 612818
PCW 115

OP PRESS

...44 NEW PROGRAMS
for the PET in the latest

PETSOFT CATALOGUE
including . . .

PAYROLL - 400 (Disk) £50 A totally new and complete disk based payroll system designed and written to meet the needs of small businesses. Up to 400 employees per
disk are catered for. A 32K per 2001-32 equipped with dual floppy, an Anadex DP800 or device 4 printer is required.
Facilities provided include Holiday Pay, Sick Pay. Bonus payments and two rates of overtime, as well as allowing a "standard week" to be specified for each employee. Weekly and monthly summaries are provided and amendments necessary because of a Budget (e.g. increasing employee's tax codes) are made very easy. Each week a wage slip is printed for each employee followed by an analysis of the coins/notes required for these employees paid in cash (payments by cheque and credit transfer are also allowed for). Tax and N.I. are computed automatically from a knowledge of the tax code and N. I. rate applicable to that employee. Update service available.

6502 FORTH £30 FORTH is a unique threaded language that is ideally suited for systems and applications programming on a PET. The user may have the interactive FORTH Compiler/Interpreter system running stand-alone in 8K to I2K bytes of RAM. The system also offers a built-in incremental assembler and text editor. Since the FORTH language is vocabulary based, the user may tailor the system to resemble the needs and structure of any specific application. Programming in FORTH consists of defining new words, which draw upon the existing vocabulary, and which in turn may be used to define even more complex application. Programs written in FORTH are compact and very fast.
PHOTOGRAPHY TUTOR £12 A comprehensive course developed by a professional photographer making full use of PETs dynamic graphics capabilities to demonstrate
and explain the mysteries of exposure, focus, aperture. shutter speeds,
interchangeable lenses, depth of field, etc. The theory and practice of photography are explored interactively, and progress tested. Multiprogram pack containing eight 7K lessons. Available on Disk E I 5. '
HUNT £10 A new concept in fantasy simulations which has achieved wide acclaim. The context is that of a search for a defined object, typically Atlantis or the Holy Grail. The objective, the names and natures of the searchers, their antagonists and the properties of the space in which the hunt is conducted are defined - by you!

IOR EVALUATION £25 Conducts the evaluation necessary to establish pay structures and grades. Program computes correct weightings for factors education, training necessary, responsibility over other men and equipment. working conditions etc. - which comprise tab value. A Job Evaluation Formula is created for use as a guide to the relative value of a job based on the thinking of the company or department concerned.
STOCK CONTROL ON DISK £25 Facilities allow full or operational stock print out, total costing of items in stock and re -order level warning. Data is stored under Reference. Description. Supplier. VAT Rates, On order Quantity. Quantity in Stock. Unit of Quantity Designated, Minimum level, Stock allocated. Sale Price and Purchase Price. Approx 400 items per diskette.
COURSE HANDLER £95 A must for School Timetablers. The program handles all the information relevant to creating a 4th, 5th or 6th year Option Scheme and is particularly useful where an "Open Choice" of subjects is offered to pupils. The program maintains, via a simple dialogue with the timetabler, a file of pupils and their requests and allocations and a file containing details of the Option Scheme. Faclities are provided for viewing the scheme, the classes, the pupils and the class clash matrix. '
CRYPTO PACK CO This is the complete kit for all those interested in cryptography, codes, ciphers and cryptanalysis. Developed by Dr Michael Richter, the package includes Cryptosub. General Cipher. Cryptanalyser and New Cipher programs.
'Send for a free Data Sheet.

The Original Cassette
Magazine for the Commodore
PET . . . CURSOR
CURSOR - The cassette program magazine for PET owners. Mailed to you by first class post. each issue contains a dynamic graphic cover. table of contents and at least five new programs. There is a featured game which might cost C8 elsewhere, plus tutorials, programming aids and business routines, and of course CURSOR Notes with news and equipment reviews.
U.K.: C36 for one year's subscription (10 issues). Overseas airmail' £45 for one year.
Send for a free Data Sheet.

PETSOFT
PROGRAMMERS TOOLKIT
-10 Powerful New Commands for your PET!"
The Toolkit is a machine language program which is provided in a 2 kilobyte ROM chip. lust plug it in - no tools are necessary - and your PET's BASIC has 10 new and very useful commands including:
AUTO, RENUMBER. DELETE. FIND. APPEND. DUMP. HELP. TRACE and STEP. For the new 16K and 32K PE's. the tool lat consists of a single ROM chip which plugs into the left most empty socket inside the PET. Price £55 plus VAT. For 8K and other 'old ROM' PETS a small printed circuit board is attached to the memory expansion and 2nd cassette ports of the PET. Price £75 plus VAT. Send for a free Data Sheet
Recommended by Commodore

Programs are available on Commodore format cassettes. Some titles are available on disk for

ACT PETSOFT and Commodore Disk systems.

PET is the trade mark of Commodore

116 PCW

Please send me a copy of your latest catalogue

Radclytfe House, 66-68 Hagley Road, Edgbaston, Birmingham B16 8PF. Telephone: 021-455 8585 Telex: 339396
My name is

I live at

I have a new/old ROM PET

Postcode I have NO PET

Please mention PCW when replying to advertisers - it identifies you.

PUZZLES

LEISURE LINES

With J. J. Clessa

Most of you spotted the palindromic reading of

deliberate (?) mistake in 006600 miles (for those

our first Leisure Lines that know not, a palin-

gulp!

dromic number is one

Puzzle 1A involves which reads the same

some logical reasoning, from right to left as it

and should not have pro- does from left to right).

ved much of an obstacle "What a coincidence",

to our readers. The solu- explains Bert, "So is

tion is that the pilot's mine. The 5 -figure read-

name is SMITH.

ing at the moment is

Puzzle 1B was a bit 18981 miles".

tougher, and although it "Well I never", says

can be solved analytical- Colin, "although the

ly, by anyone who's mileometer on my

familiar with Diophan- moped only shows

tine analysis, it's a much 4 -figures, it's reading

simpler task to write a 5335 miles, which is also

small program for desk palindromic".

calculator or micro- "I wonder if we're

computer.

ever likely to get such a

Since we made the coincidence

again,"

error in defining the area says Alan.

of a triangle we decided Well, of course, since

we would accept either each vehicle does a dif-

otifotnhest-wmo paonssyibleenstorlieus-

ferent weekly mileage
from the others, there's

included both anyway. no way that the question

Using our formula for could be answered. But,

triangle area (area - axb), supposing all three mileo-

the smallest solution pos- meters were connected to

sible is a triangle with just one vehicle, and also

sides 36,48 and 60 units, supposing that they were

which has a perimeter of equally accurate, then

122 and an area (?) of what is the least number

123.

of miles that would

However, using the elapse before a) Alan's

correct formula for area and Bert's mileometers

(axb/2), the smallest are both showing palin-

solution is a triangle with dromic readings again?

sides 144,192,240, with a b) Alan's and Colin's

perimeter of 122 and an mileometers are both

area of 243 .

showing palindromic

Since there was no outright winner, we made a draw and the two lucky

readings again? c) Bert's and Colin's mileometers are both showing palin-

readers are: Puzzle 1A: dromic readings again?

D. E. Arnett of Grimsby. and d) all three mileo-

Puzzle 1B: Paul Durrant meters are mutually

of Norwich.

palindromic?

Congratulations to Answers please on a post-

both and stand by for a card to Puzzle No.

shower of chocolate bars 3, Personal Computer

(not to mention the sub- World, 14 Rath bone

sequent visit to the Place. London W 1P 1DE.

dentist).

Entries must reach our

Just one puzzle for offices by November

this month, but it's really 30th.

a rather interesting one.

Three friends, Alan, Bert PRIZES FOR THIS

and Colin each possess MONTH

vehicles. Alan owns a big This month's prize is

foreign car, Bert a small really cunning. In order

English car and Colin, a to make sure the winner

moped.

continues to send in en-

One day while discus- tries to Leisure Lines, we

sing mileages, Alan intend presenting him/

reports that his mileo- her with a hundred 10p

meter, which gives 6 - stamps.

figure mileage readings, is

currently showing a

Professional ASCII Keyboards
teeiM21,,,
SIR tititififiiitaimiliaill.1
omfei SIR el iffinancilii
adirmiitivomeismoned/P

MODEL KB 756

FULLY ASSEMBLED & TESTED CASE AVAILABLE

Accessories Available include:-

Edge Connector Numeric Key Pad Plastic Case (Black) DC to DC Converter

KB15P KB710 K B701 DC512

£1.95* £7.50* £10.75* £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
111111014TER
/KEYBOARDS

r
COLOUR

YOUR
NASCOM!

DAZZLING COLOUR GRAPHICS FOR NASCOM 1

Genuine bit -addressable "pixel" system for straightforward programming of pictorial or mathematical functions.
8 Colour display plus 8 colour independent background facility. Full documentation with FREE SOFTWARE: powerful sub -routines for vector generation, demonstration program for animated effects. All runs in Nascom 1 without expansion. Complete with UHF Colour Modulator for operation with normal colour TV set. Superior design allows connection to most other micro-
processor systems - send us diagrams etc of your b Et w video circuitry for free advice. Don't be fooled by the price: this is a top quality product which will transform your computer.

NOW AVAILABLE FORIE45 Inclusive of VAT

LIMITED PERIOD AT

and postage.

Dower House, Billericay Road, vjs4
WILLIAM Herongate, Brentwood, STUART Essex CM13 3SD.
SYSTEMS Ltd Telephone: Brentwood (0277) 810244

"Stop Press: - UK101 Compatible"

PCW 117

NRDC and NCC announce the
BRITISH MICROPROCESSOR
COMPETITION
A competition for the best invention incorporating a microprocessor

£20,000 total cash prizes
First prize £10,000
... and NRDC will give favourable consideration to investing up to £Y2 million in any of the winning projects.
The competition closes on 14 December 1979. For full details, including entry form and rules and conditions, complete the coupon and post it to:
British Microprocessor Competition, c/o The National Computing Centre Ltd, Oxford Road, Manchester, M1 7ED.

Sponsored by the

National Research Development Corporation

r - - - - - and The National Computing Centre

PC,

To: British Microprocessor Competition.

Please send me full details and entry form for this competition. BLOCK CAPITALS PLEASE.

Name

Address

ILM
118 PCV1/47

NM OM MEM NM OM OM MIN OEM OM SW OM ONO OM NM OM OM MEM OM MO OEM OM MEM UM um um um imams= gm

J milm

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SORCERER"
Now becomes a professiona
word processor...as well !

The Sorcerer Computer is a completely assembled and tested computer system ready to plug in and use. The standard conf tguartion includes 63 key typewriter -style keyboard and 16 key numeric pad, dual cassette 1/0, with remote computer control at 300 and 1200 baud data rates, RS232 serial 1/0 for communication, parallel port for direct Centronics printer attachment, Z80 processor, 4K ROM operating system, 8K Microsoft BASIC in separate plug-in Rom PacTM cartridge, composite video of 64 chars 30 lines, 128 upper/ lower case ASCII character set and a 128 user defined graphic symbols, up to 32K on -board RAM memory, operators manual,

BASIC programming manual and cassette/video cables, connection for 5100 bus expansion unit.
The Word Processor Pae creates, edits, re -arranges and formats text. Features include auto wraparound, dynamic cursor 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 form letter typing, multiple column printing or automatic forms entry.

NOW CONTACT YOUR LOCAL DEALER

PRICES

.. OR SEND COUPON

8K Sorcerer 16K Sorcerer

FOR FURTHER

32K Sorcerer

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INFORMATION

630K Dual Disc Drive 143K Single Disc Drive

,o,

'Etiss

e

ci ,,, ,,,,,

,re"/0',,

'/?,

S100 Expansion Unit Line Printer Video Display Development Pack

Cr

ce,w. /4,

Word Processing Pack Technical Manual

0,
Gress

Daisywheel type printer

eoe

Word processing pack

9/ /1/o

tSc',-/, j,

Video/disc unit

're,,,,
v ,c.,

% 16K Memory expansion

"r(C

';f,

oco 0 /. i.,,,

0 10 4 0,, -.'1 c'e4

i'& "17,o

6> 4 (5'6,` -66%,>',)

'P -°.0,:k?

6' 6.

6,'S

650.00 760.00 859.00 1,200.00 500.00 210.00 850.00 240.00
70.00 70.00
8.95 1,900.00
80.00 1,800.00
110.00

LANCASHIRE 051-2272535 MICRODIGITAL 25 Brunswick St., Liverpool L2 BJ

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APPLE II

Apple II

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32K

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48K

Disk Drive with Controller

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Parallel Printer Card

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High Speed Serial Card

Applesoft Rom Card

Speech Lab

Apple Clock

Carry Case

16K Ram Add -On Memory

Apple II Basic Manual

Apple II Reference Manual

Applesoft Reference Manual

Corvus II Fixed Disk (10 Meg)

Super Sony 14" T.V.

Super Colour Interface

750.00 819.00 888.00 398.00 355.00
110.00
132.00 190.00 110.00 110.00 127.00 140.00
25.00 69.00
6.00 6.00 6.00 3,500.00 300.00 90.00

COMMODORE BUSINESS SYSTEMS

PET 2001-4

Computer 460.00

PET 2001-8

Computer 550.00

PET 2001-16N

Computer 675.00

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Computer 795.00

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Pr inter

550.00

PET 3022

Printer

645.00

PET 2040

Dual Floppy

Disk

795.00

IEEE to IEEE

Connector 25.00

PET to IEEE

Connector 20.00

C2N

Cassette Deck 55.00

KIM 1

Micro

computer 99.95

KIM 3B

8K Memory

Expansion 129.95

KIM 4

Motherboard 69.95

PET Users Handbook

5.00

6500 Programming Manual

5.00

6500 Hardware Manual

5.00

amilm=ma iteMINPIS 111
Send S.A.E. for our extensive book list.

PRINTERS RS232
Micro Printer M879 Teletype 43 Pin Feed Teletype 43 Dual Feed Digital Decwriter LA 34 Digital Decwriter LA 36 VVhymark 201 40 Column Perkin Elmer "Pussycat" Thermal Page Printer
N.E.C. Spinwriter Trendcom 100 Trendcom Interface
(Apple II or PET)

695.00 850.00 950.00 860.00 850.00 395.00
49.00

PET ADD-ONS

Memory Boards

Expandamem

16K

Expandamem

24K

Expandamem

32K

295.00 320.00 392.00

Interface

IEEE - RS232 Unidirectional

85.00

IEEE - RS232 Bidirectional

185.00

AIM 161 A/D Converter - 16 way 130.00

T.V. Interface

42.00

PET Set (AIM 161)

166.00

Disk System Compethink Dual Drive
(Old Rom) Computhink Dual Drive (New Rom)

795.00 840.00

EXIDY

Exidy Sorcerer

8K

Exidy Sorcerer

16K

Exidy Sorcerer

32K

S 100 Interface Micropolis Dual Disk

System (630K)

Video Display Unit

1/0 Expansion Kit

650.00 760.00 859.00 210.00
1200.00 240.00 99.00

MISCELLANEOUS

C12 Blank Data Cassettes (per 10) 3.98

5%" Diskettes (per 10)

Single side/Single density

30.00

Double side/Double density 35.00

B.A.S.F.

40.00

Continuous Single Part Paper

8 x 12 (2,000 sheets)

15.00

9 x 11 (2,000 sheets)

16.00

Edge Connectors

12 way

1.60

24 way

2.55

80 way

3.00

Mains Power Adaptor

Input 240v 50Hz

Output 6v/7.5v/9v DC-300MA 4.20

Co -axial Lead Connector (2 metre) 2.00

Aerial Splitter

3.60

RS232 Printer Connector Cable 25.00

Dust Covers (4 colours)

8.00

Sound Box

13.99

A personal computer that

opens the world of programming

to your own fresh ideas!

78 Keys

SHARP
MI -80K

Built -In Clock
ClucK cucwl lure is drsprayed aCcorcling to
)1(Pl,r,1111

CRT Display
equipped with a 25 cm 110 monucnrome CRT lor up to 1.000 letters (40 letters x 25 lines) Processing results can be displayed on Ice CRT and it is possible lo program and edit (addition deletion etc while watching the operatron for contrrmatron
A Technical Masterpiece
A personal computer that makes lull use of the multi -functions of an 8 -bit microcomputer (Z-801. this model is certainly one of the most advanced anywhere It employs BASIC language, a feature which provides easy programming even to those totally unfamiliar with computer operation

HE COFT1PUTERS LT
22 NEWLAND STREET, KETTERING, NORTHANTS.
Tel. (0536) 83922 & 520910 Telex 341297
All prices are exclusive of VAT unless otherwise indicated. All items are sold subject to the Company's Conditions of Sale.

120 PCW

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OVewBear

U__P.G..._RADE KITS : ITHACA

APPLE II . .

16K .

.

TRS 80 . . . . 16K .

SORCERER . . 16K .

* SIMPLE TO FIT

* LIFETIME GUARANTEE

£69.00 £69.00
£69.00

0 DISK DRIVES

SPECTRONICS U.V. EPROM -ERASING LAMPS

PE14

Erases up to 6 chips, takes approx. 19 mins.

PE14T* Erases up to 6 chips, takes approx. 19 mins.

PE24T* Erases up to 9 chips, takes approx. 15 mins.

PR125T* Erases up to 6 chips, takes approx. 7 mins. PR320T* Erases up to 36 chips, takes approx. 7 mins.

PC1000* Erases up to 72 chips, takes approx. 7 mins.

0
£ 56.00 £ 76.58 £111.22 £237.84
£ 384.09 £842.83

U.V. EPROM -ERASING CABINET PC2000* Erases up to 144 chips, takes approx. .7 mins. £1227.69

*Includes a 60 min. Timer.

*51/4" SINGLE -SIDED SHUGART SA400 B.A.S.F. 6106 .
*51/4" DOUBLE -SIDED B.A.S.F. 6108

ACORN £190.00
.£1 9 0.00

KIT .65
6502 based

£279.50

microcomputer on Standard Eurocard Modules I

I

*514" CONNECTORS 34 way Edge Connector

. £ 4.45

SYM- 1

34 way Socket

£ 2.15

* 6502 Based

*£160.00

34 way Plug

£ 2.15

* 4K Monitor

* Fast Cassette Interface

34 way Cable per foot
*8" SINGLE -SIDED DRI 7100 SHUGART 801

£ 0.80
£365.00 £380.00 MO

K TOOLS

0

I .

*8" DOUBLE -SIDED

WIREWRAP CENTRE

DRI 7200

£430.00

BW-630 . . Battery Wirewrap Tool

. X25.17

B.A.S.F. 6104

£465.00 NO WIREWRAPPING JUSTWRAP

*8" CONNECTORS AC Power Connectors DC Power Connectors 50 way Edge Connector 50 way Socket 50 way Plug 50 way Cable per foot

£

0.80

In

JW-1 .
JWK-6

. .

.
.

Hand Wirewrap Tool Hand Wirewrap Kit
(inc. sparewire & unwrap tool)

£ 1.65

JUW-1 . . Unwrap Tool

5.60

RHW-BLUE . 15 metre wirewrap spools .

£ 2.90 £ 4.10 £ 1.20

WIRE R30.B-0050 . 15 metre roll AWG-30 BLUE DW-30B . . Dispenser

£11 40 £19.13 £ 2 67
£ 2.28 I
£ 1.38 £ 3 04

*MEDIA
51/4" Diskettes, Soft/Hard sectored Single Disk Box of 10
U 8" Diskettes, Soft/Hard sectored

NE WIRE WRAP SOCKETS

NI 14 way

£ 4.00
£ 35.00

16 way
24 way 40 way

71111

£ 0 40 £ 0 40 £ 0 79 £ 1 25

Single Disk Box of 10
*DISK STORAGE BOXES
8" Boxes

£ 4.00 £ 35.00
£ 2.50

TERMINAL POSTS

a

INS -1 . . . Terminal Insertion Tool .

£ 1.85

WWT-1

. Slotted Terminal Pack of 25

. £ 3.46

WWT-2

. Single Sided Terminal Pack of 25 . . £ 2.07

WWT-3

. IC Socket Terminal Pack of 25 . . £ 3.46

WWT-4 : . Double Sided Terminal Pack of 25 . £ 1.38

51/4" Boxes

2.10

IN/ OMNI EACH BOX HOLDS 10 DISKETTES RE

VERO

,JIM PAK

SEND FOR LIST OF VEROBOARDS, BOXES AND INTERCONNECTING SYSTEM.

I FOR RESISTORS, CAPACITORS, CMOS, REGULATORS
111.1111111 I ETC. See Catalogue for list.

NEWBEAR SYSTEMS FOR APPLE II, HORIZON AND CROMENCO
--

4ff.Ui':::tiAtiit Order: 40 Bartholomew St..

g..po twb

*40 ices, Official Ord MAMMA

vita

St A,cress we1 tout

170i(.0035) .30505 Telex: 848507 NCS
+ior..4Mi$44).Wroom: 220-222 Stockport Road,
taateltaiti Stockport
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INTEX DATALOG LTD

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*"*PRINTERS
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£ 20.00 E 25.00 £ 5.75 £ 35.00 £ 7.72 £ 4.50
5.00
£ 830.00 £ 920.00 £1010.00
£ 90.00
£ 110.00 £ 40.00
E 425.00
£ 25.00
E 35.00 £ 106.00 £ 186.00 E 45 00 £175.00
£49.00 E155.00 £110.00 £125.00
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RING 01-204 7525 ANYTIME,

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... JUST FOR STARTERS -PET 2001-4 C419 + vat PET 2001-8 C499 + vat PET 2001-16 £599 + vat PET 2001-32 E725 + vat + PRINTERS + FLOPPIES + SOFTWARE + INTERFACES

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YOU WORK OUT THE SAVING!!

L & J COMPUTERS:

01-204 7525

3 Crundale Avenue, Kingsbury, London, NW9 9PJ

V. & T. ELECTRONICS

CPU CONTROLLED CASSETTE DECK

Connects to any 8 bit 10 port & UART, full CPU control

of fast forward, reverse, read and write, searches tape

under software control for named files at up to 50 inches

per second (Z80 software supplied) includes high speed

CUTS interface - 2400 baud i.e. 1K bytes in 4.2 seconds.

One C60 tape holds 860K bytes, ideal for NASCOM 1.

Supplied ready built, not a kit, includes a.c. mains power

supply.

£110 + 15% VAT

Postage & packing £2.00

Please call for demonstration

FULLY Relocatable assembler for NASCOM 1 (easily

converted to other systems) supports pseudo-ops + all

Z80 opcodes, includes powerful text editor, uses approx.

3'/0K memory, all work areas programmable. Supplied on

tape.

+ VAT

2716 Eproms Intel Ex. Stock 4116 161< Dynamics 200ns 2114 4K Statics 200ns
Z80A Z80 PIO

1 off £23.50 8 off £56.00 2 off £10.00
1 off £14.00 1 off £10.00

NEW! TRS-80 16K upgrade

£57.00

We are usually open 7 days a week until very late, please

phone first before calling.

Please add 40p p&p.

82 CHESTER ROAD,

LONDON N19

01-263 2643

122 PCW

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QTY.

DIODES/ZENERS

MICRO's, RAMS,

-TT L-

44-79

1N914

100v

10mA

.05

CPU's, E -PROMS

QTY.

OTY.

QTY.

QTY.

1N4005 1 N 4007 1 N41 48 1 N4733 1N4749 1 N753A 1 N758A 1 N759A 1 N5243 1 N524413 1N52458 1N5349

600v 1000v
75v 5.1v 24v 6.2v
1 Ov
12v 13v 14v 15v 12v

1A 1A 10mA 1 W Zenner 1W 500 mW Zener
3W

QTV.

SOCKETS/BRIDGES

8 -pin

pcb

.16 ww

14 -pin

pcb

.20 ww

16 -pin

pcb

.25 ww

18 -pin

pcb

.30 ww

20 -pin

pcb

.35 ww

22 -pin

pcb

.40 ww

24 -pin

pcb

.45 ww

.08 .15 .05 .25 .25 .25 .25 .25 .25 .25 .25 .25
.35 .40 .45 .95 1.05 1.15 1.25

QTY. 8T13 8T23 8T24 8T97 7451 88
1 488
1 489 1702A
AM 9050 1CM 7207 1CM 7208 MPS 6520 MM 531 4 MM 531 6 MM 5387 MM 5369 TR 16028 UPD 414 Z 80 A
280 ,

2.50 2.50 3.00 1.75 3.00 1.25 1.25 4.50 4.00 6.95 13.95 10.00 4.00 4.50 3.50 2.95 3.95 4.95 22.50 17.50

7400

.20

7401

.20

7402

.20

7403

.20

7404

.20

7405

..35

7406

.25

7407

.55

7408

.20

7409

.25

741 0

.20

7411

.25

7412

.25

7413

.45

7414

.75

7416

.25

7417

.40

7420

.25

7426

.25

7427

.25

7430

.20

7432

.30

7492

.45

7493

.35

7494

.75

7495

.60

7496

.80

74100 1.15

74107

.35

74121

.35

74122

.55

74123

.55

74125

.45.

74126

.45

74132

.75

74141

.90

74150

.85

74151

.95

14153 .95

74154 1.15

74156 .70

74157

.65

74161/9316 .75

74163

.85

74H20 .25 74421 .25 74H22 .40 74H30 .30 74H40 .35 74450 .30 74H51 .30 74452 .20 74453 .25 74H55 .25 74472 .35 74474 .35 744101 .95 74H103 .55 744106 1.15 74L00 .30 74102 .30 74103 .35 74L04 .40 74L10 .30 74L20 .45 74L30 .55

741576 741586 741590 741593 741596 7415107 7415109 7415123 7415138 7415151 741S153 7415157 741S160 7415164 7415193 7415195 7415244 74 LS259 74 LS298 7415367 7415368 7415373

.70 .95 .85 .85 2.00 .90 1.50 1.95 2.00 .95 1.15 1.15 1,15 2.90 2.00 1.15 2.90 1.50 1.50 1.95 1.25 2.50

28 -pin

pcb

.50 ww

1.35

Z 80 P10 10.50

7437

.20

74164

.75

74L47 1.95

74500

.45

40 -pin

pcb

Molex pins .01

2 Amp Bridge

25 Amp Bridge

.55 ww To -3 Sockets
100 -pry 200 -pry

1.45 .35 .95 1.50

QTV.

TRANSISTORS, LEDS, etc.

2N2222M 2N2222A 2N2907A 2143906 2N3904 2N3054 2N3055 Ti P1 25 LED Green, D.L.747 MAN72 MAN361 0 MAN82A MA N74
FN D359

(2N2222 Plastic .101

.15

.19

PNP

.19

PNP (Plastic)

.19

NPN (Plastic)

.19

NPN

.55

NPN 15A 60v

.60

PNP Darlington

1.95

Red, Clear, Yellow .19

7 seg 5/8" High com-anode 1.95

7 seg corn -anode (Red) 1.25

7 seg corn -anode (Orange) 1.25

7 seg corn -anode (Yellow) 1.25

7 seg corn -cathode (Red) 1.50

7 seg corn -cathode (Red) 1.25

9000 SERIES

QTY.

QTY.

9301

.85

9322

.65

9309

.50

9601

.30

9602

.45

2102 2102L 21076-4 2114 2513 2708 271 6 D.S. 271 6 (5v) 2758 (5v) 3242 41 16 6800 6850 8080 8085 821 2 8214 8216 8224 8228 8251 8253 8255 TMS 4044

1.45 1.75 4.95 9.50 6.25 11.50 34.00 69.00 26.95 10.50 11.50 13.95 7.95 7.50 22.50 2.75 4.95 3.50 4.25 6.00 7.50 18.50 8 50 9.95

7438 7440 7441 7442 7443 7444 7445 7446 7447 7448 7450 7451 7453 7454 7460 7470 7472 7473 7474 1475 7476 7480 7481 7482 7483 7485

.30 .20 1.15 .55 .45 .45 .75 .70 .70 .50 .25 .25 .20 .25 .40 .45 .40 .25 .30 .35 .40 .75 .85 .95 .95 .75

74165 74166 74175 74176 74.117 74180
74181
74182 14190 74191 74192 74193 74194 74195 74196 74197

1.10 1.75
.90 .95 1.10 .95 2.25 .75 1.25 1.25 .75 .85 .95 .95 .95 .95

74221 74298 74367 75491 75492 74H00 74401 74404 74H05

1.50 1.50 1.35
.65 .65 .20 .30 .30 .25

74151 74155 74172 74L73 74L74 74175 74185 74193 741123 741500 741501 741502 741303 741504 741505 741508

.65 .85 .65 .70 .75 1.05 2.00 .75 1.95 .40 .40 .45 .45 .45 .45 .45

741310 .45 741311 .45 74LS20 .45 741S21 .45 741522 .45 741S32 .50 741537 .45 741538 .65 741S40 .70

74502

.45

74503

.35

74504

.35

74505

.45

74508

.45

74S10

.45

74511

.45

74520

.35

74522

.55

74S40

.30

74550

.30

74551

.35

74S64

.15

74574

.70

74S112

.60

74S114

.85

74S133

.85

745140

.75

745151

.95

74S153

.95

745157

.98

74S158

.80

745194

1.50

74S196

2.00

745257 18123 2.50

8131

2.75

QTY. 4000
4001 4002 4004 4006 4007 4008 4009
401 0 4011
401 2 401 3 401 4
401 5 4016

.15 .20 .25 3.95 .95 .25 .75 .35 .35 .30 .25 .40 .75
.75 .35

QTY. 4017 4018 4019 4020
4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4033

C MOS
QTV.

.75

4034

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4035

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4037

.85

4040

.75

4041

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4042

.25

4043

.75

4044

.25

4046

1.95

4047

.35

4048

.75

4049

1.1 5

4050

.30

4052

1.50

4053

4066

2.45 .75
1.80 .75
.69 .65 .50 .65 1.25 2.50 1.25 .65 .45 .75 .95
.75

QTY.

4069174C04 45

4071

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4081

.30

4082

.30

4507

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4511

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4512

1.50

4515 2.95

4519

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4528 1.10

4529

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LM31 8

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SPECIAL DISCOUNTS

PAYMENT SUBMITTED WITH ORDER SHOULD BE IN U.S. DOLLARS.
ALL IC'S PRIME/GUARANTEED ALL ORDERS SHIPPED SAME DAY RECEIVED. CREDIT CARDS ACCEPTED:
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WNW
Happy Memories

21L02 450ns 21L02 250ns
2114 4 5 Ons 2114 250ns 4116 3 0 Ons 4116 1 5 Ons 2708 4 5 Ons

83P 100p
525P
575P
79OP 840P 750P

TRS-80 16K Upgrade Kit
£69 for keyboard unit £ 63-50 for expansion box

Floppy Discs by VERBATIM £27-50 box of 10
I Mini soft sectored for APPLE, PET. TRS -80 etc:}

We stock the full NASCOM range of products

Large quantity of 74 LS stocked along with many

other components, free lists sent upon request

TEXAS IC SOCKETS 8 14 16 18 20 22 24 28 40

Solder tail

pence 10 11 12 16 17 19 21 27 37

Wire wrap

- - 24 36 39 46 58 61 63 70 109

Gold plated 5100 edge connectors £3-25 each 3 £9-50

4. 7 & 8 way DIP switches, all at 85p We keep a full range

of wire wrapping equipment, Wrap- Strip -Unwrap tool £5- 9 7

50 foot reel of wire f 1- 64 Just -Wrap tool with 50 wire £12-21

We've got Euroconnectors

Educational & Government

orders welcome Min £10

Shop open ten until six Access & Barclaycard Prices inc VAT, orders below £10 add 25p p & p
19 Bevois Valley Road, Southampton, Hants. SO2 OJP Tel: (0703) 39267

Which Terminal?
EMIT- OF COURSE!
TTY & IBM compatible VDUs. Top quality, high reliability & low cost. EX STOCK. Phone Slough (0753) 26713 for details.
DATA SYSTEMS LTD
295 Aberdeen Avenue SLOUGH BERKS SL1 4HQ)

PHI. New Low-cost Printer from

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Lear Siegler

ADM - 3A

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ADM - 3A Graphics from only £1395

ADM 31

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Keyboard Printers

Teletype 43

Pin Feed

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Friction Feed

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Typewriter Terminal from only f 825

Portable Models from only f 899

Digital
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Printers

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SCI Rotary Printer from only f 747

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124 PCW

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THE RESEARCH MACHINES 380Z COMPUTER SYSTEM

THE RESEARCH MACHINES 380Z

A UNIQUE TOOL FOR RESEARCH AND EDUCATION

Microcomputers are extremely good value. The outright purchase price of a 380Z installation with dual mini floppy disk drives, digital I/O and a real-time clock, is about the same as the annual maintenance cost of a typical laboratory minicomputer. It is worth thinking about!
The RESEARCH MACHINES 380Z is an excellent microcomputer for on-line data logging and control. In university departments in general, it is also a very attractive alternative' to a central mainframe. Having your own 380Z means an end to fighting the central operating system, immediate feedback of program bugs, no more queuing and a virtually unlimited computing budget. You can program in interactive BASIC or, using our unique Text Editor, run very large programs with a 380Z FORTRAN Compiler. If you already have a minicomputer, you can use your 380Z with a floppy disk system for data capture.
What about Schools and Colleges? You can purchase a 380Z for your Computer Science or Computer Studies
department at about the same cost as a terminal. A 380Z has a performance equal to many minicomputers and is ideal for teaching BASIC and Cesil. For A Level machine language instruction, the 380Z has the best software front panel of any computer. This enables a
teacher to single-step through programs and observe the effects on registers and memory, using a single keystroke.
WHAT OTHER FEATURES SET THE 380Z APART? The 380Z with its professional keyboard is a robust, hardwearing piece of equipment that will endure continual handling for years. It has an integral VDU interface -- you only have to plug a black and white television into the system in order to provide a display

unit - you do not need to buy a separate terminal. The integral VDU interface gives you upper and lower case characters and low resolution graphics. Text and graphics can be mixed anywhere on the screen. The 380Z has an integral cassette interface, software and
hardware, which uses named cassette files for both pro-
gram and data storage. This means that it is easy to store more than one program per cassette.
Owners of a 380Z microcomputer can upgrade their system to include floppy (standard or mini.) disk storage and take full advantage of a unique occurence in the history of computing - the CP/MTM* industry standard disk operating system. The 380Z uses an 8080 family microprocessor - the Z80 - and this has enabled us to use CP/M. This means that the 380Z user has access to a growing body of CP/M based software, supplied from many independent sources.
380Z mini floppy disk systems are available with the drives mounted in the computer case itself, presenting a compact and tidy installation. The FDS-2 standard floppy disk system uses double -sided disk drives, providing 1 Megabyte of on-line storage.
"Trademark, Digital Research.
Versions of BASIC are available with the 380Z which automatically provide controlled cassette data files, allow programs to be loaded from paper tape, mark sense card readers or from a mainframe. A disk BASIC is also available with serial and random access to disk files. Most BASICs are available in erasable ROM which will allow for periodic updating.
If you already have a teletype, the 380Z can use this for hard copy or for paper tape input. Alternatively, you can purchase a low cost 380Z compatible printer for under £300, or choose from a range of higher perfor-
mance printers.

380Z/56K complete with DUAL FULL FLOPPY DISK SYSTEM FDS-2
£3266.00

380Z/16K System with Keyboard
£965.00

RESEARCH MACHINES Computer Systems are distributed by RESEARCH MACHINES LTD.,

P.O. Box 75, Chapel Street, Oxford. Telephone: OXFORD (0865) 49792. Please send for the 380Z

Information Leaflet. Prices do not include Carriage or VAT @ 15%.

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PCW 12E

GPW Electronics
EXIDY SORCERER
8K -£650: 16K -£760: 32K -£859: TV Mods fitted
S100 expansion £210 Printer 5 x 7 dot £595. Micropolis S100 Disk 143K £499 : 630K £1,200.
TANDY TRS-80 Level I 4K £375 : 16K £480 Level 114K £448 : 16K £519 : 16K Expansion kit £70.50 COMPUCORP 655 System: 48K mem, 160K disk, CRT, S10 - £3,595 665 System: 60K mem, 315K disk, CRT, S10 - £4,540
SOFTWARE Large range of software available for all our computers. S100 KITS Everything you need to build your own system, including: 808A; Z80; Z80A; Static and Dynamic RMAS; Motherboards; EPROM Boards; Disk Controllers; Tape and Video Interface Boards, plus many, many more. BOOKS Large range in stock. (No VAT on books) COMPONENTS
RAMS 6504 CMOS - £15.00; 2114 (450) Static £5.40; 5101 (45) CMOS - £4.50; TMS 4033
MOS - £1.50;
All other micros, memories, chips and components available. Prices include post and packing. Please add VAT. C.W.O., Access or Barclaycard. Finance available.
146A London Road, North End, Portsmouth, Hants. Tel: Portsmouth 693341
(for components - Portsmouth 697427)

EQUINOX 300
A powerful multi-user multi -tasking multi -language
16 -bit microcomputer time-sharing system supporting * BASIC * LISP
PASCAL
Floppy discs " Hard discs including a powerful Text Formatter, Assembly Language Development System and disc -based Sort utilities.
Priced from under £5,000
Write or phone for further information
EQUINOX COMPUTER SYSTEMS LTD 16 Anning Street, New Inn Yard London E.C.2.
(Tel: 01-739 2387/8/9)

CRYSTAL ELECTRONICS CC ELECTRONICS

RYSTAL/CC ELECTRONICS 'NASCOM' SOFTWARE

XTAL BASIC - SPECIFICATION

This is an "8K Basic" Interpreter written for the

Nascom 1 system.

1. COMMANDS:- Call Clear CLoad Cont CSave Read.. Data.. Restore Def.. Fn Dim Edit End For. To.. Step.. Next Gosub.. Return Goto If.. Then Input List Nas Pop New On..Goto On.. Gosub Out Poke Print Rem Run Speed Stop Wait SPC (

Tab ( ) Print @

2. VARIABLES:- Names must start with a letter, but can be up to any length. First two characters used to distinguish one variable from another. Strings of up to 255 characters, also Multi -Dim. Arrays and String Arrays. Numbers range from
+/ - 1E+/-38, with an accuracy of six significant figures.

3. FUNCTIONS:- ABS ASC ATN CHRS COS EXP INT LEFTS LEN LOG MIDS PEEK POS RND RIGHTS SGN SIN SIZE

SIZES SOR SIRS TAN VAL

4. OPERATORS:- ARITHMETIC
RELATIONAL' AR ITHLOGICAL

-1

/

Power of "I

>
And or Not

I "To the
=

STRING + (Concatenation)

5. CASSETTE COMMANDS:- CSave CLoad for Saving and

Loading Programs. Also CSave@ Cload@ for saving and loading

of Numerical Arrays.

6. SPECIAL COMMANDS: EDIT Powerful Line Editor. -
CALL Machine -Code Subroutine Call, NAS Return to 'Nasbug' Under Software Control, OUT, INP & WAIT - For

Control of I/O Ports.

7. COMPATIBILITY:- Tape Routine Provided for Use with

T2 Monitor. Fully compatible with T2, T4 & B -BUG Monitors.

8. SIZE:- Actually Fits in 7K of RAM (1000H 2BFFH1,
but recommend 16k expansion Ram in your system.

9. AVAILABILITY:- On C12 Cassette Tape, with documen.

tation.

10. PRICE:- £35 + VAT

WHY BUY AN IMITATION GREY WHEN THE REAL CREAM IS AN
APPLE
THE SW AGENTS

416K MEMORY iNCREM APPLE II 16K 113901/

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E100

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[EMI/ INRITCC

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DURANGO

THE FIRST FULLY INT LcRATED DESK TOP SYSTEM

DUAL MAO DENSITY MINI FLOPPY DISCS FOR 1 9M BYTES ON LINE

9.9 DOT MATRIX BIDIRECTIONAL PRINTER 165c1s, VARIABLE WIDTH

ABK 64K HAM, WITH EMS cpEo

FULL KEYBOARD WITH 10 KEY NUMERIC PAD

VDU WITH 24.80 0, 16.64 CHARACTERS

POWERFUL DISC BASIC OA DIGIT ACCURACY I

MULTI TASKING TO a USERS PLUS OPTIONAL 20 MBYTE FIXED

APPLICATION SOFTWARE SMALL BUSINESS, A/C PAYABLE/RECEIVABLE

,ENERAL LEDGER ORDER ENTRY/INVENTORY CONTROL INVOICE /SALES

ANALYSIS PAYROLL E TC

PRICES FROM £7,500

TE %AS Ti PROGRAMMER A MUST FOR MACHINE LANGUAGE BUFFS OF Y OCTAL DECIMAL CCNVERSION ARITHMETICS OPS IN THREE BASES
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HOME COMPUTER

TORQUAY

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FOR DETAILS

ENGLAND

Tel 0803 22699

Shop open 0930-1730 except Wed, & Sun. 40 Magdalen Road, Torquay, Devon, England, Tel 0803 22699

Access and Barclaycard welcome. Mja

126 PCW

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IF YOU'RE CONSIDERING A MICROCOMPUTER

Be Sure to Check Out the Product Offerings of the World's Largest Full Line Microcomputer Company.

All Ohio Scientific machines come with microcomputing's fastest full feature BASIC -in -ROM or on -Disk for instant use.

The
C24P
The Protesetonal Portable by Ohio ShierstiNc

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Minimu Configuratim on

Base Price

Economical computer systems that talk in BASIC. Ideal for hobbyists, students, education and the home.
Superboard II -World's first complete system on a board including keyboard, video display, audio cassette, BASIC -in -ROM and up to 8K RAM
Challenger IP -Fully packaged Superboard II with power supply
Challenger IP Disk -Complete mini -floppy system expandable to 32K RAM

4K RAM
4K RAM 16K RAM

£ 188
£ 238 £ 865

Challenger IIP Series

Ultra high performance BUS oriented microcomputers for personal, educational, research and small business use.
C2 -4P -The professional portable
C2 -8P -The world's most expandable personal machine for business or research applications

4K RAM £ 404 4K RAM £ 548

C2 -4P Disk -The ultimate portable
C2 -8P Single Disk -Ideal for education, advanced personal users, etc.
C2 -8P Dual Disk -Most cost effective small business system

16K RAM 16K RAM
32K RAM

£1050 £1199
£1790

Challenger Ill The Ultimate in Small Computers

The unique three processor system for demanding business, education, research and industrial development applications.

C3 -S1 -World's most popular 8" floppy based microcomputer

32K RAM £2334 dual floppys

03 -OEM -Single package high volume user version
of C3 -S1
C3 -,-Rack mounted multi-user business system directly expandable to C3 -B

32K RAM dual floppys
48K RAM dual floppys

£2334 £3403

C3 -B -74 million byte Winchester disk based system. World's most powerful microcomputer
03-C -29 million byte Winchester disk based system.

48K RAM dual floppys
48K RAM dual floppys

£8654 £6320

Full Business and Data base Software

OS.AMCAP -A complete small business accounting package

including inventory, invoicing, A/R, A/P, CR, CD, general

ledger and P/L

OS.DMS -Data base Management System designed specifically

for small business information management.

-DMS based modules for inventory/order, A/R & A/P,

General Ledger, personnel/payroll, Query, Word

Processing.

WP -2

-Complete word processing system with character

justification, global editing, paging, text justification,

proportional spacing and hyphenation.

£ 656
£ 175 £ 175
each
£ 116

OHIO

-ALL PRICES ARE EX VAT.

OHIO SCIENTIFIC also offers you the broadest line of expansion accessories and

the largest selection of affordable software!

Compare the closest Ohio Scientific Model to any other unit you are

considering. Compare the performance, real expansion ability, software and

price, and you will see why we have become the world's largest full line

rmicrocomputer company.

I'm interested in OSI Computers. Send me information on:

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4 Morgan Street, London E3 5AB Tel: 01-981 3993

WE ARE LOOKING FOR DEALERS THROUGHOUT EUROPE PHONE MARK STRATHERN ON 01-981 3993

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PC \V 127

CPS
DATA SYSTEMS
The
Midlands
Micro
Sales Centre
Established by CPS to ensure that you buy the micro best suited to your particular need. During your visit you can see, and try at leisure a whole range of microcomputers.
Expert advice is always on hand to guide you through our hardware, software and back-up services.

GEMSOF'T
BUSINESS SOFTWARE FOR ITT2020/APPLE
Payroll, Sales Ledger, Stock Control, Mailing List, Invoice printer, Price listing etc.,
ALL AVAILABLE OFF THE SHELF. at Gemsoft's amazingly reasonable prices. (All programs require
ITT/Apple 32K, twin floppy disks & printer).
VISIT OUR NEW SHOWROOMS in Woking and see on demonstration:Complete business systems from £2475 (ITT 32K, twin disks & printer). We are area dealers for the new superb INTERTEC SUPER BRAIN Business and research computer. (64K RAM, CPM twin disks, 12" VDU, full edit, printer interface, fully expandable S100, at only £1995. Just add a printer for a complete system (send for leaflet). We also sell ANADE X printers at £570 (variable width tractor feed). Teletype 43's at £825. Apple disks at £425 & £375, OHIO SCIENTIFIC C2 -8P
and many others.
EXPERT IN-HOUSE PROGRAMMERS to write your Business or Industrial Control System. Please send an SAE for our Bumper Catalogue of all our services and products, including over 100 programs for PET, EXIDY, and APPLE. Games, Educational, Business, Scientific etc., or come and chat to us. Open 6 days a week 9am to 5.30 pm.
Add 15% VAT to all prices.
AERCO-GEMSOFT Ltd., 27, Chobham Road, Woking, Surrey. Tel: 04862-4667.
WE MEAN BUSINESS

At last! Britain's -ft

We're Authorised Dealers for Pet, Apple, Rair and Transdata microcomputers;
Decision Data and Datac printers; and Lear Siegler terminals -all available off -the -shelf;
phone us today, to arrange your visit, or for product information
Telephone: 021-707 3866
CPS
DATA SYSTEMS
Third Floor, Arden House, 1102 Warwick Road, Acocks Green, Birmingham B27 6BH
A member of the CPS Group
128 PCW

Immoonothwlyn
journal for Microsoftware,the
LIVERPOOL
SOFTWARE GAZETTE

First issue includes:

SARGON meets the Nascom-1 - J. Haigh.

1011

Pascal and the PET - J. Stout.

Programming practices and

Piease

techniques - Dr. M. Beer. I'm Pilot, fly me -D. Straker.

1u2bsscsn!sees
ittst
of "Liverpool Software Gazette" I enclose cheque . for £6 00

Letter from America

Access No

- D. Smith

11101.Barclaycard No

Apple pips-

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C. Phillips.

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mumism in mi EN mi - Post Code 100 Mail to Microchgelal Ltd. FREEPOST (No Stamp Requtred) Liverpool L2 Please mention PCW when replying to advertisers - it identifies you.

viii

VAi

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'"V

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trentsiffil

DI *11011

Model DMB-6400 Series dynamic 64k byte RAMS incorporate the features which are standard in the DM -6400 Series and adds
bank select for multi -user -timesharing applications.

ALPHA MICRO, CROMEMCO, and NORTH STAR output port
bank select,
Memory bank size can be incremented to 64k bytes in 16k
increments.

Four (4) 16k byte, functionally independent memory banks.
Eight (8) 64k byte banks of memory per output port for ex pan sion to 512k bytes for each output port.

Model DM -6400 Series dynamic 64k memory boards feature IEEE 5-100 compatible timing and on board transparent refresh.

Memory selectable and deselectable in 4k byte increments.

25 MHz on board crystal oscillator for independent timing.

DMB-6400 and DM -6400 Common Features:

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Low power- 8 watts maximum. Reliable, expandable memories.

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PCW 129

Personal Computer World Show

MEET THE

LITTLE GENIUS

AT STAND A9

If you find self -instruction manuals

difficult to follow, come and meet our

Little Genius.

--1

Little Genius floppy
diskettes are the fastest, do
easiest way to master your micro.

Little Genius will save you time and effort, teaching you to exploit all your micro's facilities.
Foorr a free demonstration of our first two courses visit Stand A9 at the PCW Show or phone Peter Brown : 01-580 6361.

'IdIoIq -
i;
i

TECHNALOGICS EXPANDABLE COMPUTER SYSTEM Bkt TISMOir

NOW,
POST OFFICE APPROVED FOR PRESTEL

ANC M

A T :MED

TECS: FEATURES

VIEWDATA AND PR__-
DATABASE ACCESS 'STANDARD 7A KEY KE
BOARD FULLY EXPANDABLE
COMPUTER SYSTEM MEMORY,MAPPED TV DISPLAY RAM '24 ROW 40 CHARACTER. ALPHANUMERICS AND
GRAPHICS PLUS BVV, ON UNMODIFIED COLOUR TV 'EXPANSION TO FULL 64K MEMORY
SUPPORTS BOTH 5.a" 8" FLOPPY DISCS
GENERAL PURPOSE INTERFACE CARD FOR
EXTRA RS232, 2 PARALLEL PORTS 2 CASSETTE PORTS
36 TECS MINI -BASIC, INTEGERVERS1ON WITH COLOUR DISPLAY
13K TECS BASIC; FULL FLOATING POINT VERSION OF ABOVE
TECSE1UG, POWERFUL MACHINE CODE MONITOR

TECSOFT OFFERS FULL
SOFTWARE BACKUP FOR TECS. A RANGE OF SOFTWARE TO EXPLOIT THE FULL POTENTIAL OF THE TECS SYSTEM'S UNDER
DEVELOPMENT FULL FACILITY TELE TEXT RECEPTION ICEEE AX. ORACLE/ INDUSTRY STANDARD MOTOROLA 6800cpu CHIP PROGRAM ACCESS TO TELESOFTWARE AND ON SCREEN INFO DISPLAYED IN 6 COLOURS TO NEW TELETEXT/
PRESTEL DISPLAY SPECK FICATION H1GH QUALITY PLUG-IN PCB's, GOLD PLATED CONVECTORS, PT HOLES
KANSAS CITY STANDARD CASSETTE INTERFACE

Klt Built

'SYSTEM TI

Teletext, 3.1( Basic,

4K User RAM E895 0175

SYSTEM T2

Teletext. monitor,

8K Basic, 4K

User RAM E1115 E1405

SYSTEM T2a As T2 but a 16KRAME1335 E1635

SYSTEM T2b As T2

but 32K RAM E1435 E1735

SYSTEM TR As T2 but 48K RAW, 535 0835

SYSTEM T4 'Presto

System' Toetext,

Prest el, 4K RAM,

BASIC

N/A E1955

(Kits available direct from TECHNALOGICS only)

Please send for further details (Large S.A.E., 13p stamp

please) or order now (specify rack or tabletop version)

from your dealer or in case of difficulty direct from

Tecs Sales Department.

TECHNALOGICS LTD.
8 EGERTON STREET LIVERPOOL L8 7LY TEL: 051-724 2695
All orders dealt with in strict rotation, carriage and insurance paid. All prices subject to 15% VAT.

NEW!!

INFINITE BASIC

E
NEW!!

"Infinite Basic" adds over 70 new commands to your Level II or Disk Basic. Furthermore, these are modularised so that any combination may be loaded at any time, which makes the package very memory efficient. A sampling of the additions includes complete string functions, left & right justify, truncate, rotate, text justification, reverse strings, verify, string searches etc., etc. Complete Matrix functions are also included with inverse, transpose, simultaneous equations, multiply scalars, vectors; reshape, expand and delete arrays; change arrays in mid-program, zero and move arrays etc., etc.
"Infinite Business- is an add-on package to the above and includes multiple precision -packed decimal arithmetic, eliminating round -off errors with a 127 -digit maximum accuracy. Also includes binary search of sorted arrays, automatic page headings and more!

Infinite Basic . . . £29.95.

Infinite Business . . . £16.95.

Both plus VAT & 50p p& p.

Send large SAE (121/2p) for our current catalogue of TRS-80 Software.

A.J.HARDING CNIOLINIERX3
28 COLLINGTON AVENUE,BEXHILL-ON-SEA,E.SUSSEX. TEL: (0424) 220391

BARCLAYCARD
VISA

130 PCW

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S.D. SYSTEMS inc. S100 COMPUTER CARDS & SYSTEMS

SBC 100 X-80 CPU SERIAL I/O PORT * PARALLEL I/O PORT 4 CHANNEL COUNTER TIMER 1K RAM, 8K EPROM S100 BUS " OPTIONAL VECTORED INTERUPTS
PRICE: £135.00 KIT; £183.00 BUILT AND TESTED
EXPANDORAM 8K TO 64K WRITE PROTECT INTERFACES WITH ALTAIR, I MSAI SOL-8, CROMENCO & SBC 100 5100 BUS OPERATES WITH Z-80, 8080, 8085 CPUs 2.5 MHz OPERATION KIT
PRICE: 16K £145.00; 32K £205.00; 48K £265.00; 64K £325.00 BUILT & TESTED PRICE: 16K %250.00; 32K £310.00; 48K £370.00; 64K £440.00

AIRAMCO 1050 DISK BOX CONTAINS 2 MFE 750 8" DOUBLE SIDED DRIVES PLUS POWER SUPPLY AND CONNECTOR CABLES PRICE: £1185.00
VERO S100 RACK SYSTEM 6 SLOT MOTHERBOARD POWER SUPPLY ETC PRICE: £230.00
+ V.A.T. @ 15%
TRADE DISCOUNTS ON QUANTITY PLEASE ADD £1.00 P&P FOR S100 ITEMS THEN ADD V.A.T. @ 15%
VERSAFLOPPY * IBM 3740 COMPATIBLE UP TO 4, 5 or 8" DRIVES SINGLE OR DOUBLE SIDED * Z-80, 8080, 8085 CPUs S100 BUS USES FD 17718-1 CONTROLLER CHIP PRICE: f90.00 KIT; £145.00 BUILT AND TESTED
VERSAFLOPPY II AS ABOVE BUT DOUBLE DENSITY & ANY COMBINATION OF DRIVE SIZES, UP TO 4 SIMULTANEOUSLY, USES FD1791-1 CONTROLLER CHIP
PRICE: £175.00 KIT; £224.00 BUILT AND TESTED

EXPANDORAM II AS ABOVE BUT EXPENDABLE FROM 16 to 256K * COMPATIBLE WITH Z-80 CPU 4MHz OPERATION

PROM 100 * PROGRAMS THE FOLLOWING PROMS: 2708, 2758,
2716, 2732, 2516 PROGRAM PULSE GENERATED ON -BOARD * LOW POWER REQUIREMENT * S100 BUS MAX PROGRAMMING TIME 100 SECS (16K) PROGRAM VERIFICATION SOFTWARE SUPPLIED PRICE: £89.00 KIT; £123.00 BUILT AND TESTED
AIRAMCO MIKRO 700 * S100 MAIN FRAME B&T 12 SLOT MOTHERBOARD * CUTOUTS FOR 5%" DRIVES (BLANKED ON
DELIVERY FAN, POWER SUPPLY, KEY ON/OFF SWITCH, RESET BUTTON * COMPLETE WITH SBC 100 KIT 16K EXPANDORAM KIT PRICE: £650.00

VDB 8024 * FULL 80 x 24 DISPLAY " 7 x 10 MATRIX KEYBOARD INTERFACE VIDEO & TTL OUTPUT 2K INDEPENDENT ON -BOARD MEMORY
8 ON -BOARD Z-80 CPU 96 UPPER & LOWER CASE CHARACTERS
32 SPECIAL CHARACTER SET 12B ADDITIONAL PROGRAMMABLE CHARACTER SET PRICE: £140.00 KIT; £236.00 BUILT AND TESTED

COMPLETE SYSTEM AS ABOVE BUT INCLUDING: 2 SA 400s + POWER SUPPLY
1 VERSAFLOPPY KIT WITH BIOS PROM ALL CABLES AND CONNECTORS ETC AND INCLUDING CP/M PRICE: £1295.00

STARTER KIT * ON -BOARD KEYBOARD & DISPLAY CASSETTE INTERFACE PROM PROGRAMMER 1K RAM, 6K EPROM, PI/0, CTC, MON. PRICE: E140.00 KIT; E246 BUILT AND TESTED

COMPONENTS 2708 1024 x EPROM 2716 2048 x 8 EPROM 1771B-1 FLOPPY DISK CONTROLLER 21 L02 1k x 1 (450ns) - per 8 21L02 1K x 1 (25Ons) - per 8 2114 1k x 4 (45Ons) 4115 8k x 1 (25Ons) DYNAMIC - per 8 4116 16K x 1 DYNAMIC - per 8 AY5 1013 UART AY5 1014 UART (5V) AY5 3600 ENCODER
8080A CPU 4044 4K x 1 (450ns) 4215 16K x 1 (250os) - per 8

6.50 37.50 29.95
7.50 8.95 4.99 25.00 89.00 4.50 6.50 9.99 8.99 7.45 59.50

FOR COMPONENTS PLEASE ADD 40p P&P THEN ADD V.A.T.@ 15%

AIRAMCO LIMITED UNIT A2, 9 LONGFORD AVENUE, KILWINNING INDUSTRIAL ESTATE, KILWINNING AYRSHIRE KA13 6EX
TEL: 0294 57755. TELEX: 779808

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PCW 131

MSmall
Systems Engineering
Limited

COMMODORE APPROVED PET INTERFACES

IEEE -488 Pet Disc Compatible

Serial Input and Output

£186.00

Serial Output only

£120.00

Parallel for Centronics, Anadex

£106.00

RS232C or 20mA Loop Output, Crystal controlled

Baud Rates

Special Code Conversion Chips available for non-

standard Character Codes

Micro Based General Purpose Interface Serial Input and Output with buffering Software Controllable Baud Rates Expansion Capability for additional RAM and I/O
Price £249

PETE Intelligent Terminal Software Package for PET Requires Bi-directional Serial Interface

TVIVideo Monitor Interface Video and UHF output

£ 35.00

Expansion Memory Boards

Internally mounting - available with Prom Sockets:

24K

£328.00

32K

£432.00

NEW REAL-TIME AUDIO SPECTRUM ANALYSER
Internally mounting, 32 channels, 1K ROM routines on board for analysis and graphical display, USR functions linkage to PET operating system £450.00
S100 BOARDS
Dynamic Memory Boards IEEE S100 Compatible timing and on board transparent refresh Available with Bank Select Feature, 64K, 48K and 32K 64K £487.00 64K (Bank Select) £562.00
PEtT S100 IEEE -488 Interface Board Controller, Talker, Listener capability CPM or North Star Software supplied, £350 00
All Prices exclude VAT P&P £5.00 (includes Securicor Express Delivery)
62 New Cavendish Street London W I M 7LD Telephone: 01 637 0777 Telex: 8813085 (Abacus)

COME & SEE US ON STANDS Al & A2 AT

THE P.C.W. SHOW! WE HAVE A WIDE & INTERESTING RANGE OF SOFTWARE FOR

MOST POPULAR MICROS. NEW PROGRAMS :-

TRS-80 BEEWARY (WITH SOUND !) ADVENTURE (2 VERSIONS)

19.00 18.50

APPLE :

STOCKLOCK(1 disc stock control) 150.

CITY MANAGER (RUN A CITY)

110.

PET :

ALIENS ! (STOP THEM IF YOU CAN!)I6.00

UXB (DEFUSE BOMBS!)

/5.00

MONSTERS (ZAP 'EM)

19.00

U.K.MAP (C.A.I.GRAPHICS)

112.00

COMPENDIUM(SLOTS,TANK,ESCAPE) 19.95

BREAKOUT (with sound)

15.00

ENLARGE (GRAPHIC AD DISPLAY) 16.00

SORCERER : OTHELLO SI FI SAMPLER GENERAL KNOWLEDGE QUIZ BLOCKADE RUNNER(SPACE GAME)

17.00 17.00 16.00 19.00

DENOTES PROGRAM WITH SOUND

WE ARE NOW APPLE DEALERS : APPLE II NOW ONLY 1750. + VAT ask for FREE LIST & SPECIAL OFFERS:

MORE PROGRAMS ARRIVING DAILY OUR PRICES INCLUDE 15% VAT
ORIGINAL PROGRAMS WANTED FOR WORLDWIDE DISTRIBUTION. WE PAY 15% ROYALTY ON GROSS SALES :sAAAA*%.AA;.;,; MOST PROGRAMS IN OUR CATALOG ARE AVAILABLE FROM STOCK
SEND FOR OUR FREE CATALOG.
THE JOURNAL "80 -US" FOR THE TRS-80 IS AVAILABLE ON SUBSCRIPTION FOR 110 pa. & is published BI -MONTHLY - VERY good value for money: SAMPLE FREE TO USER GROUPS. PLEASE NOTE OUR NEW ADDRESS:
146 OXFORD STREET, LONDON W.1.

132 PCW

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Research Resources Ltd
Micro -computers for Education, Science and Technology.
SWTP - New 16 Bit, 384K RAM Computer SWTP * 6809 16/8 Bit CPU replacement card for Level 1/2 * Two new 6809 computers - up to 384K RAM * New DMAF-2 8" Dual Floppy disks - 2.5 Megabyte * Memory available in 4,8,16,32,128k Boards * New Graphics VDU - CT82B - Improved 50Hz UK Standard * New TSC BASIC - very fast! * Plus LAB -BASIC, SAM, PASCAL, PILOT, FLEX. etc. * A -D, D -A converters
VECTOR MZ- up to 64k, S100, CP/M
VECTOR
* Z80A CPU, S100 Bus * 48k or 64k enhanced version * Over Y2 Megabyte of integral disk storage * Improved Micropolis disk drives * MDOS or CP/M operating system * Hardware floating point board and software. * Fast Fourier transform and digital filtering package. * Plus LAB -BASIC, SAM, FORTRAN, BASIC Compliers
PET - New Models, Disc drives, Printers PET * Up to 32k of user RAM * 360k intelligent disk drives ICBM) * 40 Column printer - only £250 * 80 Column Graphics printer * RRL Special - use a SWTP chassis as a PET
Memory/User port expander box. * LAB -BASIC for Control

THE MATRIX IS COMING * 16 Bit Machine with integral disk drives.
RRL specialises in designing micro -computer systems for educational and scientific use. We will supply the complete system - processor, VDU, printer, special interfaces, software etc. - to solve your problem. For further information: Tel: Welwyn Garden (07073) 26633
RESEARCH RESOURCES LTD, 40 Stonehills, Welwyn Garden City, HERTS. AL8 6PD.
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PM 133

OSI for LESS thanYOU EXPECT
IF YOU HAVE ALREADY DECIDED THAT YOU WANT AN OSI SYSTEM WE ARE OFFERING THE BEST PRICES AVAILABLE ON C2 AND C3 SERIES MACHINES

If you are undecided: The C3 -OEM is an Ultra High Performance Triple Processor Machine for business or industrial use, providing advanced application packages. For information management OS-DMS features a fast file handling system, and program library includes
PAYROLL, STOCK CONTROL and INVENTARY,
GENERAL LEDGER and other accountancy functions. OS-CP/M offers a complete FORTRAN and COBOL package.

C3 OEM £2450 + vAT

Expandable To T68K Ram, Multi User/Programming.

C3 -C with 23MB (formatted) hard DISC £POA. or C3 -B with 74MB Hard Disc £8995 4 VAT.

More memory? CM -3 16K static RAM £295 + VAT

INTERTUDE TERMINAL £675 + VAT

NEW! 13.4MB tape (cartridge) back up store POA.

C2 SERIES PROCESSORS

For Personal or Educational use
C2 -4P (4K RAM) £349 + VAT

The OSI specialists:

extra 4K

£ 29

MUTEK Quarry Hill,
Box, Wilts

CM -7 8K RAM £125! + VAT (expands to 24K)
C2 -8P 8 slot system £475

Tel: Bath 743289 C2 -8P 32K RAM Dual 8" Floppies £1533

to' c7VIASTER) for Casio 501/502

PACK°

with FA -1

PRE-RECORDED CASSETTE AND USER MANUAL FEATURING :

OVER 150 ready-to-run programs on cassette - with voice identification for fast access

Full CASIO PROGRAM LIBRARY ready for immediate use - PLUS

Extra GAMES - Lunar Lander, Codebreaker, Fruit Machine, Bomber Pilot, Reaction Timer, Wipeout, Roadrunner, math and strategy games

PERSONAL COMPUTER PROGRAMS - Bank account and credit card management, price comparatur, biorhythm, diet and weight calculators

POWERFUL SUBROUTINES for use in your own programs - display formatting, user prompts, plus DATA-PACKING (gives 502 100+ special function memories - essential for statistics)

EDUCATIONAL PROGRAMS - Math Exerciser sets and marks problems in basic arithmetic

PLUS USER MANUAL : See preview in Calculator Corner

Basic and Advanced Programming - fact-packed articles to develop your programming skills; everything you need to know but can't find in the CASIO manual:

Full command key-code index for fast program de-bugging

Comprehensive documentation for all MASTER PACK programs

'From Our Programmer's Notebook' - programming tips and tricks, special program sequences

_c_7VPIAACSTKE_k)_

for Casio 501/502 with FA -1

ONLY

17.95

Available from selected CASIO retailers, or send £17.95 direct to PREMIER PUBLICATIONS 15 Flaxman Road, London SE 5 (cheques/POs only - we pay p & p)

DEALER INQUIRIES INVITED - distributorships still available in some areas

134 PCW

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Happy Birthday

C -

PET

Car* ve-mort.

PETDISK !

The U.K.-designed and manufactured Novapak disk system
for Commodore's PET*, first seen at Compec '78, has now
entered its 2nd year of production. It's unique saddle configuration continues the integrated design concept of your PET, with no trailing wires or bulky desk -top modules.

Novapac Dual - disk system complete with PDOS and

Utilities on disc

£899 + VAT

Single -disk (stand alone)

£499 + VAT

Pack of 10 mini -diskettes

£30

Full cash with order is subject to 5% discount.

* Novapac may be used with any available RAM plane. Clear documentation and a range of Demonstration pro-

May be used with both types of PET

grams assist the first-time user, while for the experienced

* Data transfer takes place at 15,000 char/sec - effectively programmer full utilities are supplied to aid concise

1,000 times faster than cassette!

program development. The sophisticated, easy to use Disk

*Storage capacity is 125 K/ bytes (unformatted) on 40 Operating System supports multiple file handling and

tracks per diskette side.

incorporates extensive error -recovery software for maxi-

* Dual index sensors permit dual -side recording for 250 K/ mum data integrity. Optional password security for any file

bytes per diskette.

or any disk is provided.

* Easy operation full -width doors prevent media damage..

Several standard software packages are available, and

* System expandable to 1/2 Mbyte on-line storage (4 drives). we will tailor any of these to match your specific require-

* Industry Standard IBM 3740 recording format for indus- ment. Call now for details or a custom software quotation.

try -wide media compatibility offered only by NOVAPAK.

*Dedicated Intel 8048 microprocessor and 1771 FDC mini-

mise PET software overhead.

* Nationwide maintenance available.

anaiog Electronics 47 Ridgeway Ave, Coventry

Tel: (0203) 417761

i11111111r..-X11111011111KAM0110011111K)MIKAMOIIIIIIKVILK
APPLE II

comes to Glasgow

Why not call and see the fantastic Apple II the finest
micro currently available. Demonstration without obligation.

We also have in stock the following top quality items.

High Speed Tape Cassette Interface. Comes complete with instructions showing how to interface to Nascom giving
'normal' and high speed operation. 300, 600, 1200, 2400 baud. At the highest speed this will load our 8K basic in
about half a minute. Price (Kit) £17.50 + VAT Supercolour - at last top quality colour for your Apple II. Converts apply signals to separate red, green, blue, and sync. signals. No modulator required. 14" colour monitors available. Send for details now.
Also newly arrived - Buy brand new games for Nascom, Snarkhunt, Chase + Trail, Bulls + Cows, Life, Four in a Row. Runs on minimum Nascom - Any monitor. £10.00
inc. VAT p+p. Printers - High speed. 112 Char/sec. Top quality. User plain paper tractor fed £575 + VAT. PASCAL - Now available, the most powerful micro language PET. Features too numerous to fit this ad. Full details by return post.
Monitors - Hitachi, top quality B/W monitors now available. Plug straight into Apple. No modulator required.

Brand New Product. Chiptester. Converts Nascom to a

super powerful I.C. tester. Plugs in to existing ports. Send

now for full details. £19.50 Inc. VAT p+p

Callers welcome

Callers welc ome

STRATHAND 44 ST. ANDREW'S SQ.
ri! GLASGOW G1 5PL

v&i.

LoiTel. 041-552 6731 order welcome with Access and Barclaycard

Now on Telex 777268. 24 Hours Service

...

DISKS LTT MEMORY DISKS LTT MEMORY DISKS LTT MEMORY

U)

U)

cz)
O

O

- GODBOUT Computer Products >-

cr

WHigh quality, fast (4 MHz), reliable static S-100 memory LU 2 boards and other products e.g. -

2708 EPROM chip

U) 2716 EPROM chip

Econorom 2708, 16K EPROM (No EPROMS)

Econorom 2716, 16K EPROM (No EPROMS)

-

8K RAM (No RAMs)

CC Econoram Ha, 8K

Interfacer 2 full RS232 serial I/O

LU Econoram 1Va, 16K

Econoram Vlla, 24K

Econoram X111a, 32K

Kit Ass. £6.25 n/a p.o.e. n/a £45 £65
£55 £75 £80 £99 £99 £125
£150 £169 £230 £249 £315 £339

EXTRA LOW PRICES ON QUALITY DISKS

U)

U) BrQid name diskettes stocked for most micros.

Pack of ten 5%" disks, £19

Ten packs (100 disks), £175

.

.

Pack of ten 8" disks, £23

Ten packs (100 disks), £210

CC
UJ When ordering please specify whether you require hard or soft sectored diskettes, and if hard sectored, the number of
sectors.

Anadax DP8000 Printer. Ready to go! Includes RS232 cable, 1,000 sheets continuous stationery and Securicor delivery U) within UK. Only £525.

All prices given include postage and packing (overseas add u)

£10) Just add VAT. Send 10p stamp for details. Quantity discounts available on application. Credit terms >CC (nett 30 days) given to large companies and government cc

establishments.

LU

LLJ

1-1 Mail Order 'phone: 01-828 1785

o0--

DISKS : ITT : MEMORY : DISKS : LTT . MEMORY : DISKS : ITT ..AEMORV

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km

. . .Disks . . . calculators . . . paper . . . printers .. . magazines . . . 8K,16K,32K PET's . . Petsoft
Petact . . . Compelec Series 1 . . . and accessories like our . . .
. . .mains interference suppressor. This plug in suppressor helps stop interference from the mains which can be a threat to data in small business systems; no wiring and handles 1500 Watts at 6 amps; reduces interference between 150 kHz and 100 mHz

E0IT1PUT13-EHOP
WE ARE ON STAND 54 of the PCW SHOW (1st - 3rd November)
0245-76127 01-677 3022
Come and discuss your requirements for Business Systems and Software: Printers, Peripherals, and packages or individually written programs available: For further information phone either of the above numbers or write to: 22 Roughtons Galleywood Chelmsford
Essex
'Tandy' Equipment from S. J. Trott Ltd., (Franchise Dealer) - 01-969 6608
Printers... Printers... Printers...

* 16,20,32,40,64,80 and 132 characters per line.

Impact, electrosensitive and thermal.

If you're after a Hewlett Packard calculator, a sales accounting package, a Teletype 43 printer, a book on Basic or just a tape of
`Microchess' . . . drop in at 31 Palmer Street (by Caxton Hall) Westminster, London SW1.
We are open Mon -Fri. and are right by St. James's Park tube near the Army and Navy Store.
31 Palmer St (by Caxton Hall) London SW1 (01) 222 1122
also at: Planer Bldng. Windmill Rd., Sunbury Middx (09327) 86262

* O.E.M. mechanism/assemblies or complete packaged units.
* From only £149 for a printer mechanism with electronics.
* See them on stand A13 at the P.C.W. show.
C Cl7f CrIT.71_IMITED
"The Printer People"
Tudor Rd, Altrincharn, Cheshire, WA14 5TN Tel: 061-941 2361/2

136 PCW

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EDUCATIONAL GAMES COMPUTERS SOFTWARE SYSTEMS PRINTERS PERIPHERALS CONSULTANCY TV GAMES CALCULATORS

CONTINUING
B & B CONSULTANTS DISCOUNT DELIVERY SYSTEM

keen computers apple dealers stand

Send large stamped addressed envelope
for menu to: B & B Consultants, 124 Newport Street, Bolton, Lancs. or
Tel. Bolton (0204) 26644 or see us on
Stand A15 at the PCW Show

DEFINITELY NO SERVICE CHARGE ON
OUR MENU; THE PRICE YOU SEE IS THE PRICE YOU PAY
ALL OUR PRICES INCLUDE CHIPS

MEGABYTES FOR YOUR PET!

* Keen Computers Ltd. * P.I.P.S Computer Services Ltd. * Arden Data Processing * P.T.S. (Electronics) Ltd. * Sumlock Bondain Ltd * Pace Electronic Developments * Furness Computer Services Ltd.
Starring
Apple 11, Apple 11+, Apple peripherals, Pascal Printers, Speechlab, Supertalker
Supercolour, Corvus 11mb hard disk .... and Software for everyone
COME AND TALKIVIJS STANDS 13-18 PCW SHOW

and let apple have the last word

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PCW 137

I CAN'T AFFORD THE
But if I did Maybe I might find Microcomputers would assist me in my business Maybe I may learn how to program a microcomputer Perhaps I ought to afford the time to make just one 'phone call Contact us on 01-546-9887 or see us on Stand 42 at The Personal Computer World Show, West Centre Hotel, Lillie Road, SW6 on November lst-3rd
1979
TRAINING, SOFTWARE AND CONSULTANCY SERVICES

:: :.. ....... itil *It* II.. 11,..1 "et 111.411k*
.......

*It* it"

.

4,:*

....

.......

.

**

stle.

1.11.

gr.. **dr

North Star * COMPATIBLE

NORTHSTAR
Horizon -1 -32K -D
Horizon -2 -32K -D Horizon -1 -32K -Q
Horizon -2 -32K -Q 16K dynamic memory card 32K dynamic memory card Hardware Floating Point card Z80A CPU card Dual density/Quad controller with R E L5 S/W

£Kit 995
1195 1125
1425 195 295 145
99 225

£Ass
1165 1395 1335 1675
225 335 195 145 275

PERIPHERALS

Intertec Intertube II VDU (uses 280 + 6K EPROM) n/a

Elbit DS1920, model 30 VDU

n/a

Anadex DP8000 printer

n/a

NEC Spinwriter 55 cps letter quality printer

n/a

Digital equipment LA34 terminal

n/a

575 730
525 1395
825

All prices given are exclusive of VAT and carriage, and are correct at time of going to press.

ATTRACTIVE EDUCATIONAL, OEM AND DEALER DISCOUNTS AVAILABLE ON NORTHSTAR EQUIPMENT
NOW!

Please send 50p (inc. p+p) for our latest product catalogue which details the above and much more.

Telex: 925859 Telephone: 01-834 0261/2733 I nteram Computer Systems Ltd 59 Moreton St., Victoria, London S.W.1.
Telex: 925859
Telephone: 01-834 0261/2733 (nteram Computer Systems Ltd 59 Moreton St., Victoria, London SW1

INTER AM

COMPLETE COMPUTER SYSTEMS
(CCS)
443>CCS Microsales
LEARN "BASIC" with a £50 Voucher towards the cost of a "BASIC" course when you buy a micro from us.
ABC 80
Z80A based. Fastest in this price range. Fantastic 'BASIC' in 16K ROM plus Assemblers and FORTRAN (disc based) and over 35 Industrial I/O and memory boards.
APPLE
48K Disc based WORD PROCESSING Turnkey System inc. IBM Printer only £1990 (ex. VAT). Also 12 extra boards from CCS as options to all the usual Apple boards.
PET Our own boxed S100 interface so you can choose from the 200+ index of S100 boards and use them with your PET.
SORCERER
All sorts of S100 goodies available on order at costs which make it better than the hassle of getting them on your own.
We Know
SEEING IS BELIEVING
and invite you to come and see the ABC80 and others at our new Letchworth shop (Open Nov.). Just clip the coupon and send it to: CCS MICROHIRE/MICROSALES FREEPOST (7 The Arcade) Letchworth. Herts.

CCS Microhire

Still the Leading Microcomputer Hire Company with the best range of equipment:
PET (8k) now £4.20/day* APPLE(16K) now £5.70/day* Apple II; PET; Exidy Sorcerer; SEED System One/MS! 6800; NASCOM/MICROS; Research
Machines 380Z and Tandy
TRS-80
Over 500 million Bytes (half
megabytes memory) available
for hire in units from 4K to
48K.
Send for our NEW PRICE LIST giving the most attrac-
tive prices yet. * four day rates
CCS MICROHIRE
FREEPOST (7 The Arcade) LETCHWORTH
Herts SG2 4YA

I would like to come and

see the ABC80, PET, APPLE

Please call me back to

arrange an appointment

NAME

Company

Location

Tel

Ext

138 PCW

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WHY BUY A MICRO -COMPUTER FROM

ADVERTISERS INDEX

ELECTRONIC SERVICING LTD.
BECAUSE
1) Established company trading since 1971 2) Electronic servicing is our speciality 3) We have in house programmers/systems
analysts
4) We have our own service engineers 5) We will demonstrate the PET at your
premises
6) We can customise the PET to your requirements
7) We can arrange finance 8) We offer, after the three-month warranty, a
service contract from £69.50 9) You benefit from our experience of having
sold over 150 micro -computers to industrial, educational and business, personal users. 10) We specialise in programs and interfaces for weighing applications for average weight control and counting etc.
All 'PETS' sold with a Basic Tutorial Tape 8K £550.00 -- VAT.
16K £675.00 VAT. 32K £795.00 --- VAT.
New Large Keyboard 'PETS' Now in Stock In our showroom we sell Books, Programs etc.
Also available:
24K Memory Expansion Boards (disk -compatible)
only £320 - VAT
PET -compatible dual floppy disk unit with advanced operating system only £840 VAT
Large Extension Keyboard for the PET £89.50 -,- VAT Telephone for complete system prices. Wide Range of Printers Available.
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 69032168497
Shop at: PETALECT
Chertsey Road, Woking, Surrey. Tel. Woking 21776 23637
SEE US ON STAND 5 AT THE PCW SHOW

Abacus Computers

77

Acorn Computers

87

Adda Computers

36

Airamco Ltd

131

Almarc Data Systems

4

Analog Electronics

135

Applied Data

Education Services

90

B&B Consultants

137

The Byte Shop

90

Cambridge

Computer Store

35

Carter Keyboards

117

CCS Microhire/

Microsales

138

Comma Computers

66

Comart

5,19

Commodore Systems 34

Compelec Electronics 29

Compfer Ltd

35

Comp Shop

140,IBC

Computerama

30

Computer Centre

15

CPS (Data Systems)

128

Crystal Electronics

126

Databank

32

Datac

136

Data Systems

Engineering

36

Datron Interform

22,38

Display Electronics

23

Elbit Data Systems

124

Electronic Brokers

26

Ensign

59

Equinox

Computers

8,118,126

Eurocalc

53

Factor One

Computers

119

Gemsoft

128

GPW Electronics

17,126

GW Computers

31

Happy Memories

70,124

A.J. Harding

(Molimerx)

130

HB Computers

120

Heath (Gloucester)

26

Home and Business

Computers

14

Integrated Circuits

Unlimited

123

Interam Computer

System

138

Intex Datalog

122

Ithaca Intersystems

3

Katanna Management

Services

136

Keen Computers

137

Kingston Computers

88

Lifeboat Associates

102

Lion House

9

Little Genius

130

L&J Computers

122

Logic Box

136

London Computer

Store

30

Lotus Sound

127

LP Enterprises

24/25

LTT Electronics

135

Micro Centre

IFC

Microcomputer

Centre

35

Microdigital

14,128

Micro -Facilities

36

Micromedia (Systems) 122

Microsense Computers 12

Microsolve Computer

Services

22

Mine of Information

29

Mutek

134

Nascom Micro-

10/11,

computers

21,37

Newbear Computing

Store

28,121

Newtons Laboratories 96

NRDC

118

Peripheral Hardware 124

Personal Computers OBC

Petalect Electronic

Services

139

Petsoft/Petact

18,116

PIPS Computer Service 32

Productivity Unlimited 32

Research Machines

125

Research Resources

133

Mike Rose (Micros)

32

Rostronics

2

Sharp Elec-

tronics (UK)

62

Sintrom Microshop

2

Sirton Products

108

Small Systems

Engineering

129,132

The Software House 132

Stack Computer

Services

27

Strathand

135

Strumech (SEED)

46

Tandy Corporation

43

Technalogics

130

Teleprinter Equipment 20

Transam Components 13

Tridata Micros

38

TVJ Microcomputers 16/17

V8z T Electronics

122

William Stuart

Systems

117

Xitan Systems

33

PCW 139

TRS 80 EXPANSION Upgrade your system as your needs increase.
INTERFACE additional 16K or 32K RAM aCnodntaaindsisskocckeotns tforor ller
for up to 4 -mini -disks. Software selectable dual
cassettes can be used. Features a Centronics parallel port, real time clock, and a connector for an RS -232C interface or whatever. Requires
rnLmevneile-ItIeBawsiict.h22307/24K0VRAACM. £299 plus VAT.

THE TRS80 (Special Scoop)

Low Priced, Ready

\'0A

to Go!

ANADEX DP8000 ONLY E540 + VAT49 PET Connector £ The DP 8000 prints the 96 -character ASCII set in single or double width at 84 lines per minute. The unit operates bidirectionally to print a 9 x 7 matrix on multiple copy, pin -feed plain paper. This model accepts RS -232C or current loop serial data at baud rates swItchable from 110 to 9600 and Parallel Bit data input at over 1000 characters per second. Standard storage capacity of 256 characters Other features include Out of Paper Detector, Top of Form Programming and Skip Over Perforation Control.
...wwwwwwwwwfmowww.
THE NEW ITT APPLE (2020)

PLUGS INTO YOUR OWN TV

Use your own cassette

LEVEL II BASIC WITH 16K USER RAM provides you with possibly the most power-

ful micro around. All our TRS80s are fully converted to English Television Stan-

dard and include a U.K. Power Supply, Cassette Leads, Sample Tape, Level I &

Level II programming manuals, and special lead that enables you to connect

direct into your own television.

Special features of Level II Basic enable you to:-

- Set or reset any point on the screen - Test for the presence of a point on

the screen (these features enable easy animation) - Save or load data from

cassette under program control - File handling capabilities on cassette using

named files. - Graphics blocks as standard - design your own pictures and

many many more features for only £399 + VAT

naevr

,6111111IIIIMP-

.

PET COSTS LESS

AT COMP and it's a pedigree 8K - Comes complete with
integral cassette deck. Full manuals supplied. Powerful 8K Microsoft Basic in ROM. Masses of software available - £499 + VAT

16K - Same as above but with new

improved keyboard and cassette supplied

* Full colour - UHF output * Audio cassette tape interface * Up to 48K

as extra. Machine code monitor on board so you can program in 6502 machine code - £590 + VAT 32K - for a little extra get 32K memory providing greater storage capacity for programs or data - £690 + VAT

a 0 a 011 OP
114. *111.111.

\

RAM on board * BASIC in ROM (graphics commands include COLOUR VLIN, HLIN, PLOT and SCRN) * Built in loudspeaker * Buckets of software .

External Cassette deck for 8K, 16K or 32K - £55 + VAT

available * Disk System (110K byte per drive - includes controller) only £425 + VAT EX -STOCK
HITACHI PROFESSIONAL

rr: SORCERER SPEAKS complete with cable and connector
011H1
' YOUR LANGUAGE

MONITORS 12"

VAT

For personal or business use. The "- best value for money around.

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 at 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.

Word
Processing Pac and

video 100

12" BLACK & WHITE LOW COST VIDEO MONITOR

Development Pac now available.
Word Processing Pac
.!"-

* 512 by 256 point screen resolution * 16K or 32K User RAM * Centronics Parallel Port * RS232C Serial Port * Composite IV peak to peak video output T.V. output supplied as extra. * 64 programmable graphics + 64 standard PE1 d' graphics * 79 key keyboard including 16 ke' numeric keypad. * Expansion bus for connection to S100 Expansion Box. 16K Sorcerer - £690.00 + VAT 32K Sorcerer - £790.00 + VAT S100 Expansion Box - £210 + VAT
£70 Development Pac - £70

Ideal for home, personal and business computer systems

12" diagonal video monitor

Composite video input

Compatible with many computer systems

Solid-state circuitry for a stable & sharp

picture

Video bandwidth - 12MHz + 3DB

Input impedance - 75 Ohms

Resolution - 650 lines Minimum In Central

80% of CRT; 550 Lines Minimum beyond

central 80%.

£79 Only

+ VAT

Break the language barrier EiNia

+ VA.

At a price equivalent to learning one

language, LEXICON offers you, English,

Spanish, French, German, Italian and Greek.

0 0 0110 0100 01as
000110000010

The LK3000 comes to you with the person to person module which contains 6 languages, de -luxe carrying case and a charger adaptor

OUZO 00000/

using its own power source which will give you 4 -5 hours continuous use, and can easily

be re -charged from the mains supply,

wherever you may be in the world. Every additional module carries a concise

and understandable instruction book. Your deluxe carrying case has room for

two additional modules.

COMPUCARE
(Part of the Compshop Ltd. Group)

Compucare is a company that has been set up to provide servicing and maintenance for the popular makes of microcomputers i.e. Sorcerer, Pet, Apple, TRS80, Nascom, Compukit. Our charges are £7 per hour plus parts.
Because of the extensive range of spare parts stocked you can usually expect your micro to be repaired within 10 days for an average charge of £14 labour. Emergency 24 hour repairs can be handled for a £10 surcharge where possible. Compukits and Nascoms unsuccessfully constructed will be charged a standard £25. Maintenance contracts for these machines are available, see your local dealer for a Compucare Maintenance Application Form.

Please add VAT to all prices - Delivery at cost, will be advised at time of purchase. Please make cheques and

postal orders payable to COMP, or phone your order quoting BARCLAYCARD, ACCESS, DINERS CLUB or

- AMERICAN EXPRESS number. OPEN - 10am to 7ym - Monday to Saturday CREDIT FACILITIES ARRANGED

411111111111111111111111111MM

Armemiumusummummilei

11M10.0CAND
VISA

140 PCW

Please mention PCW when replying to advertisers - it identifies you.

AS SEEN IN P.EE. AUGUST, SEPTEMBER
OCTOBER 1979

EUROPES FASTEST SELLING ONE BOARD COMPUTER JUST CHECK THE SPEC'S.
ompuKIT UK101

SAMPLE TAPE WITH EXTENDED MACHINE CODE MONITOR AND DISSASSEMBLER INCLUDED FREE

LOW COST SUPERBOARD IN KIT FORM

The Compukit UK101 has everything a one board 'superboard' should have.
* Uses ultra -powerful 6502 microprocessor. * 50Hz Frame refresh for steady clear picture (U.S. A. products with 60Hz frame refresh always
results in jittery displays)
* 48 chars by 16 lines - 1K memory mapped video
system providing high speed access to screen display enabling animated games and graphs. * Extensive 256 character set which includes full upper and lower case alphanumerics. Greek symbols for mathematical constants and numerous graphic characters enabling you to form almost any shape you desire anywhere on the screen
* Video output and UHF Highgrade modulator (8Mz
Bandwidth) which connects direct to the aerial socket of your T.V. Channel 36 UHF.
* Fully stabilised 5V power supply including trans-
former on board * Standard KANSAS city tape interface providing
high reliability program storage - use on any
standard domestic tape or cassette recorder
* 4K user RAM expandable to 8K on board £49
extra.
* 40 line expansion interface socket on board for
attachment of extender card containing 24K RAM and disk controller. (Ohio Scientific compatible).
* 6502 machine code accessible through powerful
2K machine code monitor on board.
* High quality thru plated P.C.B. with all I C.'s
mounted on sockets.
* Professional 52 Key keyboard in 3 colours - software polled meaning that all debouncing and key
decoding done in software.

COMMANDS

CONT LIST

NEW

NULL

RUN

STATEMENTS

CLEAR DATA

DEF

DIM

END

GOTO GOSUB IF GOTO IF THEN INPUT

NEXT ON GOTO ON..GOSUB POKE PRINT

REM RESTORE RETURN STOP

FOR
LET REAL

EXPRESSIONS
OPERATORS ,/,t NOT.AND.0H,
,

=ic-r. RANGE 10.32 to 10 + 32

VARIABLES A.B.C. .Z and two letter variables The above can all be subscripted when used in an array String variables use above names plus $.e.g AS

'8K Microsoft Basic means conversion to and from Pet, Apple and Sorcerer easy. Many compatible programs already in print.
SPECIAL CHARACTERS @ Erases line being typed, then provides carriage return, line feed.
Erases last character typed. CR Carriage Return - must be at the end of
each line. Separates statements on a line.
CONTROUC Execution or printing of a list is interrupted at the end of a line. "BREAK IN LINE XXXX" is printed, indicating line number of next statement to be executed or printed. CONTROUO No outputs occur until return made to command mode_ If an Input statement is encountered. either another CONTROUO is typed, or an error occurs. ? Equivalent to PRINT

Simple Soldering due to clear and consise instructions compiled by
Dr. A.A. Berk, BSc.PhD

NO EXTRAS NEEDED JUST HIT 'RETURN' AND GO.

Build, understand, and program your own computer for only a small outlay.

KIT ONLY £219 + VAT including RF Modulator & Power
supply. Absolutely no extras.

Available ready assembled and tested, ready to go for
£269 + VAT

FUNCTIONS ABS(X) LOG(X) SPG(I)

ATNIXI PEEK(I) SOR(XI

FRE(X)
SGN(X) USRIII

INT(X) SIN(X)

STRING FUNCTIONS

ASCIXS)

CHRSSIII

RIGHTSIX$ I)

LEN(XSI MIDS(X$1..1) VAL(XS)

COS(X)
POS(I) TAB(I)

EXP(() RND(X) TAN(X)

FRE(XS) LEFTS(XS.II STRUX)

EXTRAS AVAILABLE SOON

COLOUR ADD-ON enables you to choose your foreground and background colour anywhere on the screen. Flash any character on the screen at will. Full documentation and parts in kit form.
41111111MMINI

AD -A -RAM EXTENDER CARD provides up to 32K Dynamic RAM Expansion, 8 Eprom sockets for 2708's or 2716's. Parallel Port (centronics compatible) and an RS232C serial port.

WIN YOURSELFAN ANADEX DP8000 LINE PRINTER

There's never enough good software around. That's why COMPUKIT LTD. are sponsoring a software contest. There are 2 categories: 1) Business and Education 2) Fun and Games One lineprinter will be awarded to the winner of each category. Send or bring along to the address shown below the following: 1) The program on cassette in the format used by the COMPUKIT
UK101
2) Any documentation that you have for the program (source listing not necessary) 3) This coupon signed by you accepting the rules and conditions of the competition.
RULES: 1) Entries, including documentation, must be printed by computer or typed double spaced, with your name on every page. 2) Send or bring your entries to the address shown below. 3) Entries must be received by midnight on 29/2/80, any received after this time are void. Winners will be notified by post before 31/3/80. 4) You warrant by your signature that all programs and documentation material included is entirely your own creation, and that no rights to it have been given or sold to any other party, and you agree to allow COMPUKIT LTD. to use, publish, distribute, modify, and edit it as it sees fit.

5) All entries become the property of COMPUKIT LTD. No entries will be returned nor any questions answered regarding individual entries. 6) Judging will be by a selected panel chosen by, and including representatives of COMPUKIT LTD. Judges may assign programs to any of the categories as they see fit. Decision of the judges is final. 7) Employees of COMPUKIT LTD, its dealers, distributors, advertising agencies and media are not eligible to enter. Name Address
I agree to abide by the above mentioned rules.
Signature -

COMPUTER
COMP COMPONENTS

14 STATION ROAD, NEW BARNET, HERTFORDSHIRE

TEL: 01-441 2922 (Sales)

CLOSE TO NEW BARNET BR STATION - MOORGATE LINE 01449 8596

OPEN - 10am to 7pm - Monday to Saturday

TELEX: 298755

All Products Ex -Stock Please check availability

(Part of the Compshop Ltd. G oup).

a"rMe yonbelostnAg~ptpelremprdoegproasmitsi
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 simuln`e the Tektronix 4010 family of graphics terminals. It's rather good1 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
VAT
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
APPLE PASCAL £296

Personal ofnutcr,s
Limited
194-200 Bishopsgate.London EC2M 4NR
Let us advise you about COLOUR DISPLAY on your Apple. Contact Technical Services.

Arr--LL)
24 HOUR 'NEAREST DEALER SERVICE'
01 283 3391
TECHNICAL SERVICES
01.623 7970 MAIN OFFICE 01-626 8121
6 lines

Car


PdfCompressor 6.6.1697 CVISION Technologies