1970_PDP 10_Timesharing_Handbook 1970 PDP 10 Timesharing Handbook

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MONI'foit COMMANDS
ARGUMENTS

ABB:&EVIATION

NAME
ASSIGN
ASSIGNt

ATTACH
ATTACHt
CCONT
COMPILE
CaNT
CORE
CREATE
CREF
CSTART
CTEST
D(deposit)
DAYTIME
DDT
DEASSIGN
DEBUG
DELETE
DETACH
DETACHt
DIRECT
E(examine)
EDIT
EXECUTE
FILE
FINISH
GET
HALT
KJOB
LIST
LOAD
LOGIN
MAKE
PJOB
R
REASSIGN
REENTER
RENAME
RESOURCES
RUN
SAVE
SCHEDULEt
SSAVE
START
SYSTAT
TALK
TECO
TIME
TYPE

AS
AS
AT
AT
CC
COM
CON
COR
CREA
CREF
CS

SYS

Idey
dey

.i2£

[proj, progj

D
DA
DD
DEA
DEB
DEL
DET
DET
DI
E
ED
EX
FIL
FIN
G
tC
K
LI
LOA
LOG
M
PI
R
REA
REE
REN
RES
RU
SA
SC
SS
ST
SYS
TA
TE
TI
TY

[proj, progj

core

dey
list

core
.ext

.ftk.
adr

adr

dey
list
list
dey
dey
adr
file

.ext

.fu1
arg
dey
dey

.&k

.ext

list
list
file

.ext

file
dey

.ext
job

core

file
file

.ext
.ext

[proj, progj
core

file

.ext

core

arg
dey
dey
n
dey
adr
dey
file
job
list

.ext

Key:
adr
core
dev
ldev
.ext
file
job

octal address
decimal number of lK blocks
physical device name
logical device name
filename extension
filename
job number assigned by Monitor
privileged command

octal value of left and right half words
Ih rh
[proj, progj project·programmer numbers
a single file specification or a string of
list
file specifications
a pair of file specifications or a string
arg
of pairs of file specifications
scheduled use of the system.
n
underline means always required

See Book 2 and Book 7 for further explanation of commands.
abbreviations are accurate and unique as of now, but their accuracy' 'and uniqueness may be changed in the future by the addition of
new com'inltlld~
~se

PDP-tO
TIMES
NG
HANDBOOK
Prepared by
The PDP-tO Software Writing Group ..
Programming Department
Digital Equipment Corporation

Additional copies of this handbook may be ordered from the
Program Library, Digital Equipment Corporation, Maynard, Mass.
01754. Order code AKW. $5.00 each. Discounts are available on
five or more copies.

PDP-tO HANDBOOK SERIES

All rights reserved.
Permission to reproduce this handbook or any parts thereof may be
obtained from the PDP-I0 Product Line Manager, Digital Equipment Corporation, Maynard, Mass.
The material in this handbook is for information purposes and is
subject to change without notice.

The following are trademarks of Digital Equipment Corporation,
Maynard, Massachusetts:
DEC .•
Digital
PDP

INTRODUCTION TO TIMESHARING
(pages 1-1 thru 1-,12)

GETTING STARTED WITH THE MONITOR
(pages 2-1 thru 2-20)

BASIC
(pages 3-1 thru 3-78)

AID
(pages 4-1 thru 4-99)

FORTRAN
(pages 5-1 thru 5-133)

DEMONSTRATION PROGRAMS
(pages 6-1 thru 6-49)

ADVANCED MONITOR COMMANDS
(pages 7-1 thru 7-21)

UTILITY PROGRAMS
(pages 8-1 thru 8-89)

APPENDICES
(pages A-I thru B-4)

INDEX
(pages Index-l thru Index·-lO)

III

FOREWORD
We have written this handbook for the individual with little or no
programming skill in an attempt to bring timesharing programming
competence- to an ever-expanding circle of new computer users. With
this volume as his guide, we hope he can soon acquire the necessary
programming knowledge to improve his business or professional
activity by the application of computer technology.
I'm pleased to acknowledge here the work of the many DEC programmers, designers, and engineers who continue to advance the state of
the timesharing art in both hardware and software, and the DEC
software writers and technical artists who prepared this volume.

President, Digital Equipment Corporation

PREFACE
In devel~ping its timesharing capability, Digital has built a history
of sm:cess very similar to the company's record in realtime. applications. That history started in 1960 when Digital's customers began
building timesharing systems around PDP computers. Three years
later Digital itself started dev~lopment of its own timesharing system,
the PDP-6; and 4t 1964 the PDP-6 became the first timesharing computer to be delivered with manufacturer-supplied hardware and software.
Th~ PDP-I0, which emerged in 1967,.is the successful culmination
of many years of computer research. Its power, versatility, and low
cost make ~t a leader in the general-purpose timesharing field. For its
timesharing users" the' PDP-lO perfOmis scientific data analyses,
helps make better management decisions, ~ids in engineering and
architectural design, ,makes investment analyses, and provide!! management information services.
With this handbook, Digital attempts' to bring its doctimentation
on timesharing to a par with its hardware and software accomplishments. The handbook is intended primarily for students, scientists,
engineers, and financial analysts who have little or no experience
in programming. From it they can learn timesharing programming
from a remote Tel,etype using disk input' output.
This is not to say that an experienced programmer is automatically
debarred from using this document. If the reader happens to be a'
program~er, he should skip the preliminary books, go straight to
the computer 'language in Book 5, and commence programming.
In Book 6 he will find that Demonstration Programs..~3 and 4 are
geared to his level of programming knowledge and competence.
A synoptic view of the contents of the handbook is as follows.
Book 1 describes the evolutionary hist9ry of timesharing and gives
the reader an insight into the way it operates. Book 2, in explaining the elementary monitor commands, shows the reader how 'to
get on the system. In Books, 3 and 4 the reader will find conversational programming with BASIC and AID, respectively. Book 5,
'as already indicated, contains FdRTRAN. Four demonstration ,programs constitute Book 6; advance~ monitor commands are found
in Book 7; and the four utility' programs Batch,CHAIN, LINED, and
TECO appear in Book 8.
Since the handl"ook will be revised periodically in order to improve
it and keep it up to date, we solicit the reader's constructive evaluations in the questionnaire at the back of the book. Please fill
out the questionnaire and return it to
PDP-I0 Software Writing Group
Programming Department
Digital Equipment Corporation
Maynard, Massachusetts 01754
A companion volume, the PDP-! 0 Reference Handbook; is likewise
iIi, print. It is oriented toward experienced programmers who are
interested in writing and -operating assembly;-language programs.

CONTENTS

Foreword
Preface
Book 1

VI
Introduction to Timesharing ................................................'............................... .

1-1

A general description of the operation of a variety of factors in the evolution
of timesharing.'
Book 2

Getting Started with the Monitor ........................................................................

2-1

Logging in, description of files, elementary commands to create, edit, manipulate, translate, load, and execute files, getting information from the system,
..
and logging off the system.
Book 3

Conversational Pr9gramming with BASIC

3-1

A complete book, explaining the procedures for logging in, logging off, and
writing, editing, and running programs in BASIC-a problem-solving conversational language that can be used to solve both simple and complex mathematical problems.
'-.
Book 4

Conversational Programming with AID
A complete book explaining how to program in AID, an algebraic conversational language designed to solve both simple and complex numerical problems.

4-1

Book 5

Programming in FORTRAN .................... :, .......................................... .-............

5-1

A reference ~ook describing the specific statements and features of the FORTRAN IV language, designed primarily for the experienced FORTRAN
programmer.
Book 6

6-1

Demonstration Programs
Four programs designed to utilize concepts and commands discussed in this
manual. Demonstrations three and four also make use of advanced commands
in TECO and DDT.

Book 7

Advanced Monitor Commands ............................................................................

7-]

Explanation of monitor commands not covered in Book 2-commands to
allocate system resources, produce line printer listings, manipulate core images,
start a program, and get information from the system.
Book 8

Utility Programs ....................................................................................................
Includes BATCH-sequential execution of a series of jobs, CHAIN-allows
users to deal with FORTRAN programs too large to fit or load into the amount
of core available, LINED-a line-oriented editor designed for use on the disk,
and TECO--description and explanation of the most frequently used commands of this powerful text editing program.

8-1

Appendices .............................................................................................................................

A-]

Master Index ....................... ,........................................................................................... Index-l

VII

•

VIn

Bookt
Introduction
to·.·

Timesharing

_,
1
.-

,;.t.

•

INTRODUCTION TO TIMESHARING
Why Timesharing?

Early computers were the province of the mathematician. Used
mainly to solve differential equations, the systems were narrow in
scope and poorly utilized. Since few persons were knowledgeable
enough to employ the enormous processors, one individual could
monopolize computer time-sit at the console and solve problems
in step-by-step fashion.
As more people discovered computin~ techniques, it was no
longer practical to let a few persons monopolize computer time.
To increase machine efficiency, batch processing was introduced.
In this mode of operation; no time was wasted between jobs.
Programs were punched on cards and the,cards stacked and fed
to the computer jn batches. Operation of each program was gov/ erned by control cards that took the place of the human operator.

batch processing

Since card reading is a relatively slow process, some early systems employed a small computer to read the cards and transfer
program information to magnetic tape that was then input to the
large computer. As a further refinement, programs were assigned
priorities, with short jobs being executed first to minimize job
turnaround.
But what about the computer user? As computer utilization
improved, program development took more time. To develop a
new program, a user performed the following procedure. After
writing the program on paper, he carried it to a keypunch operator to have the cards punched and verified. A day or so later,
when the program was returned, the user checked for punching
errors, then returned to the keypunch for corrections.
Next, he sent the cards to the computer center for compilation.
The compilation, which might not be returned for a half day' or
more, could ,reveal spelling or syntactical errors. The cards then
had to be changed and resubmitted-another half day's wait. If
the next compilation was successful and the program was run,
program logic errors -might be discovered-new cards, new compilation, etc., etc. In addition, the user often studied reams of
computer listings to find the errors. Using these inefficient methods, even simple programs might take weeks to develop.
Batch processing maximizes machine efficiency in routine data
processing operations where turnaround is not critical. But .for
program development and modification, the user requires another
mode of operation. The user needs a way to "interact" with the
computer-to feed-his program to the system, line by line, and
continuously check the results.

1-3

interaction

•

In .fact, the user may want to develop interactive programs.
These programs, which are extremely productive toofs, ask the
user questions and perform an analysis based on his answers.
Electronic circuit design programs are a'prime example. The computer actually designs the circuit by asking the engineer questions
and manipulating his answers. In addition, interaction provides a
'new dimension in management information reporting. Via an
interactive terminal, a manager can request summaries, plot trends
in plant operation and sales, and select special data for use in
decision making.

dedicated system ,

timesharing

If the user had unlimited funds, he might be teQIpted to buy or
lease a large computer~a system he could dedicate to his work
that would provide sufficient power, many peripherals, and a large
variety of software. With such a syst~m, the user could develop
programs interactively or utilize batch processing for routine
tasks. However, costs in excess of $20,000 per month normally
preclude the dedication of a large system to a single user,.

By using timesharing, the user has most of the benefits of a
dedicated system at a small fraction of the cost. Timesharing with
today's technology allows a large powerful computer to handle
20, 50, 100 or more users simultaneously. Through a choice of
terminals, the user can interact with the system or initiate batch
proc~ssing which runs .c9ncurrently. The user also has access to
a choice of mass storage and pedpherals and a, selection of languages and application programs. Since response is fast, the user
appears to have a 'dedicated system. Yet costs are shared. He pays
only for the time and facilities that he requires and doesn't pay
for the time the machine is idle.

The Operation of a Timesharing System -

A timesharing system isn't just any computer with some, additional hardware and software. It's a system designed specifically
for timesharing. Otherwise, facilities are limited, fewer us'ers can
be handled efficiently, and economics are unattractive. At 'a, minimum, a timesharing system requires a central processor with
sufficient speed and power, input/output terminals, and an amount
of core memory 'adequate to hold several users. '
time slice
time quantum
round robin operation

In a simple timesharing system, each program is assigned a
fixed time slice or time quantum and operation is switched from
one program to an.other in round robin fashion until each program
is completed. Essentially, if-.each user receives 1/60 of a second
and 12 users are "on" the system, each , user will receive service
every 1/5 of a second. '

1-4

The timesharing system performs multiprogramming; that is,
it allows several programs to reside in core simultaneously and
to operate sequentially. The switching between programs, called
context switching, is initiated by a clock which interrupts the central processor to signal that a certain time period has elapsed. The
interrupt function is provided by a priority interrupt system. A
monitor, also called an operating system or executive program,
directs the execution of these tasks and performs other housekeeping duties.
The monitor is also involved in keeping the actions of a user
within his assigned memory space. A hardware device, a memory
protection register, which is set by the monitor, limits the core
area that a particular user can access. Any attempt by the program to read or change information outside that limit will automatically stop the program and notify the monitor.
The system discussed so ·far services a number of users sequentially in round robin fashion. To increase the number of users
serviced, more main memory or core is required. However, since
core is expensive, a secondary memory is employed. This memory
-usually magnetic disk or drum-is slower than core or main
memory but provides greatly increased capacity at reasonable
cost. User programs can be located in secondary memory and
moved into main memory for execution. Programs entering main
memory exchange places with a program (or programs) that has
just been serviced by the central processor. This operation is called
swapping (see diagram).

MONITOR
USER 1
USER 5
USER 2

SWAPPING
DEVICE

USER 3

USER 4

SWAPPING -

1-5

multiprogramming

context switching , clock
priority interrupt system
monitor, operating system
executive program

memory protection register

main memory
secondary memory

swapping

. memory blocks
input/ output processor

asynchronous design

In· operation, main memory is divided into separate memory
blocks. Secondary memory is connected to these blocks thrQugh
a high speed input/output processol'-a hardware device that allows the disk or drum to· swap a program into anyone of th~
main memory blocks without any aid from the central processor.
This structure allows the central processor to be operating a user
program in one block of memory while .programs are being
swapped to ~d from another block. This independent overlapped
operation, which greatly improves efficiency and processing power,
is characteristic of an asynchronous system design philosophy.
See diagram.
MEMORY STRUCTURE
TO INPUTIOUTPUT
DEVICE

Dynamic Scheduling

compute bound
I/O bound
sc~eduling

algorithm

queue

Round robin scheduling, in which each program operates in
sequence and receives a fixed amount of time, is effective only if·
all programs have similar requirements. Such is not the case, however. At any particular time, a timesharing system will be handling
some programs which require extensive amounts of computing
time (and are said to be compute bound) arid other programs that
must stop frequently for input or output (I/O bound).
.
To serve programs at and between these two extremes, the
scheduling algorithm must provide frequent service to I/O bound
programs and must give compute bound jobs longer time quantums
to prevent wasteful swapping.. A simple dynamic scheme could
provide two queues-one for each type of job. When a user first
logs on to the system, he is placed in ap I/O bound queue (waiting line) where he receives frequent service and small time quantums. If the program isn't completed or does not request input
or output during the time allotted to him, the job needs more
computing time and is placed in the compute bound queue. Thus
the scheduling algorithm optimizes system efficiency by automatically adjusting to program requirements .

. 1-6

In the present state of, scheduling art, algorithms are constantly
being changed and improved. Current algorithms are extremely
sophisticated, providing excellent service for most timesharing job
mixes. They also allow fine tuning, if such modifications are necessary. The ability of the algorithm to match processing to program
requirements .insures the best service possible for all user programs.
In an efficient timesharing system, monitor functions (referred
to as monitor overhead) take 5 to 10 percent of central processor
time, making 90 to 95 percent of the time available to users.

monitor overhead

Sharing Software

Since users of large timesharing systems have varying requirements, a good system provides a wide variety of software-interactive languages such as BASIC and AID for the computations
of the engineer and scientist, FORTRAN for more complex calculations, COBOL for data processing functions. Therefore many
users can have compilers and other common programs in core
at the same time.

MONITOR

FORrRAN
COMPILER 1

FORTRAN
PURE CODE

FORTRAN
COMPILER 2
FORTRAN
COMPILER 3

NON-REENTRANT

REENTRANT

To prevent excessive core usage which results when a program
is duplicated for several users, reentrant software is employed.
That is, the program is written in two parts. One part contains
pure code that is not modified during execution and can be used
to simultaneously service any number of users. For example, the
pure code portion of FORTRAN can service multiple FORTRAN
users. A separate second part of the program belongs strictly to
each user and consists of the code and data that is developed during the compiling process (impure code). This section is stored in
a separate area of core. A comparison of memory usage in the
non-reentrant and reentrant systems is shown in the diagram
above.

'1-7

• reentrant software
pore 'code

impure code

-,-

overlay

dual me!mory protection
and relocation

What are. the benefits of reentrant software? First, less core
is required. For. example, a reentrant system can service three
FORTRAN users with 'one 8K compiler and three2K user areas,
a total of 14K. A non..reentrant system would require 30K for
the three 8K compilers and three 2K user areas. Total saviJlgs in
this case is 16K of core. Using less core means that more programs
c~ fit into a given amount of spaCe. The monitor then swaps less
often and spends less time swapping the smaller impure sections.
There are other savin~ too. Since the pure code never changes,
it doesn't have to be returned to disk storage (swapped out). As
long as a single copy is maintained on the disk, it can be called
into core at any time. Programs can be swapped in or "overlayed"
on top of the compiler to take its place in core whenever
compiler is not needed.
To protect the pure code from being modified, a. hardware
feature is provided-dual memory protection and relocation. This
feature allows a program to execute as two separate segments,
one of which is protected. User programs, can also be written to·
make use of this protection. For example, a user might develop a
reentrant information retrieval system ~tten in COBOL.

the

Communications

~set

modem

data line muitiplexOl'
data Hoe scanner

Co~unication between the remote user and the computer
passes over the conventional dial-up telephone network. User terminals can therefore be located anywhere that phone service is
available and connected to any computer system, feasibility limited only by long distance phone rates.
Each user tenirinal is connected to a data set or modem (modulator-demodulator) which converts us,er terminal output into a
signal suitable for the telephone network. At the computer end of
the phone lines, there is another data set which reconverts the
signal and feeds it to a device called a data line multiplexor or data
line scanner. This 'deviCe, in turn, feeds the information from a
number of. terminals to the central processor (see diagram).

COMMUNICATIONS
1-8

The number of data sets employed at the user end of the system
is unlimited. At the computer end of the communications network, however, the number of data sets is limited by the number
of users that can be serviced simultaneously by the system.
In order to gain access to the system, the user dials the system
phone number from his data set. The telephone network handles
the call, scanning the data sets at the computer system. If all of
the sets are busy, the user receives a busy signal, jllSt as he would
with normal phone service. If a set is available, the telephone net- work rings it, causing the data line scanner to interrupt the 'monitor. The computer answers the call, placing the user in communication with the monitor. The terminal is then on-line and
ready for operation.

on-line

Control of Inpnt/ Output
A timesharing system has performed its basic function if it
allows a number of users simultaneous access to a central computer. However, to be fully useful, the system should also allow the
users access to other system resources-storage devices for his
programs and data, line printers, card readers, etc. For example,
the user should be able to choose between magnetic tape and disk
for program storage. And it" he has a 50-page report to produce,
he should be able to employ a line printer instead of his Teletype@.
'If users controlled these devices, however, much confusion
might result. For example, two users might select the line printer
at the same time. If one user was processing Abraham Lincoln's
Gettysburgh Address and another, Mark Anthony's funeral oration, the report might look like ,the ~ollowing:
I COME TO BURY CAESAR, NOT TO PRAISE HIM
FOUR SCORE AND SEVEN YEARS AGO
THE EVIL THAT MEN DO LIVE AFTER THEM
OUR FATHERS BROUGHT FORTH ON THIS CONTINENT
To prevent users from interfering with each other, the monitor
coordinates input and output (I/O). The processor has an operating mode switch which the ,monitor sets, before a user program is
run. If the program attempts to perform input or output, the user
program is stopped and the monitor takes over. Control thus
diverted to the monitor is called' trapping. When input/output is
, prevented or trapped, the computer is said to be in user mode;
when I/O can be performed, the system is in executive or mQllitor
"~,

_....I...
....,..,.

·.of

®-registered trademark. of Teletype Corporation, Skokie, Illinois

1-9

input/ _tput control '

trapping
DSel'mode

execudve mode
• ill. . . .

When the system is in user mode, _the memory protection
feature is -in operation. In monitor -mode, this feature isoisabled and the monit()r has access to. all of core. User mode also prevents
the usecfrom issuing a HALT command, which could stop op<.
eration of the entire -system.
-

monitor calls
programmed operators

overlapped 1/0

access time

latency optimization

User-to-monitor-mode switching occurs when the user .re

Remember that the CONFIRM message is typed only if there are files on your disk area. If
there are no files on your disk area, the typeout would look like the following:

.:. KJOB )

JOB 17, USER [27,32011 LOGGED OFFTTY17 131720-FEB-70
RUNTIME 0 MIN, 00.29 SEC

2.10

HOW TO LIVE WITH THE TELETYPE

On the Teletype, there is a special key marked CTRL called the Control Key. If ,this key is
held down and a character key.is depressed, the Teletype types what is known as a controf
character rather than the character printed on the key. In this way, more characters can be
used than there are keys on the keyboard. Most of the control characters do not print on the
Teletype, but cause special functions to occur, os described in the following sections.

There are several other special keys that qre recognized by the system. The system constantly
monitors the typed characters and, most of the time, .sends the C?haracters to the program being
executed. The important characters not passed to the program are also explained in the
following sections. (See also the PDP-10 Reference Handbook, Communicating With the
Monitor .)

2. 10.1

Control - C

Control - C (t'e) interrupts the program that is currently running and takes you back to the
monitor. The monitor responds to a control - C by typing a period on your Teletype, and you

2-18,

may then type another monitor command. For example, suppose you are running a program in
BASIC, and you now decide you wanHo leave BASIC and run a program in AID. When BASIC
requests input from your Teletype by typing an asterisk, type control - C to terminate BASIC
and return to the monitor

You may now issue a command to the monitor to initialize AID

(. R AID). If the program is not requesting input from your Teletype (i.e., the program is in
the midd Ie of execution) when you type control - C, the program is not stopped immediately.
In this case, type control - C twice in a row to stop the execution of the program and return
control to the monitor.

If you w ish to continue at the same place that the program was

interrupted, type the monitor command CONTINUE. As an example, suppose you want the
computer to add a million numbers and to print the square root of the sum. Since you are
charged by the amount of processing time your program uses, you want to make sure your
program does not take an unreasonable amount of processing time to run. Therefore, after the
computer has begun execution of your program, type control - C twice to interrupt your
program. You are now communicating with the monitor and may issue the monitor command
TIME to find out how long your program has been running. If you wish to continue your
program, type CONTINUE and the computer begins where it was interrupted.

2.10.2

The RETURN Key

This key causes two operations to be

perfo~med:

(1) a carriage-return and ( 2 ) an automatic

line-feed. This means that the typing element returns to the beginning of the line (carriagereturn) and that the paper is advanced one line (line-feed). Commands to the monitor "are
terminated by depressing this key.

2.10.3

The RUBOUT Key

The RUBOUT key permits correction of typing errors. Depressing this key once causes the last
character typed to be deleted. Depressing the key n times causes the last n characters typed
to be deleted. RUBOUT does not delete characters beyond the previous carriage-return,
line-feed, or altmode. Nor does RUBOUT function if the program has already processed the
characters you wish to delete.

The monitor types the deleted characters, delimited by backslashes. For example, if you were
typing CREATE and go as far as CRAT, you can correct the error by typing two RUBOUTS and
then the correct letters. The typeout wou ~d be

CRAT\TA\EATE

2-19

Notice that you typed only two RUBOUTS, but \TA\ was printed. This shows the deleted .
characters, but in reverse order.
2~ 10.4

Control - U

Contr-ol - U

(t U ) is used

if you have completely mistyped the current line and wish to start

over aga in. Once you type a carriage-return, the command is read by the computer, and
line-editing features can no longer be used on that line. Control - U causes the deletion of
the entire Une, back to the last carriage-return, line-feed, or altmode. The system responds
with a carriage-return, line-feed so you may start again •.

2.10.5

The ALTMODE Key

The ALTMODE key, which is labeled ALTMODE, ESC, or PREFIX, is used as a command
terminator for

~veral

programs, including TECO and LINED. Since the ALTMODE is a non-

printing character,. the Teletype prints an ALTMODE. as a dollar sign ( $ ).

2.10.6

Control - 0

(t 0)

tells the computer to suppress Teletype output. For example, if you

issue a command to type out a 100 lines of text and then decide that you dcr not want the typeout, type control - 0 to stop the output. Anothe.r command may then be typed as if the typeout
had terminated normally.

2.10.7

Control - 8

(t 8)

affects the printing of Teletype output in one of two ways depending on

your Teletype; it either· restores printing of the characters or suppresses double printing of the
characters. Suppose that when you begin typing on the Teletype, you notice that the characters you are typing are not printing on the Teletype paper. Type control - 8 to restore the
printing of the characters. On the other hand, su·ppose you r~ceive double printing of your
typeiilS. To suppress this double printing, type control - ·8.

2.10.8

Control - F

This control character is needed only for the KSR37 Teletype. This key changes the way
lower case characters are handled by the system; Normally, the system converts all lower
case letters to upper case. Since the KSR37 Teletype is capable of transmitting both lower and
upper case letters, control - F is used to permit the entry of lower case letters.

2-20

Book 3
,Conversational
Programming

With
BASIC

•

CONTENTS

CHAPTER

INTRODUCTION

Page

1.1

Example of Basic Program

3-9

1.2

Discussion of the Program

3-10

1.3

Fundamental Concepts of Basic

3-13

1.3.1

Arithmetic Operations

3-13

1.3.2

Mathematical Functions

3-14

1.3.3

Numbers

3-15

1.3.4

Variables

3-15

1.3.5

Relational Symbols

3-15

1.4

Summary

3-16

1.4.1

LET Statement

3-16

1.4.2.

READ and DATA Statements

3-16

1.4.3

PRINT Statement

3-17

1.4.4

GO TO Statement

3-18'

1.4.5

IF - THEN Statement

3-18

1.4.6

ON - GO TO Statement·

3-19

1.4.7

END Statement

3-19

,CHAPTER 2 LOOPS

2.1

FOR and NEXT Statements·

3-22

2.2

Nested Loops

3-23

2.3

Summary

3-23

2.3.1

FOR and N EXT Statements

3-23

CHAPTER 3 LISTS AND TABLES
3.1

The Dimension Statement (DIM)

3-26

3.2

Example

3-27

3.3

Summary

3-28

3.3.1

The DIM Statement

3-28

CHAPTER 4 HOW TO RUN BASIC
4.1

Gaining Access to Basic

3-29

4.2

Entering the Program

3-30

3-3

•

- - - - --.-

•

CONTE~TS

(Coot)
Page

4.3

Executing the Program

3-31

4.4

Correcting the Program

3-31

4.5

Interrupting the Execution of the Program

3-31

4.6

Leaving the Computer

3-32

4.7

Example of Basic Run

3-32

4.8

Errors and Debugg ing

4.8.1

Example of Finding atic! Correcting Errors

3-34
3-34

CHAPTER 5 FUNCTIONS AND SUBROUTINES

5.1

Functions

3-31

5.1.1

The Integer Function (lNT)

3-37

5.1.2

The Random Number Generating Function (RND)

5.1.3

The RANDOMIZE Statement

3-38
,3-39

5.1.4

The Sign Function (SGN)

3-40

5.1.5
5.2 .

The Define User Function (DEF) and Function End Statement (FNEND)

3-40

Subroutines

3-41

5.2.1

GOSUB and RETURN Statements

3-41

5.2.2

Example

3-42

CHAPTER '6 MORE SOPHISTICATED TECHNIQUES
6.1

More About the Print Statement

3-45

6.2

Input Statement

3-48

6.3

Stop Statement

3-49

6.4

Remarks Statement (REM)

3-49

6.5

Restore Statement

3-49·

CHAPTER 7 VECTORS AND MATRICES

7.1

MAT Instruction Conventions

3-52

7.2

MAT C"= ZER, MAT C = CON, MAT C = ION

3-52

7.3

MAT Pril)t A, B, C

3-53

7.4

MAT Input V and the NUM Function

3-54

7.5

MAT B=A

7.6

MAT C = A + Band MAT C = A - B

·3-55

3-4

3-55

CONTENTS (Cont)
Page

=A * B

7.7

MAT C

7.8

MAT C :;: TRN(A)

3-55

7.9

MAT C :;: (K) * A

3-55

7.10

MAT C = INY(A) and the DET Function

3-55

7.11

Examples of Matrix Programs

3-56

7.12

Simulation of N-Dimensional Arrays

3-57

3-55

CHAPTER 8 ALPHANUMERIC INFORMATION (STRINGS)
8.1

Reading and Printing Strings

3-59

8.2

String Conventions

3-60

8.3

Numeric and String Data Blocks

3-61

8.4

Accessing Individua I Characters

3-61

CHAPTER 9 EDIT AND CONTROL

3-65

CHAPTER 10 DATA FILE CAPABILITY

10.1

FI LES Command

3-67

10.2

SCRATCH Command

3-68

10.3

WRITE Command

3-68

10.4

RESTORE Command

3-69

10.5

IN PUT Command

3-69

10.6

I F END Command

3-70 '

3-5

PREFACE

WHY BASIC? BASIC is a problem-solving language that is easy to learn and conversational, and has wide
application in the scientific, business, and educational communities. It can be used to solve both simple and
complex mathematical problems from the user's Teletype@ and is particularly suited for time-sharing.
In writing a computer program, it is necessary to use a language ~r vocabulary that the computer recognizes.
Many computer languages are currently in use, but BASIC is one of t~e simplest of these because of the small
number of clearly understandable and readily learned commands that are required, its easy application in
solving problems, and its practicality in an evolving educational environment.
BASIC is similar to other programming languages in many respects; and is aimed at facilitating communication
between the user and the computer in a time-sharing system. As with most programming languages, BASIC is
divided into two sections:
a.

Elementary statements that the user must know to write simple programs, and

Advanced techniques needed to efficiently organize complicated problems.

As a BASIC user, you type in a computational procedure as a series of numbered statements by

u~ing

comman

English syntax and familiar mathematical notation. You can solve almost any problem by spending an hour or
so learning the necessary elementary commands. After becoming more experienced, you can add the advanced
techniques needed to perform more intricate manipulations and to express your problem more efficiently and
concisely. Once you have entered your statements via the Teletype, simply type in RUN or RUNNH. These
commands initiate the execution of your program and return your results almost instantaneously.

SPECIAL FEATURES OF BASIC - BASIC incorporates the following special features:
a. Matrix Computations - A special set of 13 commands designed exclusively for performing matrix
computations.

h. .A~z::: Inlfm'lll'fatiori Handling - Single alphabetic or alphanumeric strings or vect.on ~n be '
read, printe-d, and defined in LET and If ••• THEN statements. Individual characters within these strings
can be easily accessed by the user. Conversion can be performed between characters and their ASCII
equivalents. Tests can be made for alphabetic order.

@Teletype is the registered trademark of Teletype Corporation.

3-7

c. Program Control and Storage Facilities - Facilities are inc1uded that store programs or data on a
mc,ss storage devic.e (e.g., disk or DECtape) and later retrieve them for execution. You,· as the user,
. can also i'1'ut programs from the standard fow-speed Teletype paper tape reader as well as fromthe highspeed paper tape reader at the PDP-l0 site.
d. Program Editing Facilities - An existing,program can be edited by adding or deleting lines, by renaming the program, or by resequencing the line numbers. The user can combine two programs into a
single program and request a listing of his program, either in whole or in part, on his Teletype or on a
high-speed line printer.
e. Formatting of Output - Controlled formatting of Teletype output includes tabbing, spacing, and
. printing columnar headings.
f •. Documentation and Debugging Aids - Documenting programs by the insertion of remarks within proc~ures enables recglJ of.needed information at some later date and is invaluable in situations in which
the program is shared by other users. Debugging of programs is aided by the typeout of meaningful
~iagnostic messages which pinpoint syntactical and logical errors detected during execution.

3-8

CHAPTER 1
INTRODUCTION

This chapter intraduces the user to PDP-l0 BASIC and to its restrictions and characteristics. The best
, introduction lies in beginning with a BASIC program and discussing each step coftl)letely.

1. 1 EXAMPLE OF A BASIC PROGRAM
The following example is a complete BASIC program, named LINEAR, that can be used to solve a system of two
simultaneous linear equations in two variables
ax+by=c
dx+ey=f
and then used to solve two different systems, each differing from the above system only in the constants c and f.
Ifae - bd is not equal to'O, this system can be solved to find that
ce - bf

= ae - bd

and

af - cd
y=ae-bd

If ae - bd = 0 j there is either no solution or there are many, but there is no unique solution. Study this example
carefully and then read the commentary and explanation.' (In most cases the purpose of each line in the pragram
is

~If-evident.)

1121
15

2121
30

37
42
55
60

65
70
80

85
90

READ A,B,D,E
LET G=A*E-B*D
IF G=eJ THEN 65
READ C,F
LET X=(C*E-B*F)/G
LET Y=CA*F-C*D)/G
PRINT X,Y
GO TO 3121
PRINT "NO UNIQUE SOLUTION"
DATA 1,2,4
DATA 2,-7,5

DATA 1,3,4,-7
END

3-9

" NOTE
All statements are terminated 'by pressing t~' RETURN'
key (represented in this text by the symbol,,) ).•. The
RETURN ~ey echoes as' a carriage return, line feed.
"

1.2 DISCUSSION OF THE PROGRAM
Each line of the program begins with a line number of 1 to 5 digits that serves to identify the line as a statement.
A program is made up of statements, most of which are instructions to the computer. line numbers serve to specify
the order in which these statements are to be performed. 'Before the program is run, BASIC sorts out and edits the
program, putting the statements into the order specified by their line numbers; thus, the program statements
can be typed in any order I as long as each statement is prefixed with a line number indicating its proper
sequence in the order of execution. Each statement starts after its line number Mth an English word which denotes the type of statement. Spaces have no significance in BASIC, except in messages which are printed out,
as in line number 65 above. Thus, spaces mayor may not be used to modify a program and make it more readable.
With this preface, the above example can be followed through step-by-step.

The first statement, 10, is a READ statement and must be accompanied by one or more DATA statements. When
the computer encounters a READ statement wh ile executing a program, it causes the variables I isted after the
READ to be given values according to the next available numbers in the DATA statements. In this example, we
read A in statement 10 and assign the value 1 to it from statement 70 and, similarly, with Band 2, and with

o and 4.

At this point, the available data in statement 70 has been exhausted, but there is more in statement

80, and we pick up from it the value 2 to be assigned to E.

LET G=A*E-B*D

Next, in statement 15, which is a LET statement, a formula ls to be evaluated.

[The asterisk (*) is used to de-

note multip~ication.] In 'this statement, we compute the value of AE - BO, and call the result G. In general,
a LET statement directs the computer to set a variable equal to the formula on the right side of the equal sign.
20

. IF G=0 THEN 65

If G is equal to zero, the system has no unique solution. Therefore, Wf!J next ask, in line 20, If G is equal to
,

zero.

, 3-10

65
70
80
85
90

PRINT "NO UMIQUE SOLUTION."
DATA 1.2.4
DATA 2.-1.5
DATA 1 • 3, Lj, -7
END

If the computer discovers a ''yes'' answer to the question, it is directed to go to line 65, where it prints NO
UNIQUE SOLUTION. Since DATA statements are not executable statements, the computer then goes to line
90 which tells it to END the program.
30

READ C.F

If the answer is "no" to the question "Is G equal to zero?", the computer goes to line 30. The computer is now
directed to read the next two entries, -7 and 5, from the DATA statements (both are in statement 80) and to
assign them to C and F, respectively. The computer is now ready to solve the system
x +2y =-7

4x+2y=5
37

LET X=(C*E-B*F)/G
LET Y=(A*F-C*D)/G

In statements 37 and 42, we instruct the computer to compute the value of X and Y according to the formulas
, provided, using parentheses to indicate that C*E - B*F is calculated before the result is divided by G.
55
60

PRINT X.Y
GO TO 30

The computer prints the two values X and Y in line 55. Having done this, it moves on to line 60 where it is
reverted to line 30. With additional numbers in the DATA statements, the computer is told in line 30 to take
the next one and assign it to C, and the one after that to F. Thus,
x + 2y

4x + 2y =3
As before, it finds the solutions in 37 and 42, prints them out in 55, and then is directed in 60 to revert to 30.
In line 30, the computer reads two more values, 4 and -7, which it finds'in line 85. It then proceeds to solve
the system
x +2y

4x + 2y =-7

3-11

and print out the solutions. Since there are no mOre pairs of numbers in the DATA statement a~ilable for C
and 'F, the computer prints OUT OF DATA IN 30 and stops.
If line number 55 (PRINT X, Y) had been omitted, the computer would have solved the three systems and then
told us when it was out of data. If we had omitted line 20, and G were equal to zero, the computer would
print DIVISION BY ZERO IN 37 and DIVISION BY ZERO IN 42. Had we omitted statement 60 (GO TO 30),
the computer would have solved the first system, printed out the values of X and Y, and then gone to line 65 ,
where it would be directed to print NO UNIQUE SOLUTION.
The particular choice of line numbers is arbitrary as long as the statements are numbered in the order the

machine is to follow. We would normally number the statements 10, 20, 30, ••• , 130, so that later we can
find that we have omitted
two statements between those numbered 40
insert additional statements. Thus, if we
.
.
and 50, we can give them any two numbers between 40 and 50 -- say 44 and 46. Regarding DATA statements,

' .

we need only put the numbers in the Order that we want them read (the first for A, the second for B, the third
for D, the fourth for E, the fifth for C, the sixth for F, the seventh for the next C, etc.). In place of the three
statements numbered 70, 80 , and 85 I we could have written the statement:

or, more naturally I
70
75

80
85

DATA
DATA
DATA
DATA

1 .. 2 .. 4 .. 2
-7 .. 5
1 .. 3
4 .. -7

to indicate that the coefficients appear in the firSt data statement and the various pairs of right-hand constants
appear in the subsequent statements.
The program and the resulting run is shown below as it appears on the Teletype.
10
15

20
30
37
42
55
60

65
70
80

85
90
RUN

READ A .. B .. D.. E
LET G=A*E-B*D
IF G=0 THEN 65
READ C .. F
LET X=(C*E-B*F)/G
LET Y=(A~F-C*D)/G
PRINT X.. Y
.GO TO 30
PRINT "NO UNIQUE SOLUTION"
DATA 1 .. 2 .. 4·
DATt) 2 .. -7 .. 5
.DATA 1-..3 .. 4 .. -7
END

(continued on ,next page)

"
3-12

11 : 0 3

LINEAR

10/19/69

-5.50000
0.166667
3.83333
OUT OF DATA IN 30
4

0.666667
-3.66667

NOTE
Remember to terminate all statements by pressing the
RETURN key.
After typing the program, we type the word RUN, followed by a carriage return to direct the computer to execute the program. Note that the computer, before printing out the answers, printed the name
LINEAR which we gave to the problem (refer to paragraph 4.1) and the time and date of the computation. fhe
message OUT OF DATA IN 30, may be ignored here. However, in some instances, it indicates an error in the
program.

1.3,\ FUNDAMENTAL CONCEPTS OF BASIC
BASIC can perform many operations such as adding, subtracting, multiplying, dividing, extracting square roots,
raising a number to a power, ,and finding the sine of an angle measured in radians.

1.3.1

Arithmetic Operations

The computer performs its primary function (that of computation) by evaluating formulas similar to those used in
standard mather:natical calculation, with the exception that all BASIC formulas !Oust be written on a single line.
Five arithmetic operations can be used to write a formula.

If we type A + B * C

to,

Meaning

Symbol

Example

A+B

add B to A

A-B

subtract B from A

A*B

multiply B by A

A/B

divide A by B

X t 2

find X2

the computer first raises C to the power 0, multiplies this result by B, and then adds

the resulting product to A. We must use parentheses to indicate any other order. For example, if it is the
product of Band C that we want raised to the power 0, we must write A + (B * C) t 0; or if we want to multiply
A + B by C to the power 0, we write (A + B) * C t D. We could add A to B, multiply their sum by C, and raise
the product to the power 0 by writing «A + B) * C)

to.

The order of precedence is summarized in the following

rules.

3-13

The formula inside parentheses is evaluated before'the parenthesized quantity is used in computations •

: b. In the absence or parentheses in a formula, BASIC performs exponentiations first, multiplications
; and divisions second, and additiOns and subtractions third.
~. In the absence of parentheses in a formula involving only multiplications a'nd divisions, BASIC
performs the operations from left,to right, in the ordertliat 'they_are read.

d. In the ,absence of parentheses in a tormula involving only additions and subtractions, BASIC performs the operations from left to right, in the order that they are read.
The rules te II us that the computer, faced with A - B - C, (as usua I) subtracts B from A, and then C from their
difference; faced with

A/B/C,

it divides Aby B, and that quotient by C. Given A t B t C, the computer raises

the number A to the power B and takes the resulting number and raises it to the power C. If there is any question
about the precedence, put in more parentheses to eliminate possible ambiguities.

1.3.2 Mathematical Functions
In addition to these five arithmetic operations, BASIC can evaluate certain mathematical functions. These
functions are given special three-letter English names.

•

Interpretat ion

Function
SIN

(X)

Find the sine of X

COS (X)

Find the cosine of X

TAN (X)

Find the tangent of X

;nte

A>= B

A is greater than or equal to B

A<>B

A is not equal to B

=
<
<=

A
A

A is less than or equal to B
A is greater than B

3-15

1.4 SUMMARY
.,... ,

;::~.;

.' , - :

Several elementary BASIC commands have been introduced in our discussions. In describinr, dClch of these
commands,. a line number is assumed, and brackets are used to denote a general type~ For example, {variablel
; refers to any variable.

1.4. 1

LET Statement

The LET statement is used when computations must be performed. This command is not of algebraic equality,
but a command to the computer to perform the indicated computations and assign the answer to a certain variable.
Each LET statement is of the form:
LET [variab Ie 1 = [formula]
Generally, several variables may be assigned the same value by a single LET statement. Examples of assigning
a value to a single variable are given in. the following two statements:
100
259

LET X=X+1
LET W7=(W-X4t3)*(Z-A/(A-B)-17)

Examples of assigning a value to more than one variable are given in the following statements:
(

LET X=Y3=A(3,1 )=1

The variables X, Y3, and A(3, 1) are assigned
the value 1.
The variables W and Z are assigned the value
3,*X-4X f 2

1.4.2

READ and DATA Statements

READ and DATA statements are u"sed to enter information into the computer. We use a READ statement to assign
to the listed variables th~ values which are obtained from a DATA statement. Neither statement is used without the other. A READ statement causes the variables listed in it to be given in order, the next available num,

bers in the collection of DATA statements. Before the program is run, the computer takes all of the DATA
statements in the order they appear and creates a large

~ta

block. Each time a READ statement is encountered

anywhere in the program, the data block supplies the next available number or numbers. If the data block runs
out of data, the program is assumed to be finished and we get an OUT OF DATA message.
Since we have to read in data before we can work with it,. READ .statements normafly occur near the beginning
....

of a program. The location of DATA statements is arbitrary, as lorig as they occur in the correct order. A
common practice is to collect all DATA statements and place them just before the END statement.

3-16

Each READ statement is of the form:
READ [sequence of variables]
Each DATA statement is of the form:
DATA [sequence of numbers]

150
330
340

READ X,Y,Z,X1 .. Y2,Q9
DATA 4,2,1.7
DATA 6.734E-3 .. -174.321,3.1415927

234
263

READ BCK)
DATA 2,3,5,7,9,11,10,8,6,4

10
440
450

READ RCI, J)
DATA -3,5,-9,2.37,2.9876.-437.234E-5
DATA 2.765, 5.5576. 2.3789E2

Remember that only numbers are put in a DATA statement, and that 15/7 and. SQRT(3) are formulas, not numbers.
Refer to Chapter 3 for a discussion of the subscripted variables.
1 .4.3

PRINT Statement .

The common uses of the PRINT statement are:
a.

to print out the result of some computations

to print out verbatim a message included in the program

a combination of the two

to skip a line.

The following are examples of

100
135

a type a .:

PRINT X,SQR(X)
PRINT X,Y,Z .. B*B-4*A*C .. EXPCA-B)

The first example prints X, and a few spaces to the right, the square root of X. The second prints five
different numbers:

X, Y, Z, 8 -4AC, and e

A-8

The computer computes the two formulas and prints up to five numbers per line in this format.
Thefollowi~ are examples of type b.:

100
430
500

PRINT. "NO UNIQUE SOLUTION~'
PRINT "X VALUE", nSINE", "RESOLUTION"
PRINT X,M, D

3-17

Line tOO prints the sample statement, and line 430 prints the three labels with spaces between them. The labels
in 430,automatically line up with the' thr~e numberS called for in

~RINT stafement 500 ~. "

The following is an example of type c.:
150
3!2J

PRINT -'THE VALUE OF X IS" X
PRiNT "THE SQUARE ROOT OF" X .. "IS" SQR(X)

If the first has computed the value of X to be 3, it prints out: THE VALUE OF X IS 3. If the second has computed the value of X to be 625, it prints out: THE SQUARE ROOT OF 625 IS 25,.
The following is an example of type d.:
250

The computer advances the paper one line when it encounters this command.

t .4.4

GO TO Statement

The GO TO statement is used when we want the computer to unconditionally transfer to some command other
than

th~

next sequential command., In the LINEAR

pro~lem,

we direct the computer to go through the same

process for different values of C and F with a GO TO statement. This statement is in the form of GO TO
[ line number] •
150

1.4.5

GO TO 75

IF - THEN Statement

The IF - THEN statement is used to transfer 'conditionally from the seq\Jential order of commands according to
the truth of some relation. It is sometimes called a conditional GO TO statement. Each IF - THEN statement
is of the form:
IF [formula] [relation} [formula] THEN [line number]
The following are two examp!es of this statement:
40
20.

IF SIN(X)<=M THEN 80
IF G=f2l THEN ,65

If the first <;Isks if the sine of X is less than or equal to M, and skips to line 80 if so. The second asks if G is
equal to 0, and skips to line 65 if so. In each case, if the answer to the question is no, the computer goes
the next line.
3-18

1.4.6

ON - GO TO Statement

The IF - THEN statement allows a two-way fork in a program; the ON - GO TO statement allows a many-way
switch. For example:

This condition causes the following to occur:
If X = 1, the program goes to line 100,
If X = 2, the program goes to line 200,
IfX=3, the program goes to line 150
In other words, any formula may occur in plac.e of X, and the instruction may contain any number of line
numbers, as long as it fits on a _single line. The val ue of the formula is computed and its integer part is taken.
If this is 1, the program transfers to the line whose number is first on the list; if its integer part is 2, the program
transfers to the line whose number is the second one, etc. If the integer part of the formula is below 1, a- larger
than the number of line numbers listed, an erra- message is printed. To increase the similarity between the
ON - GO TO and IF - THEN instructions, the instruction
75

IF X>5 THEN 200

may also be written as:
75

IF X>5 GO TO 200

Conversely, THEN may be used in an ON - GO TO statement.

1.4.7 END Statement
Every p~ogram must have an END statement, and it must be the statement with the highest line number in the
program.
999

END

3-19

I
I
I
I
I

I
I
I
I

I
I
I
I
/

I
I

I
I
I
I
I
I

I
I
I
I

CHAPTER 2

LOOPS

We are frequently interested in writing a program in which one or more portions are executed a number of times,
usually with slight variations each time. To write the simplest prOgram in which the portion of the program to
be repeated is written just once, we use a loop. A loop is a block of instructions that the computer executes
repeatedly until a specified terminal condition is met •.
The programs which use loops can be best illustrated and explained by using two versions of a program for the
simple task of printing out a table of the positive integers 1 through 100 together with the square root of each.
Without a loop, the first program is 101 lines long and reads
113
20
313

PRINT 1, SQR ( 1 )
PRINT 2,SQP..(2)
PRINT 3,SQR(3)

9913
1131313
113 10

PRINT 99,SQR(99)
PRINT 1130;SQR( 1013)
END

....

With the following program example, using one type of loop, we can obtain the same table with far fewer lines
of instructions (5 instead of 101):
10
20
313
~

LET X=1
PRINT X,SQR(X)
LET X=X+1
IF X<=100 THEN 20
END

Statement 10 gives the value of 1 to X and initializes the loop. In line 20, both 1 and its square root are
printed. Then, in line 30, X is increased by 1, to,a value of 2. line 40 asks whether X is less than or equal'
to 100; an affirmative answer directs the computer back to line 20, where it prints 2 and/2 and goes to 30.
Again, X is increased by 1, this time to 3, and at 40 it goes back to 20. This process is repeated -- line 20
(print 3 and

./3), 'Iine 30 (X = 4),

line 40 (since 4

< 100, go back to

line 20), etc. -- until the loop has been

traversed 100 times. Then, after it has printed 100 and its square root, X becomes 101. The computer now
receives a negative answer to the question in line 40 (X is greater than 100, not less than or equal to it), does
not return to 20 but moves on. to line 50, and ends the program. A" loops contain four characteristics: .

3-21

initianzcitiori (line 10)

b., the body (line 20)

2.1

modification (line 30)

an exit test (line 40)

FOR AND NEXT STATEMENTS

BASIC provides two statements to specify a loop: the FOR statement and the NEXT statement.
113
213
313
50

FOR X=l TO 11313
PRINT X,SQR(X)
NEXT X
END

In line 10, X is'set equal to 1, and a test is set up, like that of line 40 above. Line 30 carries out two tasks:
\

X is increased by 1, and the test is carried out to determine whether to go back to 20 or to go on. Thus, lines

•

10 and 30 take the place of lines 10,30, and 4O·in the previous prograrri.
Note that the value of X is

increa~d

by 1 each time BASIC goes through the loop. If we want a different

increase, we could specify it by writing the following:
113

FOR X= 1 -TO 11313 STEP 5

and the computer would assign 1 to X on the first time through the loop, 6 to
third

X on the second time, 11 on the

and 96 on the last time. Another step of 5 would take X beyond 100, allowing thC!' program to proceed

to the end after printing 96 and its square root. The STEP may be positive or negative, and we could have obtained the first table, printed in reverse order, by writing line 10 as follows:
113

FOR X=100 TO 1 STEP-1

In the absence of a STEP instruction,' a step-size of +1 is assumed.
More complicated FOR statements are allowed. The initial value, the final value, and the step-size may all
be formulas of any complexity. For example, if Nand Z have been specified earlier in the program, we could
write the following:
FOR X=N+7*Z TO

(Z-N)/3 STEP

te..

r.~, ~-befere. ShHthtt ~iCKt nms, you ~rt ~ 10"0."",:
RANDOM

5.1.4,

The Sign ~uACtiCln (SGN)

The SGN function is one which assigns .the value , to a~ positiVe number, 0 toze~, and -1 to any negative
number. Thus, SGN (7.23) = 1, SGN (0) =0, and SGN (-.2387) =-Y. For exampte, the fotlowing statement:
,
~

SGN(X)+2 GO TO 1@0,200,300

trol1$fen to 100 if X < 0, to 200 if X =0, and to 300 if X> O.

5.1.5

The Define User Function (DEF) and Function End Statement (FNEND)

In addition to the 14 functions BASIC provides, you may define up to 26 functions of your own with the.DEF
The'name of the defined function must be three letters, the first two of which are FN, e.g., FNA, FNB,'•• _,
FNZ. Each DEF statement introduces a single function. For example I if you repeatedly use the function
e ~X2 + 5, introduce the
30

f~nction by the following:
DEF FNECX)=EXPC-Xt2)+5

_ and call for various values of. the function by'FNE (.1), FNE (3.45), FNE ~A+2),

etc.

This statement saves a

great deal of time when you need values of the function for a nuR,ber of different values of the variable.
The DEF statement may occur anywhere in the program, and the expression to the right of the equal sign may' be
any formula that fits on one lin~. It may include any combination of other functions, such as those defined

b)r

different DEF statements;
it also can involve other variables besides those denoting the argument
of the functi~.
,
I
-

Each defined function may have zero, one, two, or more Variables as in the
10
105
530

DEF FNB(X,Y)=3*X*Y-Yf3
DEF FNC(X,Y,Z,W)=FNB(X,Y)/FNB(Z,WJ
DEF FNA=3.1416*Rf2

3-40

fo"~ing

example:

. In-the definition of FNA"; the current value of R is ~sed when FNA occurs. Similarly, iffNR
the following:
W

DEF

is defined by

•

FNR(X>=SQRC2+LOGCX)-EXP{Y*~>*CX+SIN(2*Z»)

you ~an ask for FNR(2.7), and give new values to Y and Z before the next" use of FNR.
The methcxf of having multiple line PEFs is illustrated by the "max" function shown below. Using this method,
the possibility of using IF ••• THEN as
10
20
30
40
50

part

of the definition is a great help as shown in the following example:;

DEF FNMCX,Y)
LET FNM=X
IF Y<= X THEN 50
LET FNM=Y
FNEND

The absence of the equals sign (=) in line 10 indicates that this is a multiple line DEF. In line SO, FNEND
terminates the definition. The expression FNM, without an argument, serves as a temporary variable for the
computation of the function value. The following example defines N-factorial:
10
20
30
40
50
60

DEF FNFCN>
LET FNF=1
FOR K=l TO N
LET FNF=K*FNF
NEXT K
FNEND

Any variable which is not an argument of FN in a DEF loop has its current value in the program. Multiple
line DEFs may not be nested and there must not be a transfer fram inside the DEF to outside its range, or yice
versa.

5.2

SUBROUTINES

" When you have a procedure that is to be followed in several places in your program, the procedure may be
written as a subroutine. A subroutine is a self-contained program which is incorporated into the main program
at specified points. A subroutine differs from other c .
LET R=X-Q*Y
IF R=0 THEN 300
LET X=Y
LET Y=R
"
GO TO 200

3-42

30f2)
310
320
RUN

LET G=Y
RETURN
END

GCD3NO

13:38

10/20/69

GCD

6(21

90
64872
384

120
98765
72

39456
32

OUT OF DATA IN 20

3-43

CHAPTER 6
MORE SOPHISTICATED TECHNIQUES

The preceding chapters have covered the essential elements of BASIC. At this point, you are in a position to
write BASIC programs and to input these programs to the computer via your Teletype. The commands and techniques discussed so far are sufficient for most programs. This chapter and remaining ones are for a programmer
who wishes to perform more intricate manipulations and to express programs in a more sophisticated manner.

6.1

MORE ABOUT THE PRINT STATEMENT

The PRINT statement permits a greater flexibil,ity for the more advanced programmer who wishes to have a
different format for his output. The Teletype line is divided into 5 zones of 14 spaces each. A comma is a
signal to move to the next print zone or, if the fifth print zone has just been filled, to move to the first print
zone of the next line. If a label (expression in quotes) is followed by a semicolon, the label is printed with no
space after it. If a variable is followed by a semicolon, its value is printed in the following format:
snnn •• n

one space
numeric value

sign: space if positive; - if negative
When you type in the following program:
10

FOR 1=1

20
30
40

PRINT I
NEXT I
END.

TO 15

the TeletyPe prints 1 at 'the beginning of a line, 2 at the beginning of the next line, .and, finaUy, 15 on the
fifteenth line. But, by changing line 20 to read as follows:
20

PRINT I!

3-45

1
6
11

3
8

1
12

.4
9
14

5
10
15

If you want the numben printed in this fashion, but compressed, change line 20 by replacing the comma 'with a
example: ~
semicolon as in the following
.
(

PRINT I;

The following results are printed:
2

A label inside quotation marks is printed as it appears, and the end of a PRINT statement signals a new line,
unless a comma or semicolon is the last symbol. Thus, the follOYiing instruction:
50

PRINT X, Y

prints two numbers and then returns to the next line, while the instruction:
50

PRINT X, Y,

prints these two values and does not return •. The next number to be printed appears in the third zone, after the
values of X and Y in the first two zones.
Since the end of a PRINT statement sigflC!ls a new
250

line,

causes the Teletype to advance the paper one line, to put a blank line for vertical spacing of your res':llts, or
to complete a partially filled line.
50
110
120
130
140
150

FOR M=1 TO N
FOR J=0 TO M
PRINT BCM,J);
NEXT J
PRINT
NEXT M

This program prints B(1,O) and next to it B(1, 1). Without line

140, the Teietype would go on printing 8(2,0),

8(2',1), and B(2,2) on the same line, and. then J(3,.G},. B(3,.1'),. etc. After~. Tef.etype·pr.tftftt'" 1(1 "l) value
corresponding to M = 1, line 1-40 directs it to start a new line; after printing the value'of B(2,2) corresponding
to M =2, line 140 directs it to start anOther new line, §tc.
3-46

The following instructions:
50
51

PRINT "TIME-"; "SHAR"; "ING";
PRINT "ON"; "THE"; "PDP-leI"

cause the printing of the following:
TIME-SHARING ON THE PDP-10

Formatting of output can be controlled even further by use of the function TAB, in the form TAB(n), where n is
the desired print position (0 through 74).
Insertion of TAB(l7) causes the Teletype to move to column 17, as if a 'tab had been set there. For this purpose,
the positions on a ,line are numbered from 0 through 71, and 72 is assumed to be the 0 position on the next line.
More precisely, TAB may contain any formula as its argument. The value of the formula is computed, and its
integer part is taken. This, in tum, is treated modulo 75, to obtain a value from 0 through 74, as indicated
above. The Teletype is then moved forward to this position (unless it has already passed this position, in which
case the TAB is ignored). For example, inserting the following line in a loop
55

PRINT X; TAB(12); Y; TAB(27); Z

causes the X values to start in column 0, the Y vCllues in column 12, and the Z values in column 27.
The following rules are used to interpret the printed results:
a. If a number is an integer, the decimal point is not printed. If the integer contains more than eight
digits, it is printed in the format as fotlows.

L
nl'~i-

E (Exponent) followed by p (power of 10)

next five digits
first digit
For example, 32,437,580,259 is written as 3.24376E+10
b.

For any dpcimal number, no more than six significant digits are printed.

c. For a number less than 0.1, the E notation is used, unless the entire significant part of the number
can be' printed as a 6-digit decimal number. Thus, 0.03456 indicates that the number is exactly
.0345600000, while 3.45600E-2 indicates that the number has been rounded to .0345600.
d.

Trailing zeros after the decimal point are not printed.

3-47

Ie
20
30

FOR N=-5 TO,3121
PRINT 2fN;
NEXT N

4?l

END

RUN

PO WERS

11 : 54

1121/2121/69

3. 125121I21E-2 6.25121121121~-2 121.125 121.25 121.5 1 2 4 8 16 32 64 128
256·512 112124 212148 412196 8192 16384 32768 65536 13112172 262144
~4288 112148576
212197152 419431214 838861218
16777216 33553332
6711218864 1.34218 E+8 2.68435 E+8 5.36871 E+8 1.1217374 E+9

6.2

INPUT STATEMENT

At times, during the running of a program, it is desirable to have data entered. This i~ particularly true when
one person writes the program and saves it on the storage device as a Iibrary program (refer to SAVE command,
Chapter. 9), and other persOns use the program and suppy their own data.
-

Data may be entered by an INPUT

statement, which acts as a READ but accepts numbe~ of alphanumeric data from the Teletype keyboard. For
example, to supply values for X and Y into a program, type the follCNiing:
40

INPUT X, Y

prior to the first statement which.uses either of these numbers. When BASIC encounters this statement, it types
,a question mark. The user types

two numbers, separated by a comma, and presses the RETURN key, and BASIC

continues the program. No number can be I~nger than 8 digits.

Frequently, an INPUT statement is combined with a PRINT statement to make sure that the user knCNis what the
question mark'is asking for. You might type in the follCNii~ statement:
2121
30

PRINT "YOUR VALUES OF X,Y, AND Z ARE";
INPUT X,Y,Z

and BASIC types out'the following:
YOUR VALUES OF X,Y, AND Z ARE?

Without the semicolon cit the end of line 20, the question mark would have been printed on the !"8xt line.
Data entered via an INPUT statement is not saved with the program. Therefore, INPUT should be used only
~hen

small amounts of data are'to be entered, or when necessary during the running of the program.

3-48

6.3

STOP STATEMENT

STOP is equivalent to GOTO xxxxx, where xxxxx is the line number of the END statement in the program. For
example, the following two program portions are exactly equivalent:

6.4

250

GO TO 999

250

STOP

340

GO TO 999.

340

STOP

999

END

999

END

REMARKS STATEMENT (REM)

REM provides a means for inserting explanatory remarks in the program. BASIC completely ignores the remainder
of that line, allowing you to follow the REM with directions for using the program, with identifications of !he
parts of a long program, or with any other information. Although what follows REM is ignored, its line number
may be used in a GOTO or IF-THEN statement as in the following:

200

REM
REM
REM
REM

300

RETURN

520

GOSUB 200

100

110
120

INSERT IN LINES 900-998. THE FIRST
NUMBER IS N, THE NUMBER OF POINTS.
THEN
THE DATA POINTS THEMSELVES ARE ENTERED, BY
THIS IS A SUBROUTINE FOR SOLVING EQUATIONS

A second method for adding comments to a prpgram consists of placing an apostrophe ( I) at the end of the line;
and following it by a remark. Everything following the

is ignored except when the line ends in a string (refer

to Chapter 8).

6.5

RESTORE STATEMENT

The RESTORE statement permits READing the data in the DATA statements of a program more than once. When.

ever RESTORE is encountered in a program, BASIC restores the data block pointer to the first number. A subsequent READ statement then starts reading the data all over again. However, if the desired data is preceded by
code numbers or parameters, superfluous READ statements should be used to pass over these numbers. As an
example, the following program p~ion reads the data, restores the data block to its original state, and reads
the data again. Note the use of line 570 (READ X) to pass over the value of N, which is already known.
100
110
120

READ N
FOR I =1 TO N
READ X

.......

.
3-49

200

NEXT1

560
570
580
590

RESTORE
READ X
FOR 1=1 TO N
READ X

700
710

DATA •••••
DATA •••••

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

3-50

CHAPTER 7
VECTORS AND MATRICES

Operations on lists and tables occur frequently; therefore, a special set of 13 instructions for matrix computations,
all of which are identified by the starting word MAT, is used. These instructions are not necessary and can be
replaced by combinations of other BASIC instructions, but use of the MAT instructions results in shorter programs
that run much faster.
The MAT instructions are as follows:
MAT READ a, b, c

Read the three matrices, their dimensions
having been previously specified.

MAT c '" ZER

Fill out c with zeros.

MATc =CON

Fill out c with ones.

MATc=IDN

Set up c as an identity matrix.

MAT PRINT a, b, c

Print the three matrices. (Semicolons can be
used immediately following any matrix which
you wish to have printed in a closely packed
format.)

MAT INPUT v

Call for the input of a vector.

MAT b =a

Set the matrix b equal to the matrix a.

MATc=a+b

Add the two matrices a and b.

MAT c = a - b

Subtract the matrix b from the matrix a.

MAT c = a

MA T c = TRN(a)
MAT c = (k)

MAT c = INV (a)

Multiply the matrix a by the matrix b.
Transpose the matrix a.
Multiply the matrix a by the number k. The
number, which must be in a parentheses, may
also be given by a formula.
Invert the matrix a.

3-51

7.1

MAT INSTRUCTION CONVENITONS

The following convention has been odopted for MAT instru~ions: while every vector has ~ cOmponent 0, and
every matrix has a rON 0 and a column 0,- the MAT instNctions ignore these. Thus, if we have a matrix of
dimension M-by-N in a MAT instNction, the rows are numbered 1,2, '••• , M, and the columns I, 2, ••• , N.
The DIM statement may simply indicate what the maximum dimension is to be. Thus, if we write the foliONing:
DIM M(20 .. 35)

Mmay have up to 20 rows and up to 35 columns. This statement is written to reserve enough space for the
matrix; consequently, the only concern at this point is that the dimensions declared are large enough to accommodate the matrix. HONever, in the absence of DIM sTarements, all vectors may have up to 10 components and
matrices uP.to 10 rows and 10 columns. This is to say that in the absence of DIM "statements, this much space
is automatically reserved for vectors and matrices on their appearance in the program. The actual dimension
I

of a matrix may be determined either when it is first set up (by a DIM statement)

or when it is computed.

the following

reads

DIM M(20 .. 7)

MAT READ M

a 20-by-7 matrix for M, while the following:
50

MAT READ M( 17 .. 30)

reads a 17-by-30 matrix for M, provided sufficient space has been saved for it by writing
10

7.2

DIM M(2eJ .. 35)

MAT C = ZER, MAT C = CON, MAT C

= ION

The following three instNctions:
MAT M= ZER
MAT M= CON
MAT M= ION

(sets up matrix M with all components equal to zero)
(sets up matrix M with all components equal to one)

32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

A
B
C
D
E
F
G
H
I
J
K
L
M
N
0

P
Q

R
S
T
U
V

W
,X
Y
Z
[

]
t

...

Additional symbols useful on output..are as follows:
LF (I i ne feed)
CR (carriage return)

10
13

The above list is not complete; there are 128 characters numbered 0 through 127.

3-62

64
65
66
67
68
69
70
71
72

73
74
75
76
77

78
79
80
81
82
83
84
85
86
87
88
89
90
91'
92
93
94
95

The other use of CHANGE is. illustrated by the following:
1121
15
2121
25
3I2J

35
LtlJ

FOR 1=121 TO 5
READ ACI)
NEXT I
DATA 5,65,66,67,68,69
CHANGE A TO A$
PRINT A$
END

This program prints ABCDE because the numbers 65 through 69 are the code numbers for A through E.
Before CHANGE is used in the vector-to-string direction, we must give the number of characters which are to be
in the string as the zero component of the vector. In line 15,A(O) is read as 5. The following is a final example:
5
1121
2121
3I2J
~

5I2J
6I2J
7I2J
RUN

EXAMPLE

DIM V(128)
PRINT "WHAT DO YOU WANT THE VECTOR V TO BE".;
MAT INPUT V
LET V(I2I)=NUM
CHANGE V TO A$
PRINT A$
GO TO 1121
END
13: 59

1121/2121/69

WHAT DO YOU WANT THE VECTOR V TO BE? 4121.32,45,6121,45,89,9121
(-<-YZ
WHAT DO YOU WANT THE VECTOR V TO BE? 32,33,34,35,36,37,38,39,4121,41,42,&
? 43,44,45,46,47,48,49,5121
!"#$%&' ()*+, -./12112
~HAT DO YOU WANT THE VECTOR V TO BE? 4

Note that in this example we have used the availability of the function NUM after a MAT INPUT to find the
number of characters in the string which is to result from line 40. Giving the input "4" on the last request
obtains the response EOT (end of transmission), which turns off the Teletype.

3-63

CHAPTER 9

EDIT AND, CONTROL

Several commands for editing BASIC programs and for controlling their execution enable you, for example, to:
a.

delete lines

list the program

change or resequence I ine numbers with set increments

save programs on a file-structured storage device (disk or DECtape)

replace old programs on the storage device wi th new programs

call in programs from the storage device.

These commands are summarized as follows:
Command

Action

DELETE n

Delete line number n and the contents of the line from user core.

DELETE n,m

De lete line numbers n through m from user core.

LENGTH

Print length of source program {expressed as the number of characters}.

LIST

List program with heading.

LIST n

List program with heading, beginning at line number n.

LIST n,m

List program with heading, from line number n through m.

LISTNH
}
LISTNH n
LISTNH n,m

Same as LIST, but with heading suppressed.

NEW

BASIC asks for new program name and checks to make certain that it
does not already exist.

OLD

BASIC asks for program name and replaces current contents of user core
with existing program of that name from the storage device.

RENAME filename

Change name of program currently in user core.

REPLACE

Replace old fi Ie of current name with contents of user core. '

RUN

Compile and run program currently in core.

RUNNH

Same as RUN, but with heading suppressed.

3-65

Action

Command

SAVE

Save the contents of user core as file whose filename is current program,
name and whose extension is • BAst.

SAVE filename

Save user cor~ as filename • BAst •

SCRATCH

Delete all program statements from user core.

RESEQUENCE n

Change line numbers to n, n +-10, ••••

RESEQUENCE nllk

Change line l1u",bers to n, n + k, ••••
Commas are necessary as argument delimiters.

RESEQUENCE n, f, k

Change line numbers from line f upward to n, n + k, ••••
f must not be greater than n.
.

SYSTEM

Exit to Monitor.

WEAVE filename

Read program statements from the file named filename. BAS
(existing statements in user core are replaced by new statements
having same Ii.,e numbers).

To stop a running program and enter Monitor level, type tC twice.

To suppress output (typeout), type

t SAVE commands do not overwrite an existing file of the same
3-66

to.

name (use REPLACE instead).

CHAPTER 10
DATA FILE CAPABILITY

The data file capability allows information to be written onto the disk for immediate or semipermanent storage.
The user can save this information until the disk is refreshed, or he can utilize PIP (Peripheral Interchange
Program) to save it permanently on DECtape or paper tape.
With each BASIC program, a user can save up to nine files, each with a different filename. The filename is
assigned by the user and must follow the filename rules described in Chapter 4. The extension is assigned by
the BASIC compiler and is set to .BAS. (All BASIC files~have this extension.) The current date and time are
placed into the file directory along with the project-p.rogrammer numbers. The file protection key is set to the
standard protection when the file is !=reated, indicating protection-protection and write-protection against all
users except the owner of the file.

10.1

FILES COMMAND

The FILES command specifies what files are to be read or written. The command format appears as follows:
FilES name 1 , name2, .. :, name9
where name 1, name2, •.. , name9 are filenames. The filenames may be separated by commas or semicolons.
This command may come after any executable command, but must precede any command that is associated with
creating a new file or referencing an old file.
I/O channels ~re assign~d consecutively, starting with channell, to the files. The names are positional, where
name 1 corresponds to software channell, name2 to software channe I 2, and so forth, up to name9 to software
channel 9. Since the filenames are positional, commas must precede filenames that are not sequentially ordered,
for example:

indicates that input or output is desired on channel 3 (filename S), channel 5 (fi lename R), and channel 6
(fi lename T).

3-67

Files are in either read or write mode ahd are assumed fo be initially in ~ad1Ylode_ -An error message is given
,
if an attempr is made to read a file which does not exist or to read a file which is being written _ Examples of
. the FILES command are as follows:
FILES
FILES
FILES

AAA

X, V,Z
.D,F

10.2 SCRATCH COMMAND
The SCRATCH command opens a file for writing_ More than one channel may be referenced. The command
format is as follows:

,
(

SCRATCH

1M I IN I Ipor

SCRATCH

1M, N,P

where M, N, and P are channel specifiers. The I must precede the first channel specifier, but need not be
duplicated for subsequent channel specifiers in the same command. This command must be used prior to. the
writing of

afile.

Examples of the SCRATCH command are-as follows:

SCRATCH
SCRATCH
SCRATCH

10.3 WRITE COMMAND
The WRITE cOrRmand causes data to be output to the disk on the specified channel. The data may be an area
of storage previously dimensioned, or any information appearing in a PRINT statement _ The format of I/O to
the disk is the same as the format to the Teletype. The command format is as follows:
WRITE

IN, (sequence of variables)

where N is a channel specifier. When writing a file, BASIC inserts line numbers, startfng with 10 and incrementing by 10. After each line number, BASIC inserts the letter 0 to separate the line nvmber from the data.
When reading a file, BASIC recognizes the-nondigit character (D) following the line numbers, and ignores it~
Examples of the WRITE command are as follows:
WRITE
WRITE

3-68

The following is an example of the storage of the sines of 1-10 radians in file RRR:
10

20
30
40
50
60

70
80

10.4

DIM ACl0)
F1j-ES RRR
SCRATCH # 1
FOR 1=1 TO 10
A(!)=SIN(1)
WR I T E # 1 , A ( 1 )
NEXT I
END

RESTORE COMMAND

The RESTORE command opens a file for reading. More than one channel may be referenced. The command format is as follows:
RESTORE

#M, #N, #p or

RESTORE

#M,N,P

where M, N, and P are channel specifiers. The main use of the RESTORE command is to reread a file or read
a file that has just been written. If the first function in the program is to read an already existing file, the
command is not necessary. In other words, if a different program created the files, then a new program does
not need the RESTORE command in order to read the files; this is because files are initially in read mode.·
Examples of the RESTORE command are as follows:
RESTORE
RESTORE

10.5

INPUT COMMAND

The INPUT command causes data to be input from the disk on the specified channel into the specified area.
Each command can reference only one channel and, therefore, only one file. The command format is as follows:
INPUT

# N, (sequence of variables)

where N is a channel specifier. The READ and INPUT commands are equivalent when data files are read from
the disk, and the PRINT and WRITE commands are equivalent when data files are written on the disk.
of the I NPUT command are as follows:
INPUT
INPUT
INPUT

#2, A(i)

#6, Z$
#3, B(K)

3-69

Examples

The foHoWing example demonstrates-access to previously stored~atues in the file RRR:
10

DIM 1:1.(10)

2QJ
30

FILES RRR
FOR 1=1 TO 1 Ql
I NPUT If 1 , A CI )
PRINT ACI)
NEXT I
END'

4121
50

6I2l
70

RUNN H

121-841411
0.909297
0.14112
-0.756802
-0.958924
-0 .21941 6
0.656981
0.989358
0.412119
-0.544021

10.6' IF END COMMAND
This command provides control in a program when an End-of-File is detected during input from the disk. The
command fonnat is as follows:

, {THEN} •
IF END N GO TO (lme number)
where N is a channel specifier. The line number must follow the rules discussed in Chapter 1. Either THEN or
GO TO is acceptable. Examples of the IF END command are as follows:
IF END '1 GO TO 160
IF END '4 THEN 435

3-70

APPENDIX A
SUMMARY OF BASIC STATEMENTS

A.l

ELEMENTARY BASIC STATEMENTS

The following subset of the BASIC command repertoire includes the most commonly used commands and is
sufficient for solving most problems.
DATA [data list]
READ [sequence of variables]

DATA statements are used to supply one or more
numbers or alphanumeric strings to be accessed by READ
statements. READ statements, in tum, assign the next
available data in the DATA string to the variables
listed. Numeric and alphanumeric data are kept in
separate tables and must be accessed by separate READ
statements; however, they both may be entered in the
same DATA statement.

PRINT [arguments]

Types the values of the specified arguments which may
be variables, text, or format control characters.

LET [variable] = [formula]

Assigns the value of the formula to the specified
variable.
.

GO TO [line number]

Transfers control to the line number specified and
continues execution from that point.

IF [formula] [relation] [formula]

If the stated relationship is true, then transfers control
to the line number specified; if not, continues in
sequence.

[lirie number]
{ THEN
GOTOj
FOR [variable] = [formula] ] TO
[formula 2] STEP [formura3]
NEXT [variable]

Used for looping repetitively through a series of steps.
The FOR statement initializes the variable to the value
of formulal and then performs the following steps until
the NEXT statement is encountered. The NEXT statement increments the variable ny the va.lua of fo,mul~.
(If omitted, the increment YUlue it.ossumed,to·be + 1 :)
The resultant value is then compared to the value of
formula2. If variable OR
. The line is ignored.

OUT OF ROOM

Can't get more core to make room for:
a. More compilation space.
b. Maximum space for all the vectors and arrays.
c. Space to store another string during execution.

TOO MANY FILES

A maximum of nine files may be read or written in a
progrom.

ILLEGAL DSK READ IN LINE N

File was never accessed for reading.

FILE NEVER ESTABLISHED-REFERENCED
IN LINE N

File was not referenced in a FILES command.

FILE NOT FOUND BY RESTORE COMMAND
IN LINE N

File was never written.

ILLEGAL DSK WRITE IN LINE N

File was not opened for writing.

FAILURE ON ENTRY IN LINE N

Channel is not available for SCRATCH command.

EOF IN LINE N

An attempt was made to read data from a file after all
data had been read.

BAD DATA INTO LINE N

Input data is not in correct form.
Execution mors

Message

bcplanation

SUBROUTINE OR FUNCTION CALLS ITSELF
IN NN

FNA is defined in terms of FNB which is defined in
terms of FNA, or a similar situation with FUNCTIONS
or GOSUBS.

ON EVALUATED OUT OF RANGE IN NN

The value of the ON index was the number of
branches.

OVERFLOW IN NN
UNDERFLOW IN NN
DIVISION BY ZERO IN NN

These all work according to specifications whenever
the APRENB UUO is implemented.

RETURN BEFORE GOSUB IN NN
NOT ENOUGH INPUT--ADD MORE
INPUT DATA NOT IN CORRECT FORM-RETYPE LINE
OUT OF DATA IN NN
TOO MANY ELEMENTS--RETYPE LINE

3-77

Execution Errors (Cont)
Explanation

Message
IMPOSSIBLE VECTOR LENGTH IN NN

In a CHANGE (to string) statement, the zeroth element
of the number vector was negative or exceeded its
maximum dimension.

NON-ASCII CHAR SEEN IN NN

In a change operation of the same kind, one of the other
elements of the number vector was negative or exceeded
octal 177.

NO ROOM FOR STRING IN NN

In a CHANGE A$ TO A I the number of characters in A$
exceeds the maximum size of A.

LOG OF NEGATIVE NUMBER IN NN
SQRT OF NEGATIVE NUMBER IN NN
TAN OF Pl/2 OR COTAN OF ZERO IN NN
EXP TOO LARGE IN NN
ZERO TO A NEGATIVE POWER IN NN
ABSOLUTE VALUE RAISED TO POWER IN NN
DIMENSION ERROR IN NN
LOG OF ZERO IN NN

•

3-78

Book 4
Conversational
Programming
With AID .

CONTENTS
CHAPTER 1
INTRODUCTION

1.1

Gaining Access to the AI D System

4-9

1.2

Terminating AID

4-9

1.3

AI D La "guage

4-10

1.3.1

Rules of Form

4-11

1.3.2

Arithmetic Accuracy and Notations

4-11

1.4

Teletype Consoles

4-12

1.5

Correction of Typing Errors

4-13

CHAPTER 2
STEPS AND PARTS

2.1

Direct Steps

4-15

2.2

Indirect Steps

4-15

2.3

Parts

4-15

CHAPTER 3
IDENTIFIERS ARIABLES}

3.1

Defining an Identifier by a Value (SET and DEMAND Commands)

4-17

3.2

Defining Identifiers by Formulas (LET Command)

4-19

3.2.1

Arithmetic Formulas

4-19

3.2.2

Boolean Expressions (Propositions) Defined by the LET Command

4-20

3.2.3

User Functions Defined by the LET Command

4-20

3.3

Identifier References

4-20

3.4

Indexed Identifiers (Arrays)

4-21

CHAPTER 4
ARITHMETIC OPERATORS, FUNCTIONS, PROPOSITIONS and ITERATIONS

4.1

Arithmetic Operators

4-23

4.2

AID Functions

4-25

4.3

User-Defined Functions

4-29

4.3.1

Examples of User-Defined Functions

4-30

4.4

Propositions

4-31

4.4.1

Conditional Expressions

4-32

4-3

CONTENTS (continued)

4.5

Iterative S:;lauses (Ranges)

4-34

4.5.1

Series of Values

4-34

4.5.2

Incrementation

4-34

4.5.3

Combinations

4-34
CHAPTER 5
AID VERBS

5.1

4-37

CANCEL

Parenthetical CANCEL (CANCEL)

4-37
4-37 .

Diagnostic Messages

4-38

Description

5.2

DELETE

4-39
4-39

Description

5.3

5.4

5.5

4-41

DEMAND
Description

4-41

DEMAND ••••. AS "Any Text" Option

4-41
4-45

DISCARD
Description

4-45

Diagnostic Messages

4-45
4-46

DO
Description

4-46

TIMES Option

4-46

Range Option (FOR Clause)

4-46

IF Clause

4-48

Parenthetical DO (DO .•.••. )

4-48

Diagnostic Messages

4-50
4-51

DONE

5.7

5.8

Description

4-51

Diagnostic Messages

4-52

FILE

4-53
Description

4-53

Diagnostic Messages

4-53

FORM

4-54
4-54

Description

4-4

CONTENTS (continued)
5.8 (cont)

SPfJ!cific Notations

4-54

Multiple Results on a Single Line
/

5.9

5.10

4-55

Report-Type Headings

4-56

Diagnostic Messages

4-56

4-57
Description

4-57

Diagnostic Messages

4-58

IF Clause

4-59
4-59

Description
5.11

5.12

LET

4-60
Description

4-60

Arithmetic Formulas

4-60

Boolean Expressions (Propositions)

4-60

User Functions

4-.60

LINE

4-62
4-62

Description
5.13

4-63

PAGE

4-63

Description
5.14

4-64

QUIT
Description

5:15

5.16

4-64

RECALL

4-65

Description

4-65

Diagnostic Messages

4-65

RESET TIMER

4-66

Description
5.17

4-66

SET

4-67
Description

5.18

4-67
4-68

STOP
Description

5.19

4-55

Interspersing Text with Results

4-68
4-69

TO
,

Description

4-69
4-70

Diagnostic Messages

4-5

CONTENTS (continued)
5.20

5.21

TYPE

4-71

Description

4-71

Combined TYPE Commands

4-71

I N FORM Option

4-71
4-75

USE
Description

4-75

Diagnostic Messages

4-75

APPENDIX A
TABLES
A-1

A Glossary of AID Terms

4-78

A-2A

AID Command Summary

4-80

A-2B

Fi Ie Command Subset

4-84

A-3

AID Character Set

4-85

A-4

AID Diagnostic Messages

4-87

TABLES
4-1

AID Arithmetic Operators

4-23

4-2

AID Functions

4-26

4-6

PREFACE
AID (for Algebraic Interpretive Dialogue) is a PDP-10 adaptation of language elements of
JOSS 1 , the well -known computing service program developed by The RAND Corporation under contract to the Uni ted States Ai r Force.
The system is designed to assist scientists and engineers in solving complex numerical problems. The language is direct and relatively easy to learn. No previous programming experience is
needed, either to understand this manual or to use AID at a Teletype console. Commands are typed in
the form of imperative English sentences and mathematical expressions are typed, for the most part, in
standard notation.
Digital Equipment Corporation is grateful to The RAND Corporation for permission to adapt
the language processors of JOSS for the PDP-l o. We also wish to express our appreciation to the programmers and computer scientists who developed the system, and to The RAND Corporation and
E. P. Gimble of the Air Force's Sacramento Air Materiel Area for the use of RAND publications in the
preparation of this AID manual.

1 JOSS is the trademark and service mark of The RAND Corporation for its computer program and
servi ces usi ng that program.

4-7

•

CHAPTER 1
INTRODUCTION

AID is available on all PDP-10 systems and provides each user with a personal computing
service, interacting with the user and responding to commands expressed in a simple language via the
user's Teletype. AID has proven to be easy and convenient to use in solving both simple and complex
numerical problems.
AID is device independent. It provides the user with a facility to create external files for
storage of subroutines and data for subsequent recall and use. For ac~essibi lity and speed, such fi les
are normally stored on directory devices such as disk or DECtape; however, files may be stored on any
retrievable medium such as magnetic tape.
AID runs in approximately 11 K of core memory (with 1K of user data area) and expands to
14K of core (with 4K of user data area) as required. Note that AID will not run on a 16K machine if
Iv\onitor occupies more than 5K of core.
1.1

GAINING ACCESS TO THE AID SYSTEM
To gain access to AID, the user must first gain access to the Monitor. In the case of all but

the disk monitors, this is accomplished simply by typing

C (hold down the CTRl key while striking

C). In the case of the PDP-I0/50 Monitor, the user must log in (see either the Time-Sharing Monitors:
10/40, 10/50 manual or the PDP-I0 System Users Guide, found in the PDP-I0 Reference Handbook,
order code AIW.
When access to the Monitor is gained, and the Monitor has responded with a period (.), the
user types
.R AIDJ
When AID is loaded into core, it responds with the message
AID (revision date) AT YOUR SERVICE. ••

*
The asterisk (*) indicates that AID is ready to accept a command from the user.

1 .2

TERMINATING AID
AID is terminated and control is returned to Monitor level by typing

l' C J

(hold down the CTRl key and strike C)

4-q

AID can then be re-entered by typing
.CONTJ 1
or killed by either typing

,.KJOBJ
or running another program.
1.3

AID LANGUAGE
Table A-2 contains all AID commands and fUllctions. Each command occupies a single line

and is terminated by a carriage return. A period at the end of a command is optional. A command can
be entered as a direct command (to be executed immediately) or as an indirect command (to be stored for
later execution). Variables in commands are represented by single alpltlabetic letters, A through Z and
a through z, called identifiers. Entire routines can be stored as a series of indirect commands to be
executed in a"specific order. An expression is defined as one number or identifier (or a combination of
numbers and/or identifiers and/or AID functions) which is reducible to a number when AID is called upon
to use it. The standard mathematical Qp-erators can be expressed in AID as follows:

[

(

)

absolute value (equivalent·to.the mathematical symbol
2
brackets
2
parentheses

II ) _

addition
subtraction

· I'Icahon
. 3
mu ItiP

division'

exponentiation4

(x 3

=x~3)

The order of precedence for these operations is conventional:

!, [

] , and (

) from the innermost pair to the outermost pair

* (multiplication) and / (division) from left to right within each term

+ (addition) and - (subtraction).

(exp~nentiation)

1If AID was performing an iterative process when interrupted by the
proceeds .automatically following the CONT command to Monitor.

~reviously

typed

tc, execution

If it is desired to have AID halt before continuing, type, RE-ENTER instead of CONT. In this case,
AID wil,l execute the next step of the interrupted process, type the message "I'M AT STEP m.n" and
halt. To continue, type GO.

2~rackets and parentheses can be used interchangeably in pairs.
3The ampersand (&) will perform multiplication also, ho'wever when returning the result, AID will type
an asterisk (*) in place of the ampersand.
.

N key with SHIFT on Teletype Models 33
4The tip arrow for exponentiation is typed by striking the
and 35. On Teletype Model 37 strike the """, 1\ without SHIFT. In either case do not use the CTRL key
for exponentiation.

4-10

Examples:
a/3*c

(~)c not

x/y,3

-x
y

a
3c

not

(Ieft-to-right rule)

(order of precedence)

( ;)3

Boolean expressions composed of arithmetic statements using the operators
= (equal to), # (f not equal to),
>= (2:greater than or equal to),

(~ less than or equal to),

< (I~ss than), > (greater than).

and the negation
not
and connected in turn by logical operators
and, or (inclusive)
are handled by AID.

1 .3.1

Rules of Form
a.

Only one step (command) can be typed per line and only one line can be used for each

Each step begins with a verb and terminates with a carriage return. A period at the end

step.
of a step is optional.
c.

Words, variables (identifiers), and numerals can neither abut each other nor contain em-

bedded spaces; spaces cannot appear between an identifier (when it appears in an array, a formula, or
. a function) and its associated grouped operators and arguments. Otherwise, spaces can be used freely.
d.
typing

When operating via the Teletype Model 37 in upper and lower case mode (entered by

- CTRL F), the initial letter of the first word of each command may be typed in upper case.

All other letters within the command must be in lower case (with the exception of letters in a character
string enclosed by quotation marks, or in the case of identifiers of the range A through Z).
Examples:

1.3.2

Step Number
(indirect)

Verb

Arguments

Modifiers

1) *1.23

Type

a, a+2, at3

in form 1 if a>O.J

2) *1.4

part 2

for c = 5(lO)100.~

Arithmetic Accuracy and Notations
All results are rounded to the nine most significant digits.

All results with a value of less than 10 and equal to or greater, than .001 are typed by AID
in fixed point notation.

4-11

Examples:
a)

~Type 1/3+2 J
1/3+2

b) • *Type 100**3 J
100**3
c)
d)

*Type 1/4*1 J
1/4*1

=
=
=

'«Type cos (2 .5)J
cos (2 .5) =

2.33333333
1 *10t6
.25
-.801143616

All other results are typed in scientific notation.
Examples:
a)

1.4

*Type
365*24*60*60J
• 365*24*60*60 =
*Type (.0005)* (17)*(.01)J
(.0005)* (17)*(.01) =

3.1536*10t7

(Read as 3.1536 times 10 raised
to the 7th power)

8.5*10t(-5)

(Read as 8.5 times 10 raised to
the minus 5th power)

TELETYPE CONSOLES
A Teletype console is the link between the user and AID. A PDP-10 system may be equipped

with anyone of three Teletype models, /IAodel 33, Model 35, or /IAodel 37. The essential difference
between /IAodel 37 and Models 33 and 35 is that Model 37 has both upper and lower case letters 1 (with
special characters occupying other keys), while Models 33 and 35 have upper case letters only (typed

without use of the SHIFT key - some of the special characters occupy what are normally the upper case
positions on the letter keys)2 •
1l!'"

Command examples shown in this publication use both upper and lower case letters (rules
governing capitalization are similar to those of the English language, the initial letter of the first word
of a command is capitalized). Thus, commands can be typed on the ,/IAodel 37 exactty as shown on the
following pages, while only upper case characters can be typed on Models 33 and 35.
Table A-3lists the Alp character set, corresponding,standard mathematical symbols, c~rre
sponding JOSS symbols, and the method used to obtain each character on the various Teletype models.

1The system accepts only upper case letters (typed without use of the SHIFT key) from Teletype Model 37
unless , F (CTRl F) is first typed, in which case both upper case and lower case letters are recognized.
2The difference between /IAodel 33 and Model 35 is that fv40del 33 does not have TAB, FORM, or VT
~ertical lab) mechanisms.

4-12

1 .5

CORRECTION OF TYPING ERRORS
If the user should make an error while typing a command to AID, he can correct it by one of

two methods; (1) he can strike the RUBOUT key once for each character to be erased and then type the
correct data, or (2) he can type an asterisk followed, by a carriage

retur~

to delete the entire line, and

type the line over.
1)

*Type VEC\CEV\ VECTOR CALCULATION"J

User omitted the quotation mark
before the V; he erases C, E,
and V by striking the RUBOUT
key three times (deleted characters
are pri nted between \), types the
missing quotation mark, and
continues •

*Type "VECTOR CALCULATION*d
*Type "VECTOR CALCULATION'~

User realizes that he has omitted
a space between the e and the
quotation mark; he decides to
delete the line and retype it.

Should the user type an incorrect command, AID, when it attempts to interpre! it, will respond with the
message
EH?

*
NOTE
When indirect commands are entered, AID merely checks
the validity of the step number; the validity of the command
is not checked until it is called upon for execution.
,"

4-13

CHAPTER 2
STEPS AND PARTS

A user requests AID functions by typing single-line commands called steps. The user can enter a step
whenever AID responds with an asterisk (*) typeout. Each step is terminated by a carriage return (~).
Steps can be entered in two ways: (1) as direct steps, or (2) as indirect steps.
2.1

DIRECT STEPS
A direct step is interpreted and executed by AID immediately (following the terminating

carri age return typed by the user).
*Type 2+2 ~

User types dJ rec t step.
2+2

AID responds immediately
by interpreting and executing the
step.

Direct steps are performed only once each time they are typed, and must be retyped each time th'e user
desires to execute them.
2.2

INDIRECT STEPS
An indirect step is entered by preceding the' step with a nume'ric label containing both an

i'lteger and a decimal portion (1.1, 2.53). By preceding a step with a numeric label, the user signals
to AID that the step is not to be executed immediately, but is to be stored for later execution as part of
a routine. AID files away labeled steps in sequelJce according to the numeric value of the IQbel or
step number.

Thus, a step number can be used to indicate that a step is to be inserted into, deleted

from, or substituted in a series of previously entered indirect steps. Step numbers can contain a maximum of nine significant digits.
*1.1
*1.2
*1.3

*1 • 15 Set x=3

*1.3

...

J
J

Type "X VALUES"
Type x d
Type x*2, x/2, x~

User inserts a step between steps 1.1 and 1.2 by
assigning it a number which falls between these
two step numbers.

Type x*2; x/2, x~, xt3 ~

*Delete step 1.2

User types i,n a 3-step routine for later execution.

'User changes step 1.3 by substituting a new step
having the same step number.
.
User del etes step 1 .2.

*
2.3

PARTS
Steps are organized into parts according to the integer portion of their step numbers. All

steps with step numbers containing the same value in their integer portion belong to the same part.

4-15

Thus,

all of the steps in the previous example can be referred to as part 1.
*Type part 1

1.1
. 1.15
1.3

User ~equests AID to type a II steps in part 1 .

Type fiX VALUES"
Set x=3
.
Type x*2, x/2,x ~2, x ~3

*00 part 1

, User requests AIO to interpret and execute (i .e. I
00) all steps in part 1.

, X VALUES
x*2 =
x/2
xt2 =
~3 =

6
1.5
9
27
I

*
Steps and parts are units which may be entered, changed I deleted, typed out, executed, or
filed in (and later recalled from) a file stored on some retrievable

I/o

medium (e.g., disk or OECtape).

In addition, they are available in core storage as stored routines for repetitive execution.
Examples:
a)

*1ype step 1 .1

*Type part 1

J
*00 step 2.3 J
*00 part 4 J

*File step 3.65 as item 4

*'File part 3 as item 2

All steps or parts can be referred to collectively (except by 0(3).
Examples:
a)

*Type all steps

*1ype a II ,parts

c)
d)

J
J

J
*File all parts as item 9 J
*File all steps as item 8

4-16

CHAPTER 3
IDE NT I FIE RS (VA RI A Bl E S)

An identifier (variable) is used in expressions to represent a variable quantity. In AID,
identifiers are

repres~nted ~y

single alphabetic characters to which arithmetic or logical values have

been assigned. On Tel~type Models 33 and 35 (and Model 'Jl in the upper case mode), 26 unique
identifiers are available. However, when the Model 37 Teletype is operated in the upper/lower case
mode, 52 unique identifiers (A through Z, and a through z) can be used.
3.1

DEFINING AN IDENTIFIER BY A VALUE (SET AND DEMAND COMMANDS)
A fixed value can be assigned to an identifier by typing
*Set x = value
NOTE
When this command is typed as a direct command, the verb
(SED may be omitted, e.g.,
-*x = 95

In a SET command, the single -character identifier on the left of the equals sign (~) is not a number, but
an identifier being defined (or redefined).

The value or expression on the right of the equals sign is a

numeric value (or truth value) and must always, if a numeric expression, be immediately reducible to a
number.
Examples:

*x = 10

*Set x =3.5 ~

*y = cos (25)+2

*Set a = sqrt(20)+5

*m = false ~

cos is a standard function provided by AID (see
Chapter 4).

is also a standard AID function.

!!! is set equa I to the value false.

The SET command is a convenient way to shorten a lengthy expression by using identifiers to represent
its parts.
Example:

34 2
(5 + 73) +

4-17

42 - .[50
19

This expression can be simplified and solved as follows.
*0 = 5+34/73.}
*b = [42-sqrt(50)l!19 ~
*Type (at2+b)/a ~
(at2+b)ja =
5.80209589
Common algebraic funi::tions{e.g., sqrt, cos, sin, log)are provided in AI Dforuse inexpressions
(see Chapter 4).
Example:
Define the value of pi ('If)
*p = arg(-l, 0) ~
*Type p

arg is the AID function of a rectangular coordinate point (see Table 4-2).
f

p =

3.14159265

*Type p*36t2 .}

Calculate the area of a circle having a radius
of 3p.
4071.50407

An identifier can also be set to a value, to be typed in by the user prior to execution of the
associated routine. This is acco~plished by using the, DEMAND command, which can be used indirectly
only. Execution of a DEMAND command causes a typeout of the specified variable, which is followed
by the val ue to be used, typed by the user.
'Example:

*1.1 Demand x
*1.2 Demand y ~
*1.3 Type x*y, (x¢2)*(y¢2) ~
*Do part 1 ~
x=

y =

* (xt2)* (yt2) :

AID requests value ,for x. User responds by typing
in 4.
AID requests value for y. User responds by typing
in 6.

24
576

An identifier can be set to a ran~e of values by the "DO ••• FORx=lst-value (increment)
last-value" command (see"DO", Chapter 5). When this form of the DO command is used,
the series of staps is executed repetitively for each requested value,' beginning with 1st-value and incrementing it by "increment" following each repetition until "last-value" is reached. 1

1 As described in Section 4.5, the range given for a variable can be greatly expanded beyond this
simple format. For example,
Do part 1 for x = 1 ,2,3(2)25(i)2tt(k)200,500 •
. In this example, part 1 is performed for x = 1, 2, 3, tlien in increments of 2 up through 25, then in
increments of i up through the value of 2t, then in increments of k up through 200, and 500.

Example:
Type x,x'?2, x~3 ~

*1.1

*Do part 1 for x == 2(2~1 0 ~

2
4

4
16
64
6
36
216
8
64
512
10
100
1000

x~2 ==
x~3 ==

Directs AID to perform step 1.1 for values of x, beginning with a value of 2 and incrementing this value
by 2 until lOis reached in a series of repetitive
exec uti ons .
AID types out results.

x~2 ==
x~3 ==

x
xt2 ==
x~3 ==

x~2 ==

xt3 ==
*
3.2

DEFINING IDENTIFIERS BY FORMULAS (LET COMMAND)

3.2.1

Arithmetic Formulas
AID can be told how to calculate the value of an identifier rather than associating the identi-

fier with a fixed value. This is done with the LET command. The use of LET causes the identifier on
the left of the equals sign to be set to the formula (not necessari Iy a numeric val ue) on the ri ght of the
equals sign (==).
*Let d == sqrt(a) + b + c
*Type formula d

sqrt(a) + b + c

Note that AID associates a formula, not a numeric
value, with the identifier d.

In the above example, the formula for d is an expression reducible to a number, but this value is not
calculated until d is called for.

However, before d can be calculated, the user must supply values for

all variables in the formula associated with d.
*Type d ~
Error in formula d:

a == ??

User has assigned no value to a.

*a ==
*b == 5~
*c == 8~
*Type d ~
d ==

4-19

3.2.2

Boolean Expressions (Propositions) Defined by the LET Command
A second use of the LET command is to define an identifier as being equivalent to the value

(true or false) of a proposition/ i.e./a Boolean expression compose~ of arithmetic and logical statemen!;, using common relational operators (e.g./ =/>/<)/ the logical negation (not)/ and logical operators
(and/ ~).

Example:

J,
J

*Set a = true
*b = false~
* Let c = a and b
*Type c ~
c =

false

Proposit,ions are discussed in detail in Chapter 4.
3.2.3

User Functions Defined by the LET Command

AID provides many of the common algebraic and geometric functions (sqrt - square root/
cos - cosine/ log - logarithm, etc.). AID functionsare specified in expressions by using the appropriate function mnemonic (sqrt = square root).
A third use of the LET command is to equate an

identifi~r

to a user-defined function. Once

defined/ a user function can be used the same as an AID function.
Example:
Defines the user function, a. l

*Let a(b,c) = (b~2)-t{2*b*c)+(c~2) ~
*Type a(4, 10) cJ

a(4,10) =

196

Both AID functions and user-defined functions are discussed further in Chapter 4.
3.3

IDENTIFIER REFERENCES
In addition to an identifier in a formula referring to its associated value or formula, it can

also be used to delete, type, or file that value or formula.
Examples:

Delete a and its associated value.

*Delete a

*Delete formula b

*Type c

*Type formula d

*File e as item 1 ~

Delete b and its associated formula.
Type the value of c.

Type the formula associated with d.
Store e and its associated val ue on the currently
open file (see "FILE") as item 1.

All current identifiers and their associated values or formulas can be referred to collectively.

lin the function a(b/c)/ band care dummy 'arguments and do not conflict with variables-of the same
letter outside of the formula (b and c-can be used as identifiers elsewhere).

Examples:
*Type all values

J
*Delete all values J
*Delete all formulas J

*File all values as item 3

*File all formulas as item 4

b)
c)

3.4

*Type all formulas

INDEXED IDENTIFIERS (ARRAYS)
Values may be organized into vectors and arrays by using indexed letters for identifiers. The

letters may then be used to refer to the arrays. Identifiers defined by formulas may not be indexed.
The index or subscript is, enclosed in parentheses immediately following the identifier.
Example:
*x(1)
*x(2)
*x(3)

= 12

6tJ

*Type x(1), x(2), x(3), x(1)*x(2)*x(3)J
x(1)
= 12
x(2)
4
x(3)
= 6
x(1) *x (2) *x(3)= 288
*Type x ~
x (1)

x (2)

x(3)

x refers to all indexed x's; thus, a nonindexed
identifier cannot coexist with the same identifier
indexed.

Multiple subscripts can be specified for an identifier to create a multidimensional array. An
identifier can be indexed by one to ten subscripts, and each subscript may have an integer value in the
range -250 through +250.
Examples:

*x(l) = 6

*a(1,2) = 10

*c(100,50,67) = 130J

An individual identifier can be used in only one way at anyone time and redefinition deletes any previous definitions. "Thus, the definition of an identifier with n dimensions deletes all definitions of the same identifier having other than n dimensions.
Example:
The identifier x (unindexed - 0 dimension) is
defined as equal to 5.

*x =5J
*Type xJ
x

:::

5
4-21

*x(1) = 10 ~
*x(2) = 20 ~
*Type x ~
x(1) = 10
x(2) = 20
*x(1 , 1)

The identifier x is now redefined with one dimension
" '(subscript); the unindexed x is deleted.
~

"~',

! ~

= 33 ~

"r,

The identifier xis now redefined QS describing a
two-dimensional array; XIS' having other dimensions
are deleted.

*Type!< ~
x(1,1) = 33
*x(1,2) = 44 ~
*x(2, 1) = 55 ~

*Type x ~
"x(1, 1)
, x(l ,2)
X{2i 1}

=
=

Additional x values having the same number of
subscripts as the previously defined x are entered;
no deletions occur.
33
44

NOTE
Undefined elements of the x array in thi-s example can-be set to a
,value of '0 by the use of the command
Let x be sparse.
*Typ'e x(2,2) rl
x{2,2) = ?'??
*Let x be sparse ~
*Type x (2,2) ~
x(2,2) =
0
*Type x ~
x(1,1) = 33

x(1,2)

x(2,1)
x is sparse.

•

4-22

CHAPTER 4
ARITHMETIC OPERATORS, FUNCTIONS,
PROPOSITIONS, AND ITERATIONS
4.1

ARITHMETIC OPERA TORS
As discussed in Chapter 1, paragraph 1.3" "AI D Language", all standard arithmetic operators

can be expressed in AID. These are presented'in Table 4-1, in their order of precedence.
Table 4-1
AID Arithmetic Operators
Standard Designation

AlP Symbology

Ix I
[

! x !
[
1

(

)

(

e
x
a . b, (a)(b),
or a X b
a
alb or Ii

Meaning

Absol ute val ue of x
Second level grouping 1

1st Ievel grouping 1

)

The value "x II raised to the power of. "e".

x*e
a*b

Multiply a times b.

alb

Divide a by b.

a + b

a+b

Add a to b.

a- b

a-b

Subtract b from a.

l. Within nested pairs of brackets (or parentheses), the order of evaluation is from
the innermost pair outward.
Examples:

-5J

*x =
*y = +2~
*Type x+y
x+y =
*Type !x-ty! ~
!x+X! =
*Type x+yi'2-15
x+yt2-15 =
*Type (x+y)~2-15 ~
(x-ty )t2- 15 =
*Type (x+y )t(2- 15)
(x+y)t(2-15) =

-3
3

-16

-6
-6. 27225472*1 Ot(-7)

4-23

*x == sqrt (16}-+sqrt (9) J
*y == sqrt [16-+sqrt (9)] J
*z = sqrt [sqrt (16+9)] d
*Type xrJ
x
*Type y J
=
y
*Type zJ
Z

7
.

.,'

4.35889894,
2.23606798

Computing simple interest
r

=rate of interest per year

=, time (in years)
= principal

(in %)

(p)(r}(t)
== 100
*Let i = (p*r*t}/lOOJ
*p = 1000£1:' . ,.
*r == 6rl
*t = 3rJ
*Type iJ
180
d}

Computing total accumulated principal and compound interest
a =accumulated principal and interest, compounded annually.
r I t', and p are the same as above.
a = p(Hr/l00}t
*Leta =p*(1+r/l00} ~
*p = 1000rl
*r =6rl
*t =3£1
*Type arJ
a
=

trl
.

1191.016

Formula for a catenary curve

x
x
a(a +ea)

=2'

where a is a constant, and
e is Euler's number
*Let m = x/a tJ
*Let n = O-m d (optional)
*Lete =2.71828183rl
*Let y .= (a/2) *[ (6 m) +(e

t (O-m}}J £I

or
*Let y = (a/2)*[(e t m)+(e
*1.1 TypeYJ
*a =-3£1
*Do part 1 for x = 1(1)5J
y
y
y
y
y

=
=
==
==

n)] £I

-3.1682156
-3.69172674
-4.62924191
-6.08589753
-8.22504851

4-24

Execute part 1 for y with val ues
of x beginning with 1 and incremented by 1 until 5 is reached.

4.2

AID FUNCTIONS
Many common algebraic and geometric functions are provided by AID for use in expressions.

Two of the most commonly used functions ore
sqrt

SQUARE ROOT

log

NATURAL LOGARITHM

Examples:
sqrt(10)
log(x*y)
Note that the argument for a function is enclosed in parentheses a-nd immediately follows the
function mnemonic.
Table 4-2 lists AID functions in alphabetic order. The symbols x and y represent any expression reducible to a number and are the arguments of the function. The variable i is a dummy variable and does not affect any real identifier denoted by the same alphabetic character.

-' ~ ,

4-25

Table 4-2
AID Functions
Description

Function

The ARGUMENT function takes two arguments (x, y) and computes the angle between
the +x axis of the x,y plane and the line
joining point 0,0 and point x,y, The result
is in radians

arg(x,y)
+Y

arg(x,y)

•

The value of arg (0,0) is 0. The range of arg
is through 21f or -1f through 1f.

X,Y

Y~----------

I
I

'i':

Jr6;9~ ,

0,0 ---..t.--~x:-----L-- +x

'The COSINE f~nction requires one argument, assumed to be in radians.

cos(x)

I'x I must be < 100.
dp(x)

The DIGIT PART function,
dp(13456.5432)= 1.~4565432

exp(x)

The EXPONENTIAL function:
eX , where e is Euler's
number (2.718281828).
The argument (x) must fulfill the requirement that
e X-

prod(i=range ••• : ••• i expression •• )

The PRODUCT function requires the same
two types of arguments as the MAXIMUM,
MINIMUM and SUM functions.
The expression is computed iteratively for
each value of i, and the result (product of
all the iterations) is typed out.1

sgn(x)

sin(x)

The SIGNUM function. The val ue of a
signum function of an argument greater than
zero is +1, of an argument equal to zero is
0, of an argument less than zero is -1.

The SINE function requires one argument,
assumed to be in radians •
I x I must be

,sqrt(x)

< 100.

The SQUARE ROOT function. The argument
(x) must be equal to or greater than zero.

sum(i=range ••• : •• i expression •• )

The SUM function requires the same two types
of arguments as the MAXIMUM, MINIMUM,
and PRODUCT functions.

The expression is computed iteratively for each
value of i, and the result (sum of al I iterations)
is typed out.1

1The iterative clause and i funcHon can, in all of these cases, be replaced by a simple series of value:
for i.
Example: max(S, -4.3, y,x,2)

.see Section 4.S.

4-27

Table 4-2 (Cont)
AID Functions
<

Function
tv (proposition)

Description

The TRUTH VALUE function requires one
argument, a proposition, and converts this
argument into a numeric. value: 1, if the
proposition is true; 0, if the proposition is
false .

.
xp(x)

The EXPONENT PART function.
xp(13456.5432) = 4
i.e., 13456.5432 = 1 .34565432*10 ~ 4

Examples:
*a

*b
*c
*d
*e
*f
*i
a)

b)
c)

= 12ll

= -2.5J
= 100£1

= 1.325ll

= 10.435J

=25J

*Let z
= sum(i=0(10)100:i*2) J
*Type zrl
.
z =
1100
*Type sum (a,b,c ,d,e,f, i ,z) rl
sum (a,b,c,d,e,f,i,z) =
1256.26
*Let z = prod (i =1 (1)5:i
*Type zll
z =.

2) rl

*Let z = max(i=-15(l)15:{i.~ 2)-(-5*i))J
*Type ztJ.
z =
300

*Let z = min (i=-15(1)15:(i ~ 2)-(-5*i»tl
"'Type ztJ
z =
-6

*Type min(a,b,c,d,e,f,i)J
min(a,b,c,d,e,f,i) =

h)
. i)

j)
k)

NOTE
The i in .,(a) is a dum~y variable and
in no way relates to the i in (b). The
latter is an identifier and refers to the
variable and defined above.

14400

•

= lOll

-2.5

*Type arg{-l,O)J
arg(-l,O) =

3.14159265

*Type arg{c ,a) J
arg{c,a) =

1.81577499

*Type sin(10) J
sin(10) =

-'.544021111

*Type cos (a) J
cos{a) =

, ':'.839071529

*Type sin«a*eH)J
sin«a*e)-i) =

't..

.728664976

4-28
".

I}
m}
n)

"Type exp(. 346} ~
exp(.346} =

1.41340262

J
*Type fp(e+F) J
*Type dp(etf)
dp(e+F) =

1.176

fp(e+F) =

0)
p)
q)
r)
s)

.76

*Type ip(e+F) ~
ip(e+f) =

*Type log(650) ~
log(650) =

6.47697236

*Type log(e+f) ~
10g(e+F) =

2.46470394

. *Type sgn(d-~bt2}+i) ~
sgn(d-(bt2}+1) =
-1
";m = -5~
*n =
*Tr.pe tv«m>=n) or (m=O) or (m-4»
tv(m>=n) or (m=O) or (m<0) and (m>-4» = 0

*Type sqrt(a-+b+C'+cHe)
sqrt(a-+b+C+d-le) =
*1.1 Let a(x) = xt2-20
*00 step 1.1 for x=1(1 )30

10.9920426

*Type a (25) ~
a(25) =
*Type first(I=1 (1)30:a (I) =0)
first(I=1(1)30:a(I)=O) = ???
*Type first{I=1 (1)30:a (I) >700)
first (I=l (1)30:a(I»700) =
*Type a (27)
a(27) =

Set up a table (or array) of 30 items
calculated according to the formula
given in step 1 .1.
605

4.3

No such value found in table.

J
27
709

USER-DEFINED FUNCTIONS
Functions not included in AI D can easi Iy be defined for repetitive use.
As discussed in Chapter 3, the LET command is used to equate an identifier to some user-

defined function.

Following this function identifi,er, up to ten dummy arguments (enclosed as a group

in parentheses) can be specified; these are replaced by actual arguments when the function is to be
used. Dummy arguments are also represented by single alphabetic characters, but the use of a letter
as a dummy in no way affects the use of that same letter as an identifier. Following the dummy arguments, an equals sign and the expression representing the user function are typed.
f(a,b,c, •••• ) = expression
f = function identifier (any single alphabetic character)

(a,b/c, •••• ) = dummy arguments (also single alphabetic characters)
expression = the arithmetic 'e~pression representing the user fl,lnction
Arguments supplied for functions can themselves be functional.

4-29

4.3.1

Examp/es-of User-Defined Functions
*let a(b,c) = sqrt(b*c) + b~2 + c~2 ~

Define the user.function a, with two
dummy -arguments band c, as being
equivalent to the formula
sqrt(b *c )+b~2+c ~2

*Type a(120.555,32.076)
a(120.555,32.076)=

b
15624.5624

*Type a ~
a(b,c): sqrt(b*c) + b~2 + c~2
*Type formula a ~
a(b,c): sqrt(b*c) + b~2 + c~2
*Type a(b,c} ~
b = ???

Use the newly-defined function by
specifying two actual arguments in
place of the dummy arguments, b
and c.
Note that a is equated to the formula,
not'a value, since a alone is not an
expression.
Same typeout.
No values -have been specified for
the identifiers (not dummy arguments),
band c.

*b = (4~6)/9~
*c = 5.23P
*Type a(b,c) ~
a(b,c) =

207202.264

Many common functions can be defined as user functions, as shown below.
Tangent
*Let T(a) = sin(a)/cos(a)
*Type T(10) P
T(10) =

b
.648360828

Arc cos
*Let F(a) =arg(a, sqrt(1-a~2»
*Type F(.10) t:J
F(.10) =

'b
1.47062891

Arc cot
*Let C(a) = arg(a, 1)
*Type C(10) ti
C(10) =

tJ.
.0996686522

Arc csc
*Let 5(0) = arg(sqrt(1-1/a~2), 1/a) tJ.
*Type 5(10) .d
5(10) =;
.100167421
Arc sec
*Let K(a) = arg(1/a,sqrt(1-1/a~2» ~
*Type K(10) t3 K(10) =
1.47062891

4-30

Arc sin
*Let N (a) = arg (sqrt (1-0 ~ 2),a) rl
*Type ~(.10)rl
N(.10) =

.100167421

Arc tan
*Let T(a) = arg(1 ,a) J
*Type T(10) rl
1(10) =

1.47112767

Log to base 10
*Let L(a) = log (a}/Iog (10)J
*Type L(25.38)~
L(25.38) =

1.40449162

Derivative of a function of a variable
*Let D(a) = (F(a+.005)-F(a- .005»/ .01 rl
*let F(a) =3*a ~3-4*a ~2+2*a+5tl
*Type D(4) ~
D(4) =
114
4.4

PROPOSITIONS

As discussed in Chapter 3, propositions are Boolean expressions composed of arithmetic or
logical statements using the relational operators.
= (equal), # (not equal), >(greater than),
> = (greater than or equal to),

< = (less

<(less

than),

than or equal to)

the negation
not
and the logical operators
and
or
A proposition has either of two possible values: true or false.
Example:
*x = trueJ
*y = falseJ
*Let z = (x) and (y) or (x) and (100 >Sqrt(959» tl
*Type z rJ
z=
true
The order of execution within a proposition is:
a) evaluation of expressions
b) ( ) Within nested pairs of parentheses, the order of evaluation is from the
innermost pair outward.
c) relational operations

4-31

•
d)
e)

!!Q!.
and

Q!.

~ ::
"

A series of relational operations is assumed to be an ~ chain if no logical operator intervenes.
a=b>cc and cSqrt(30*5-20»
*Type tv (y) tJ.

tJ.

*Type 'J.4+tv(x(J
24+tv(x)
=
4.4.1

Conditional Expressions
A conditional expression allows an expression (e.g., a variable) to have different values de-

. pendin~ upon which of a numbe'r of conditions is true •. It is composed of a series of clauses separated by
semicolons, ~ith each clause ~ade up of a proposition followed by a colon follow'ed by an expression.
The entire conditional expression must be enclosed by parentheses or brackets.
(proposition:expression; proposition:expression; •••• )
Example:
Express the function:
If x> 0, C(x) = x~2;
if x=O, C(x) =0;
. if x0:x~2;x=0:0;x<0:x)
*Type C(5)', C(-10), C(O), C(10) iJ
C(5) =
25
-10
C(-10) =
C(O) =
0
C(10) =
100

If the last expression is to be true for all cases which do not satisfy any o(the stated condi - '
tions, the expression can be typed without a preceding proposition. For example, in the case above r
the user could have typed:
*let C(x) = (X>0:x~2;x=0:0;x)

tJ
NOTE,

Every possible combination of the variable must be provided for,
either by explicitly stating a conditional expression arid a proposition for it, or by simply specifying 0 terminating expression to
be executed for all cases which do not satisfy any of the explicitly
stated propositions. '1f this provision is not mode, and an unprovided -for condition'occurs, AID responds with the message
ERROR IN FORMULA X .

4-32

A conditional expression can be used to perform a fable lookup for all items whose values
satisfy one or more conditions.
Example:
*1.1 SetA(x)=xi2 +x*.5-5*x

Generates a 35 - item tabl e.

*00 step 1. 1 for x = 1(1)35 ~
*Type A(20) tJ
A(20) =
310
*Type A(3) ~
A(3) =
-4.5
*Let F(x) = (x<0:xix>700:Xifp(X»0 and x>300:x;

*00 step 1 .1 for i = 1(5)35
F(A(i)) =

Test every fifth item in the table.
-3.5

F(A(i)) =

346.5

Values, in tested items which do not
satisfy any of the three propositions
result in line feed/carriage return
(because of the terminating + symbol in the conditional expression).

. 821.5

*Let E(x) = (fp(x/2)=0:x;

Find all values which are (1) less
than zero; (2) greater than 700;
or (3) greater than 300 and have
a fractional part which is nonzero.
If x is none of these, perform a
line feed, carriaQe return (indicated
by the + symbol).

*1.1 Type .F(A(i)) ~

F(A(i))
F(A(i»

+ )

1067.5
+ ) "

Find all even-numbered values in
the table.

*1.1 Type E(A(i» ~
Test every item in the tabl e •

*Do step 1 • 1 for i = 1(l)35 "
E(A(i» =

-2

E(A(i» =

E(A(i»

184

E(A(i)) =

310

E(A(i» =

468

E(A(i»

658

E(A(i»

880

4-33

4.5'

ITERATIVE CLAUSES"(RANGES)
Iterative clauses are 'used with the DO command and with the functions FIRST, NtA.X, MIN,

PROD, and SUM. In bO.th cases, the iterative clause specifies a range of values to be acted upon by
the command or function.
4.5.1

Series of Values
One format of an iterative clause lists the individual values which make up the range:
n, n I' n2.' n3 ,·······

For exampl,e,
Do part m for x',= range
Do part 1 forA:::; 1, M, 100,50, -25, xt3
Type sum(x=range)
Type sum(A = -4.6, M*N, 240.5,C)
4.5.2

Part 1 wi II be executed for each of
the individual values of A.
The SUM function is performed on
'all values listed and the result (the
, SUM of all values) typed out.,

Incrementation
The range of values for a variable can also be expressed as a first value, an incremental

value, and an ending value. As a result, the variable values range from the'first value ,upward in steps
of the specified increment until the

e~ing

value is reached. The ending value is always taken as the

last value in the range, even though the incremental steps may not hit it exactly.
The general form of an incremental iterative clause is:
x = first-value{increment)ending-value
,For example:
Do step m. n for x = range
Dostep2.3forA= 1(2)12

Step 2.3 will be executed for each
individual value of A:

1,3,5,7,9,11,12
Type sum (x =range )'
Type sum(A = -50(B)C)

4.5.3

The SUM of all values of ,A, as indicated by the range, is calculated.
This range begins with -50 and contin!J~s in increments of B until C
is reached.

Combinations
A range can be expressed as a combination of value series and increments.

4-34

= a(b)c,d,e(f)g(h)i,j,k

The-range pf x values begins with a,'
continues in increments of b through
c, then d, e, then in increments of
f until g is r.eached, then in increments of h until; is reached, then
j and k.
'

For example,
Do part 3 for W = 20(Y)50(50)500, 1000(100)Z

Part 3 will be performed for all value$ of W, beginning with 20, continuing in increments of Y through
50, then continuing in increments of
50 through 500, and from 1000 in increments of 100 through Z.

Type sum(W = A(30)B, C, 800(0) 1500)

The SUM function will be applied to
all valves of W, beginning with A
and continuing in increments of 30
through B, then C, followed by 800
through 1500 in increments of O.

'4-35

CHAPTER 5
AID VERBS

This chapter contains a summary of AID verbs, their command formats, optional features, and
examples of usage. Some of these verbs (e.g., TYPE, DO) hove appeared frequently in examples in previous
chaptersiothers(e.g., LET, SET) have already been describedextensivelyandare included here only as a
review.
Some verb descriptions include diagnostic messages which are associated with a specific
command or group of commands. A complete list of diagnostic messages can be found in Table A-4.

5.1

CANCEL

DESCRIPTION
The CANCEL command cancels a currently stopped (interrupted) process, if the user does
not desire to resume execution. 1
CANCEL is the antithesis of the GO command.
CANCEL also releases any immediate memory currently assigned to the interrupted execution.
NOTE
The CANCEL command does not, however, delete any commands,
formulas, variables, etc., associated with the interrupted process.
The CANCEL command can be given directly only.
Parenthetical CANCE L (CANCE L)
Typing
(CANCEL)
cancels any currently stopped process that was initiated by a parenthetical DO.

1 An interrupted process is automatically cancelled whenever the user types a direct DO command to
initiate another part or step.

4-37

EXAMPLE
*1.1 Let x =

..... ~

*2.10 Type .... ~
'*00 part 1

••

Error 'at step 2.5: i"egal set of values for iteration.
*Cancel. ~

User does not desire to correct step and resume
execution.

*
DIAGNOSTIC MESSAGES
DON'T GIVE THIS COMMAND INDIRECTlY

4-38

The CANCEl command can 'be given
directly only (with no step number
precedi ng it).

5.2

DELETE

DEseRI PTION
The DELETE command erases a step, port, form, value, or formula from immedio.te storage
and frees that storage for some other use. This command should be used frequently to delete.routines,
tables, and other items which are no longer needed. By doing this, unnecessary waste of storage and
possible storage overflow can be avoided.
Delete a
Delete identifier a and its associated value{s) from immediate storage. If identifier a is
a subscripted variable, the entire a array is deleted.
Delete a(b, ••J
Delete the particular array item, a{b, •• ), and its associate value from immediate
storage.
Delete step m.n
Delete the step numbered m.n.
Delete port m
Delete port m (all steps having numbers whose integer portion is m).
Delete formula a
Delete the formula associated with a.
Delete form m
(See "FORM" and "TYPE" for on explanation of forms.)

Delete form m.
values
steps
Delete all

ports

Delete all entries of the named type.
Delete all
Delete all entries.
Several individual DELETE commands can be combined into one. For example,
Delete x, form 3, formula b, all ports.

4-39

EXAMPLES

*1.1 TyPe '''STEP A"
*1.2 Type a+b in fann 1 ~
*1.3 To step 2.1 ~ l
*2.1 Type a~2+b~2 p
*2.2 Type "END" /J
*Leta= 10+b t>
*b = 25A
*Form 1:~

Type entries into immediqte storage.

*"""""0"" ~
*00 part 1 ~

Test routine.

STEP A

60.00
1850

at2-1bt2 =
END

Delete identifier b and its associated
value. Attempt to use b.

*Delete b
*00 part 1 p
STEP A

Error at step 1.2 (in fonnula A): b ~ ???
*Delete step 2. 1

Delete step 2.1.

*00 step 2.1 ~
I can't find the required step.
*Delete a ~

Attempt to execute it.

*Type a ~
0= ???
*Del~;e' 01 I ~

Attempt to type it.

*Type all ~

Test that all have been deleted.

Delete formula a.

Delete remaining entries.

•

4-40

5.3

DEMAND

DESCRIPTION
DEMAND causes AID to type out a request for a user-supplied value during execution of a
routine. The DEMAND command can be given indirectly only.
Demanda.
AID types out a request for the value of a.

tJ.

*1 • 1 Demand a
*1.2 Type .•••• ~
*Do part 1 t>
a

*(user types value here)~

Demand a(b, •• ).
AID types out request for the value of the subscripted variable a(b, •• ).
*1.1 Demand M(3,5,7) !>
*1.2 Type ••••• 1>
*Do part 1 P
M(3,5,7)

*(user types value here)!>

DEMAND ..... AS "ANY TEXT" OPTION
Demand a as "any text" .
AID types "any text" to request a value for a.
*1.1 Demand p as "NUMBER OF SAMPLES WANTED" r:l
*1.2 Type •••• ~
*Do part 1 tJ
NUMBER OF SAMPLES WANTED

*(user types value here)!>

Demand a(b, .. ) as "any text" .
AID types "any text" to request a value for the subscripted variable a(b, .. ).

4-41

....

,J.

~"'!

....

"':.-d

*1.1 Demand y(3) as "MAXIMUM SPEED"
*1.2 Type ..... ts
*00 part 1 tl
MAXIMUM SPEED =
*(user types ~alue hEm9)~
~

Depending upon the use of the variable specified, values r~quested b)la 'D~MAND command
can be entered in the form of
a)

a numeric expression (e.g., a numberin fixed or floating point notqtion, or an identifier

representing a numeric value),
b)

a formula, or

a Boolean value (true or false).
NOTE
Only one variable can be specified in each DEMAND command.

EXAMPLES

*x=25 ~

*y=50.25~

__ *z=16.4~
*1.1 Type "CONVERSION OF POUNDS TO KI LOGRAMS"
*1.2 Demand a ~
*1.3 Type a,b in form 1 ~
*1.4 To step 1.2 ~
* Let b =. 45359*a P
*Form 1:1>

.................... • ................ POUNDS
*Do part 1

= . . . . . . . . . . •. . . . . . . . KILOGRAMStl

CONVERSION OF POUNDS TO KILOGRAMS
a = *25.8"
25.8000 POUNDS = .\ 11.7026 KILOGRAMS
a = *100.543p
100.5430 POUNDS = .1 45.6053 KI L9 GRAMS
a = *5567.98p
5567.9800 POUNDS =
2525.5801 KILOGRAMS
a = *1>
I'm at step 1.2.

~a'rriage return by user
terminates iterations.

*1.2 Demand a as "POUNDS"
*Do part 1 ~
CONVERSION OF POUNDS TO KI LOGRAMS
POUNDS ~ *25.8"
25.8000 POUNDS =
POUNDS = *~
I'm at step 1.2.

11.7026 KI LOGRAMS

4-42

*Let a = m and' n f)
*Let b = m or n ~
*1 • 1 Demand m
*1 .2 Demand n
*1.3 Type tv(a) in. form 1 ~
*1.4 Type tv(b) in form 2 V
*1 • 5 To step 1. 1
*Form 1: t>
*
Logical AND: +
*Form 2: ~
*
Logical OR:
...
*00 part 1 t>
.\
m = *true V:.
n = *falset>
Logical AND: 0
Logical OR:
1

t>
t>

m = *false ~
n = *false V
Logical AND: 0
0
.\
Logical OR:
m = *not true V
n = *not false t>
Logical AND: 0
Logical ~R~.\ 1
m -

11m at step 1 • 1 •

*
Carriage return terminates iterations.

*1. 1 Do part 2 for B = 1(1)3 t>
*1.2 Type A I>
*2.1 Do part 3 for C = 1 (1)5 t>
*3.1 Demand A(B,C) t>
*3.2 Set A(B,C) = sqrt(A(B,C» t>
*00 part 1 ~
A(1,1)
A(1,2)
A(1,3)
A(1,4)
A(1,5)
A(2, 1)
A(2,2)
A(2,3)
A(2,4)
A(2,5}
A(3,1)
A(3,2)
A(3,3)
A(3,4)
A(3,5)
A(1, 1)
A(f,2)
A(1,3)
A(1,4)

= *30

= *65

=
=
=
=

*4
*50
*43.55677
*32·
= *1
= *45.99

*29

= *22.3333

*56.77

= '*66,.7777
= *99

= *100

*1234.33

.
=

5.47722558
8.06225775
2
7.07106781

4-43

A(1,5)
'A(2,1)
A(2,2)
A(2,3)
A(2,4)
A(2,5)
A(3,1)
A(3,2)
A(3,3)
A(3,4)
A(3,5)

='
=
=

=
=
=
=
=
=
=

6.5997553
5.65685425
1

6.78159273
5~ 38516481
4.7258121
7.53458692
8.17176236
9.94987437
10
35.1330329

4'"744

5.4

DISCARD

DESCRIPTION
DISCARDdeletesanitemfromtheexternal storage file currently in use.
Discard item m (code).
Erase item #m (where m can be in the range 1 through 25) from the currently open external storage file and make the item available for some other use.
Immediate storage is not affected in any wdy.
Code is optional for documentation purposes only and is ignored by AID; however, code,

if used, cannot exceed five characters in length.
EXAMPLE
*Discard item 20
Done.

Item 20 of the external storage fi Ie currently in use has been cleared successfully, as
evidenced by the AID message, DONE •• Item 20 can now be used for storing some
other data, via the FI LE command.
DIAGNOSTIC MESSAGES
I CAN'T FIND THE REQUIRED ITEM.

The specified item cannot be found in
the currently open file. Ei ther the
wrong file is open, or the item number is incorrect.

ITEM NUMBER MUST BE POSITIVE
<=25.
INTEGER

An invalid item number was given.

YOU HAVEN'T TOLD ME WHAT FILE TO USE

A DI SCARD command was attempted
before an external storage file was
opened via a USE command.

4 .... 45

c, '

\:1 '

5.5
DE'SCRIPTION
The DO command executes an indirect step or part. DO is completed when either (1) in a
noniterative operation, the last step in the sequen~e has been completed, or (2) in an iterative operation, the last iteration has been completed. 1 If the DO command is a direct step,' control returns to
the user at the compretion of the DOi if the DO command is indirect, control returns to the step following the DO. 'If the step or part being executed contains imbedded DO or TO commands, they are
executed normally.
Do step m.n
Execute step Hm•n and return control as descri bed above.
TIMES Option
Do step m.n, p times
Execute step Hm•n the nu~ber of times specified by integer p and return control as described above. Note that a comma must immediately follow th!Sl step number.
RANGE Option (FOR Clause)
Do step m. n for x = range
Execute step m.n iteratively for each specified value of x as indicated by range (see
Section 4.~~,.
When the range is sat1sfied, control ,is returned as described above.
Do step 1 ~ 2 for x = 1(1 )5

Execute step 1:2 iteratively, beginning with an initial x value of 1 and
incrementing x by 1 prior to each
iteration until the maximum value of
5 is reached.

Do step 5.25 for a = -10.25(.25)4.50

Execute step 5.25 iteratively, beginning with an initial a value of
-10.25 and incrementing a by the
value .25 each time until the maximum value of 4.50 is reached.

Do step 1.3 for m = 1,-2.5,100"':'43.666

Execute step 1.3 for each of the four
specified m values.

1Remember that steps are always executed according to the n~merical
regardless of the order in which the steps were originally entered.
4 ... 46

s~quence of their step numbers,

Do step 10.6 for p = 200, -30.667, -2.3(.1)1.9, 5.75
Execute step 10.6 for three val~s of
p (200, -30.667, anclS.7~ and 'for
a range of values of p (4.3 through
1 .9, in increments of .1).
Do step 1.3 for m = 1(4)26(5)50{25)155

Perform step 1.3 iteratively for m =
1 to 26 in increments of 4
26 to 50 in increments of 5
50 to 150 in inc(ements of 25.
Thus, the values ofm will be 1,5,9,
13,17,21,25,26,31,36,41,46,
50,75, 100, 125, 150, and 155 for
the 18 iterations of step 1.3.

Do part m
Execute part m {all steps having the value m as the integer portion of their step number}.
All steps are executed in numeric sequence; any jump (via a DO or TO) to a step which
is outside part m is handled correctly. Control is returned as described above.
Do part m, p times
Execute part m the number of times specified by integer p and return control as described above.
Do part m for x = range
Execute part m iteratively·for each specified value of x in the same manner as described
under" Do step m.n for x

= range".

The FOR clause of a DO command is

interpr~ted

only once, at the point where the DO com-

mand is encountered; therefore, if a variable specified within the FOR clause is changed during execution of the DO-initiated routine, the change has no effect on the performance of the FOR clause.
The number of iterations performed and the setting of the variable at the beginning of each iteration is
the same as if no modification of the variable were performed by the routine.
*1.1 Do part 2 for x=1(1)5 },
*2.1 Type x C>
'*2.2 Set x = x+l00 ~
*2.3 Type x tJ
*00 part 1 {)

x =
x =
x =
-x =

x =
x ==

1
101
2
102
.3
103

x =

104
5
105

x =

4-47

Note that, when the FOR clause is used, the end-range v~1u~'i~ hif~~~tjy. For example,
given the DO command
.
:. '~: . ,~. :_:
Do part 1 for x

1(3)14.5

iterations will be performed for x = 1, 4, 7, 10, 13, and 14.5.
IF Clause
The IF clause (q.v.) when appended to a DO command is also interpreted only once (when
the DO command is encountered) and has no effect once execution of the DO has begun. Thus, even
though the DO-initiated routine might perform some action which would make the IFcondition no
longer satisfied, once execution has begun it continues to its normal termination.

*x = 20
*1.1 Do part'2, 3 times if X>O ~
*2.1 Set x = x-50 ~
*2.2 Type x ~
*00 part 1 b
x
x

-30

At the start, x = 20.
x is now <0, but iteration continues.

-80

x =

-130

Parenthetical DO (DO •••••• )
The parenthetical DO command is used to initiate execution of a step or part, while another
process is waiting to continue after a STOP or "other type of interrupt, without cancelling that other
process.
NOTE
A normal DO command automatically cancels any currently
stopped process.
The parenthetical DO command inc ludes all the options of the normal DO command. Its general format
is:
(Do •••••••••••
a)

(Do part 3 )

(Do step 1.4 for x = 5(5)25 )

The parenthetical DO command is commo;nly used to execute a step or part to test its validity; thus, this
commanc/ is primari Iy a debugging aid.
Any stopped process which was originally initiated by a parenthetical DO can be cancelled
by a parenthe.tical CANCEL command.
Examples of parenthetical DOs can be found under" GO" in this chapter.
EXAMPLES
a)

* 1 . 1 Type
*1.2Type
*1.3 Type
*1.4 Type

"A" ~
"0" rJ,
"F" ~

"J"

*1.25 Type "E" ~
*2.1 Type "8" ~
~2~2 Type "e" cs
*3. 1 Type "G" r:J
*3.2 Type "H" r:J
*3 .3 Type "I" ~
*Do part 1 ~

A
D
E

F
J
*1.15 Do part 2
*Do part 1 ~
A

e
D

E
F
J
*1.35 To part 3 t:l
*Do part 1

A
8

e
D
E
F
G
H
I

*
b)

*let I = sqrt (a ~ 2+b ~ 2) J
* 1 . 1 Do part 2 for b = 1 (3)9 ~
*2.1 Type a I b I lin form 1 t:l
*Form 1: t:l
* a= ............ b=+-"'''' c=_ ............. · .............. tl
*Do part 1 for a = 1 (2)12 t:l
a=
1 b=
1
c=
1.4142
a =
1 b =
4
c =
4. 1231
a =
1
b =
7
c =
7.0711
9.0554
a =
1 b =
9
c =
a =
3
b =
1
c =
3.1623
a =
3
b =
4
c =
5.0000
a=
3
b=
7
c=
7.6158
a=
3
b=
9
c=
9.4868
a =
5
b =
1
c =
5.0990
a =
5
b =
4
c =
6.4031
8.6023
a =
5
b =
7
c =
a =
5
b =
9
c =
10.2956
a =
7
b =
1
c =
7.0711
a =
7
b =
4
c =
8.0623

4-49

Note that no return is made to step
1.4. (the TO command does not
return control).

JVlOO
0=
0=
. '0=
a'"
' 0=
0=
0=
0=
a'"
a':"
0=
0=

7
7
9
9
9,
9
II
11
11

12,
12
12
12

b=
b=
b=
b=
b=
b;'"
b=
b=
b=
b=
b=
b=
b=
b=

c=
c=
9
1 c=
c=
4
7 '. c=
9
c=
1 c=
c=
4
7
c=
9
c=
1 c=
4
c=
c=
7
9
c=

o. . \:

9.8995
11.4018
9.0554
9.8489
11..4018
12.7279
11.0454
11.7047
13.0384
14.2127
12.0416
12.6491 .
'13.8924
15.0000

.If~'!~"'jt" ~~j<~(

*
c)

t> ,

*Delete all,
*Let A = (B~2)/4*sqrt(3) t>
*1.1 Type A, 2*A, +- I>
*1.2 Stop if A> 100 t>
*2.1 Type B tJ
*Do part 1 for B=10(25)100 ~
A=
43.3012703
2*A =
86.6025406
.A =
530.440561
2*A =
1060.88112
Stopped b,3 step 1.2.
*Type A
.
A=
*1.0 Stop if A>100 ~
*Do part 1 for B=10(25)100 "
A=
2*A =

530.440561
43.3012703
86.6025406

Stopped by step 1.
*
DIAGNOSTIC MESSAGES
I CAN'T FIND THE REQUIRED STEP.

An incorrect step number has been
specified; no such step number exists •
. '.i

I CAN'T FIND THE REQUIRED PART.

An incorrect part number has been
specified; no ,such part number exists.

"
.J

". c'.
....

. 4-50

-",

""'

/.),

... ,-

5.6

DONE

DESCRIPTION
The DONE command skips execution of the remaining steps of a part during the current
iteration. This command can-be given indirectly only. It is usually given conditionally.
Done

(unconditional)

Normally used only as a temporary step (during the testing of a routine) when performing a partial execution.,
Done if ••..•.

(conditional)

Used to skip execution of the remaining steps of a part when certain conditions (specified in the IF clause) are met.
EXAMPLE
*LetA = 8~2+2*8+10 t>
*Let C =,At2+2*A*8+8t2 t>
*1.1 Type A / 8 / C in form 1 C.
*1.2 Type A*8 ~
*1. 3 Type A*C , <4*Form 1:

*+++++-++++ + .... +++.++++ +++++.++++ "

*Do part 1 for 8 = 1(1)4 ~
13.0000
1.0000
A*8 =
13
A*C =
2548

25.0000
A*8 =
A*C =

2.0000
36
7200
3.0000
75
19600

34.0000
A*8 =
A*C =

4.0000
136
49096

18.0000
A*8 =
A*C=

*1.15 Done

196.0000

400.0000

784.0000

1444.0000

*Do part 1 for 8=1 (1)4 P
13.0000
1.0000
18.0000
2.0000
25.0000
3.0000
34.0000
4.0000
*1.15 Done if 8>2
*Do part 1 for 8=1 (1)4
13.0000
1.0000
A *8 =
13
A*C =
2548

18.0000
A*8 =
A*C =

2.0000
36
7200

Insert temporary premature termination step following 1.1.
196.0000
400.0000
784.0000
1444.0000
Change unconditional DONE to
conditional.
196.0000

400.0000

4-51

3.0000
4.0000

784.0000
1444.0000

*
DIAGNOSTIC MESSAGES
DON'T GIVE THIS COMMAND DIRECTLY

4-52.

The DONE command must only be
given indirectly {preceded by a step
number}.

5.7

DESCRIPTION

FILE

FILE stores an item in the external storage file currently in use. Immediate storage is not
affected in any wr:;Jy.
E.

a(b, ... )
form m
step m
part m
formula f
all steps
File

all parts

as item n (code)

all formulas
all forms

Store the specified information as
item n (where n can be in the range
1 .through 25) in the currently open
externa I storage fi Ie. Code is optional for documentation only and
has no meaning to AID; however,
code, if used, must not exceed five
characters in length.

all values
all
EXAMPLE
*File all parts as item 5
Done.

All parts'" existing in immediate storage are stored on the currently open external storage file
as item 5. Successful execution of the command is evidenced by the AID response, DONE .. Item
contents can be retrieved by the RECALL command.
DIAGNOSTIC MESSAGES
ITEM NUMBER MUST BE POSITIVE INTEGER
<=25.

An invalid item number was given.

PLEASE DISCARD THE ITEM OR USE A NEW
ITEM NUMBER.

The specified item is already occupied; no change in either immediate or external storage occurs.

PLEASE LIMIT ID'S TO 5 LETTERS AND/OR
DIGITS

Code exceeds five characters in
length.

YOU HAVEN'T TOLD ME WHAT FILE TO USE.

A FILE command was attempted before an external storage file was
opened via a USE command.

NOTE
Only 22 items are allowed, if DECtape is used for external storage.

4-53

FORM

5.8
DESCRIPTION
FORM is used to edit typeouts of results ,for purposes of readibi lity, e.g., to (l)specify that results be typed in a specific notathn, (either scientific or fixed point), (2) specify that multiple results
are to be printed on a single line, usually to conserve space, (3) intersperse text .with results, and (5)
produce report-type headi ngs.
The elements which can be typed in a form are:
a)

Numeric values, including variables, $ (line counter), TIME, TIMER, and SIZE.
1.

Type -23.466 in form 1

Type

b, c

in form 2

3. Type $ in form 3
4.
b)

Type TIMER in form 4

Propositional values (TRUE and FALSE). Both of these values must be provided with on

integral form field containing at least five character positions.
Type F in form 5
c)

...

(where F is a proposition).

{indicating a blank field}.

Type a, b, ... , f in form 6.
Forms are entered as two lines:
*Form n:~

n identifies the specific form and
must be on integer.

user types actual format here •.

Once a form is defined, it can be used by sp'acifying itin

TYPE

c~n;Jmand.

Type ......... in fqrm .n
Specific Notations
Fixed-point notation is specified by a series of left arrows, one for each digit position and
one for a si9':l (if any).

If less integer places appear in the form than in the result, the error message

I CAN'T EXPRESS THE VALUE IN YOUR FORM is typed; if less decimal places appear in the form than
in the result, rounding occurs. A period is used to indicate the decimal point position.
++++.+++

-- -345.667

++++a ++++++

- 345.666667
\

4-54

At least seven periods must appear in a scientific notation form.
,.,.'

-3.3-01
Reducing the number of periods in a scientific notatipn form reduces the number of fraction
digits appearing in the result; these digits are dropped after rounding.
Multiple Results on a Single Line
More ,than one result can be typed on a single line through the use of the FORM command.
Such a technique might be used to conserve space, increase output speed, and/or couse results to
appear under previously typed col umn headings.
*Form l:~
* + ... + +++++++ • + +++++++ • ++ +ofo:++++. +++ "
* 1.1 Type Il, a~2, a~3, a~4 in form 1 p
*00 step 1.1 for a = 10(.5)15 f)
10.0
100.0
1000.00
10000.000
10.5
110.3
1157.63
12155.063
11.0'
121.0
1331.00
14641.000
11.5
132.3
1520.88
17490.063
12.0
144.0
1728.00
20736.000
12.5
156.3
1953.13
24414.063
13.0
169.0
2197.00
28561.000
13.5
182.3
2460.38
33215.063
14.0
196.0
2744.00
38416.000
14.5
210.3
3048.63
44205.063
~5.0
225.0
3375.00
50625.000

*
Interspersing Text with Results
A form can be used to intersperse explanatory text with typed results.
*Form 2:~
* If a = +++. +
then 0~2 = +++++. ++++
*2.1 Type 0, 0~2 in form 2 ~
*00 part 2 for a = 10(.5)12 J)
'100.0000
Ifo=10.0
then oC12=
110.2500
If a = 10.5
then oC12 =
121.0000
If a = 11.0
then oC12 =
132.2500
If a = 11 .5
then oC12 =
144.0000
lfa=12.0
thenoc.2=

"4-55

Report-Type Headings
A form containing only text can-be used to- generate columnar- headings~"
*Form 3:tl
a
*
*1 .1 Type form 3
*1.2 Do step 1.3 for a = 10(.5)12~
*1.3 Type a, a ~2, a ~3, a ~4 in form 1 cJ
*Form 1:
* ......... ................................ . . ................ Iof-o .....
*00 part ltJ
a
a~3
a~2
10.0
1000.0000
100.0000
10.5
110.2500
1157.6250
11.0
121.0000
1331.0000
11.5
132.2500
1520.8750
12.0
1728.0000
144.0000
1728.0000
12.0
144.0000
*

'c"

. . ........................... t!
a~4
10oo0.0pOO
12155.0625
14641.0000
17490.0625
20736.0000
20736.0000

DIAGNOSTIC MESSAGES
FORM NUMBER MUST BE INTEGER AND
1 <= FORM<1049.

Form numbers must be integers in the
range 1 through 109-1 .

I CAN'T EXPRESS THE VALUE IN YOUR FORM.

A value cannot be expressed in the
format given (the value is to~ large).

I CAN'T FIND THE REQUIRED FORM.

The specified form does not exist;
the form number is incorrect.

I HAVE TOO MANY VALUES FOR THE FORM.

The TYPE command specifies more
elements to be typed than there are
fields in the form. '

5.9

'GO

DESCRIPTION
GO continues execution of a currently-stopped (interrupted) process.
GO is the antithesis of the CANCEL command.
The GO command is normally used to continue execution after control has been returned to
the user via a STOP command.
Go
The GO command must be given directly only.
EXAMPLE
*let v=p*(rt2)hd
*p=3 .1421l
*1.1 Do part 2 for h=.5(.5)3 d
*1.2 Stopd
*2 • 1 Type r , h, v inform 1 J
*3.1 Type r'2~
*3.2 Delete step 1 .2 ~
*Form 1:
* ............................................. tl
*Do part 1 for r=l (1)3 ~
Error at step 2.1 (in formula v): eh? .
*Type formula v rJ
v: p *(r t2)h
*let v=p*(rt2)*h J
*GocJ

.5
1.0
1.5
2.0
2.5
3.0

Multiplication symbol was omitted.
Correct formula.
Execute GO to continue.
·1.5710
3.1420
4.7130
6.2840
7.8550
9.4260

STOP command at step 1 .2 is
Stopped by step 1 .2
encountered.
*(Do part 3) r:l
rt2 =
Done. I'm ready to go from step 1.2, although I can't find it.
*Go~

2
2
2
2
2
2

3
3
3
3
3
3

.5
1.0
1.5
2.0
2.5
3.0

6.2840
12.5680
18.8520
25.1360
31.4200
37.7040

14.1390
28.2780
42.4170
56.5560
70.6950
84.8340

*Go
I have noth i ng to do.

*
4-57

Execute part 3 via a parenthetical
DO; then GO to continue.

The GO command can be given dionly (with no step number' '
preceding it).

recty

I HAVE NOTHING TO DO.

When the GO command was given,
no process was in a stopped or interrupted status. Control retl,lrns to
the user and AID waits for a new
command.

4-58

5.10

IF CLAUSE

DESCRIPTION
The IF clause can be appended to ~ command (except the short SET command) to make that
command conditional; (the command is executed only if the proposition following the word IF is
satisfied).
Verb (arguments) IF proposition
EXAMPLES
a}

*1.1 Setb=50ifa>100"

Set b equal to 50 if, and only if,
a is greater than 100; otherwise
leave the value of b undisturbed.

*3.3 To part 5 if fp(d)=O ~

Transfer control to part 5 if, and only
if, d is an integer; otherwise, continue in sequence.

*2.9 Do part 3 if tv(f)=l "

Execute part 3 if the truth value (tv)
of proposition f is equal to 1; otherwise, continue in sequence.

4-59

LET
5.11
DESCRIPTION

LET defines arithmetic formulas, Boolean expressions (propositions), and user functions. The·
formula, expression, or function with which an identifier is associated is re-evaluated each time that
identifier appears during execution of a routine.
Arithmetic Formulas
The LET command can be used to tell AID how to calculate the value of an identifier (versus"
associating the identifier with a fixed value, as with the SET command). LET causes the identifier on
/

the left of the equal's sign to be set to the formula on the right of the equals sign.
a)

*Let v = p *(r ~ 2) *L
*Set p =3.1416cl

*Let L ::: w *h ~

Boolean Expressions (Propositions)
LET can also be used to equate an identifier to the value (true or false) of a proposition (a
Boolean expression) composed of
(e.g., =,<,

»,

arit~metic

the logical negation (not), and logical operators (and, or).

*Let a ::: true J

*Let c ::: a ane! b or c or d J

. c)

and logical statements using common relational operators

*Let y ::: X and yor (sqrt(100)

*~5 ~

*c=12 r)
*Do part 1

VOLUME CALCULATION
AID advances paper form one line. '
a =
b=
c ==
a*b*c =

3
5
12

180
NOTE

The steps above perform essentially the same process as the
command:
*1.1 Type "V.oLUME CALCULATION"
*1.2 Type + ,a,b,c,a*b*c

,"":'

5.13
DEseRI PTION
PAGE advances the Teletype paper form to the top of the next page.
Page.
The PAGE command can be used in conjunction with the $ symbol, which represents the
current line count, (the number of lines printed thus for on the current page).
mum of 54 I ines per page.
EXAMPLE

*1.0 Page
*1.1 Type"SQUARE ROOT VALUES FOR 1 - 100"
*1 .2 Do part 2 for a = 1 (1)100
*2.1 Type a, sqrt(a) ~ .l
*2.2 Do part 3 if $>45 V
*3.1 Page
*3.2 Do steR 1.1
*Do part 1 ~

( skip to new page)
SQUARE ROOT VALUES FOR 1-100

(44 lines of typeout)

(skip to next page)
SQUARE ROOT VALUES FOR 1-100

(44

of typeout)

(skip to next page)
SQUARE ROOT VALUES FOR 1-100

(remaining 12 lines of typeout)

+
4-63

AID allows for a maxi-

DESCRIPTION
-QUIT skips execution of the remaining steps of a part and satisfies the DO command for that
part by cancelling any further iterations.
The QUIT command is uSl.!OlIy given conditionally.
Quit. (unconditional)
Normally used only as a temporary step (inserted for the purpose of testing a portion of
a routine) when performing a partial execution.
Quit if ....•. (conditional)
Used to skip execution of the remaining steps of a part (and any further iterations of the
part by the current DO command)' when certain conditions are present.
EXAMPLE
*let A = B~ 2+2*B+10 d
*Let C =A ~ 2+2+A+B+B ~ 2 ~
*1.1 Type A,B,C ~
*1.2 Type A*B~
*1.3 Type A*ccl
*Do part 1 for B = 5(5) 15J

B
C
A*B
A*C =
A
B

A*B
-A*C =

AB
C =
A*B =
A*C
*1.15 Quit if A >lOocl
*Do part 1 for B = 5(5) 15 J

2102
225
94590
130
10
17142
1300
2 .22846*10 ~6
265
15
70732
3975
1 .874398*10~ 7

C
A*B
A*C
A
B
C

2102
225
94590
130
10
17142

=
=
=
=
=

*
4-64

5.15

RECALL

DESCRIPTION
RECALL reads an item, previously stored by a FI LE command, from the currently open external storage file into immediate storage. The contents of the item then exist both on the external file
and in immediate storage. All steps, identifiers, forms, etc., which were in immediate storage before
the RECALL command was given remain unchanged, with the exception of those which are redefined by
the recalled item.
*Recall item m (code)

Read in item #m (where m can be in
the range 1 th rough 25) from the
currently open external storage file.
Code is optional for documentation
purposes only and is ignored by AID;
however, code, if used, cannot exceed five characters in length.

EXAMPLE
*Recall item 23
Done.

*
The contents of item 23 of the currently open file are read into immediate storage. Successful execution sf the RECALL command is evidenced by the AID response, DONE..
DIAGNOSTIC MESSAGES
I CAN'T FIND THE REQUIRED ITEM.

The specified item cannot be found
in the currently open file. Either
the wrong file is open, the item
number is incorrect, or the item was
never filed.

ITEM NUMBER MUST BE POSITIVE
INTEGER <=25.

An invalid item number was given.

PLEASE LIMIT ID'S TO 5 LETTERS
AND/OR DIGITS.

Code exceeds five characters in
length.

YOU HAVEN'T TOLD ME WHAT FILE TO USE.

ARECA LL command was attempted
before an external storage file was
opened via a USE command.

4-65

5.16

DESCRIPTION

1
Resets TIMER to zero.
Reset timer
TIMER is a counter used by AID to keep track of the amount of central processor time spent
by the user in running AID. This cumulative running time can be obtained ot any point by typing the
request Type timer •• Each time the user wishes to reset the timer and to begin timing a new operation,
he types Reset timer ••

lThe least significant digit of TIMER is freguently used to supplypseudo-random decimal numbers.
/

4-66

5.17

~ET

DESCRIPTION
SET defines an identifier as equivalent to a fixed value. This value is calculated once and
the result is then used whenever the identifier appears in a calculation.

If an expression, the expression must
be immediately reducible to a
numeric val ue.

*Set x = expression or value

NOTE
When the SET command is typed as a direct command,
the verb (SET) may be omitted. This form is cafled a
short SET command.
a)

*Set ci = 20

*a = 20~

*Set a = sqrt(20)+43.5~2

*Set d = true

*f = false

EXAMPLES
A more complete discussion of the use of SET commands, including additional examples, can
be found in Chapter 3.

4-67

5.18

OESCRI PTION
The STOP command temporari Iy halts the current process at the point where the STOP com. mand appears and returns control to the user. The stopped process can be resumed by typing GO. If
the user does not desire to continue the process, he types CANCE L.
The STOP command can be given indir~ctly only.
Stop

(unconditional)
Normally used only as a temporary step (during the testing of a routine) when performing a partial execution.

Stop if ••••

(conditional)

Used to temporarily halt execution and return control to the user when certain condi tions (specified in the IF clause) are met.
EXAMPLE

tJ.

*Let B=16-C
*Let A=3. 17568/B
*1.1 Stop if 8=0 C>
*1.2 Type A, B, C in form 1
*Form

tJ.

I:J

STOP command prevents attempt to
divide by 0 in formula A.

* ~~;t'1'f~~'C~~4(4)24 .jj.......... .
*00
1.58784000..01
1.98480000..01
2.64640000-01
3.96960000-01
7.93920000-01
Stopped b¥ step 1. 1
*Type C t>
C =
*Type B ~
B=

2.00000000
I. 60000000
1.20000000
8.00000000
4.00000000

01
01
01
00
00

16
0

'.I

............. -6
-4.00000000 00

4.00000000 00
8.00000000 00
1.2000000001

5.19

DESCRIPTION
TO discontinues the sequential execution of the part currently being executed and transfers
control to another step or part. When the new part is finished, the direct command which initiated the
execution is satisfied.
The TO command can be given indirectly only.

{:t:;

:.n }

EXAMPLE
*1.1 Demand G ~
*1.2 Demand T ~
*1.3 To part 2 if T>=560 ~
*1.4 Let d = G*.046 ~
*1.5 To part 3 if (T+d»560 ~
*1.6 Type "DEDUCTIONS" p
*1 • 7 Type d, d+ TI'" ,'" t>
*2.1 Type "NO DEDUCTION REQUIRED"
*2 • 2 Let d = 0
*2.3 To step 1.6 ~ .1
*3. 1 Let d = 560 - T p
*3.2 To step 1.6 ~
*Do part I, 4 times.
.l
G = *125.00p.
T = *340.00
DEDUCTIONS
5.75
d =
d+T =
345.75

G
T
DEDUCTIONS
d
d+T
G
T
DEDUCTIONS
d
d+T

*350.00

== *545.00

~
~
15
560

=
= *103.45 ~
= *559.04

G = *300.00~
T = *565.00 ~
NO DEDUCTION REQUIRED
DE DUCTI ONSd =
d+T =

.96
560

o
565

4-99

Demand gross pay for week.
Demand total FICA year-to-date.
$560 = maximum deduction/year.
d = current deduction.

-.
~iAGN~Y~' MES"S~ES

.;.,,.,,::'I··:'·;:;·<·'i·tfCfi:l~t-E

THIS COMM.AND DIRECTlY.

t :.. ?

The TO command must (Ilnly be given
indirectly (preceded by a step
number),

.,1

5.20
DESCRIPTION
Types out the specified information on the user's console.

-n
s
-

where n is numeric value or expression

where p is a proposition

where s is a subscripted var"iable

s(a,b, •• )

"any text"
form m

Type

ste~

.. represents a null item (a blank field when typing
in form x, or a blank line)

m.n

part m
formula f
f(n, ... )

function of (n, ••• )

function (tv) of a proposition

all ste~s
all ~arts
all formulas
all forms
all values
all
time

current time of day in min~tes since midnight

timer

processor ti me used (see RESET TIME R)

size

amount of immediate storage being used

item-list
users
Combi ned TYPE Commands

item list of currently open external storage file
always returns an answer of 0 ..

Several individual TYPE commands (except for TYPE "any text" or TYPE ITEM-LIST) can be
combined into one command.
*Type all parts, 1243, formula 0, form 5
Each entry, however, is still typed on a separate line.
IN FORM Option
Output edi ting can be performed by appendi ng the IN FORM ••• opti on to a TYPE command.
See "FORM". Note that only certain types of entries can be typed in forms.

4-71

EXAMPLE
*b = 20~
*c = 30~
*d = 111. 333

Variables

*Let a(b,c) = (b~2)*(c~2)
,*Let f(b) = b/2

User functions
Subscripted variables

*e(l) = 16"
*e(2) = 25~
*e(3) = 35~
*Let 9 = h.}or i and j
*h = true Po
*i = falseq
*j = false p

Propos i ti ons

*Let k = b*c*d
.*Let m = k/2*sqrt(k) ~

Formulas

*Form I:P

*
*Form 2:P
*
POUNDS
*1.1
*1.2
*1.3
*2.1
*2.2

Forms
OUNCES~

POUNDS IS
OUNCES

Type b,c ~
Type d,e t:l
To part 2 "
Type form 2 f)
Type d/e(1), d in form 1 ~

Parts and steps

*3.1 Type k, m f)
*3.2 Type a(e(l ),e(2» "
*Do part 1 tJ

b =
20
c =
30
d =
111. 333
e(l) =
16
e(2) =
25
'35
e(3) =
POUNDS' OUNCES
6.95800 POUNDS IS
1.113 02 OUNCES
A command to type the values of a
*Type e "
e(l) =
subscripted letter results in typeouts
16
e(2) =
of all values.
25
" e(3) =
35
*Type 0(3,6) p
324
0(3,6) =
*Type a t>
o(b,c):
(b,2)*(c'2)
*iype 9 "
9 =
~ue
*Type tv(g) "
. tv(g) =
*Type form 1 J)
......... POUNDS IS ......... OUNCES
*Type step 1.3 t3
1.3 To part 2.
*Type formula k " '
k: b*c*d
*Type all steps "

4-72

1.1 Type b,e.
1.2 Type d,e.
1.3 To port 2.
2.1 Type form 2.
2.2 Type d/e(1), d in form 1.
3.1 Type k,m.
3.2 Type a(e(1 ),e(2}).
*Type all formulas C>
a(b,e): (b'2)*(e~2)
9: h or i and i
k: b*e*d
m: k/2*sqrt(k)
*Type all forms 6
Form 1:
POUNDS IS .•••••••• OUNCES
Form 2:
POUNDS
OUNCES
*Type all values ~
b=
20
e =
30
d =
111.333
h=
true
i =
false
false
:
16
e(2) =
25
e(3) =
35
*Type all
1.1 Type D,e.
1.2 Type d,e.
1.3 To part 2.
2.1 Type form 2.
2.2 Type d/e(1), d in form 1.
3.1 Type k,m.
3.2 Type a(e(1 ),e(2».
Form 1:
OUNCES
POUNDS IS
Form 2:
POUNDS
OUNCES
a(b, e): (b~2)*(e ~2)
9: h or i and i
k: b*e*d
m: k/2*sqrt(k)
b =
20
30
e =
d =
111.333
true
h =
i =
false
false
:
16
e(2) =
25
e(3) =
35
*Type time
24-hour time
time: 1453

e(1~

4-73

*Type timer ~
timer

The total central processor time uti lized by the user thus for.
.
,

mm ss.ss

mm = minutes
= seconds to the nearest
hundredth

55.55

*Type size rJ
size:

*Use file 110 (DSK) ~
.
Roger.
.
*File all formulas as item 1 (FMULA) };
Done.
*File all forms as item 2 (FORM) ~
Done.
1
*File all values as item 3 (VALUE) I>
Done.
*File all steps as item 10 (STEP) ~
Done.
*Type item-list };
ITEM-LIST
ITEM
DATE
1
mm/dd/yy
2
mm/dd/yy
3
mm/dd/yy
10
mm/dd/yy

•

4-74

The number of "cells" of immediate
storage currently occupied by the
user's work area. In a 13K environment, approximately 1900 such "cells"
are avaitable for this purpose.

DATE is the creation date.

5.21

USE

DESCRIPTION
USE makes an external storage file 1 available for use. The external file thus addressed remains open for use until another USE command is given or until the AID program is terminated.
USE file filename (device)
where

filename is a positive integer-, greater than 0 and less than or equal
to 2750, which identifies the particular file on the device.
device

is the device name (logical or physical) of the device containing the file. Device can be one of the following.
DSK

disk

OTAn

OECtape, where n is the drive number and
can be in the range 0 through 7.

or any logical device name assigned to either of the above
device types.

If device is omitted, DSK is assumed. Mag-

netic tape may also be used, provided the user positions the
the tape directly before the desired file before issuing a
RECALL or FILE command; the TYPE ITEM-LIST and DISCARD
commands have no meaning for magnetic tape.
Once a file has been opened by a USE command, all DISCARD, FILE, RECALL, and TYPE
ITEM- LI ST commands are assumed to refer to that file.

EXAMPLE
*Ose file 103 (OSK) ~

(or Use file 103)

Roger.~

*
Makes file 103, on disk, avai lable for use. Successful execution of the command is evidenced by the AID response ROGER.
DIAGNOSTIC MESSAGES
FI LE NUMBER MUST BE POSITIVE
INTEGER <= 2750.

Filename is less than 0 or greater than
2750.

1 External storage files created by AID are in a special AID (8-bit) character format, Dot ASCII.

4-75

APPENDIX A
TABLES

This appendix contains five tables:
A-I

A Glossary of AID Terms

A-2A

AID Command Summary

A-2B

File Command Subset

A-3

AID Character Set

A-4

AID Diagnostic Messages

4-77

Table A-I.
A Glossary of AID Terms
+

Indicates a blank field, when typed in conjunction with a FORMi otherwise,
\
a blank line.

A spe~ial symbol which refers to the line counter kept by ~ID. This symbol
can be used in TYPE commands, or it can be tested within a conditional command to cause a line feed (LINE) or advance to next head of form (PAGE) at
appropriate points.

Conditional expression

A series of clauses separated by semicolons, with
each clause made up of a proposition followed by
a colon and then by an expression. The entire
conditional expression must be enclosed in parentheses or brackets.

External storage

See "File".

Expression

An arithmetic formula, Boolean proposition, or
function.

File

A peripheral storage medium (usually disk or
DECtape) used for the preservation of user subroutines, values, etc. Files are manipulated by
the DISCARD, FILE, and RECALL commands.

Form

A user-specified format for editing output via the
TYPE command.

Formula

An arithmetic expression defined by the user via
the LET command.

Function

An arithmetic or Boolean function providecl by
AID (see Table 4-2) or defined by the user via the
LET command.

Identifier

A single alphabetic character associated with a
variable (via the LET or SET commands) and then
used to access the current value of the variable.

Immediate storage

Core storage work area. In a 13K environment,
approximately 4K of core is available to the user
for his steps, values, tables, etc.

Item-list

The file directory associated with an external storage file. The user can obtain a listing of the
directory of the currently open file by typing the
command TYPE ITEM-LIST.

Part

A series of indirect steps, the step numbers of
which have the same integral value.

SIZE

A noun which can be specified in a TYPE command to obtain a typeout of the amount of core "cells"
used. (1 ce II .= approx. 2 core words)

4-78

Table A-l (Cont)
A Glossary of AID Terms
Step

Anyone -line command typed by the user. A step
can be direct (executed immediately), in which
cose no step number precedes it, or indirect (to
be executed later), in which case it is preceded
by a step number.

TIME

A noun which can be specified in a TYPE command to obtain a typeout of the time of day (in
24-hour format).
r

TIMER

A noun which can be specified in a TYPE command to obtain a typeout of the amount of central
processor time spent thus for by the user during
the current AID run.

Variable

An element defined by ei ther the LET or SET commands which is associated with some value. It is
referred to by an associated tag called an
identifier.

4-79

Table A-2A
AID Command Summary Command Format

Type

Description

CANCEL

0,0

Cancels a currently stopped process when the user
does not desire to resume execution.

(CANCEL)

0,0

Cancels a currently stopped process which was
initiated by a parerithetical DO.
•

Erases the specified item from immediate storage
and frees the space occupied by it for some other
use.

DE LETE

S(m,n)
form m
stepm.n
part m
formula f
a II steps
all parts
all formulas
all forms
all values
all

SCm, n)
l.
DEMAND l as "any text"
SCm, n) as "any
text"

DISCARD ITEM m(code).

step m.n
step m .n, p times
step m.n for l=range
part m
partm, p times
port m for L=range

Several DELETE commands can be combined into
one.

1,0

Causes AID to type out a message requesting the
user to supply a value for the specified item.
Only one variable can be specified in each
DEMAND command.

Deletes item 1m from the external storage fi I~
currently in use. (Code) is optional.

(DO .... same as above .• )

DONE

Executes an indirect step or part. If the DO command is a direct step, control r~turns to the user at
. the completion of the DO; if an indi rect step,
control returns to the step following the DO.
Initiates a new execution without cancelling the
currently stopped process.

1,0

Skips execution of the remaining steps of ~ part
during the current iteration.

4-80

Table A-2A (Cont)
AI D Command Summary
Command Format

FILE

l
S
S(m,n}
form m
step m.n
part m
formula f
a II steps
all parts
a II formu las
all forms
all values
all

AS ITEM n
(code)

FORM m:
•••••••• • ++++

Description

Type

Text

Stores the specified item in the external storage
fi Ie currently open. Immediate storage is not
affected in any way. (code) is optional.

Defines a format to be used in editing typeouts
for purposes of readabi Ii ty .
fixed point notation
(up to nine digit positions plus the decimal
point)

+++++e++++

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

scientific notation
(minimum of seven positions
maximum of fourteen)

text

any text to be included
in the line; not enc losed
in quotation marks unless
they are port of the text.

.
QQ..

D,O

Continues execution of a currently stopped process;
opposi te of the CANCE l command.

-IF Clause

Can be appended to any command (except the abbreviated-5ET command) to make the command conditional; the command is executed only if the proposition is true.

Verb .... IF proposition.

-LET

l = formula
F(l) = m
F(l} = proposition

LET S be sporse

.
0

Defines arithmetic formulas, Boolean expressions
(propositions), and user functions and associates
them with identifiers. The formula, expression,
or function with which an identifier is associated
is re-evaluated each time the identifier appears
during an execution.

Sets undefined array elements to zero.

4-81

Table A-2A (Cont)
AI D Comman~ Summary
Command Format

Type

Description

LINE

Advances the Te letype paper form one line.

PAGE
---

Advances the Teletype paper form to the top of
the next page.

QUIT

Skips execution of the remaining steps of !J part and
satisfies the DO command for that part by cance IIi ng any further i terati ons. Usua IIy given conditionay.

RECALL ITEM m (code)

RESET TIMER

Resets TIMER to zero.

Defines an identifier as equivalent to a fixed
value, which is calculated once and thenused
whenever the identifier appears. A short form
of the SET command, where the word SET is
omitted, can be used if the command is direct.

1,0

Temporari Iy halts the current process at the point
where the STOP command appears and returns control to the user. The stopped process con be resumed by typing GO.

1,0

Discontinues the sequentia I execution of the part
currently being executed and transfers control to
another step or part; when the new part is finished,
the direct command which initiated the execution
is satisfied. '

SET

L=proposition
s(m, n) =m
S(m, n )=proposition

STOP

{"",.m

stepm.n

Reads 'an item, previously stored by a FI LE command, from the currently open external storage
file into immediate storag'e. (Code) is optional
and is for documentation on Iy.

4-82

Table A-2A (Cont)
AI D Command Summary
Command Format
m

Description

Type

S
S(m,n}
proposition
"any text"

Types out the specified information on the user's
console. Several individual TYPE commands may
be combined into one (except for TYPE "any text"
or TYPE ITEM-LIST).

TYPE

form m
step m.n
part m
formula f
F(x}
F(proposition}
a II steps
all ports
all formulas
all forms
all values
all
time
timer
size
item-list

USE FILE filename (device)

The command
Type

in form n

causes the listed items to be typed out in the format specified by form n. n can be a numeric value
(for example, form 3) or it can be a numeric formula (for example, form (2*x-y».

S
I- S
S
F

Makes an external.storage fi Ie avai lable for use.
The externa I fi Ie thus addressed remains open for
use (by DISCARD, FI LE, RECALL, and TYPE
ITEM-LIST commands) until another USE command
is given or the AI D program is terminated.

Command Format Symbology
L = letter
S = subscripted letter.
m, n, p = numeric values.
f = formula.
F = function.
range =an i nterati ve sequence or series of va lues.
Type Symbology
D = Can be given directly only
I = Can be given indirectly only.
0= Operational command.
F = Fi Ie command.
S = Special command.

4-83

Command Format
D1SCARD ITEM m ~code)

""L
S
S{m,n,}
form m
step m.n
part m
FILE< formula f
all steps
all parts
all formulas
all forms
all values
.....all

Table A-2B
Fil e Command Subset
Section
Reference

Description

5.4

Deletes item 1m from the external storage file currently in use. (Code) is optional.

5.7

Stores the specified item in the external storage
file currently open. Immediate storage is not
affected in any way. (Code) is optional.

....

AS
ITEM
n {code}

RECALL ITEM m (code)

5.15

Reads item 11m, previously stored by a FI LE command' from the currently open external storage
file into immediate storage. (Code) is optional
and is for documentation only •
. il!

TYPE ITEM-LIST

5.20

Obtains a typeout of the directory of the currentlyopen external sJorage file.

USE FILE filename (device)

5.21

Makes an external storage fi Ie available for use.
lhe external storage file thus addressed remains
open for use (by DISCARD, FILE, RECALL, and
TYPE ITEM-LIST commands) until another USE
command is given or the AID program is
terminat.ed •

4-84

Table A-3
AID Character Set
Typing Method

Standard
Math
Symbol

AID Symbol

JOSS
Symbol

Model 37

Models 33 and 35

A through Z

Strike appropri ate key with
SHIFT.

Strike appropriate key; no
SHIFT.

A through
Z

a through z

Strike appropriate key wi thout
SHIFT.

Not avai lable;
use upper-case
letters.

a through
z

0,1 through 9

Strike appropriate key; no
SHIFT.

Strike appropri ate key; no
SHIFT.

0, 1
through 9

I I (absolute)

Strike the I, 1
key with SHIFT.

I I

[

] (brackets)

[

Strike appropri ate keys.

[ Strike K with
SHIFT
1 Strike M with
SHIFT

[

(

) (parentheses)

(

)

( Strike the ca
(
key wi th SHI FT.
) Strike the ),9
key with SHIFT.

)

Operators:

( Strike the (,a
key with SHIFT •
) Strike the), 9
key with SHIFT .

x e (exponent)

x~e

Strike the "',
/\ key; no SHIFT •

Strike the ~ , N
key with SH 1FT .

Strike the.? ,I
key; no SHIFT .

Strike the?,/
key; no SHI FT.

• (mul tipl ication)

Strike the *,:
key with SHIFT .

Strike the *,:
key with SHIFT.

+ (addition)

Strike the +,;
key with SHIFT .

Stri ke the +,;
key with SHIFT.

Strike the =,key; no SHIFT.

Strike the =,key; no SHI FT.

= (equal)

Strike the =,key with SHIFT .

Strike the =,key with SHIFT.

/' (not equa I)

Strike the # ,3
key with SHIFt.

Strike the #,3
key with SHIFT.

(divide)

•

- (subtraction)

Boolean
Expressions:

4-85

Notes

Table A-3 (Cont)
AID Character Set
Typing Method

Standard
Moth
Symbol

< (equal
-

than)

to or less
.

> (equal to or
- greater than)

AID Symbol

JOSS
Symbol

Model 37

Models 33 and 35

(2 characters)

Strike the <, <
key; then strike
the=, -key
with SHIFT.

Strike the<, .key
with SHIFT; then
strike the =,-key
with SHIFT.

> = (2 characters)

Strike the >, >
key; then strike
the =,-key with
SHIFT.

Strike the>,.
key with SHIFT;
then strike the
=,- key with
SHIFT.

RUBOUT (types
back as deleted
characters between \.

Strike DELETE
key to erose
each preceding
character in
error; then type
correctly.

Strike RUBOUT
key to erase each
preceding character in error;
then type
correctly.

BACKSPACE
and type
over

Example:
TPE\EP\ YPE
PART 1.
null item

-+-

Strike the ,
key with orwithout SHIFT •

Strike 0 key
with SHIFT.

$ (current line
number)

Strike the $,4
key with SHIFT.

* (cancel entire
line)

Strike the * ,:
key with SHIFT.

Strike the *,:
key with SHIFT.

(underscore)

...

4-86

Notes

Used to
correct
typing
errors.

Table A-4
AID Diagnostic Messages
Meaning

Message

= ???

A value has not been supplied by the user for
variable x.

DONE.

Signals completion of a File command (DISCARD,
FI LE, RECALL).

DONE. "M READY TO GO iJiOM} STEP m.n .

•• • AT STEP m.n .•• Task was suspended by an
interruption or error during
the interpretation of an
indirect step •
•• • FROM STEP m.n ••• Task was suspended by a
stopping command •
•• • IN STEP m.n ••• Task was suspended during an
indirectly initiated DO
command.
AID resumes execution whenever the user types

Go.
DONE. "M READY TO GO

~iOM}

Same as above, except that the step at which
AID is prepared to resume can no longer be found
in i mmed i ate storage. Possibl y, a di rec t command (or a routine initiated by a parenthetical
DO) has deleted the step in the interim. Upon
receipt of a GO command from the user, AID will
attempt to resume at the step following the missing step.

STEP m.n, ALTHO I CAN'T FIND IT.

DON'T GIVE THIS COMMAND {

DIRECTLY}
INDIRECTLY

EH?

This command can be given only indire~tly (TO,
DONE, STOP, DEMAND) or only directly
(CANCEL, GO).
The previously entered line is incorrect.
Indirect commands:

The step number was
incorrectly typed.

Direct LET commands:

LET x portion is
incorrect.

Other direct commands:

A space was omitted.
The terminating
period was omitted.
The command is not
legitimate.
An expression is incorrectly written.

To continue, retype the command correctly.

4-87

Table A-4 (Cont)
AID Diagnostic Messages
Meaning

Message
ERROR AT STEP m.n:

The step number is correct, but the command is
incorrect.

EH?

Request a typeout of the step in error.

b .• Check for the errors listed under "Eh ?".
c.

Retype the command correctly.

d. Type GO. to continue.
The step in error refers to a nonexistent step or
part.

ERROR AT STEP m.n:

I CAN'T FIND THE REQUIRED

{~[5:M

Correct the error and type GO. to cOl')tinue •.
}.

PART
FORMULA
The variable z has not been assigned a value by
the user.

ERROR AT STEP m.n: (IN FORMULA x):

= ???

ERROR IN FORMULA x:

Check for any other errors, define variable z
correctly, and type GO. to continue.
(Fo"owing a direct command in which x was
used) The form of the expression for x is in error.

EH?

Request a typeout of formula x.

b. Check for the errors listed under "Eh?".
c. Formula x m~y be correctly written, but the
definition of one or more identifiers is not
consistent with their use in formcrla x.
FILE NUMBER MUST BE POSITIVE
INTEGER <=2750.

The fi lename of a USE command must not be
greater than the value 2750.

FORM NUMBER MUST BE INTEGER AND
1 <= FO RM < lOt 9.

Form numbers must be integers in the range 1
through 109- 1•

I CAN'T EXPRESS THE VALUE IN YOUR FORM.

A value cannot be expressed in the format specified by the FORM (e.g., the value is too large to
specify in fixed point notation). To correct,
follow the steps given under "I HAVE TOO
MANY VALUES FOR THE FORM."

I CAN'T FIND THE REQUIRED

{

FORM}
ITEM
•
PART
STEP

Either the element has never been defined or has
been deleted.

4-88

Table A-4 (Cont)
AID Diagnostic Messages
Message

Meaning

I CAN'T MAKE OUT YOUR FIELDS IN THE
FORM.

The fields in the form specified were typed in
such a way that AID cannot distinguish their beginning or ending. Possibly, there are either no
fields in the form or two or more are run together
with no intervening space.

I HAVE AN ARGUMENT <=0 FOR LOG.

The argument for the LOG function must be
greater than o.

I HAVE A NEGATIVE ARGUMENT FOR SQRT.

Square root arguments must be positive.

I HAVE A NEGATIVE BASE TO A FRACTIONAL
POWER.

An attempt was made to raise a negative value to
a fractional power. For example,
Type (-y)t(1/2).

I HAVE AN OVERFLOW.

Some number has exceeded 9.99999999. 10t99
in magnitude.

I HAVE A ZERO DIVISOR.

An attempt was made to divide by O.

I HAVE NOTHING TO DO.

The user has typed GO., but there is no currently
stopped process which can be continued.

I HAVE TOO FEW VALUES.

An insufficient number of arguments have been
supplied for a function.

I HAVE TOO MANY VALUES FOR THE FORM.

There are not enough fields in the form to receive
all the values to be typed.
a. Type the form and the values.
b. Check for errors.
c. Change either the TYPE command or the
FORM to make them compatible and then
type GO. to continue.

I HAVE ZERO TO A NEGATIVE POWER.

An attempt was made to rai se 0 to a negative
power.

IlLEpAL SET OF VALUES FOR ITERATION.

An error has been detected in a range clause of
a function or a DO command, such that the ending value can never be reached (e.g., the increment is 0).

I'M AT STEP m.n.

When the user responds to a DEMAND-produced
request (x=*)with a carriage return only, AID
types back this message.

4-89

Table A-4 (Cont)
AI D Diagnostic Messages
Message

Meaning

INDEX VALUE MUST BE INTEGER AND
! INDEX! <250

All index value.s (subscripts) must be integral and
must have an absolute value of <250.

I NEED INDIVIDUAL VALUES FOR A FORM.

A command was given to type a subscripted variable in a form (e.g., Type B in form 1, where
B is a subscripted variable). Individual values
only can be specified for TYPE .... IN FORM n.
commands.

I RAN OUT OF SPACE.

User's immediate memory is filled due to one of
the following errors ..
a. Endless loops because of DO commands or
because DO was typed instead of TO.
b. Unlimited recursive definition.
c. Variable x defined in terms of y, and variable y defined in terms of x via LET command.
d. Program is too large for avai lable memory;
use TYPE SIZE command to determine how
much immediate storage has been used.
File commands can be used to store parts of
the routine and execute them one at a time.

I RAN OUT OF FILE SPACE.

DECtape directory is full (limit = 22 items).

ITEM NUMBER MUST BE <= 25.

The item number in fi Ie commands (DISCARD,
FI LE, RECALL) must be less than or equal to 25.

NUMBER-OF- TIMES MUST BE INTEGER AND
>= O.

The value specified in the TIMES clause of a DO
command must be a positive integer.

PART NUMBER MUST BE INTEGER AND
1 <=PART<10~9.

Part numbers must be integers and in the range
1 through 109-1.

PLEASE DELETE THE ITEM OR USE A NEW
ITEM NUMBER.

The user has attempted to FI LE information into an
item which already exists on the currently open
external storage file. The user must either
DISCARD the item prior to filing the new information or use a di fferent item number in the FI LE
command •

..
PtEASEKEEP !X!<100 FOR SIN(X) AND
COS(X).

Arguments for the SINE and COSINE functions
must be less than 100.

PLEASE LIMIT ID'S TO 5 LETTERS AND/OR
DIGITS.

Filename in a USE file command or code in a
DISCARD, FILE, or RECALL command exceeds
five characters in length or contains special
characters.

4-90

Table A-4 (Cont)
AID Diagnostic Messages
M.essage

Meaning

PLEASE LIMIT LINES TO 78 UNITS (CHECK
MARGIN STOPS) SAY AGAIN:

User typeins are limited to singleline, 78 -character strings.

PLEASE LIMIT NUMBERS TO 9 SIGNIFICANT
DIGITS.

Numeric values are limited to nine significant
digits.

PLEASE LIMIT NUMBER OF INDICES TO 10.

The number of subscripts following an identifier
cannot exceed 10.

PLEASE LIMIT NUMBER OF PARAMETERS TO
TEN.

The number of arguments for a function is limited
to 10.

PLEASE LIMIT STEP LABELS TO 9 SIGNIFICANT
DIGITS.

Step numbers can be up to nine di gits in length.

REVOKED. I RAN OUT OF SPACE.

See "I RAN OUT OF SPACE.II

ROGER.

Signals successful completion of a USE file
command.

SOMETHING'S WRONG. I CAN'T ACCESS
THE FILES.

A system I/O error (or other type of AID error)
has occurred. Begin again.

SOMETHING'S WRONG. TRY AGAIN.

AID has found something unusual in its internal
records or has received contradictory signals from
its I/O routine. Begin again.

SORRY. SAY AGAIN:

A transmission error occurred on the previous
typein. This message is preceded by the erroneous
line with # symbols typed where the failure occurred. Retype the line.
.

STEP NUMBER MUST SATISFY
1<= STEP< 10t9.

Step numbers must be in the range 1 through 109-1.

STOPPED BY STEP m.n.

Process has been temporarily halted by a STOP
command at step m. n •

YOU HAVEN'T TOLD ME WHAT FILE TO USE.

The user has issued a DISCARD, FILE, RECALL,
or TYPE ITEM-LIST command before he has given
a USE file command.

4-91

Book 5
Programming

In
FORTRAN .

•

CONTENTS
Page
CHAPTER 1 INTRODUCTION TO THE FORTRAN LANGUAGE

1.1

Line Format

5-15

1. 1.1

Statement Number Field

5-15

1.1.2

Line Continuation Field

5-15

1.1.3

Statement Reid

5-16

1.1.4

Comment Li ne

5-16

1.2

Character Set

5-17

CHAPTER 2 CONSTANTS, VARIABLES, AND EXPRESSIONS

2.1

Constants

5-19

2.1.1

Integer Constants

5-19

2.1.2

Real Constants

5-19

2.1.3

Double Precision Constants

5-20

2.1.4

Octal Constants

5-20

2.1.5

Complex Constants

5-20

2.1.6

Logical Constants

5-21

2.1.7

Literal Constants

5-21

2.2

Variables

5-22

2.2.1

Scalar Variables

5-22

2.2.2

Array Variables

5-22

2.3

Expressions

5-24

2.3.1

Numeric Expressions

5-24

2.3.2

Logical Expressions

5-26

CHAPTER 3

3.1

THE. ARITHMETIC STATEMENT
General Description

5-29

. CHAPTER 4 CONTROL STATEMENTS

.c1;.1

GO TO Statement

5-31

4.1.1

Unconditional GO TO Statements

5-31

4.1.2

Computer GO TO Statements

5--31

4.1.3

Assigned GO TO Statement

5-32

4.2

IF Statement

5·-32

5-3

CONTENTS (COnt)
Page
4.2.1

Numerical IF Statements

5-33

4.2.2

logical IF Statements

5-33

4.3

DO Statement

5-34

4.4

5-36'

,CONTINUE Statement

4.5

PAUSE Statement

5-36

4.6

STOP Statement

5-37

4.7

END Statement

5-37

CHAPTER 5

DATA TRANSMISSION STATEMENTS

5.1

Nonexecutable Statements

5-39

5.1.1

FORMA T Statement

5-39

5.1.2

NAMELIST'Statement

5-49

5.2

Data Transmission Statements

5-51

5.2.1

Input/Output Lists

5-52

5.2.2

Input/Output Records

5-53

5.2.3

PRINT Statement

5-53

5.2.4

PUNCH Statement

5-54

5.2.5

TYPE Statement

5-54

5.2.6

WRITE Statement

5-54

5.2.7

READ Statement

5-56

5.2.8

REREAD Statement

5-57

5.2.9

ACCEPT Statement

5-58

5.3

Device Control Statements

5-58

5.4

Encode and Decode Statements

5-59

.:t'
".,

... ';,"',

-.',

CHAPTE,R 6

SPECIFICA TIO N STATEMENTS

6.1

Storage Specification Statements

5-62

6.1.1

DIMENSION Statement

5-62

6.1.2

COMMON Statement

5-64

6.1.3

EQUIVALENCE Statement

5-65

6.1.4

EQUIVALENCE and COMMON

5-66

6.2

Data Specification Statements

5-66

6.2.1

DATA Statement

5-66·,

6.2.2

BLOCK DATA Statement

5-68

5-4

CONTENTS (Cont)
6.3

Type Declaration Statements

Page
5-68

6.3.1

IMPLICIT Statement

5-68

CHAPTER 7

SUBPROGRAM STATEMENTS

7.1

Dummy Identi fi ers

5-71

7.2
7.3

Li brary Subprograms

5-71

Arithmetic Function Definition Statement

5-71

7.4

FUNCTION Subprograms

5-72

7.4.1

FUNCTION Statement

5-72

7.5

SUBROUTINE Subprograms.

5-74

7.5.1

SUBROUTINE Statement

5-74

7.5~2

CALL Statement

5-75

7.5.3

RETURN Statement

5-75

7.6

BLOCK DATA Subprograms

5-76

7.6.1

BLOCK DATA Statement

5-76

7.7

EXTERNAL Statement

5-76

7.8

Summary of PDP-l0 FORTRAN IV Statements

5-77

CHAPTER 8 LIB40
8.1

The FORTRAN Operating System

5-83

8.1.1

FORSE.

5-83

8.1.2

I/O Conversion Routines

5-84

8.1.3

, FORTRAN UUOs

5-85

8.2

Science Library and FORTRAN Utility Subprograms

5-86

8.2.1

FORTRAN IV Library Functions

5-86

8.2.2

FORTRAN IV Library Subroutines

5-90

CHAPTER 9 SUBPROGRAM CALLING SEQUENCES
9.1

Macro Subprograms Called by FORTRAN Main Programs

5-95

9.1.1

Calling Sequences

5-95

9.1.2

Returning of Answers

5-96

9.1.3

Use of Accumulators

5-96

9.1.4

Examples of Subprogram Linkage

5-96

5-5

Page
.

9.2

Macro Main Programs Which Reference FORTRAN SubprOgrams

9.• 2.1

C~lIing

9.2.2

Returning of Answers

5-103

9.2.3

Exampl e of Subprogram li nkage

5-104

Sequences

5-103
5-103,

CHAPTER 10 ACCUMULATOR CONVENTIONS FOR MAIN PROGRAMS AND SUBPROGRAMS
10.1

Locations

5-111

10.2

Accumulators

5-111

10.2.1

Accumulators 0 and 1

5-111

10.2.2

Accumulators 2 Through 15

5-112

10.2.3

Accumulators 16 and 17

5-112

10.3

UUOS

5-112

10.4

Subprograms Ca II ed by JSA 16, Address

5-112

10.5

Subprograms Called by PUSHJ 17, Address

5-112

10.6

Subprograms Called by UUOS

5-113

CHAPTER 11

SWITCHES AND DIAGNOSTICS

11.1

FORTRAN Switches and Diagnostics

5-115

CHAPTER 12 RELATED FEATURES OF THE PDP-l0
12.1

ASCII Character Set

5-125

12.2

PDP-10 Word Formats

5-126

12.3

FORTRAN Input/Output

5-127

12.3.1

Logical and Physical Peripheral Device Assignments

5-128

12.3.2

DEC tape and Disk Usage

5-128

12.3.3

Magnetic Tape Usage

5-130

12.4

PDP-l0 Instruction Set

5-132

APPENDIX A THE SMALL FORTRAN IV COMPILER

5-6

'f"

ILLUSTRATIONS
Page
1-1

Typical FORTRAN Coding Form

5-16

2-1

Array Storage

5-23

4-1

Nested DO Loops

5-35

TABLES
2-1

Types of Resultant Subexpressions

5-25

3-1

Allowed Assignment Statements

5-30

5-1

Magnitude of Internal Data

5-41

5-2

Numeric Field Codes

5-42

5-3

Device Control Statements

5-59

8-1

I/o Conversion

5-84

8-2

FORTRAN UUOs

5-85

8-3

FORTRAN IV l-ibrary Functions

5-87

8-4

FORTRAN IV Library Subroutines

5-90

10-1

Accumulator Conventions for PDP-10 FORTRAN IV Compiler and Subprograms

5-1~

11-1

FORTRAN Compiler Switch Options

5-115

11-2

FORTRAN Compiler Diagnostics (Command Errors)

5-116

11-3

FORTRAN Compiler Diagnostics (Compilation Errors)

5-117

11-4

FORTRAN Operating System Diagnostics (Execution Errors)

5-120

1~-1

ASCII Character Set

5-125

12-2

PDP-10 FORTRAN IV Standard Peripheral Devices

5-127

12-3

Device Table for FORTRAN IV

5-129

Routine

5-7

•

PREFACE
This is a reference manual describing the specific statements and features of the
FORTRAN IV language for the PDP-10. It is written for the experienced
FORTRAN programmer who is interested in writing and running FORTRAN IV pro- grams alone or in conjunction with MACRO-10 programs in the single-user or
time-sharing environment. Familiarity with the basic concepts of FORTRAN programming on the part of the user is assumed. PDP-10 FORTRAN IV conforms to
the requirements of the USA Standard FORTRAN.

5-9

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INTRODUCTION TO THE FORTRAN IV SYSTEM

The FORTRAN compiler translates source programs written in the FORTRAN IV language into the machine
language of the PDP-10. This translated version of the FORTRAN program exists as a retrievable, relocatable
binary file on some storage device. All relocatable binary filenames have the extension .REL if they reside on
a directory-oriented device (disk or DECtape). Binary files may also be created by the MACRO-10 assembler
(see Chapter 9) 1 •
In order for the FORTRAN program to be processed, the Linking Loader must load the relocatable binary file
into core memory. Also loaded are any relocatable pinary files found in the FORTRAN library (LIB40) which
are necessary for the program's execution. Within the FORTRAN source program, the library files may

called

explicitly, such as SIN, in the statement.

x = SIN(Y)
or implicitly, such as FLOUT. '- the floating-point to ASCII conversion routine, which is implied in the followi ng statements.

PRINT
3,X
FORMAT(1X,F4.2)

A FORTRAN main program and its FORTRAN and/or MACRO-10 subprograms may be compiled or assembled separatelyand then linked together by the Linking Loader at load time. The core image may then be saved on a
storage device. When saved on a directory storage device, these files have the extension .SAV in a multiprogral'!lming Monitor system and • SVE in a single-user Monitor system.
The Time-Sharing Monitors act as the interface between the user and the computer so that all users are protected
from one another and appear to have system resources available to themselves. Several user programs are loaded
into core at once and the Time-Sharing Monitors schedule each program to run for a certain length of time. All
Monitors direct data flow between I/O devices and user programs, making the programs device independent, and
overlap I/O operations concurrently with computations.
In a multiprogramming system, all jobs reside in core and the scheduler decides which of these jobs should run.
In a swapping system, jobs can exist on an external storage device (usually disk) as well as in core. The scheduler
lFor further information on the MACRO-10assembler, see the MACRO-10ASSEMBLER manual, DEC-10-AMZA-D.

5-11

decides not only which ,job is to run but al~ when a job is to be swapped out onto the disk or brought back into
core.
The number of users that can be handled by a given size time-sharing configuration is further increased by using
the reentrant user-programming capability. This means that a sequence of instructions may be entered by more
than one user job at a time. Therefore, a single copy of a reentrant program may be shared by a number of users
at the same time to increase system economy. The FORTRAN compiler and operating system are both reentrant.

SECTION I
The PDP-10 FORTRAN IV Language
The seven chapters of this section deal with the PDP-10 FORTRAN IV language.
Included in these chapters are the language elements of FORTRAN IV and the
five categories of FORTRAN IV statements {arithmetic, control, input/output,
specification, and subprogram}.

CHAPTER 1
INTRODUCTION TO THE FORTRAN LANGUAGE

The term FORTRAN IV (FORmula TRANslation) is used interchangeably to designate both the FORTRAN IV
language and the FORTRAN IV translator or compiler. The FORTRAN IV language is composed of mathematicalform statements constructed in accordance with precisely formulated rules. FORTRAN IV programs consist of
meaningful sequences of FORTRAN statements intended to direct the computer to perform the specified operations
and computations.
The FORTRAN IV compi ler is itself a computer program that examines FORTRAN IV statements and tells the computer how to translate the statements into machine language. The compiler runs in a minimum of 9K of core.
The program written in FORTRAN IV language is called the source program. The resultant machine language
program is called the object program. Digital's small FORTRAN compiler, which runs in 5.5K of core, is virtually identical to the larger compiler, except for differences explained in Appendix 2. Operating procedures
and diagnostic messages for both compi lers are explained in the PDP-10 System Users Guide (DEC-10-NGCC-D).

1. 1

LINE FORMAT

Each line of a FORTRAN program consists of three fields: statement number field, line continuation field, and
statement field. A typical FORTRAN program is shown in Figure 1-1.

1. 1. 1

Statement Number Field

A statement number consists of from one to five digits in columns 1-5. Leading zeros and all blanks in this field
are ignored. Statement numbers may be in any order and must be unique. Any statement referenced by another
statement must have a statement number. For source programs prepared on a teletypewriter, a horizontal tab may
be used to skip to the statement field. This is the only place a tab is not treated as a space.

1. 1.2

Line Continuation Field

If a FORTRAN statement is so large that it cannot conveniently fit into one statement field, the statement fields
of up to 19 additional lines may be used to specify the complete statement. Any line which is not continued,. or
the first line of a sequence of continued lines, must have a blank or zero in column 6. Continuation lines must

5-15

CODER
I.
r .."'O:-c"-:-'M---------'---'-'--~--ir:~.
DATE

FORTRAN
COOINGFOItM

CCofl".. e.,t

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PAGE

FORTRAN STATEMENT

~~
'.
=

IDEN'lfICATION

,.~,

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THI S PR OGRAM CA-lC UlA.T~ ,S, ,P,R,I,"'lE, ,!::lY"'lB,E,R,S, ,F,R,9!:!1,I.J..- TO 50
, D,O 10 1:'11
50
2
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A=,J.
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,,,
11.,=,1 [,J, , ,
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10
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DIGITAL EQUIPMENT CORPORATION

Figure

1-1

•

MAYNARD. MASSACHUSETTS

100 - 12/64

Typical FORTRAN Coding Form

have a character other than blank or zero in column 6. If a continuation line is desired when a TAB is used in
the statement number field, a digit from 1 to 9 must immediately follow the TAB .

•
1.1.3, Statement Field
Any FORTRAN statement, as described in later sections, may appear in the statement field (columns 7-72). Except for alphanumeric data within a FORMAT statement, DATA statement, or literal constant, blanks (spaces)
and TABS are ignored and may be used freely for appearance purposes.

1• 1.4 Comment li ne
Any line which starts with the letter C in column 1 is interpreted as a line of comments. Comment lines are
printed onto any listings requested but are otherwise ignored by the compiler. Columns 2-72 may be used in any
format for comment purposes. A comment line must not immediately precede a continuation line.

5-16

1.2

CHARACTER SET

The following characters are used in the FORTRAN IV language:
Blank

I/>

L
M

NOTE
ASCII characters greater than Z (1328 ) are replaced by
the error character lit". See Chapter 12 for the internal
representati on -Qf these characters.

5-17

CHAPTER 2
CONSTANTS, VARIABLES, AND EXPRESSIONS

The rules for defining constants and variables and for forming expressions are described in this chapter.

2.1

CONSTANTS

Seven types of constants are permitted in a FORTRAN IV source program: integer or fixed point, .real or singleprecision floating point, double-precision floating point, octal, complex, logical, and literal.

2. 1. 1 Integer Constants
An integer constant consists of from one to eleven decimal digits written without a decimal point. A negative.
constant must be preceded by a minus sign. A positive constant may be preceded by a plus sign ••
Examples:

3
+10
-528
8085

An integer constant must fall within the range _235+1 to 235 -1. When used for the value of a subscript
an index in a DO statement, the value of the integer is taken as modulo 2 18 .

2. 1:2

01"

Rea I Constants

Real constants are written as a string of decimal digits including a decimal point. A real constant may consist

of any number of digits but only the leftmost 9 digits appear in the compiled program. Real constants may be
given a decimal scale factor by appending an E followed by a signed integer constant. The field following the
letter E must not be blank, but may be zero.
Examples:

15.
0.0

.579
-10.794
5. OE3(i.e., 5000.)
5.0E+3{i .e., 5000)
5.0E-3{i.e., 0.005)
5-19

A real constant has precision to eight digits. The magnitude must lie'approXimately within the range

-38
38
O. 14 x 10
to 1.7 x 10 • Rea I constants occupy one word of PDP-lO storage.

2.1.3

Double Precision Constants

A double precision constant is specified by a string of decimal digits, including a decimal point, which are
followed by the letter D and a signed decimal scale factor. The,field following

th~

letter D must not be blank,

but may be zero.
Examples:

24.67132598213400
3.6D2 (i.e., 360.)
3.60-2 (i .e., .036)
3.000

Double precision constants have precision to 16 digits. The magnitude of a double precision constant must lie
.
-38
38
approximately between O. 14x 10
and 1.7 x 10
Double-precision constants occupy two words of PDP-10
storage.

2.1.4

Octal Constants

A number preceded by a double quote represents an octal constant. An octal, constant may appear in an arithmetic or logical expression or a DATA statement. Only the digits 0-7 may be used and only the last twelve
digits are significant. A minus sign may precede the octal number, in which case the number is negated. A
maximum of 12 octal digits are stored in each 36-bit
Examples:

2.1.5

word~

"7777
"-31563

Complex Constants

FORTRAN IV provides for direct operations on complex numbers. Complex constants are written as an ordered
pair of real constants separated by a comma and enclosed in parentheses.
Examples:

(.70712, -.70712)
(8 •763E3 ,2.297)

The first constant of the pair represents the real part of the complex number I and the second constant represents
the imaginary part. The real and imaginary parts may ~ach be signed. The enclosing parentheses are part of
the constant and always appear, regardless of context. Each part is internally represented by one singleprecision floating point word. They occupy consecutive locations of PDP-10 storage.

5-20

Fo,RTRAN IV arithmetic operations on complex numbers, unlike normal arithmetic operations, must be of the
form:
A±B

= a 1ib 1+i(a2 ib2)

A*B

= (albl-a2b2)+i(a2bl+alb2)

(a 1b 1+a 2b 2 ) +i (a 2b 1-Ql b2)
A/B=
2
2
2
2
b 1 +b2
b 1 +b2
where A

2.1.6

=a 1 + ia2 , B =b 1 + ib 2 , and i =J-]:

Logical Constants

The two logical constants, .TRUE. and .FALSE., have the internal values -1 and 0, respectively. The enclosing periods are part of the constant and always appear.
Logical constants may be entered in DATA or input statements as signed octal integers (-1 and 0). Logical
quantities may be operated on in either arithmetic or logical statements. Only the sign is tested to determine the
truth value of a logical variable.

2.1.7

Literal Constants

A literal constant may be in either of two forms:
a. A string of alphanumeric and/or special characters enclosed in single quotes; two adjacent single
quotes within the constant are treated as one single quote.
b.

A string of characters in the form
nHx 1x 2 •• .x n

where x 1x 2 .•• x n is the literal constant, and n is the number of characters following the H.
Literal constants may be entered in OAT A statements or input statements as a string of up to 57-bit ASCII characters per variable (10 characters if the variable is double-precision or complex). Literal c~nstants may be
operated on in either arithmetic or logical statements •

•

NOTE
Literal constants used as subprogram arguments will have a
zero word as an end-of-string indicator.

5-21

Exampl~s:

2.2

CALL SUB·('LITERAL CONSTANT i )
'DONT"T'
5HDON'T
A == 'FIVE' + 42
B == (5HABCDE .AND. "376)/2

VARIABLES

A variable is a quantity whose value may change during the execution of a program. Variables are specified
b.y name
alphal'lumeric characters, the first one of
. and type. The name of a variable consists of one or more
.
which must be alphabetic. Only the first six characters are interpreted as defining the variable name. The
type of ,variable (integer, real, logical, double preciSIon, or complex) may be specified explicitly by a type
declaration statement o~ implicitly by the IMPLICIT statement. If the variable is not specified in this manner,
then a first letter of I, J, K, L, M or N indicates a fixed point (integer) variable; any other first letter indicates a floating-point (real) variable. Variables of any type may be either scalar or array variables.

2.2.1

Scalar Variables

A scalar variable represents a single quantity.
Examples:

A
G2
POPULATION

2.2.2

Array Variables

An array variable represents a single element of an n dimensional array of quantities. The variable is denoted
by. the array name followed by a subscript list enclosed in parentheses. The subscript list is a sequence of integer expressions, separated by commas. The expre"ssions may be of any form or type providing they are explicitly
changed to type integer when each is completely evaluated. Each expression represents a subscript, and the
values of the expressions determine the array element referred to. For example, the row vector A. would be
"

represented by the subscripted variable A(J), and the element, in the second colu'mn of the first row of the square
matrix A, would be represented by A(1,2). Arrays may have any number of dimensions.
Examples:

Y(l)
STATION (K)
A (3* K+2, I, J-1)

The three arrays above (Y, STATION, and A) would have to be dimensioned by a DIMENSION, COMMON,
or type. declaration statement prior to their first appearance in an executable statement or in a DATA or
NAMELISI statement. (Array dimensioning is discussed in Chapter 6).

5-22

l-Dimensional Array

A(10)

lAC II

I A( 21

1A( 31 1A(4) I A(5) I A(61 1A( 71 1A(8) IA(9) I AClO) I

CONSECUTIVE STORAGE LOCATIONS - - - - - - - -

2-Dimensional Array

8(5,5)
I

B(I,I) 6

B(I,2) II B(I,3) 16 B(I,4) 21 B(I,5)

2 B(2,1) 7 B(2,21 12 B(2,3) 17 B(2,4) 22 B(2,5)
3 B(3,1) 8 B(3,21 13 B(3,3) 18 B(3,41 23 B(3,5)
4

B(4,11 9

8(5,1) 10 8(5,21 15 8(5,31 20 B(5,41 21 B(5,51

8(4,21 14 8(4,31 19 8(4,4) 24 B(4,5)

8(3,1) IS THE THIRD STORAGE WORD IN SEQUENCE
B(3,4) IS THE EIGHTEENTH STORAGE WORD IN SEQUENCE

3-Dimensional Array

C(5,5,5)
III C(I,3,5) 116
112 C(23,5) 117
96 C(l54) 118
76 CII 14) 81
97 C(2,5,4) 119
77 C(2,I,4) 82
C(3,5,4 ) 120
CII,I,3) 56 CO,2,3) 61 C(I,3,3) 66 C(I,4,3) 71 CO,5,31 98
c(2,I,3) 57 C(2,2,3) 62 C(2,3,3) 67 C(2,431 72 C(2,5,3I 99 C(4,5,4)
CO,2,2) 36 CO,3,2) 41 C(I,4,2) 46 C(I,5,2) 73 C(3,5,3) 100 c(5.5,4)
C(22 2) 37 C(2.3.2 ) 42 C(242) 47 C(2,5,2) 74 C(4,5,3)
CII 3,1 I 16 C(l4 I ) 21 C05 I I 48 C(3,5,21 75 C(5,5,31
C(2,3,11 17 C(2,4,11 22 C(2,5,1) 49 C(4,5,2)
C(3311 18 C(3411 23 C(3511 50 C(5,5,21
C(43 II 19 C(44 I) 24 C(~~II
C(5,3,11 20 C(5,4,1) 25 C(5,5,11
101
102
CII,2,4) 86
C(2,2,4) 87

I
2
3
4
5

CO I I )
C(2,I,I)
C(3,I,I)
C(41 II
C(5,I,11

26
27
6
7
8
9
10

C(t,I,2)
C(2J.2)
C(l2 I)
C(2,2,11
C(3,2,11
C(4211
C(5,2,1)

51
52
31
32
II
12
13
14
15

C(I,I,5) 106 C( I .2,5)
C(2,I,5) 107 C(2,2,5)
C(I 34) 91 C(144)
C(2,3,4) 92 C(2,4,4)

C(I,4,5)
C(2,4,5)
C(3,4,5)
C(4,45)
C(5,4,5)

121
122
123
124
125

CII,5,5 )
C(2,5,5)
C(3,5,5)
C{4,5,5)
C(5,5,5)

C(1 ,3,2) is the 36th storage word in sequence.
C(l, 1,5) is the 101st storage word in sequence.

Figure 2-1

Array Storage

5-23

Arrays are stored in increasing storage locations with the first subscript varying most r.apidly and the lost subscript
. varying least rapidly. For example,-the 2-dimensional array B(I,J) is stored in the following order: B (1,1),
B (2,1), •.. , B (I, l),B (1,2),B (2,2), ..• ,B (1,2), .•. ,8 (I,J).

2.3

EXPRESSIONS

Expressions may be either numeric or logical. To evaluate an expression, the object program performs the
calculations specified by the quantities and operators within the expression.

2.3. 1

Numeric Expressions

A numeric expression is a sequence of constants, variables, and function references separated by nu~eric
operators and parentheses in accordance with mathematical convention and the rules given below.
The numeric operators are +, -, *,

I, **,

denoting, respectively, addition, subtraction, multiplication,

division, and exponentiation.
In·addition to the basic numeric operators, function references are also provided to facilitate the evaluation
of functions such as sine, cosine, and square root. A function is a subprogram which acts upon one or more
quantities, called arguments, to produce a single quantity called, the function' value. Function references are
denoted by the identifier, which names the function (such as SIN, COS, etc.), followed by an argument list
enclosed in parentheses:
identifier(argument, argument, ... , argument)
At least one argument must be present. An argument may be an expression, an array identifier, a subprogram
identifier, or an alphanumeric string.
Function type is given by the type of the ic!e"ntifier which names the function. The type of the function is independent of the types of its arguments. (See Chapter 7, Section 7.4.1.1.)

A numeric expression may consist of a single element (constant, variable, or function reference):
2.71828
Z(N)
TAN(THETA)
Compound numeri~ expressions may be formed by using numeric operations to combine basic elements:
X+3.
TOTAL/A
TAN(PI*M)
(X+3.) -(TOTAL/A) * TAN (PI*M)

5-24

Compound numeric expressions

m~st

be constructed according to the following rules:

a. With respect to the numeric operators +, -, *, /, any type of quantity (logical, octal, integer,
real, double precision, complex or literal) may be combined with any other, with one exception:
a complex quantity cannot be combined with a double precision quantity.
The resultant type of the combination of any two types may be found in Table 2-1. The conversions
between data types will occur as follows:
(1) A literal constant will be combined with any integer constant as an integer and with a real
or double word as a real or double word quantity. (Double word refers to both double precision
and complex.)
(2) An integer quantity (constant, variable, or function reference) combined with a real or double
word quantity results in an expression of the type real or double word respectively; e.g., an integer
variable plus a complex variable will result in a complex subexpression. The integer is converted
to floating point and then added to the real part of the complex number. The imaginary part is
unchanged.
(3) A real quantity (constant, variable, or function referenee) combined with a double word quantity results in an expression that is of the same type as the double word quantity.

A logical or octal quantity is combined with an integer I real, or double word quantity as if
it were an integer quantity in the integer case, or a real quantity in the real or double word case
(i .e., no conversion takes place).

(4)

Any numeric expression may be enclosed in parentheses and considered to be a basic element.
(X+y)/2
(ZETA)

(COS(SIN(PI*M)+X»
Table 2-1 ,
Types of Resultant Subexpressions
Type of Quantity

+,-,*,/

Type of
Quantity

Real

Integer

Complex

Double
Precision

Logical,
Octal, or
Literal

Real

Complex

Double
Precision

Real

Integer

Real

Integer

Complex

Double
Precision

Integer

Complex

Not
Allowed

Complex

Double
Precision

Not
Allowed

Double
Precision

Logical,
Octal, ,or'
Literal

Real

Integer

Complex

Double
Precision -:

Logical,
Octal, or
Literal

.' '

5-25

,c.

Numeric expressions whicli are preceded by-a + or - sign are alS? numeric expressions~

+X
-(ALPHA *BET A)
-SQRT( -GAMMA)
d. If the precedence of numeric operations is not given explicitly by parentheses, it is understood
to be the following (in order of decreasing precedence):
Explanation

Operator
**

numeric exponentiation

*and/

numeric multiplication and division

+and-

numeric addition and subtraction

In the case of operations of equal hierarchy, the calculation is performed from left to right.
e.

No two numeric operators may appear in sequence. For i.nstance:

x*-y
is improper. Use of parentheses yields the correct form:

x*(-y)
By use of the foregoing rules, all permissible numeric expressions may be formed .. As an example of a typical
numeric expression using

num~ric

operators and a function reference, the expression for one of the roots of the

general quadratic equati on:

would be coded as:
(-B+SQRT(B**2-4. *A*C»/(2. *A)

2.3.2

Logical Expressions

A logical expression consists of logical constants, logical variables, logical function references, and arithmetic
expressions, separated by logical operators or relational operators. Logical expressions are

provi~ed

FORTRAN IV to permit the implementation of various forms of symbolic logic. Logical constants are defined
by arithmetic statements, which are described in Chapter 3. Logical variables and functions are defined by
the LOGICAL statement, described in Chapter 6. Binary variables may be represe-nted by the logical constants

• TRUE. and .FALSE. , which must always be written with enclosing periods. Logical masks may be represented
by using octal constants. The result of a logical expression has a logical value (i .e., either true or false) and
therefore, only uses one word.

5-26

2·.3.2.1

Logical Operators - The logical operators, which include the enclosing periods and their definitions,

are as follows,' where P and Q ':Ire logical expressions:
. NOT. P

Has the value. TRUE. only if P is . FALSE. , and has the
value .FALSE. only if Pis .TRUE.

P.AND.Q

Has the value. TRUE. only if P and Q are both. TRUE. ,
and has the value .FALSE. if either P or Q is .FALSE.

P.OR.Q

(Inclusive OR) Has the value. TRUE. if either P or Q is . TRUE. ,
and has the value .FALSE. only if both P and Q are .FALSE.

P.XOR.Q

(Exclusive OR) Has the value. TRUE. if either P or Q but not
both are . TRUE., and has the va lue . FALSE. otherwise.

P.EQV.Q

(Equivalence) Has the value. TRUE. if P and Q are both
• TRUE. or both . FALSE. , and has the value . FALSE. otherwise.

Logical operators may be used to form new variables, for examp Ie,

x = Y.AND.Z
E = E.XOR. "400000000000

2.3.2.2

Relational Operators - The relational operators are as follows:
Operator

Relation

.GT.

greater than

.GE.

greater than or equal to

· LT.

less than

• LE.

less than or equal to

.EQ.

equal to

· NE.

not equal to

The enclosing periods are port of the operator and must be present.
Mixed expressions involving integer, real, and double precision types may be combined with relationals.
The value of such an expression will be . TRUE. or .FALSE..
The relational operators .EQ. and. NE. may also be used with COMPLEX expressions. (Double word quantities
are equal if the corresponding parts are equal.)

5-27

A logical expression may consist of a single elemenf (constant, variable, function rererence, or relation):'
-

.TRUE.
X.GE.3.141S9
Single elements may be combined through use of logical operators to form compo~nd logical expressions, such as:
TVAL. AND. INDEX
BOOL(M). OR. K.EQ.LIMIT
Any logical expression may be enclosed in parentheses and regarded as an element:
(T .XOR.S).AND.(R.EQV.Q)
CALL PARITY ((2.GT.Y .OR.X.GE. Y).AND. NEVER)
Any logical expression may be preceded by the unary operator. NOT. as in:
.NOT.T
. NOT.X+7.GT.Y+Z
BOOL(K).AND •. NOT. (TVAL.OR. R)
No two logical operators may appear in sequence, except in the case where. NOT. appears as the second of
two logical operators, as in the example above. Two decimal points may appear in sequence, as in the example above, or when one belongs to an operator and the other to a constant.
When the precedence of operators is not given explicitly by parentheses, it is understood to be as follaws (in
order of decreasing precedence):
**

*,/
+,.GT. ,.GE. ,.U. ,. LE. ,.EQ. ,. NE.
• NOT.
.AND •
• OR •
. EQV., .XOR.
For example, the logical expression
.,NOT.ZETA**2+Y*MASS.GT.K-2. OR. PARITY .AND.X.EQ.Y
is interpreted as
(. NOT. (((ZET A**2)+(y*MASS». GT. (K-2))). OR. (PARITY .AND.(X .EQ. V))

5-28

CHAPTER 3
THE ARITHMETIC STATEMENT

3.1

GENERAL DESCRIPTION

One of the key features of FORTRAN IV is the ease with which arithmetic computations can be coded. Computations to be performed by FORTRAN IV tire indicated by arithmetic statements, which have the general form:
A=B
where A is a variable, B is an expression, and = is a replacement operator. The arithmetic statement causes the
FORTRAN IV object program to evaluate the expression B and assign the resultant value to the variable A.
Note that the = sign signifies replacement, not equality. Thus, expressions of the form:
A=A+B and
A=A*B
are quite meaningful and indicate that the value of the variable A is to be replaced by the result of the expression to the right of the = sign.
Examples:

Y=l*Y
P=. TRUE.
X (N)=N*ZETA(ALPHA*M/PI)+(l.', -1.)

Table 3-1 indicates which type of expression may be equated to each type of variable in an arithmetic statement.
D indicates that the assignment is performed directly (no conversion of any sort is done); R indicates that only
the real part of the variable is set to the value of the expression (the imaginary part is set to zero); C means that
the expression is converted to the type of the variable; and H mea~s that only the high-order portion of evaluated
expression is assigned to the variable.
The expression value is made to agree in type with the assignment variable before replacement occurs. For example, in the statement:
THET A=W*(ABET A+E)
if THETA is an integer and the expression is real, the expression value is truncated to an integer before assignment to THETA.
5-29

Table, 3-1
Allowed Assignment Statements
Expression
Logical,
Octal, or
Literal
Constant

Real

Integer

Complex

Double
Precision

Real

R,D

H,D

Ioteger

R,C

H,C

Complex

D,R,I

C, R',I

H,D,R,I

D,R,I

Double
Precision

D,H,L

C,H,L

R~D,H,L

D,H,L

R,D

H,D

Variable

Logical

D - Direct Replacement
C - Conversion between integer and floating point
R - Real only
- Set imaginary part to 0,
H - ,High order only

l - Set low order part to 0

•

5-30

CHAPTER 4
CONTROL STATEMENTS

FORTRAN compiled programs normally execute statements sequentially in the order in which they were presented
to the compiler. However, the following control statements are avai lable to alter the normal sequence of statement execution: GO TO, IF, DO, PAUSE, STOP, END, CALL, RETURN. CALL and RETURN are used to enter and return from subroutines.

4. 1 GO TO STATEMENT
The GO TO statement has three forms: unconditional, computed, and assigned.

4. 1. 1

Unconditional GO TO Statements

Unconditional GO TO statements are of the form:
GO TO n
where n is the number of an executable statement. Control is transferred to the statement numbered n. An unconditional GO TO statement may appear anywhere in the source program, except as the terminal statement of
a DO loop.

4. 1.2

Computed GO TO Statements

Computed GO TO statements have the form:
GO TO (n 1 ,n 2 , ... ,nk ),i
where n 1,n 2 , ... ,n k are statement numbers, and i is an integer

~xpression.

This statement transfers control to the statement numbered n l' n2 , .•. , nk if i has the value 1, 2, .•. , k, respectively. If i exceeds the size of the I ist of statement numbers or is less than one, execution wi II proceed to the
next

~xecutable

statement. Any number of statement numbers may appear in the list. There is no restriction on

other uses for the integer variable i in the program.

5-31

In the example
GO TO (20,10,5),K
the variable K acts as a switch, causing a transfer to statement 20 if K= 1, to statement 10 if K=2, or to statement 5 if K=3.
A computed GO TO statement may appear anywhere in the source program, except as the terminal statement of
a DO loop.

4. 1.3

Assigned GO TO Statement

, Assigned GO TO statements have two equivalent forms:
GOTO k
and

where k is a nonsubscripted integer variable a'nd n 1, n 2 , ... nk are statement numbers. Any number of statement
numbers may appear in the list. Both forms of the assigned GO TO have the effect of transferring control to the
statement whose number is currently associated with the vqriable k. This association is established th'rough the
use of the ASSIGN statement, the general form of which is:
ASSIGN i TO k
If more than one ASSIGN statement refers to the same integer variable name, the value assigned by the last ex-

ecuted statement is the current va lue.
Examples:

ASSIGN 21 TO INT

ASSIGN 1000 TO INT

GO TO INT

GO TO INT, (2,21,1000,310)

An assigned GO TO statement may appear anywhere in the source program, except as the terminal statement of
a DO loop.,

4,2

IF STATEMENT

IF statements have two forms in FORTRAN IV: numerical and logical.

5-32

4.2.1

Numerical IF Statements

Numerical IF statements are of the form:
IF (expression) n 1,n 2 , n3
where n l' n2 , n3 are statement numbers. This statement transfers control to the statement numbered n l' n 2 , n3 if
the value of the numeric expression is less than, equal to, or greater than zero, respectively. All three state ....
ment numbers must be present. The expression may not be complex.
Examples:

4.2.2

IF (ETA) 4,7,12.
IF (KAPPA-L (10)) 20,14,14

Logical IF Statements

Logical IF statements have the form:
IF (expression)S
where S is a complete statement. The expression must be logical. S may be any executable statement other than
a DO statement or another logical IF statement (see Chapter 2, Section 2.3.2). If the value of the expression
is .FALSE., control passes to the next sequential statement. If value of the expression is . TRUE., statement S
is executed. After execution of 5, control passes to the next sequential statement unless S is a numerical IF
statement or a GO TO statement; in these cases, control is transferred as indicated. If the expression is . TRUE.
and S is a CALL statement, control is transferred to the next sequential statement upon return from the subroutine.
Numbers are present in the logical expression:
IF (B)Y=X*SIN(Z)
W=Y**2
If the value of B is •TRUE., the statements Y=X*SIN(Z) and W=Y**2 are executed in that order. If the value of
B is .FALSE." the statement Y=X*5IN(Z) is not executed.
Examples:

IF (T .OR.S)X=Y+1
IF (Z.GT.X(K)) CALL SWITCH (S,Y)
IF (K .EQ.INDEX) GO TO 15
NOTE
Care should be taken in testing floating point numbers
for equality in IF statements as rounding may cause
unexpected results.

5-33

4.3
Th~

DOSTATEMENT
DO statement simplifies the cocltng of iterative procedures. DO statements are of the-form:

where n is a statement number, i is a nonsubscripted integer variable, and m1,m 2,m 3 are any integer expressions.
If m3 is not specified, it is understood to be 1.
The DO statement causes the statements which follow, up to and including the statement numbered n, to be executed repeatedly. This group of statements is called the range of the DO statement. The integer variable i of
the DO statement is called the index. The values of m1,m2 , and m3 are called, respectively, the initial, limit,
and increment values of the index.
A zero incremen! (m 3 ) is not allowed. The increment m3 may be negative if m1~m2'.. If m1~m2' the increment,
m3 must be positive. The index variable can assume legal values only if (m2-mi)*m~O. (m i is the current valu~
, , of the index variable m1.)
Examples:

Form

Restri cti on

DO 101=1,5,2
DO 10 1=5, 1,-1
DO 10 I=J,K,5

DO 10L=I,J,-K

I~J,KO

DO 10 L=I,J,I<

I~J,X>O

or I~J,K>O

Initially, the statements of the range are executed with the initial value assigned to the index. This initial execution is always performed, regardless of the values of the limit and increment. After each execution of the
range, the increment value is added to the value of the index and the result is compared with the limit value.
If the value of the index is not greater than the limit value, the range is executed again using the new value

, of the index. When the increment value is ~egative, another execution will be performed if the new value of
the index is not less than the limit value.
After the last execution of the range, control passes to the statement immediately

fol~owing

the range. This

exit from the range is called the normaJ"exit. Exit may also be accomplished by a transfer from within the range.
The range of a DO statement may include other DO statements, provided that the range of each contained DO
statement is entirely within the range of the containing DO statement'. That is, the r:anges of two DO statements
must intersect completely or not at all. A transfer into the range of a DO statement from outside the range is
not allowed.

5-34

Invalid Dq Loop Nest

Valid DO Loop Nest

IA _ __

B ........

B
A

Loop Cis not fu II y wi th in the range of
loop B even though it is within the range
of loop A.

Control must not pass from within loop A
or loop B into loop 0, or from loop 0 into
loop A or loop B.
Figure 4-1

Nested DO Loops

Within the range of a DO statement, the index is available for use as an ordinary variable. After a transfer
from within the range, the index retains its current value and is available for use as a variable. The value of
the index variable becomes undefined when the DO loop it controls is satisfied. The values of the initial, limit,
and increment variables for the index and the index of the DO loop, may not be altered within the range of the
DO statement.
The range of a DO statement must not end with a GO TO type statement or a numerical IF statement. If an
assigned GO TO statement is in the range of a DO loop, all the statements to which it may transfer must be
either in the range of the DO loop or all must be outside the range. A logical IF statement is allowed as the
last statement of the range. In this case, control is transferred as follows. The range is considered ended when,
and if, control would normally pass to the statement folloWing the entire logical IF statement.

As an example, consider the sequences:
DO 5 K = 1,4
5 IF(X(K).GT. Y(K»Y(K) = X(K)

6 ...
Statement 5 is executed four times whether the statement Y(K)
ecuted unti I statement 5 has been executed four times.

5-35

= X(K)

is executed or not. Statement 6 is not ex-

DO 22 L = 1,30
DO 45 K =2, LIMIT, -3
DO ZX ~'T,MAX,L

Examples:

4.4 CONTINUE STATEMENT
The CONTINUE statement has the form:
CONTINUE
This statement is a dummy statement, used 'primarily as a target for transfers, particularly as the last statement in
, the range of a DO statement. For example, in the sequence:
DO 7 K

= START, END

IF (X (1<»22, 13,7
7

CONTINUE

a positive value of X (K) begins another execution of the range. The CONTINUE provides a target address for

the IF statement and ends the range of the DO statement.

4.5 PAUSE STATEMENT
The PAUSE statement enables the program to incorporate operator activity into the sequence of automatic events.
The PAUSE statement assumes one of three forms:
PAUSE
PAUSE n
PAUSE 'xxxxx'
where n is an unsigned string of six or less octal digits, and 'xxxxx' is a literal message".
Exec:ution of the PAUSE statement c:auses the message or the oc:tal digits, if any, to be typed on the user's teletypewriter. Program exec:ution may be resumed (at the next exec:utable FORTRAN statement) from the console
by typing "G," followed by a carriage return. Program execution may be terminated by typing '~X," followed
by 'c:arriage return.
Example:

PAUSE 167
PAUSE 'NOW IS THE TIME'

5-36.

4.6

STOP STATEMENT

The STOP statement has the forms:
STOP
STOP n

where n is an unsigned string of one to six octal digits.
The STOP statement termi.nates the program and returns control to the monitor system. (Termination of a program
may also be accomplished by a CALL to the EXIT or DUMP subroutines.)

4.7

END STATEMENT

The END statement has the form:
END
The END statement informs the compiler to terminate compilation and must be the physically last statement of
the program.

5-37

CHAPTER 5
DATA TRANSMISSION STATEMENTS

Data transmission statements are used to control the transfer of data between computer memory "and either
peripheral devices or other locations in computer memory. These statements are also used to specify the format
of the output data. Data transmission statements are divided into the following four categories.
a. " Nonexecutable statements that enable conversions between internal form data within core memory
and external form data (FORMAT), or specify lists of arrays and variables for input/output transfer
(NAMELIST).
"b. Statements that specify transmission of data between computer memory and
WRITE, PRINT, PUNCH, TYPE, ACCEPT.

I/o devices:

READ,

"c. Statements that control magnetic tape unit mechanisms: REWIND, BACKSPACE, END FILE,
UNLOAD, SKIP RECORD.
d. Statements that specify transmission of data between series of locations in memory: ENCODE",
DECODE.

5.1

NONEXECUTABLE STATEMENTS

The FOR.v\AT statement enables the user to specify the form and arrangement of data on the selected external
medium. The NAME LIST statement provides for conversion and input/output transmission of data without
reference to a FORMAT statement.

5.1.1

FORMAT Statement

FORMAT statements may be used with any appropriate input/output medium or ENCODE/DECODE statement.
FORMAT statements are of the form:

where n is a statement number, and each 5 is a data field specification.
FORMAT statements may be placed a~ywhere in the source program. Unless the FORMAT statement contains
only alphanumeric data for direct input/output transmission, it will be used in conjunction with the list of a
data transmission statement.

5-39

Slashes are used to specify unit records, which must be one of the following:

m~imum length correspondirlg t~~a" line- buff~r

A tape or disk record with a

A punched card with a maximum Qf 80 characters.

(ngAscII

characters).

c. A printed line with a maximum of 72 characters for a Teletype ®and either 120 or 132 characters
for the line printer.
During transmission of data, the object program scans the designated FORMAT statement. If a speciftcation
for a numeric field is present (see Section 5.2.1 of this chapter) and the data transmission statement contains
items remaining to be transmitted, transmission takes place according to the specifications. This process ceases
and execution of the data transmission statement is terminated as soon

asa~1

specified items have been transmitted.

Thus, the FORMAT statement may contain specifications for more items than are specified by the data transmission statement. Conversely, 'the FORMAT statement may contain specifications for fewer items than are specified
by the data transmission statement.
The following types of field specifications may appear in a FORMAT statement: numeric, numeric with scale
factors, logical, alphanumeric. The FORMAT statement also provides for handling multiple record formats,
formats stored as data, carriage control, skipping characters, blank insertion, and repetition. If an input list
requires more characters than the input device supplies for a given unit record, blanks are supplied.

5.1. 1.1

Numeric Fields - Numeric field specification codes designate the type of conversion to be performed.

These codes and the corresponding internal and external forms of the numbers are listed in Table 5-2.
The conversions are,specified by the forms:

2.
3.
4.
5.
6.

Dw.d
Ew.d
Fw.d
Iw
Ow
Gw.d
Gw
Gw.d,Gw.d

. (for real or double precision)
(for integer or logical)
(for complex)

respectively. The letter 0, E, F, I, 0, or G designates the conversion type; w is an integer specifying the
field width, which may be greater than required to provide for blank columns between numbe~s; d is an integer
specifying the number of decimal places to the right of the decimal point or, for G conversion, the number of
significant digits. (For 0, E, F, and G input I the position of the decimal point in the external field takes
precedence over the value of d in the format.)

® Teletype is a registered trademark of Teletype Corporation.
5-40

For example,
FORMAT (I5,F10.2,D18.10)
could be used to output the line,
bbb32bbbb-17.60bbb.5962547681D+03
on the output listing.
The G format is the general format code that is used to transmit real, double precision, integer, logical, or
complex data. The rules for input depend on the type specification of the corresponding variable in the data
list. The form of the output conversion also depends on the individual variable except in the case of real and
double-precision data. In these cases the form of the output conversion is a function of the magnitude of the
data being converted. The following table shows the magnitude of the external data, M, and the resulting
method of conversion.

Table 5-1
Magnitude of Internal Data
Magn itude of Data

Resulting Conversion

0.15. M < 1
1

F(w-4). d, 4x

-< M < 10
.

F(w-4).(d-1),4x

10d- 2 ~ M < lOd - 1
10d-1 5. M < lOd

F(w-4). 1, 4x
F(w-4). 0, 4x

All others

Ew.d

The field width w should always be large enough to include spaces for the decimal point, sign, and exponent.
In all numeric field conversions if w is not large enough to accommodate the converted number, the excess
digits on the left will be lost; if the number is less than w spaces in length, the number is right-adjusted in the
field.

5-41

Table 5-2
Numeric Field Codes
. ,
'

Conversion
Code

Internal Form

External Form

Binary floating point
double-precision

Decimal floating point
with 0 exponent

Binary floating point

Decimal floating point
with E exponent

Binary floating point

Decimal fixed point

Binary integer

Decimal integer

Binary integer

Octal integer

One of the following:
single precision
binary floating point,
binary integer,
binary logical, or
binary complex

Single -'precision
decimal floating point
integer, logical (T or
F), .or complex (two
decimal floating point
numbers), depending
upon the internal form

5.1.1.2

'- "

Numeric Fields with Scale Factors - Scale factors may be specified for O,.E, F, and G conversions.

A scale factor is written nP where P is the identifying character and n is a signed or unsigned integer that
specifies the scale factor.
For F type conversions (or G type, if the external field is decimal fixed pointL the scale factor specifies a
power of ten so that
•
(scale factor)
externol number = (mternal number)* 10
For 0, E, and G (external field not decimal fixed point) conversions, the ,scale factor multiplies the number by
a power of ten, but the exponent is changed accordingly leaving the' number unchanged except in form. For
example, if the statement:
FORMAT (F8.3,E16.5)
corresponds to the line
bb26.451bbbb-0.41321E-Ol
then the statement
FORMAT (-lPF8.3,2PE 16.5) ,

5-42

might correspond to the line
.

bbb2. 645bbb-41 . 32157E -03
In input operations, F type (and G type, if the external field is decimal fixed point) conversions are the only
types affected by sca Ie factors.
When no scale factor is specified, it is understood to be zero. However, once a scale factor is specified, it
holds for all subsequent 0, E, F, and G type conversions within the same format unless another scale factor is
encountered. The scale factor is reset to zero by specifying a scale factor of zero. Scale factors have no
effect on I and 0 type conversions.

5. 1. 1.3

Logical Fields - Logical data can be transmitted in a manner simi lar to numeric data by use of the

specification:
Lw
where L is the control character and w is an integer specifying the field width. The data is transmitted as the
value of a logical variable in the input/output list.

If or input, the first nonblank character in the data field is T or F, the value of the logical variable will be
stored as true or false, respectively. If the entire data field is blank or empty, a value of false wi" be stored.
On output, w minus 1 blanks followed by Tor F will be output if the value of the logical variable is true or
false, respectively.

5.1.1.4

Variable Field Width - The 0, E, F, G, I, and "0 conversion types may appear in a FORMAT state-

ment without the specification of the field width (w) or the number of places after the decimal point (d). In
the case of input, omitting the w implies that the numeric field is delimited by any character which would
otherwi~

be illegal in the field, in addition to the characters -, +, ., E, 0, and blank provided they follow

the numeric field. For example, input according to the format
10 FORMAT(2I,F,E,0)
might appear on the. input medium as
-10,3/15.621-.0016E-10,777.

5-43

In thi,s case, commas delimit the numeric fields, blanks may also be used as field delimiters. On output,
omitting the w has the following effect:
Format

5. 1. 1.5

Becomes

D25.16

E15.7

F15.7

G15.7 or G25. 16

115

015

Alphanumeric Fields - Alphanumeric data can be transmitted in a manner simi lar to numeric data by

use of the form Aw, where A is the control character and w is the number of characters in the field. The alphanumeric characters are transmitted as the value of a va!iabJe in an input/output list. The variable may be of any
. type. For the sequence:
READ 5, V
5 FORMAT (A4)
causes four characters to be read and placed in memory as the value of the variable V.
Although w may have any value, the number of characters transmitted is limited by the maximum number of
characters which can be stored in the space allotted for the variable. This maximum depends upon the variable
type. For a double precision variable the maximum is ten characters; for all other variables, the maximum is
five characters. If w exceeds the max imum, the leftmost characters are lost on input and replaced with blanks
on output. If, on input, w is less than the maximum, blanks are

fj lied

in to the right of the given characters

unti I the maximum is reached. If, on output, w is less than the maximum, the leftmost w characters are transmitted to the extemal medium. Since for complex variables each word requires a separate field specificCJtion,
the m~ imu~ value for w. is 5. For example,
COMPLEX C
ACCEPT 1 i C
1 FORMAT (2A5)
could be used to transmit ten alphanumeric characters into complex variable C.

5.1.1.6

Alphanumeric Data Within Format Statements - Alphanumeric data may be transmitted directly into or

from the fOmlat stateme~t by two different methods: H-conversion, or the use of single quotes.

5-44 .

In H-conversion, the alphanumeric string is specified by the form nH. H is the control character and n is the
number of characters in the string counting blanks. For example, the format in the statement below can be used
to print PROGRAM COMPLETE on the output lis,ting.
FORMAT (17H PROGRAM COMPLETE)
The statement
FORMAT (16HPROGRAM COMPLETE)
causes ROGRAM COMPLETE to be printed.
Referring to this format in a READ statement would cause the 17 characters to be replaced with a new string
of characters.
The same effect is achieved by merely enclosing the alphanumeric data in quotes. The result is the same as in
H-conversion; on input, the characters between the quotes are replaced by input characters, and, on output,
the characters between the quotes (including blanks) are written as part of the output data. A quote character
within the data is represented by two successive quote marks. For example, referring to:
FORMAT (' DON"T')
with an output statement would cause DON'T to be printed. Referring to
FORMAT ('DON"T')
causes ON'T to be printed. The first character referenced by the FORMAT statement for output is interpreted
as a carriage control character (see 5. 1 • 1. 13).

5.1.1:7

Mixed Fields - An alphanumeric format field may be placed among other fields of the format. For

example, the statement:
FORMAT (I5,7H FORCE=FlO.5)
can be used to output the line:
bbb22bF ORCE=bb 17. 68901
The separating comma may be- omitted after an alphanumeric format field, as shown above.

5-45

5.1.1.8

Complex Fields.- Complex q~antities are transmitted as two independent n::al quantities. The format

specification consists of two successive .real specifications or one' repeated real specification. For instance,
the statement:
FORMAT (2E15.4,2(F8.3,F8.5»
could be used in the transmission of three complex quantities.

5.1.1.9

Repetition of Field Specifications - Repetition of a field specification may be specified by preceding

the control character 0, E, F, I, 0, G, L, or A by an unsigned integer giving the number of repetitions desired. For example:
FORMAT (2E12.4,315)
is equivalent to:
FORMAT (E 12.4,E 12.4, IS ,15 ,15)

5.1.1. 10

Repetition of Groups - A group of field specifications may be repeated by enclosing the group in

parentheses and preceding the whole with the repetition number. For example:
FORMAT (218, 2(E 15.5 ,2F8 .3»
is equivalent to:
FORMAT (218,E 15.5 ,2F8.3,E 15.5 ,2F8 .3)

5.1.1.11

Multiple Record Formats - To handle a group of input/output records where different records have

different field specifications, a slash is used to indicate a new record. For example, the statement:
FORMAT (308/I5,2F8.4)
is equivalent to
FORMAT (308)
for the first record and
FORMAT (I5, 2F8 .4)
for the second record.
5-46

The separating comma may be omitted when a slash is used. When n slashes appear at the end or beginning of

a format, n blank records may be written an output or records skipped on input. When n slashes appear in the
middle of a format, n-1 blank records are written or n-1 records skipped.
Both the slash and the closing parenthesis at the end of the format indicate the termination of a record. If the
list of an input/output statement dictates that transmission of elata is to continue after the closing parenthesis
of the format is reached, the format is repeated starting with that group repeat specification terminated by the
last right parenthesis of level one or level zero if no level one group exists.
Thus, the statement

•

FO~MAT

level

(F7. 2,(2(E 15.5,E 15.4),17»

level 1

level 0

causes the format
F7 .2,2(E 15.5,E 15.4) ,17
to be used on the first record, and the format
2(E15.5,E15.4),I7
to be used on succeeding records.
As a-further example, consider the statement'
FORMAT (F7. 2/(2(E 15.5,E 15 .4) ,17»
The first record has the format
F7.2
and successive records have the format
2(E15.5,E 15.4),17

5. 1.1.12

Formats Stored as Data - The ASCII character string comprising a format specification may be stored

as the values of an array. Input/output statements may refer to the format by giving the array name, rather than
the statement number of a FORMAT statement. The stored format has the same form as a FORMAT statement excluding the word "FORMAT." The enclosing parentheses are included.

5-47 '

As an example, consider the sequence:
,

DIMENSION SKELETON {2}
READ 1, (SKELETON{I), 1=1,2)
1 FORMAT (2M)
READ SKELETON,K,X
The first READ statement enters the ASCII string into the array SKELETON. In the second READ statement,

SKELETON is referred to as the format governing conversion of K and X •

5.1. 1. 13

Carriage Control - The first character of each ASCII record controls the spacing of the line printer

or Teletype. 'This character is usually set by beginning a FORMAT statement for an ASCII record with 1Ha,
where a is the desired control character. The line spacing actions, listed be low, occur before printing:
Effect

Character
space

skip to next line with a FORM FEED
after every 60 lines

zero

skip a line

one

form feed - go to top of next page

plus

suppress skipping - will overprint line

asterisk

skip to next I i.ne with no FORM FEE DS

minus

skip 2 lines

two

sk i p to nex t 1/2 of page

three

skip to next 1/3 of page

slash

skip to next 1/6 of page

period

skip to next 1/20 of page

comma

skip to next 1/30 page

A $ (dollar sign) as a format field specification code suppresses the carriage retum at the end of the line.

5.1.1.14

Spacing - Input and output can be made to begin at any position within a FORTRAN record by use

of the format code
Tw
where T is the control character and w is an unsigned integer constant specifying the character position in a
FORTRAN record where the transfer of data is to begin. When the o~tput is printed, w corresponds to the {w-l)th
print position. This is because the first character of the output buffer is a carriage control character and is not
printed. It is recommended that the first field specification of the output format be lx', except where a carriage
control character is used.
5-48

For example,
2 FORMAT (T50, 'BLACK'T30, 'WHITE')
would cause the following line to be printed
Print Position 29

+WHITE

Print Position 49

BLACK

For input I the statement
] FORMAT(T35, 'MONTH')
READ (3,1)
cause the first 34 characters of the input data to be skipped, and the next 5 characters would replace the characters M, 0, N, T, and H in storage. If an input record containing
ABCbbbXYZ
is read with the format specification
10 FORMAT (T7 ,A3, T] ,A3)
then the characters XYZ and ABC are read, in that order.

5. ]. ].15

Blank or Skip Fields - Blanks may be introduced into an output record or characters skipped on an

input record by use of the specification nX. The control character is Xi n is the number of blanks or characters
skipped and must be greater than zero. For example, the statement
FORMAT (5H.STEPI5, lOX2HY=F7.3) .
may be used to output the line
bSTEPbbb28bbbbbbbbbbY=b-3.872

5.1.2

NAME LIST Statement

The NAME LIST statement, when used in conjunction with special forms or the READ and WRITE statements,
provides a method for transmitting and converting data without using a FORMAT statemen't or an
NAME LIST statement has the form

5-49

I/o

I.ist. The·

where the X's are NAMELIST names,'\and the A's, B's, and C's are variable or array names.
Each list or variable mentioned in the NAME LIST statement is given the NAMELIS! name immediately preceding
the list. Thereafter, an

I/o statement may

refer to an entire list by mentioning its' NAMELIST name. For

example:
NAMELIST/FRED/A,B,C/MARTHA/D,E
states that A, B, and C belong to the NAME LIST name FRED, and D and E belong to MARTHA.
The use of NAMELIST ~tatements must .obey the following rules:
a. A NAMELIST name may not be longer than six characters; it must start with an alphabetic character; it must be enclosed in slashes; it must precede the list of entries to which it refers; and it must
be unique within the program.
b. A NAME LIST name may be defined only once and must be defined by a NAMELIST statement.
After a NAMELIST name has been defined, it may only appear in READ or WRITE stateme~ts. The
NAMELIST name ,must be defined in advance of the READ or WRITE statement.
c. A variable used in a NAME LIST statement cannot be used as a dummy argument in a subroutine
definition.
d. Any dimensioned variable contained in NAME LIST statement must have been defined in a
DIMENSION statement preceding the NAMELIST statement.

5.1.2.1

Input Data For NAMELIST Statements - When a READ statement refers to a NAMELIST name, the

first character of all input records is ignored. Records are searched until one is found with 6 $ or & as the
second character immediately followed by the NAMELIST name specified. Data is then converted and placed
in memory until the ~nd of a data group is signaled by a $ or'& eith~r in the same record as the NAMELIST name,
or in any succeeding record as long as the $ or & is the second character of the record. Data items must be
separated by commas and be of the following form:

where V may be a variable name or an arra~ name, wi th or without subscripts. The K's are constants which may
be integer, real, double precision, complex {written as (A, B) where A and B are rea!), or logical (written as
T for true and'F for false). A series of J identical constants may be represented by J*K where J is an unsigned
integer and K is the repeated constant. Logical and complex constants must be equated to logical and complex
variables, respective ly. The other types of constants (real, double precisi9n, and integers) may be equated to

5-50

any other type of variable (except logical or complex), and will be converted to the variable typel For
example, assume A is a two-dimensional real array, B is a one-dimensional integer array, C is an integer
variable, and that the input data is as follows:
$FRED A(7,2)=4, B=3,6*2.8, C=3.32$
t

Column 2
A READ statement referring to the NAMELIST name FRED will result in the following: the integer 4 will be
converted to floating point and placed in A(7,2). The integer 3 will be placed in B(l) and the floating point
number 2.8 will be p'laced in B(2), B(3), •.. , B(7). The floating point number 3.32 will be converted to the
integer 3 and placed in C.

5.1.2.2

Output Data For NAMELIST Statements - When a WRITE statement

ref~rs TO

a NAMELIST name, all

variables and arrays and their values belonging to the NAMELIST name will be written out, each according to
its type. The complete array is written out by columns. The output data wi" be written so that:
a.

The fields for the data will be large enough to contain all the significant digits.

The output can be read by an input statement referencing the NAMELlST nome.

For example, if JOE is a 2x3 array, the statement
NAMELIST/NAM l/JOE, K I,ALPHA
WRITE (u, NAM 1)
generate the following form of output.
Column 2
~

$NAMJ
JOE = -6.75,
-17.8,
Kl=73.1,

5.2

. 234E-04,
0.0,
ALPHA=3,$

68.0,
-. J97E+07,

DATA TRANSMISSION STATEMENTS

The data transmission statements accomplish input/output transfer of data that may be listed in a NAMEL:ST
statement or defined in a FORMAT statement. When a FORMAT statement is used to specify formats, the data
transmission statement niust contain a list of the quantities to be transmitted. The data appears on the external
media in the form of records.

5-51

5.2.1

Inpot/Output Lists

The list of' an-input/output statement specifies the order of transmission of the variable values.

During input,

the new values of listed variables may be used in subscript or control expressions for variables appearing later
in the list. For example:
READ 13,L,A(L),B(L+1}
reads a new value of L and uses this value in the subscripts of A and B:
The transmission of array-variables may be controlled by indexing similar to that used in the DO statement. The
list of controlled variables, followed by the index control, is enclosed in parentheses. For example,
READ 7, (X(K),K=1,4),A
is equivalent to:
READ 7, X(1) ,X(2) ,X(3) ,X(4),A
As in the DO statement, the initial, limit, and increment values may be given as integer expressions:
READ 5, N, (GAIN(K), K=l ,M/2, N)
The indexing may be compounded as in the following:
READ 11, «MASS(K, L), K= 1,4), L= 1,5)
The above statement reads in the elements of array MASS in the following order:
MASS(l, 1), MASS(2, 1}, ... ,MASS(4, 1} ,MASS(l ,2), ... ,MASS(4,5)
If on entire array is to be transmitted, the index ing may be omitted and only the array identifier written. The
array is transmitted in order of increasing subscripts with the first subscript varying most rapidly. Thus, the
example above could have been written:
READ 11, MASS
Entire arrays may also be designated for transmission by referring to a NAME LIST name (see description of
NAMELIST statement).

5-52

5.2.2

Input/Output Recorc!s

All information appearing on external media is grouped into records. The maximum amount of information in
one record and the manner of Separation between records depends upon the medium. For punched cards, each
card constitutes one record; on a teletypewriter a record is one line, and so forth. The amount of information
contained in each ASCII record is spec ified by the FORMAT reference and the
binary records, the amount of information is specified by the

I/o

list. For magnetic tape

list.

Each execution of an input or output statement initiates the transmission of a new data record. Thus, the
statement
READ 2, FIRST ,SECOND, THIRD
is not necessarily equivalentto the statements
READ 2, FIRST
READ 2, SECOND
READ 2, THIRD
since, in the second case, at least three separate records are required, whereas, the single statement
READ 2, FIRST ,SECOND, THIRD
may require one, tWo, three, or more records depending upon FORMAT statement 2.
If an input/output statement requests less than a full record of information, the unrequested part of the record
is los! and cannot be recovered by another input/output statement without repositioning the record.

If an input/output list requires more than one ASCII record of information, successive records are read.

5.2.3

PRI NT Statement

The PRI NT statement assumes one of two forms
PRINT f, list
PRINT f
where f is a format reference.
The data is converted from internal to external form according to the designated format. If the data to be
transmitted is contained in the specified FORMAT statement, the second form of the statement is used.

5-53

Examples~

PRINT 16, T , (B(I<) ,K=1,M)
PRINT F 106, seEE 0, MISS

In the second example, the format.is stored in array F106.

'5.2.4

PUNCH Statement

The PUNCH statement assumes one of two forms
PUNCH f, list
PUNCH f

:\It

where f is a format reference.
Conversion from internal to externa I data forms is specified by the formqt reference. If the data to be transmitted is contained in the designated FORMAT statement, the second form of the statement is used.
Examples:

5 • 2.5

PUNCH 12,A,B(A),C(B(A»
PUNCH 7

TY PE Statement

The TYPE statement assumes one of two forms
TYPE f, list
TYPE f
where f is a format reference.
This statement causes the values of the variables in the list to be read from memory and listed on the user's
teletypewriter. The data is converted from internal to external form according to the designated format. If
the data to be transmitted is contained in the designated F ORMAT
is used.

Examples:

5.2.6

TYPE 14,K,(A(L) ,L=1,K)
TYPE FMT

WRITE· Statement

The WRITE statement assumes one of the following forms

5-54

state~ent,

the second form of the statement

WRITE (u,f) list
WRITE(u ,f)
WRITE(u,N)
WRITE(u) list
WRITE(u#R,f) list
where u is a unit designation, f is a format reference, N is a NAMELIST name, and R is a record number where

I/o is to start.
The first form of the WRITE statement causes the values of the variables in the list to be read from memory and
written on the unit designated in ASCII form. The data is converted to external form as specified by the designated FORMAT statement.
The second form of the WRITE statement causes information to be read directly from the specified format and
written on the unit designated in ASCII form.
The third form of the WRITE statement causes the names and values of all variables and arrays belonging to the
NAMELIST name, N, to be read from memory and written on the unit designated. The data is converted to
external form according to the type of each variable and array.
The fourth form of the WRITE statement causes the values of the variables in the list to be read from memory
and written on the unit designated in binary form.
The fifth form of the WRITE statement -allows the FORTRAN programmer to access fixed-length records in a
disk file directly. This eliminates sequential writing of data in order to access one or more records within a file.
The file must be defined properly and the record from which the writing is desired must be specified. The file
whose records are to be accessed is defined as follows.
CALL DEFINE FILE (D, S, V, F, Pj, Pg)
D = data set (device)
S
size of records in the file in characters (ASCII) or words (binary)
V = associate~ variable which initially contains the length of the file
that would be accessed next if the program were to continue I/o
sequentially
*F = file name .ext defined first in DATA statement
*Pj = project number
'
*Pg = programmer number
Output begins when the random WRITE is specified in the correct format. The arguments designated by an
asterisk (*) may be zero. This impl ies a defau It filename and/or user's project and programmer numbers;
for example,
CALL DEFI NE FILE (3,80, NX ,0,0,0)

5-55

•

5.2.7

READ Statement

The READ statement assumes one of the following forms
READ f, list
READ f
READ(u , f) list
READ(u ,f)
READ(u, N)
READ(u)list
READ(u# R, f) list
READ(u,f,END=C, ERR=d) list
READ(u,f,END=C) list
READ(u,f, ERR=d) list

''\IIiiit:,

,,~-.

where f is a format reference, u is a unit designation, N is a NAME LIST name, R is a record number where

I/o

is to start, C is a statement number to whi ch control is transfe~red upon encountering an end-of-fi Ie, and d is
the statement number to which control is transferred upon encountering an error condition on the input data.
The first form of the READ statement causes information to be ,read from cards and put in memory as values of the
variables in the list. The data is converted from external to internal form as specified by the referenced
FORMAT statement.
Example:

READ 28,Zl,Z2,Z3

The second form of the READ statement is used if the data read from-cards is to be transmitted directly into the
s~cified

format.

Example:

The third form of the READ statement causes ASCII information to be read from the unit designated and stored
in memory as values of the variables in the list. The data is converted to internal form as specified by the
referenced FORMAT statement.
Example:

READ( I, 15)ET A, PI

The fourth form of the READ statement causes ASCII information to be read from the unit desi.gnated ,and transmitted directly into the specified format.
Example:

READ(N,105)

The fifth form of the READ statement causes data of the form described in the discussion of input data for
NAMELIST statements to be read from the unit designated and stored in memory as values of the variables or
arrays specified.

READ(2,FRED)

Example:

The sixth form of the REAb statement causes binary information to be read from the unit designated and stored
in memory as values of the variables in the list.
READ(M)GAIN,Z ,AI

Example:

The seventh form of the READ statement allows random access of fixed-length records in a disk file. The file
whose records are to be read is defined by the DEFINE FILE call where the arguments are the same as described
in Section 5.2.5 of this chapter.
Example:

DOUBLE PRECISION FIL
DIMENSION A(6)
DATA FIL/'FILE. ONE'I
CALL DEFINE FILE (4,30, NV,FIL,"l1,"23)
READ (4#54,5)A

This example reads the 54th record from FILE. ONE on the disk area belonging to programmer [11,23] into the
list variables A(1) through A(6).

The eighth form of the READ statement causes control to be transferred if an end-of-file or error condition is
encountered on the input data. The argument$ END=c and ERR=d are optional and mayor may not be included.

If an end-of-file is encountered, control transfers to the statement specified by END=c. If an END parameter
is not specified, I/O on that device terminates and the program halts with an error message to the user's TTY.

If an error on input is encountered, control transfers to the statement specified by' ERR=d. If an ERR=d parameter
is not specified, the program halts with an error message to the user's TTY .
Example:

5.2.8

READ (7,7,END=888, ERR=999)A

888

(control transfers here if an end-of-file is encountered)

999

(control transfers here if an error on input is encountered)

REREAD Statement

The reread feature allows a FORTRAN program to reread information from the last used input file. The format
used during the reread need not correspond to the original read format, and the informati on may be read as
many times as desired.

5-57

To reread from an input device, the following coding would be u~d:
READ (16, l(0)A
REREAD 105,A

The REREAD 105,A statement causes the last input device used to be reread according to format st~te
ment 105. The original read format and a subsequent reread format need not be the same.
b. The reread feature cannot be used until an input from a file has been accomplished. If the feature
is used prematurely, an error message will be generated.
c. Information may be reread as many times as desired using either the same or a new format statement
each time.
d. The reread feature must be used with some forethought and care since it
file used, i.e.:

re~ads

from the last input

The following example will reread from the file on Device No. 10, not Device No. 16:
READ (16, l(0)A
READ (10,200)B
REREAD 110,A

5.2.9

ACCE PT Statement

The ACCEPT statement aSSumes one of two forms
ACCEPT f, list
ACCEPT f
where f is a format reference.
This statement causes information to be input from the user's teletypewriter and put in memory as values of the
variables in the list. The data is converted to internal form as specified by the format. If the transmission of
data is directly into the designated format, the second form of the statement is used.
Examples:

5.3

ACCEPT 12,ALPHA,BETA
ACCEPT 27

DEVICE CONTROL STATEMENTS

Device control statements and their corresponding effects are listed in Table 5-3.

5-58

Table 5-3
Device Control Statements

'5.4

Statement

Effect

BACKSPACE u

Backspaces designated tape one ASCII record or one
logical binary record.

END FILE u

Writes an end-of-fi Ie .

REWIND u

Rewinds tape on designated unit.

SKIP RECORD u

Causes skipping of one ASCII record or one logical
binary record.

UNLOAD u

Rewinds and unloads the designated tape.

ENCODE AND DECODE STATEMENTS

ENCODE and DECODE statements transfer data, according to format specifications, from one section of user's
core to another.

No peripheral equipment is involved. DECODE is used to change data in ASCII format to

data in another format. ENCODE changes data of another format into data in ASCII format.
The two statements are of the form
ENCODE(c,f,v),l(1), ••. ,L(N)
DECODE (c, f, v), L(1), .•• ,L(N)
where
c = the number of ASCII characters
f = the format statement number
v = the starting address of the ASCII record referenced
L(1), ••. ,L(N) = the list of variables.
Example:

Assume the contents of the variables to be as follows:
A(I) contains the floating-point binary number 300.45
A(2) contains the floating-point binary number 3.0

contains the binary integer value 1.

is a four-word array of indeterminate contents

contains the ASCII string 12345

DO 2 J = 1,2
.
ENCODE (16, 10,B) J, A(J)
FORMAT (IX,2HA(,Il,4H) = ,F8.2)

TYPE 11 ,B
11
2

FORMAT (4A5)
CONTINUE
DECODE (4, 12, C) B

5-59

12
13

FORMAT (3F1.0,IX,F1.0)
TYPE 13,B
FORMAT (4F5.2)
END

Array B can contain 20 ASCII·characters. The result of the EN~ODE statement after the first iteration of the
. DO loop is:
Typed as

B( 1) 1--_.;...:.A(,l..;.;1):""'-_-I
B(2) 1-----::=="......,....----1
B(3) t--_3_O-;::-0_.4_ _--i
B(4) L -_ _5_ _---'

A(1)

= 300.45

The result after the second iteration is:

B.(1) t - - _A
. . . ;(.. .;.2)_ _--i
B(2) 1--_,.....-_ _---I
B(3) t--_ _
3_.0_ _~
B(4) '--_ _ _ _--1

Typed as
A(2) = 3.0

The result of the DECODE statement is to extract the digits 1, 2, and 3 from C and convert them to floatingpoint binary values and store them in B(1}, B(2), and 8(3). Then skip the next character (4) and extract the
digit 5 from C, convert it to a floating-point binary value, and store it in 8(4).

5-60

CHAPTER 6
SPECIACATION STATEMENTS

Specification statements allocate storage and furnish information about variables and constants to the compiler.
Specification statements may be divided into three categories, as follows:
a.

Storage specification statements: DIMENSION, COMMON, and EQUIVALENCE.

pata specification statements: DATA and BLOCK DATA.

c. Type declaration statements: INTEGER, REAL, DOUBLE PRECISION, COMPLEX, LOGICAL,
SUBSCRIPT INTEGER, and IMPLICIT.
By extending the USA Standard in regard to specification statements, PDP-lO FORTRAN IV allows the following
statements to be used anywhere in the program, provided that the variables they specify appear in executable
statements only after the particular specification statement. The specification statement must not appear in the
range of a DO loop.
DIMENSION statement
EXTERNAL statement (described in Chapter 7)
COMMON statement
EQUIVALENCE statement
Type declaration statements
DATA statement
A sample program that incorporates these statements follows.

DOUBLE PRECISION 0
DIMENSION Y(10), 0(5)
Y{l) = -1.0
INTEGER XX(5)
Y(2) = ABS(Y(l»
DATA XX/l,2,3,4,5
DO 10 1= 3,7
Y(I) = XX(I-2)
COMMON Z

Z=Y(1)*Y{2)/(Y{3) + Y(5»
END
Only IMPLICIT statements and arithmetic function definition statements (described in Chapter 7) must appear in
the program before any executable statement.

5-61 -

In addition, arrays must be dimensional before being referenced in a NAMEUST, EQUIVALENCE, or DATA
statement. ,DOUBLE PRECISION and COMPLEX arrays must be declared before they are dimensioned.

6.1

STORAGE SPECIACATION STATEMENTS

6. 1. 1 DIMENSION Statement
The DIMENSION statement is used to declare identifiers to be array identifiers and to specify the number and
bounds of the array subscripts. The information supplied in a DIMENSION statement is required for the allocation of memory for arrays. Any number of arrays may be declared in a single DIMENSION statement. The
DIMENSION statement has the form

where S is an array specification.
Each array variable appearing in the program must represent an element of an array declared in a DIMENSION
statement, unless the dimension information is given in a COMMON or TYPE statement. Dimension information
may appear only once for a given variable.
Each array specification gives the array identifier and the minimum and maximum values which each of its subscripts may assume in the following form:
identifier(min/max, min/max, ••• ,min/max).
The minima and maxima must be integers. The minimum must not exceed the maximum. For example, the statement
DIMENSION EDGE(-1/1,4/8)
specifies EDGE to be a two-dimensional array whose first subscript may vary from -1 to 1 inclusive, and the second from 4 to 8 inclusive.
Minimum values of 1 may be omitted. For example,
NET(5, 10)

is interpreted as:
NET(1/5,1/to)

5,..62

Examples:

PIMENSION FORCE(-l/1, 0/3, 2,2, -7/3)
DIMENSION PLACE(3,3,3), JI(2,2/4), K(256)

Arrays may also be declared in the COMMON or type declaration statements in the same way:
COMMON X(10,4), Y,Z
INTEGER A(7, 32), B
DOUBLE PRECISION K(-2/6, 10)

6.1.1.1

Adjustable Dimensions - Within either a FUNCTION or SUBROUTINE subprogram, DIMENSION and

TYPE statements may use integer variables in an array specification, provided that the array name and variable
dimensions are dummy arguments of the subprogram. The actual array name and values for the dummy variables
are given by the call ing program when the subprogram is called. The variable dimensions may not be altered
within the subprogram (i.e., typing the array DOUBLE PRECISION or COMPLEX after it has been dimensioned)
and must be less than or equal to the explicit dimensions declared in the calling program.
SUBROUTINE SBR(ARRAY,M1,M2,M3,M4)
DIMENSION ARRAY (Ml/M2,M3/M4)

Example:

DO 27 L=M3, M4
DO 27 K=M1,M2

ARRAY(K,L)=VALUE

END
The calling program for SBR might be:
DIMENSION Al(10,20),A2(l000,4)

CALL SBR(Al,5, 10, 10,20)

CALL SBR(A2, 100,250,2,4)

END

5-63

6.1.2 COMMON Statement
The COMMON statement causes specified variables or arrays to be stored in an area available to other programs.
By means of COMMON statements,' the data of a main program and/or the ,data of its subprograms may share a
common storage area.
The common area may be divided into separate blocks which are identified by block names. A block is specified
as follows:
. ,/block identifier/identifier, identifier, ••• ,identifier
The identifier enclosed in slashes is the block name. The identifiers which follow are the names of the variables
or arrays assigned ,to the block and are placed in the block in the order in which they appear in the block specification. A common block may have the same name as a variable in the same program.
The COMMON statement has the general form
COMMONjBLOCK 1/A, B,C/BLOCK2/D, E, F/ •••
where BLOCK 1,BLOCK2, ••• are the block names, and A,B,C, ••• are the variables to be assigned to each
block. For example, the statement
COMMON/R/X, Y, T/C;\J, V, W,Z
i ndi cates that the elements X, Y, and T are to be placed in block R in that order, and that U, V, W, and Z are
to be placed in block C.
Block entries are linked sequentially throughout the program, beginning with the first COMMON statement. For
example" the statements
COMMON/D/ALPHA/R/A,B/C/S
COMMON/C/X, Y/R/U, V, W
have the same effect as the statement
COMMON/D/ALPHA/R/A,B,U, V, W/C/S,X, Y
One block of common storage, referred to as blank

~ommon,

may be left unlabeled. Blank common is indicated

by two consecutive slashes. For example,
COMMON/R/X, Y//B,C,D
indicates that B, C, and D are placed in blank common. The slashes
first block of the statement.
5-64

m~y

be omitted when blank common is the

COMMON B,C,D
Storage allocation for blocks of the same name begins at the same location for all programs executed together.
For example, if a program contains
COMMON A, B/R;?<, ViZ
as its first COMMON statement, and a subprogram has
COMMON/R/U, V, W//D,E,F
as its first COMMON statement, the quantities represented by X and U are stored in the same location. A similar correspondence holds for A and D in blank common.
Common blocks may be any length provided that no program attempts to enlarge a given common block declared
by a previously loaded program.
Array names appearing in COMMON statements may have dimension information appended if the arrays are not
declared in DIMENSION or type declaration statements. For example,
COMMON ALPHA, T(15, 10,5),GAMMA
specifies the dimensions of the array T while entering Tin bl(Jnk common. Variable dimension array identifiers
may not appear in a COMMON statement, nor may other dummy identifiers. Each array name appearing in a
COMMON statement must be dimensioned somewhere in the program containing the COMMON statement.

6.1.3

EQUIVALENCE Statement

The EQUIVALENCE statement causes more than one variable within a given program to share the same storage
location. The EQUIVALENCE statement has the form
EQUIVALENCE(V l' V2' ... ), (Vk , Vk+ 1'· •• ), ..•
where the V's are variable names.
The inclusion of two or more references in a parenthetical list indicates that the quantities in the list are to share
the same memory location. For example,
EQUIVALENCE(RED, BLUE)
specifies that the variables RED and BLUE are stored in the same location.

5-65

The relation of equivalence is transitive; e.g., the two statements,
EQUIVALENCE(A, B), (B,C)
\ EQUIVALENCE(A,B,C)
have the same effect.
Tne subscripts of array variables must be integer" constants.
EQUIVAlENCE(X,A{3), V{2, 1,4», (BETA{2(2),ALPHA)

Example:

6.1.4

EQUIVALENCE and COMMON

Identifiers may appear in both COMMON and EQUIVALENCE statements provided the following rules are observed.
a.

No two quantities in common may be set equivalent to one another.

b. Quantities placed in a common block by means of EQUIVALENCE statements may cause the end of
the common block to be extended. For example, the statements
COMMON/Rft, V,Z
DIMENSiON A(4)
EQUIVALENCE{A, V)
causes the common block R to extend from X to A(4), arranged as follows:

X
V A(1)
Z A(2)
A(3)
A(4)

(same location)
(same location)

c. EQUIVALENCE statements which cause extension of the start of a common block are not allowed.
For example, the sequence
COMMON/Rft, V,Z
DIMENSION A(4)
EQUIVALENCE(X ,A(3»
is not permitted, since it would require A(1) and A(2) to extend the starting location of block R.

6.2

DATA SPECIFICATION STATEMENTS

The DATA statement is used to specify initial or constant values for variables. The specified values are compiled
into the object program, and become the values assumed by the variables when program execution begins.

6.2.1

DATA Statement

The data to be compiled into ,the object program is specified in a DATA statement. The DATA statement has the
form
5-66

DATA Iist/d 1,d 2 ,· • •1, list/dk,d k+1" . .I, ...
where each list is in the same form as an input/output list, and the d's are data items for each list.
Indexing may be used in a list provided the initial, limit, and increment (if any) are given as constants. Expressions used as subscripts must have the form

where c 1 and c 2 are integer constants and i is the induction variable. If an entire array is to be defined, only
the array identifier need be listed. Variables in COMMON may appear on the lists only if the DATA statement
occurs in a BLOCK DATA subprogram. (See Chapter 7, Section 7.6)
The data items following each list correspond one-to-one with the variables of the list. Each item of the data
specifies the value given to its corresponding variable. Data items may be numeric constants, alphanumeric
strings, octal constants, or logical constants. For example,
DATA ALPHA, BETA/5, 16.E-2/
specifies the value 5 for ALPHA and the value. 16 for BETA.
Alphanumeric data is packed into words according to the data word size in the manner of A conversion;

how~ver,

excess characters are not permitted. the specification is written as nH followed by n characters or is imbedded
in single quotes.
Octal data is specified by the letter 0 or the character ", followed by a signed or unsigned octal integer of one
to twelve digits.
Logical constants are written as • TRUE.,. FALSE., T, or F.
Example:

DATA NOTE,K/4HFOOT, 0-7712/
DATA QUOTE/,QUOTE'/

Any item of the data may be preceded by an integer followed by an asterisk. The integer indicates the number
of times the item is to be repeated. For example,
DATA(A(K},K=1, 20)/61 E2, 19*32E1/
specifies 20 values for the array A; the value 6100 for A(1); the value 320 for A(2) through A(20).

5-67

6.2.2

BLOCK OATA Statement

The BLOCK DATA statement has the form:
BLOCK DATA
This statement declc:'res the program which follows to be a data specification subprogram. Data may be entered
into labeled or blank common.
The first statement of the subprogram must be the BLOCK OAT A statement. The subprogram may contain only the
declarative statements associated with the data being defined.
Example:

BLOCK DATA
COMMONft/S, Y/C/z', W, V
DIMENSION Y(3)
COMPLEX Z
DATA Y/1E-1 ,2*3E2/,X, Z/ll. 87700,(-1.41421,1.41421)/
END

Data may be entered into more than one block of common in one subprogram.

6.3 TYPE DECLARATION STATEMENTS
The type declaration statements INTEGER, REAL, DOUBLE PRECISION, COMPLEX, LOGICAL, IMPLICIT; and
SUBSCRIPT INTEGER are used to specify the type of identifiers appearing in a prograJ!l. An identifier may appear in only one type statement. Type statements may be used to give dimension specifications for arrays.
The explicit type declaration statements have the general form
type identifier, identifier, identifier •••
where type is one of the following:
IN TEGER, REAL, DOUBLE PRECISION,COMPLEX,LOGICAL,
SUBSCRIPT INTEGER
The listed identifiers are declared by the statement to be of the" stated type. Fixed-point variables in ci SUBSCRIPT INTEGER statement must fall between _2 27 and 227.

6.3. 1 IMPLICIT Statement
The IMPUCIT statement has the form

5-68

where type represents INTEGER, REAL, LOGICAL, COMPLEX, or .DOUBLE PRECISION, and a 1a 2 , ... represent
single alphabetic characters, each separated by commas, or a range of characters (in alphabetic sequence) denoted by the first and last characters of the range separated by a minus sign (e.g., (A-D».
This statement causes any program variable which is not mentioned in a type statement, and whose first character
is one of those listed in the IMPLICIT statement, to be classified according to the type appearing before the list
in which the character appears. As an example, the statement
IMPLICIT REAL(A-D, L, N-P)
causes all variables starting with the letters A through D, L, and N through P to be typed as real, unless they are
explicitly.declared otherwise.
The initial state of the compiler is set as if the statement
IMPLIOT REAL(A-H,O-Z), INTEGER(I-N)
were at the beginning of the program. This state is in effect unless an IMPLICIT statement changes the above
interpretation; i.e., identifiers, whose types are not explicitly declared, are typed as follows.
a.

Identifiers beginning with I, J, K, L, M, or N are assigned interger type.

Identifiers not assigned integer type are assigned real type.

If the program contains an IMPLICIT statement, this statement will override throughout the program the implicit

state initially set by the compiler. No program may contain more than one IMPLICIT declaration for the same
letter.

5- 69

CHAPTER 7
SUBPROGRAM STATEMENTS

FORTRAN subprograms may be either internal or external. Internal subprograms are defined and may be used
only within the program containing the definition. The arithmetic function definition statement is used to define
internal functions.
External subprograms are defined separately from (i. e., external to) the programs that call them, and are complete programs which conform to all the rules of FORTRAN programs. They are compiled as closed subroutines;
i.e., they appear only once in the object program regardless of the number of times they are used. External subprograms are defined by means of the statements FUNCTION and SUBROUTINE.

7.1

DUMMY IDENTIFIERS

Subprogram definition statements contain dummy identifiers, representing the arguments of the subprogram. They
are used as ordinary identifiers within the subprogram definition and indicate the sort of arguments that may appear and how the arguments are used. The dummy identifiers are replaced by the actual arguments when the subprogram is executed.

7.2

LtBRARY SU BPROGRAMS

The standard FORTRAN IV library for the PDP-10 includes built-in functions, FUN~TION subprograms, and
SUBROUTINE subprograms, listed and described in Chapter 8. Builf-in functions are open subroutines; that is,
they are incorporated into the object program each time they are referred to by the source program. FUNCTION
and SUBROUTINE subprograms are closed subroutines; their names derive from the types of subprogram statements
used to define them.

7.3

ARITHMETIC FUNCTION DEFINITION STATEMENT

The arithmetic function definition statement has the form:
identifier(jdentifier, identifier, ••• }=expression

5-71

This statement defines an internal subprogram,. The entire definition is contained in the single statement. The
first identifier is the name of the subprogram being defined.
Arithmetic function subprograms are single-v~lued functions with at least one argument. The type of the function
is determined by the type of the function identifier.
The identifiers enclosed in parentheses represent the arguments of the function. These are dummy identifiers;
they may appear only as scalar variables in the defining expression. Dummy identifiers have meaning and must
be unique only within the defining statement. Dum'my identifiers must agree in order, number, and type with
the actual arguments given at execution til1le.
Identifiers, appearing in the defintng expression, which do not represent arguments are treated as ordinary variables. The defining expreSsion may include external functions or other previously defined arithmetic statement
functions.
All arithmetic function definition statements must precede the first executable statement of the program.
Examples:

SSQR(K)=K*(K+1)*(2*K+l )/6
ACOSH(X)=(EXP(X/A)+EXP(-X/A))/2

In the last example above, X is a dummy identifier and A is an ordinary identifier. At execution time, the
function is evaluated using the current value of the quantity represented by A.

7.4

FUNCTION SUBPROGRAMS

A FUN<;:TION subprogram is a single-valued function that may be called by using its name as a function name
in an arithmetic expression, such as FUNC(N), where FUNC is the name of the subprogram that evaluates the
corresponding function of the argument N. A FUNCTION subprogram begins with a FUNCTION statement and
ends with an END statement. It returns control to the calling program by means of one or more RETURN statements.

7.4.1

FUNCTION Statement

The FUNCTION statement has the form:
FUNCTION identifier(argument ,argument, ••. )
This statement declares the program which follows to be a FUNCTION subprogram. The identifier is the name of
the function being defined. This identifier must appear as a scalar variable and be assigned a value during execution of the subprogram which is the function value.

5-72

Arguments appearing in the list enclosed in parentheses are dummy arguments representing the function argument.
The arguments must agree in number, order, and type with the actual arguments used in the calling program.
FUNCTION subprogram arguments may be expressions, alphanumeric strings, array names, or subprogram names.
Dummy arguments may appear in the subprogram as scalar identifiers, array identifiers, or subprogram identifiers.
A function must have at least one dummy argument. Dummy arguments representing array names must appear
within the subprogram in a DIMENSION statement, or one of the type sta.tements that provide dimension information. Dimensions given as constants must equal the dimensions of the corresponding arrays in the calling program. In a DIMENSION statement, dummy identifiers may be used to specify adjustable dimensions for array
name arguments. For example, in the statement sequence:
FUNCTION TABLof(A,M, N, B,X, Y}
DIMENSION A(M,N}, B(10),C(50)
The dimensions of array A are specified by the dummies M and N, while the dimension of a~ray B is given as a
constant. The various yalues given for M and N by the calling program must be those of the actual arrays which
the dummy A represents. The arrays may each be of different size but must have two dimensions. The arrays are
dimensioned in the programs that use the function.
Dummy dimensions may be given only for dummy arrays. In the example above the array C must be given absolute dimensions, since C is not a dummy identifier. A dummy identifier may not appear in an EQUIVALENCE
statement

the FUNCTION subprogram.

A function must not modify any arguments which appear in the FORTRAN arithmetic expression calling the function. Modification of implicit arguments from the calling program, such as variables in COMMON and DO loop
indexes, is not allowed. The only FORTRAN statements not allowed in a FUNCTION subprogram are SUBROUTINE, BLOCK DATA, and another FUNCTION statement.

7.4. 1.1

Function Type - The type of the function is the type of identifier used to name the function •. This

identifier may be typed, implicitly or explicitly, in the same way as any other identifier. Alternatively, the
function may be explicitly typed in the FUNCTION statement itself by replacing the word FUNCTION with one
of the following.
INTEGER FUNCTION
REAL FUNCTION
COMPLEX FUNCTIO N
LOGICAL FUNCTION
DOUBLE PRECISION FUNCTION

5-73

For example, the statement
COMPLEX FUNCTION HPRIME{S,N)
is equivalent to the statements
FUNCTION HPRIME(S, N)
COMPLEX HPRIME
Examples:

7.5

FUNCTION MAY{RANGE,EP, YP,ZP)
COMPLEX FUNCTION COT{ARG)
DOUBLE PRECISION 'FUNCTION LIMIT{X, Y)

SUBROUTINE SUBPROGRAMS

A SUBROUTINE subprogram may be multivalued and can be referred to only by a CALL statement. A SUBROUTINE subprogram begins with a SUBROUTINE statement and returns control to the calling program by means of
one or more RETURN statements.

7.5. 1

SUBROUTINE Statement

The SUBROUTINE statement has the form:
SUBROUTINE identifier(argument ,argument, ••• )
This statement declares the program which follows to be a SUBROUTINE subprogram. The first identifier is the
subroutine name. The arguments in the list enclosed in parentheses are dummy arguments representing the arguments of the subprogram. The dummy arguments must agree in number, order, and type with the actual arguments
used by the calling program.
-

SUBROUTINE subprograms may ha'\i'e expressions, alphanumeric strings, array names, and subprogram names as
arguments. The dummy arguments may appear as scalar, array, or subprogram identifiers.
Dummy identifier:s which represent array names must be dimensioned within the subprogram by a DIMENSION 'or
type declaration statement. As in the case of a FUNCTION subprogram, either constants or dummy identifiers
may be used to specify dimensions in a DIMENSION statement. The dummy arguments must not appear in an
EQUIVALENCE or COMMON statement in the SUBROUTINE subprogram.
A SUBROUTINE subprogram may use one or 'more of its dummy identifiers to represent results. The subprogram
name is not used for the J:'etum of results. A SUBROUTINE subprogram need not have any argument at all.

5-74

Examples:

SUBROUTINE FACTOR(COEFF,N,ROOTS)
SUBROUTINE RESIDU(NUM,N,DEN,M,RES)
SUBROUTINE SERIES

The only FORTRAN statements not allowed in a function subprogram are FUNCTION, BLOCK DATA, and
another SU BRO UTI N E statement.

7.5.2

CALL Statement

The CALL statement assumes one of two forms:
CALL identifier
CALL identifier (argument, argument, .•. ,argument)
The CALL statement is used to transfer control to SUBROUTINE subprogram. The identifier is the subprogram
name.
The arguments may be expressions, array identifiers, alphanumeric strings or subprogram identifiers; arguments
may be of any type, but must agree in number, order, type, and array size (except for adjustable arrays, as
discussed under the DIMENSION statement) with the corresponding arguments in the SUBROUTINE statement of
the called subroutine. Unlike a function, a subroutine may produce more than one value and cannot be referred
to as a baiic element in an expression.
A subroutine may use one or more of its arguments to return results to the calling program. If no arguments at all
are required, the first form is used.
Examples:

CALL EXIT
CALL SWITCH(SIN,2.LE. BETA,X**4, Y)
CALL TEST(VALUE, 123,275)

The identifier used to name the subroutine is not assigned a type and has no relation to the types of the arguments.
Arguments which are constants or formed as expressions must not be modified by the subroutine.

7.5.3

RETURN Statement

The RETURN statement has the form:
RETURN
This statement returns control from a subprogram to the calling program. Normally, the last statement executed
in a subprogram is a RETURN statement. Any number of RETURN state'ments may appear in a subprogram.

5-75

7.6 ,BLOCK DATA

SUBPRO~RAMS

A BLOCK DATA subprogram is a data specific~tion subprogram and is used to enter initial values into variables
in COMMON for use by FORTRAN subprograms and MACRO-lO main programs (see Chapter 9). No executab~e
statements may appear in a BLOCK DATA subprogram.

7.6.1

BLOCK DATA Statement

The BLOCK DATA statement has the form:
BLOCK DATA
This statement declares the program which follows to be a data specification subprogram and it must be the first
statement of the subprogram (see Chapter 6, Section 6.2.2) .

. 7.7

EXTERNAL STATEMENT

FUNCTION and SUBROUTINE subprogram names may be used as the actual arguments of subprograms. Such
subprogram names must be distinguished from ordinary variables by their appearance in an EX TERNAL statement.
The EXTERNAL statement has the form:
EXTERNAL identifier, identifier, .•. , identifier
This statement declares the listed identifiers to be subprogram names. Any subprogram name given as an argument to anoJher subprogram mU,st have previously appeared in an external declaration in the calling program

(i .e., as an identifier in an EXTERNAL or CALL statement or as a function name in an expression).
Example:

EXTERNAL SIN,COS
CALL TRIGF(SIN, 1. 5, ANSWER)
CALL TRIGF(COS, • 87, ANSWER)
END

SUBROUTINE TRIGF(FUNC,ARG,ANSWER)

ANSWER

= FUNC(ARG)

RETURN
END

5-76

To reference external variables from a MACRO-lO program by name, place the variables in named COMMON.
Use the name of the variable as the name of the COMMON block:
COMMON /A/A /B/B (13) /C C(6,7)

7.8

SUMMARY OF PDP-10 FORTRAN IV STATEMENTS
CONTROL STATEMENTS
Section References

General Form
ASSIGN i to m

4.1.3

CALL name (a 1,a 2, ... )

7.5.2

CONTINUE

4.4

DO i m=m 1,m 2 ,m 3

4.3

GO TO i

4.1.1

GO TO m

4.1.3

GO TO m, (i l' i2 , ... )

4.1.3

GO TO (i 1,i 2, ... ),m
IF (e 1)i 1,i 2,i 3

4.1.2

IF (e 2)s

4.2.2

PAUSE

4.5
4.5
4.5
7.5.3
4.6
4.7

PAUSE

4.2.1

PAUSE 'h'
RETURN
STOP
END
DATA TRANSMISSION STATEMENTS
General Form

Section References

ACCEPT f

5.2.9

ACCEPT f, list

5.2.9

BACKSPACE unit

5.3

DECODE (n,f,v)list
ENCODE (n,f,v)list

5.4
5.3
5.4

FORMAT (g)

5.1.1

PRINT f

5.2.3

PRINT f, list

5.2.3

END FILE unit

5-77

Section References

General Form
PUNCH f

5.2.4

READ f

5.2.7

READ f, list

5.2.7

READ (unit, f)

5~2.7

READ (unit,f)list

5.2.7

READ (unit)list

5.2.7

READ (unit,name 1)
READ (unit #R,f)list

5.2.7

READ (unit,f,END=c,ERR=d)list

5.2.7

READ (unit,f,END=c)list

5.2.7

READ (unit, f, ERR=d)1 ist

5.2.7

REREAD f,list

5.2.8

REWIND unit

5.3

SKIP RECORD unit

5.3

TYPE f

5.2.5

TYPE f,list

5.2.5

WRITE (unit,f)

5.2.6

WRITE (unit, f) list

5.2.6

WRITE (unit)list

5.2.6

WRITE (unit ,name 1)

5.2.6

WRITE (unit HR, f)list

5.2.6

UNLOAD unit

5.3

5.2.7

SPECIACATION STATEMENTS
Section References

General Form
COMMON a(n , ,n 2,.· . ),b(n 3,n4 , .•• ), •••

6.1.2

COMPLEX a(n 1, n2, .•. ),b(n 3 ,n4" •• ), •••
DATA t,u, ..• ;1 1.0 IN MAGNITUDE
ASIN OF ARG > 1.0 IN MAGNITUDE

ACOS OF ARG

NOTE
nnnnnn = location at which the error occurred.
After two typeouts of a particular error message, further typeout of that error message is suppressed. At the end
of execution, a summary listing the actual number of times each error message occurred is typed out. If the user
wishes to permit more than two type outs for each error message, he may do so by calling the routine ERRSET at
the beginning of the executable.part of his main program. ERRSET accepts one argument in integer mode. This
argument is the number of typeouts that are permitted for each error message before suppression occurs. This
routine is used to obtain the PC information which would otherwise be lost, Alternatively, because of the slowness of the Teletype output, the user may wish to suppress typeout of the messages entirely. This can be done by'
calling ERRSET wrth an argument of zero. Suppression of typeout can also be accomplished during execution by
typing

on the Teletype.

Error messages and the summary are output to the Teletype (or the output device when running BATCH), regardless of the device assignments that have been made.

5-122

The treatment of overflow, underflow, and divide check errors in MACRO programs (those that are loaded with
OVTRAP) can, to a certain extent, be manipulated by the user. (See OVTRAP in the Science Library and
FORTR~O\.N

Utility Subprogram manual.)

5-123

CHAPTER 12
RELATED FEATURES OF THE PDP-l0

12.1

ASCII CHARACTER SET
Table 12-1
ASCII Character Set

SIX BIT

Character

00
01
02
03
04
05
06
07

Space
!

ASCII
7-Bitt

SIX BIT

Character
@

II
$
%

043

046
047

40
41
42
43
44
45
46
47
50
51
52
53
54
55
56
57

H
I

P
Q
R
S
T
U
V

040
041
042

044
045

10
11
12
13
14
15
16
17

050
051
052 .
053
054
055
056
057

20
. 21
22
23
24
25
26
27

0
1
2
3
4
5
6
7

060
061
062
063
064
065
066
067

60
61
62
63
64
65
66
67

30
31
32
33
34
35
36
37

8
9

070
071
072
073
074
075
076
077

70
71
72
73
74
75
76
77

tFORTRAN IV also

(
).

;

=
>
?

A
B
C
D
E
F
G

J
K
L
M
N

W
X

Y
Z
[

]
f

ASCII
7-Bitt

Character

100
101
102
103
104
105
106
107

110
111
112
113
114
115
116
117

h
i

a
b
c
d
e
f

I
m
n
0

120
121
122
123
124
125
126
127

p
q

r
5

t
u
v

130
131
132
]33
134
135
136
137

y
z
{

I
}

.....,

Delete

ac~epts the following control codes in 7-bit ASCII:
Horizontal Tab
Line Feed

011
012

Carriage Return
Form Feed
5-125

015
014

ASCII
7-Bitt
140
141
142
143
144
145
146
147
150
151
152
153
154
155
156
157
160
161
162
163
164
165
-166
167
170
171
172
173
174
175
176
177

12.2

PDP-lO WORD FORMATS

BASIC INSTRUCTIONS

INSTRUCTION CODE
(INCLUDING MODEl

IN-OUT INSTRUCTIONS

1111 111
0

I' NS~~~iTlON II I

DEVICE CODE

9 10

2 3

12 13 14

17 18

PC WORD
flAGS

•

10 I 0 I 0 I 0 I 01
17 18
-----------------

12: 13

BLT POINTER [XWD}
SOU RCE ADDRESS

DESTINATION ADDRESS
)5

17 18

BLK 1/ BLKO POINTER, PUSHDOWN POINTER, DATA CHANNEL CONTROL WORD [IOWD}

- WORD COUNT

ADDRESS-l

17 18

BYTE POINTER
POSITION P

SIZE S

-5 6

'1 12

13 14

17 1e

BYTE STORAGE

I--s

P BITS

BITS

BYTE

35 P-$-1

NEXT BYTE
35-P 35-P"

FIXED POI NT OPERANDS
SIGN

BINARY NUMBER (TWOS COMPLEMENT)

FLOATING POINT OPERANDS
SIGN

EXCESS 128 EXPONENT

,O·

FRACTION (TWOS COMPLEMENT)

10NES COMPLEMENT}

o ,

8 9

LOW ORDER WORD IN DOUBLE LENGTH FLOATING POINT OPERANDS

o
o

EXCESS 128 EXPONENT-27
IN POSITIVE FORM
1

LOW ORDER HALf Of fRACTION (TWOS COMPLEMENT 1
8 9

5-126

12.3

FORTRAN INPUT/OUTPUT

In addition to the arithmetic functions, the PDP-10 FORTRAN IV library (LIB40) contains several subprograms
which control FORTRAN IV I/O operations at runtiml". The I/O subprograms are compC!tible with the PDP-10
Monitors.
In general FORTRAN IV I/O is done with double buffering unless the user has either specified otherwise through
calls to IBUFF and OBUFF or is doing random access I/O to the disk. In these cases, sin~le buffers are used.
The standard buffer sizes for the devices normally available to the user are given in Table 12-2. Note that the
devices and buffer sizes are determined by the Monitor and may be changed by a particular installation. Also a
user may specify buffer sizes for magtape operations through the use of IBUFF and OBUFF.
The logically first device in a FORTRAN program is initialized on software I/O channel one, the second on
software I/O channel two, and so forth. Software I/O channel 0 is reserved for error message and summary
output. The SIXBIT name of the device that is initialized on channel N can be found in a dynamic device table
at location DYNDV. + N. A device may be initialized for input and output on the same I/O channel. Devices
are initialized only once and are released through either the CALL [SIXBIT/EXIT/J executed at the end of every
FORTRAN program or the LIB40 subroutine RELEAS.

Table 12-2
PDP-10 FORTRAN IV Standard Peripheral Devices
Name

Mnemonic

Input/Output
Formatted
Unformatted

Buffer Size
In Words

Operation

Card Punch

CDP

Yes

WRITE

Card Reader

CDR

Yes

READ

Disk
(includes disk
packs and drums)

DSK

Yes

128

READ,lWRITE

DECtapes

DTA

Yes

127

READ,lWRITE

line Printer

LPT

Yes

WRITE

Magtape

MTA

Yes

128

READ,lWRITE

Plotter

PLT

Yes

WRITE

Paper Tape Punch

PTP

Yes

WRITE

Paper Tape Reader

PTR

Yes

READ

Pseudo Teletype

PTY

Yes

READ,lWRITE

Teletype - User

TTY

Yes

READ,lWRITE

Teletype - Console

CTY

Yes

READ,lWRITE

5-127

12.3.1

Logical and Physical Peripheral Device Assignments

Logical and physical device assignments are controlled by either the user at runtime or a table called DEVTB.
The first entry in DEVTB. is the length of the table. Each

en~ry

after the first is a sixbit ASCII device name.

The position in the table of the devi ce name corresponds to the FORTRAN logical number for that device., For
example, in Table 12-3, magnetic tape 0 is the 16th entry in DEVTB. Therefore, the statement
WRITE (16, 13)A
refers to magnetic tapeO. The last five entries in DEVTB. correspond to the special FORTRAN statements READ,
ACCEPT, PRINT, PUNCH, and TYPE. Any device assighments may be changed by reassembling DEVTB.
If the user gives the Monitor

comma~d

ASSIGN DSK 16
prior to the running of his program, a file named FOR16. DAT would be written on the disk. Similarly, the
Monitor command
ASSIGN LPT 16
causes output to go to the line printer.

12.3.2 DECtape dnd Disk Usage

12.3.2.1, Binary Mode - In binary mode, each block contains 127 data words, the first of which is a record
control word of the form:

where w is the word count specifying the number of FORTRAN data words in the block (126 for a full block) and
n is 0 in all but the last block of a logical record, in which case n is the number of blocks in the logical record.
(A logical record contains all the data corresponding to one READ or WRITE statement.)

12.3.2.2 ASCII Mode - In ASCII mode, blocks are packed with as many full lines (a line is a unit record as
specified by a format statement) as possible. Lines always begin with a' new word. If a line terminates in the
middle of a word, the word is filled out with null characters and the next line begins with the next word. Lines
are not split across blocks.

5-128

Table 12-3
Device Table for FORTRAN IV
TITLE
SUBITL

DEVTB V.Ol?
l-APR-69

ENTRY
ENTRY
ENTRY
P=1?

DEVTB. ,DEVND. ,DEVLS. ,DVTOT.
MTABF., MBFBG., TABPT., TABP1.
MTACL. ,DATTB., NEG1. ,NEG2. ,NEG3., NEG5.

DEVTB. :

EXP

DEVND. -.

SIX BIT
SIXBn
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIXBn
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIXBn
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT

.DSK.
.CDR.
.LPT.
.CTY.
.TTY.
.PTR.
.PTP.
· DIS.
· DTA l.
.DTA2.
.DTA3.
.DTA4.
.DTA5.
.DTA6.
.DTA7.
.MTAO.
.MTAl.
.MTA2.
."FORTR.

SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT
SIX BIT

.DSKO.
· DSK l.
.DSK2.
.DSK3.
.DSK4.
.DEV1.
.DEV2.
.DEV3.
.DEV4.
.DEV5.
.REREAD.
.CDR.
.TTY.
· LPT.
.PTP.
.TTY.

CORPOS:
LPTPOS:
TTYPOS:
PTPPOS:

DEVLS. :

DEVND.:

;NO. OF ENTRIES
;LOGICAL# /FILENAME/DEVICE
DISC
; 1 FOROL DAT
CARD READER
; 2 FOR02. DAT
LINE PRINTER
; 3 FOR03. DAT
; 4 FOR04. DAT
CONSOLE TELETYPE
; 5 FOR05. DAT
USER TELETYPE
; 6 FOR06. DAT
PAPER TAPE READER
PAPER TAPE PUNCH
; 7 FOR07. DAT
; 8 FOR08. DAT
DISPLAY
; 9 FOR09. DAT
DECTAPE
; 10 FOR10.DAT
; 11 FORll. DAT
; 12 FOR12.DAT
; 13 FOR13.DAT
; 14 FOR14. DAT
; 15 FOR15.DAT
MAGNETIC TAPE
; 16 FOR16.DAT
i 17 FOR17.DAT
i 18 FOR18.DAT
; 19 FORTR.DAT
ASSIGNABLE DEVICE, FQRTR
;
;
;
;
;
;
;
;
;
;

20
21
22
23
24
25
26
27
28
29

FOR20.DAT
FOR21 . DAT
FOR22.DAT
FOR23.DAT
FOR24. DAT
FOR25. DAT
FOR26. DAT
FOR27.DAT
FOR28.DAT
FOR29.DAT
-6
-5
-4
-3
-2
-1

DISK

ASSIGNABLE DEVICES

V.OO6
REREAD
READ
ACCEPT
PRINT
PUNCH
TYPE

12.3.2.3 File Names - File names may be declared for DECtapes or the disk through the use of the library subprograms IFILE and OALE. In order to make an entry of the file name FILE1 on unit u, t~e following statement
could be used:

5-129

CALL OALE (u,FILE1)
Similarly, 'the following statements might be used to open the file, RALPH, for reading:
RALPH=5HRALPH
CALL IFILE(u,RALPH)
After writing a file, the END FILE u statement must be given in order to close the current file and allow for
reading or writing another file or for reading or rewriting the same file. If no call to IFILE or OFILE has been
given before the execution of a READ or WRITE referencing DECtape or the disk the fi Ie name FORnn. DAT is
assumed where nn is the FORTRAN logical number use.d in the I/O statement that references device nn.
The FORTRAN programmer can make logical assignments such that each device has its own unique file as intended, but each can be on the DSK. In order to use the-devices available, the programmer can make assignments
at run time and assign the DSK to those not available.
For example, the FORTRAN logical device numbers, e.g., 1 = DSK, 2 = CDR, 3 = LPT, are used in the file
name. The written file names are FOROl.DAT, FOR02.DAT, etc. The same is true for READ. For example, a
WRITE (3, 1) A, S, C, in the FORTRAN program generates the file name FOR03.DAT on the DSK if the DSK has
been assigned LPT or 3 prior to running the program. (Note: REREAD rereads from the file belonging to the device last referenced in a READ statement, not FOR-6. DAT, as usual.) The programmer must, of course, realize
his own mistake in assigning the DSK as the TTY in the case that FORSE tries to type out error messages or
PAUSE messages.
More than one DSK File may be accessed, without making logical assignments at runtime, by using logical device numbers 1, and 20 through 24 in the FORTRAN program. Logical device number 19 refers to logical device
FORTR which must be assigned at runtime and accesses file name FORTR.DAT to maintain compatibility with the
past system of default file name FORTR. DAT. In all cases when the operating system fails to find a file specified,
an attempt will be made to read from file FORTR.DAT as before.
The magnetic tape operation REWIND is simulated on DECtape or the disk. Thus, a program which uses READ,
WRITE, END FILE, and'REWIND for magnetic tape need only have the logical device number changed or assigned to a MTA at runtime in order to perform the proper input/output sequences on DECtape or the disk.

12.3.3

Magnetic Tape Usage

Magnetic tape and disk/DECtape I/O are different in the following ways. When a READ is issued, a record is
read,in for both magnetic tape and disk. If a WRITE is then issued, the next sequential record is written on magnetic tape but not on disk. When one or more READs have been executed on a disk file and a WRITE is issued,
the file is closed prior to the WRITE and then reopened. The WRITE causes the writing over of the first logical
record in that file.
5-l30

12.3.3.1

Binary Mode - The format of binary data on magnetic tape is similar to that for DECtape except that

the physical record size depends on the magnetic tape buffer size assigned in the Time-Sharing Monitor or by
IBUFF/OBUFF (see Section 8.2.2). Normally, the buffer size is set at either 129 or 257 words so that either
128 or 256 word records are written {containing a control word and 127 or 255 FORTRAN data words}.
The first word, control. word, of each qlock in a binary record contains information used by the operating system. The left half

the first word contains the word count for that block. The right half of the first word con-

tains a nuJI character except for the last block in a logical record. In this case, the right half of the first word
contains the number of blocks in the logical record.

12.3.3.2

ASCII Mode - The format for ASCII data is the same as that used on DECtape.

12.3.3.3

Backspacing and Skipping Records - Both the BACKSPACE u and SKIP RECORD u statements are ex-

ecuted on a logical basis for binary records and on a line basis for ASCII records.
a. Binary Mode - Both BACKSPACE and SKIP RECORD space magnetic tape physically over one (1)
logical record; i.e., the result of one WRITE (u) statement.
b. ASCII Mode - ASCII records are packed, that is WRITE (u, f) statements do not cause physical writing on the tape until the output buffers are full or a BACKSPACE, END FILE, or REWIND command is
executed by the program. BACKSPACE and SKIP RECORD on ASCII record space over one (1) line.
c.

BACKSPACE and SKIP RECORD following WRITE ASCII commands.
(1)

BACKSPACE closes the tape, writes 2 EOF's (tapemark) and backspaces over the last line.

(2)

SKIP RECORD cannot be use~ during a WRITE operation. This is an input function only.

5-131

12.4 PDP-10 INSTRUCTION SET

MOVl

Negat.ive
e Magnttude
e Swapped

1--------,

Right}
{Right}
Half word { Left to Left

to AC

no effect
Ones
Zeros

ADD
SUBtract
• MULtiply

Immediate to

to Memory
to Self

Extend sign
BLock Transfer'
EXCHange

to Memory

~~~:~:~: ~~ract 1["'d Roood I~>:th
Floating MultiPly
Floating DiVide

and memory

~I--Immediate

Integer MULllply
DiVide
Integer DIVIde

to Memory
to Both

use present pOinter} d I LoaD Byte mto AC .
Increment pointer an i DePosit Byte in memory

Floating SCale

Increment Byte Pointer

Unnormalized Floatmg Add

PUSH down}
POP up

f --

1and Jump

Double Floating Negate

Ant~lmetic .SHift
LogIcal SHIft
ROTate

I{C

b' d
om me

Zeros
Ones
SETto Ac
Memory
Complement of Ac
Complement of Memory

1 l

AND
} ;ith Complement of Ac
inclusive OR
with Complement of Memory .Complements of Both

AC Immediate
Memory
Both

Inclusive OR
eXclusive OR - - - - - - - - - - - - '
EQuiValence
SKlPifmemoryl _______________~
JUMP if AC
f
Add One to
\ {memory and SkiP} 'f
Subtract One from
AC and Jump
. 11Immediate }
. '.
and skIp If ACCompare Ac \ . h M
WIt
emory

never
Less
Equal
Less or Eqwil
Always
Greater
Greater or Equal
Not equal

.lest

with Direct mask
with Swapped mask
Righ tWIt
.hE
Left with E

eXeCuTe
DATA}
BLocK : { { I n

5-132

•

Out

.
111

No modification
set masked bits to Zeros
d k'
an s Ip
set masked bits to Ones
Complement masked bits

HALT (JRST 4,)

CONditions

. {POSitive
.
Add One to Both halves of AC and Jump If N
egatJve

to SubRoutine
and Save Pc
and Save Ac
and Restore Ac
if Find First One
on Flag and Clear it
on OVerflow (JFCL 10,)
Jump
on CaRrY 0 (JFCL 4,)
on CaRrY I (JFCL 2.)
on CaRrY (JFCL 6,)
on Floating OVerflow (JFCL I.)
and ReSTore
and ReSTore Flags (JRST 2,)
and ENable PI channel (JRST 12.)

.
d Sk' 'f all masked bits Zero
an
Ip I \ some masked bit One

Inever
if all masked bits Equal 0
if Not all masked bits equal 0
Always ,

APPENDIX A
THE SMALL FORTRAN IV COMPILER

This compiler runs in S. SK of core, and to the user, is identi cal to the large compi ler, with the exception of the
following language differences. Operating procedures are given in the Systems User's Guide (DEC-l0-NGCC-D).

Language Differences
The IMPLICIT , DATA, and NAMELIST statements are not recognized; constant strings are not collapsed (for example, A=S*3 will not be treated as A=lS).

5-133

Book 6
Demonstration
Programs

•

rhe following demonstration programs illustrate the flexibility of the PDP-lO software system.
Each demonstration is aimed at a specific class of user and should be studied with this in mind.

Demonstration #1 is an elementary FORTRAN main program and subroutine. It is intended for a
beginning programmer interested in creating and editing files with LINED. The subroutine calculates the sum of the square of twenty numbers and returns the answer to the main program.
The main program prints this answer on the Teletype. A bug is found in the subroutine and
cQrrected with elementary LINED commands.

Demonstration #2 is a FORTRAN program which fits a curve to a set of points by the method of
least squares. LINED is used to edit and debug the program.

This demonstration was created for the applications programmer or th~ engine€r with some
mathematical background. There are four sections within the program; each section can be
examined separately without detracting from the reader's comprehension.

Demonstration #3 is an advanced example of the procedure used for creating a FORTRAN main
program and a MACRO-10 subprogram. It is. intended primarily for the experienced systems
programmer.

The two programs are inputted using TECO (Text Editor and- Corrector) and then translated and
executed together. A listing file is created for each program in case a bug is encountered
during execution. Since a bug is found, the listings, along with DDT (the Dynamic Debugging
Techn ique program), are used to debug the program. The erroneous program is then corrected
with TECO and saved on the disk for later use. For a complete description of DDT, see the
PDP-10 Reference Hardbook.

Demonstration #4 is an advanced demonstration of a FORTRAN subroutine that is used to return
a random number, and a FORTRAN testing program that tests the accuracy of the subroutine.
This demonstration is intended for the experienced programmer familiar with DDT and TECO.

The two programs are inputted using TECO and then executed together. Errors are detected by
the FORTRAN compiler and corrected with advanced TECO commands. Execution is again
attempted, but now the program returns incorrect results. Cross-reference listings, along with
advanced DDT commands, are used to debug the program. The program is then permanently
corrected with TECO and saved on the disk for future use.

6-3

Demonstration , 1
tC

.LOGIN
4SP74G
JOB 10
#27,235
PASSWORD:
1525
05-MAR-70
TTY~5
PLEASE DELETE ANY FILES THAT ARE NOT NEEDED FROM YOUR
DISK AREA •••

• CREATE MAIN.F4

*1
00010
00020
00030
00040
00050
00060
0121070

TYPE 69
FORMATe' THIS PROGRAM PRINTS THE SUM OF THE SQUARES')
CALL SUB1CISUM)
TYPE 70,ISUM
FORMATe' THE SUM OF THE SQUARES IS',3X,I5)
END

69
70
$

.CREATE SUB1.F4
*1
00010
00020
0012130
00040
12101215121
0121060
00070

11210

SUBROUTINE SUBRCJ)
J=0
DO 100 1=1,20
J=J+I**2
CONTINUE
RETURN

.EXECUTE MAIN.F4,SUB1.F4
FORTRAN: MAIN.F4
SUB1.F4
FORTRAN:
LOADING
000001 UNDEFINED ~LOBALS

6-4

Establish communication with the monitor by typing

while depressing the CTRL key.

Begin the login procedure by typing the monitor command LOGIN followed by a carriage-return.
The monitor responds with your job number and the mon itor name and version number. The
login program requests your identification by typing the number sign (#). Type in your
project programmer numbers, followed by a carriage-return. The login program requests your
password. Type it in; to maintain password security, it is not printed.

If your identification

matches the identification stored in the system, the monitor responds with the time, date,
Teletype number, message of the day (if any), and a period.

CREATE a new disk file with LINED. Call the new file MAIN.F4.

Command to LINED to insert line numbers starting with 10 and incrementing by 10.

Statements of the FORTRAN main program.

The Altmode ends t.he insert.

Command to LIN ED to end the creation of the file and to write the fi Ie on the disk.

Return to monitor.

CREATE a disk file for the subroutine. Call the file SUB1.F4.

Command to LINED to insert line numbers starting with 10 and incrementing by 10.

Statemenfs of the FORTRAN subroutine.

Altmode ends the insert.

LIN ED command to end the creation of the file and to write the file on the disk.

Return to monitor.

Request execution of the two progra·ms created.

FORTRAN reports its progress.

6-5

SUB 1

000156

LOADER 4K CORE
?EXECUTION DELETED
EXIT
tC

.EDIT SUB1.F4
*P10
11'00111'
*110
11'011'111' ,
$
11'11'11'211'

SUBROUTINE SUBR(J)
SUBROUTINE SUB! (J)

.EXECUTE MAIN.F4,SUB1.F4
FORTRAN: SUB1.F4
LOADING
LOADER 4K CORE
EXECUTION
THIS PROGRAM PRINTS THE SUM OF THE SQUARES
THE SUM OF THE SQUARES IS
2870
EXIT
tC

.KJOB
CONFIRM: K
JOB 111', USER (27,235J LOGGED OFF TTY25
15411' 5-MAR-70
DELETED ALL 6 FILES (INCLUDING UFD, 7. DISK BLOCKS)
RUNTIME ,0 MIN, 04.95 SEC

6-6

There is no subroutine named SUBl

This includes the space for the Loader. No execution was done.

Ask to edit SUB 1. F4
Type line 10 on the Teletype.

Insert a new line 10.

Request execution. Only the subroutine is recompiled since it has been edited.

Both MAl Nand SU Blare loaded.

Execution begins.

Execution ends.

Issue KJOB command to log off the system. Answer the CONFIRM: message with K and a
carriage-return if you wish to delete all files you have created. See the following demonstrations for other options available with the KJOB command.

6-7

Demonstration 112

.LOGIN

DEC PDP-10 #40 4561H PR

JOB 7

#27 .. 20
PASSWORD:
0927

29-0CT-69

TTY3

.CREATE SAMPLE.F4
*110

6-8

Introduction
Given a set of n sample points [(xl' Yl),(x 2'Y2) ••• (x n 'Yn»)
lates the coefficients of the quadratic equation, a 1+a
minimizes the expression

this demonstration program calcu+a3x 2) such that the value of 01 a 2 ,a 3

This method of minimizing a 1,a 2 ,a 3 is called least squares.
The program logically divides into four sections. Section 1 sets up a set of simultaneous
equations (the normal equations); section 2 solves the equations for a I' a 2 , a 3 • The polynomial
approximation (a l+a +a 3x 2) and the sample points are graphed in section 3. In section 4,
a subroutine evaluates 3x3 determinates.

The programmer logs into the system by typing LOGIN (abbreviated LOG); the monitor
responds by typing the ·job number assigned to the programmer and a version number of the
monitor. Following the printout of a # symbol, the programmer types his project-programmer
number. The monitor types PASSWORD: and awaits'an entry. The programmer then-types his
password (echo typeout suppressed). If the password and project-programmer number match
correctly with the password and project-programmer number stored in the system, the monitor
types out the time, the date and the number of the Teletype. The monitor may also type out.
some other information (the message of the day) before awaiting a command.

the monitor command:

CREATE SAMPLE.F4

ca lis in LI N ED and opens file SAMPLE for creation. The extension F4 marks the fi Ie as
FORTRAN. The monitor responds to the CREATE command by typinS an * indicating that a
LINED instruction is now to be typed.

Th~

LINED command 110 will begin line numbering at

10, incrementing by 10 for each new line.

An explanation of the mathematical ca Iculafions is given for each section. Note: not all
variables which appear in the explanation appear in the program. When the same variables
occur in both the explanation and program, they occur in lower case in the explanation and,
by necessity, occur in upper case in the program.

6-9

00010
00020
00030
00040
00050
00060
00070
00080
00090
00100
, 00110
00120
00130
00140
00150
00160
00170
00180
00190
00200
00210
00220
00230
00240
00250
00260
0027121
00280
00290
00300
00310
00320
00330
00340
00350
00360
00370
00380
00390

c
c
c
c
c
c
c
c
c
C
C
C
C
C

C
C

20
30
40
500
510
520
530

THIS PROGRAM FITS A QUADR4TIC POLYNOMIAL
('THE APPROXIMATION POLYNOMIAL') TO A SET OF
SAMPLE POINTS BY THE METHOD.OF LEAST SQUARES.
***SECTION 1***
THE ELEMENTS'OF Z,X,IX,TEMP ARE INITIALIZED
TO ZERO BY THE DIMENSION STATEMENT.
DIMENSION Z(3,4),X(9,4),IX(9,4),A(4),TEMP(3)
COMMON Z
TYPE 500
N IS THE NUMBER OF SAMPLE POINTS. N CAN NOT
BE GREATER THAN 9 CTHIS RESTRICTION IS IMPOSED
BY FORMAT 510). FORMAT 500 WILL BE TYPED ON
THE TELETYPE TO INDIC~TE WHEN THE USER IS
TO ENTER THE DATA FOR N.
ACCEPT 510,N
FORMAT 520 WILL BE T-YPED ON THE TELETYPE TO
INDICATE WHEN THE USER IS TO ENTER THE SAMPLE
POINTS.
TYPE 520
ACCEPT 530,(XCI,2),XCI,4),I=1,N)
DO 10 1=1, N
THE TWO STATEMENTS BELOW ROUND THE X AND Y
COORDINATES OF THE SAMPLE POINTS TO THE
NEAREST INTEGER. IXCI,1) AND IXeI,2) WILL
BE USED F.OR GRAPHING.
IXeI,1)=IFIXCXCI,2)+.5)
IX(I,2)=IFIX(XCI,4)+.5)
XCI,1)=l
XCI,3)=XCI,2)**2
DO 40 1=1,3
DO 30 K=1 .. N
DO 20 L=1,4
zeI,L)=Z(I,L)+XCK,L)*X(K,l)
CONTINUE
CONTINUE
FORMATelX,'NUM. OF POINTSlFORMATCI1)l2

.EXECUTE SAMPLE.F4
FORTRAN: SAMPLE.F4
01170

121-2 SUBROUTINE IS NOT A SEPARATE PROGRAM
COMMON Z

121118121

A-2 ATTEMPT TO ENTER A VARIABLE INTO COMMON TWICE
DIMENSION Ze3,4),B(4)

01190
1211280

SUBROUTINE DETR(DEE>

2121121

1-2 ARRAY NAME ALREADY IN USE
B(K)=Z(2,M)
t

1211290
~IN.

S-1 SYNTAX
B(K+2)=Z(3,M)

S-1 SYNTAX
ERRORS DETECTED: 5

? TOTAL ERRORS DETECTED:5
LOADING
12100002 UNDEFINED GLOBALS
B
DETR

000556
00121276

LOADER 5K CORE?EXECUTION DELETED
EXIT
tC

6-18

Th is system of determ inants reduces further:

To return to LINED command mode, the programmer types an ALTMODE ($) and LINED returns a

Upon reviewing the listing, the programmer discovers that a line has been

omitted after 1140.

A new line, line 1141, is inserted for the omitted coding. After line

1141 is typed, LINED responds with line number 1151. The double quote after the line number
1151 indicates a pre-existing line has been skipped (line 1150).
file by typing an E.

A control C

The Monitor command:

(t C)

The programmer closes the

returns the program to monitor level.

EXECUTE SAMPLE. F4

initiates loading and execution of

SAMPLE. F4. Five errors are detected in SAMPLE. F4, however, terminating the program before
execution. The errors are generated by the omission of an END statement. This omission has
led the FORTRAN compiler to consider the main program and the subroutine as one program;
hence the messages:

"ATTEMPT TO ENTER VARIABLE INTO

"UNDEFINED GLOBALS", and "ARRAY ALREADY IN USE."

COMMO~

Since the DIMENSION

statement is in error, any use of array b generates additional errors.

6-19

TWICE",

'.EDI T SAMPLE. F4
*11145
01145
END
01155" $
*E
*tC
.EXECUTE
FORTRAN: SAMPLE.F4
LOADING
LOADER 5K CORE
EXECUTION
NOM. OF POINTS;FORMAT( 11 );2
SAMPLE.REL
6. BLKS
:P
SAMPLE.BAK
<055>
10. BLKS
SAMPLE.F4
<055>
10. BLKS :P
JOB 7, USER 27, 20 OFF TTY3 AT 29-0CT-69
DELETED 1 FILES
SAVED 2 FILES (INCLUDING UFD, 28. DISK BLOCKS)
RUNTIME 0 MIN, 20.29 SEC

6-.24

The programmer logs off the Teletype with the Monitor command: KJOB. The Monitor asks
for confirmation, CON FIRM:

The programmer types a carriage return causing the Monitor to

type an explanation and then ask again for a confirmation. Since the programmer typed an I,
the Monitor responds with SAMPlE.REl <055> 6. BlKS:

SAMPlE.REl is the relocatabJe binary file of the source program SAMPlE.F4.

SAMPlE.REl

uses six disk blocks (6. BlKS:). The octal number in angular brackets is the protection code.
Protection code 055 means the fi Ie is sharable (the file can be read from or written on by a
programmer with any project-programmer number). Typing a P following the colon changes the
protection to 455 meaning that only a programmer logged in under the present project programmer number can write on the file.

After the programmer types the P and a carriage return, the Monitor prints:
SAMPlE.BAK < 055 > 10. BlKS:

SAMPlE.BAK is a backup file. The backup file is the next-to-Iast closed file. In this case,
the backup file is the FORTRAN file without the addition of lines 445, 1142, 1143, 1144
and the change of line 450.! The programmer deletes file SAMPLE .BAK.

The Mon itor types

SAMPlE.F4 <055> 10. BlKS:

By typing a P, the programmer saves and protects the current FORTRAN source file. The
Monitor then types the terminating message which includes the total number of disk blocks saved
(The User File Directory, UFO, uses two blocks).

6-25

Demonstration #3 (Advanced)

•

.LOGIN
JOB 14 4SP74G 640PROD
627~ 560
PASSWORD:
121859
23-FEB-70

TTY11

.MAKE MO DULO
*IC
C

ROUTINE TO TYPE IN TWO INTEGERS
AND TO TYPE OUT NI MODULO N2.

1
5.

TYPE 5
FORMA T C' TYPE Nl AND N2' II>
ACCEPT 10~NI~N2
FORMATC2I)
M=MODCNl ~N2)
TYPE 20~N1 ~N2~M
FORMATC1X~ I5~' MOD • I5~' IS • 151/)
GO TO 1
END

1121
2121

NI~N2

$$
*EX$$

EXIT
fC'

.MAKE MACSUB.MAC
*1

;MOD SUBROUTINE WITH STANDARD FORTRAN CALLING SEQUENCE
;FORTRAN STATEMT M=MOD(Nl~N2)
;RESULTS IN CALL TO MOD IN THE FORM
;
JSA I6~MOD
;
ARG eJ~NI
;
ARG 0~N2
;THUS UPON ENTRY TO MOD~ ACI6 POINTS TO NI
;THE REMAINDER OR "MOD" FUNCTIO:\T IS RETUrtNED IN AC0
;AS THE RESULT OF DIVIDING NI tIN ACI7) BY N2.

;ENTRY POINT FOR LOADER
ENTRY MOD
121
MOVEM I 7 ~ SAVI 7 ; SAVE ACl7
MOVE 17~@(l6)
;PICK UP Nl
IDIV 17~@
000000
;DIVIDE BY"N2 (R
IDIV 17,@(l6)
000000
000006'
000002
000000

MOVE l7,SAVl7
JRA. 16,2(16)
SAV17:

;RESTORE AC17
;RETURN TO CALLI

0
END

NO ERRORS DETECTED
PROGRAM BRK4K IS 000007

.MAIN"

MA.CRO.V40 09:14 23-FEB-70 PAGE 2
SYMBOL TABLE

~CSUB.MAC

MOD

-000000' ENT

SA.V17

000006'

The error seems to be here. In line 000003 a 1 has been om itted between the @ and the ( 16 ).
A patch is inserted

the program with DDT to check its va lid ity.

6-33

•

• DEBUG MODULO,MACSUB.MAC
LOADING

LOADER 4K CORE
EXECUTION

.MAIN$: MOD+3/
$G

IDIV 17,@0(16)

IDIV 17,@1(16)

TYPE N1AND N2
10 3
10 MOD

3 IS

TYPE N1 AND N2
12 8
12 MOD

8 IS

TYPE N1 AND· N2
43762 10822
43762 MOD 10822 IS

474

TYPE Nl AND N2
tC
.TECO MA.CSUB.MAC
*JSIDIV 17,@$ll$0LT$$
IDIV 17,@1(16)
*EX$$

;DIVIDE BY N2 (REMAINDER IN AC0)

EXIT
TC
.KJOB
CONFIRM: I
MODULO
MACSUB.BAK
MODULO.LST
MODULO.REL
MACSUB.REL
MACSUB.LST
MACSUB.MAC

<055>
<055>
<055>
<055>
<055>
<055>

1. BLKS
1. BLKS

2.·BLKS
DELETED
1. BLKS
:S
1. BLKS
:S
2. BLKS
DELETED
~05'5>
1. BLKS
:S
uUB.,J.~~·.tlSER,. [.27 ..:56~ ] LPQ"OE;D OFF 1;1"Y11, ~924 ,23-FEB-,70
DELETED 4 FILES (6. DISK BLOCKS)'
SA.VED 4 FILES (INCLUDING UFD, 6. DISK BLOCKS>
RUNTIME 0 MIN, 05.54 SEC

6-34

o·

To load DDT with the programs, type DEBUG MODULO,MACSUB.MAC. Note that the two
source files are not translated again since they have not been modified since the previous trans-

•

lation occurred •

Before execution of the program is begun, the system transfers control to DDT.
the symbol table for the MACRO-tO subprogram.
MACRO since no name was specified.)

.MAIN$: opens

(.MAIN was automatically assigned by

DDT acknowledges the command with a TAB. Then type

MOD+3/ to examine the contents of location MOD+3.

After DDT responds with the erroneous

instruction, simply retype the instruction correctly. The $G then starts the program v.i th the
correction included.

The program now returns correct resultsl

It is now necessary to return to TECO to permanently

correct the program.

The command TECO MACSUB.MAC opens the already existing file for editing. A command
string is then given which inserts the t in the proper place, and the correction is typed out.

It is now necessary to log off the system. Type KJOB to accomplish this. When the system types
CONFIRM:

, type I to individually save or delete your files. The MACSUB.BAK file is a

backup file which was created when the TECO MACSUB.MAC command was given. This file
contains the file as it was before the command was executed. Since this file is no longer needed,
only a carriage return is typed to delete it. The listing files are automaticatly deleted by the
system. An S is typed after the colon to save all the

oth~r

files on the disk for future use. The

system then completes the logout procedure by typing out the number of files deleted and saved,
their length in disk blocks, and the total runtime of your job.

6-35

Demonstration #4 (Advanced)
.LOG
4SP74G
JOB 7
~: :
#27,560
PASSWORD:
TTY3
0902
25-FEB-70
SYS 40 WILL BE DOWN FROM 1800-2400 TUE FEB 24 •.....

•

.MAKE RANDOl"!
*
C
C
C·

SUBROUTINE RANDOM (ARG)
RANDOM NUMBER GENERATING SUBROUTINE
RETURNS A SINGLE PRECISION FLOATING POINT (REAL)
PSEUDO-RANDOM NUMBER UNIFORMLY DISTRIBUTED OVER <0,1>.

C
C
C

C
C

C
2
C
C
C
C

THIS SUBROUTINE ATTEMPTS TO D~LICATE THE ASSEMBLY
LANGUAGE PROGRAM RANDOM USED IN THE PDP-10 REFERENCE HANDBOOK
DEMONSTRATION #2
EQUIVALENCE (T,I)
INTEGER RNUMB,MAGIC,IT(3)
DATA RNUMB/1/
MAGIC = 5**15
GET THE TIME IN ASCII HH:MM SS.T
CALL TIME (I,ARG)
USE TIME TO SELECT 1-4 ITERATIONS
DECODE (5,1,ARG) (IT(K),K=1,3)
FORMAT (1X,2I1,1X,I1)
K=«( IT(1) + 15) I IT(2) ) + IT(3) ) .AND. "3
DO 2 I =K, 0, -1
MULTIPLICATIVE R4NDOM NUMBER GENERATOR
R~UMB = RNUMB * MAGIC
CONVERT TO FLOATING POINT FORMAT IN THE RANGE <0,1>,
BY CL.EARING THE EXPONENT FIELD WITH A "Sl-IIFT" AND SETTING
THE EXPONENT TO 0 (EXCESS 200).
I = ( RNUMB /256 ) .OR. "20000000000
NORMALIZE AND STORE RESULT
ARG = T + 0.0
RETURN
END

$$
*HT$$
C
C
C

SUBROUTINE RA~DOM (ARG)
RANDOM NUMBER GENERATING SUBROUTINE
RETURNS A SINGLE PRECISION FLOATING POINT (REAL)
PSEUDO-RANDOM.NUMBER UNIFORMLY DISTRIBUTED OVER <0,1>.

C
C
C

C
C

C
2

THIS SUBROUTINE ATTEMPTS TO DUPLICATE THE ASSEMBLY
LANGUAGE PROGRAM RANDOM USED IN THE PDP-10 REFERENCE HANDBOOK
DEMONSTRATION #2.
EQUIVALENCE (T,I)
INTEGER RNUMB,MAGIC,IT(3)
DATA RNUMB/l/
MAGIC = 5**15
GET THE TIME IN ASCII HH:MM SS.T
CALL TIME (I,ARG)
USE TIME TO SELECT 1-4 ITERATIONS
DECODE.(5,l,ARG) (IT(K),K=l,3)
FORMAT(lX,2Il,lX,Il)
f{=«( IT(l) + 15) / IT(2) ) + IT(3) ) .A~D. "3
DO 2 I =K, 0, -1
MULTIPLICATIVE RANDOM NUMBER GENERATOR
RNUMB = RNUMB * MAGIC

6-36

LOG (abbreviation for LOGIN) starts the process of logging in to the system. Type the appropriate "login" information for your particular system, and it w ill respond with the time, date,
Teletype number, and the message of the day (if there is a message to be given).

MAKE RANDOM creates the file RANDOM with TECO for the FORTRAN random number generating subroutine. The TECO insert command ( I ) is not needed since the first character to be
input is a TAB. The TAB causes it, along with the rest of the text up to the two ALTMODEs
( $$ ), to be inserted into the buffer.

HT$$ causes TECO to type the entire buffer on the Teletype. This is used to check the previously
inserted text for errors.

6-37

C
C
C
C

CONVERT TO FLOATING POINT FORMAT IN THE RANGE <0,1>
BY CLEARING THE EXPONENT FIELD WITH A "SHIFT" AND SETTING
THE EXPONENT TO. 0 .( EXCESS 2(0).
I = ( RNUMB /256 ) .OR. "202100000000
NORMALIZE AND STORE RESULT
~RG = T + 0.0
RETURN·
END

*EX$$
EXIT
tC

.MAKE TESTIT

*110
1
2
3

5
$$
*HT$$
10
1

4
5

TYPE 1
FORMAT(' COMPUTE THE AVERAGE OF ',5X, '.
9PSEUDO-RANDOM NUMBERS')
TYPE 2
FORMAT(lH+,T25,$)
ACCEPT 3,1
FORMAT(15)
T=0.0
DO 4 K=l,1
CALC RANDOM (R)
T=T+R
T=T/l
TYPE 5,T
FORIYJAT <1 X, 'IS: ',F)
GO TO 10
END
TYPE 1
FORMAT(' COMPUTE THE AVERAGE OF ',5X, '.
9PSEUDO-RANDOM NUMBERS')
TYPE 2
FORMAT(lH+,T25,$)
ACCEPT 3,1
FORMAT< 15)
T=0.0
DO 4 K=l,I
CALL RANDOM (R)
T=T+R
T=T/I
TYPE 5,T
FO RMA T ( 1X, , IS: " F)
GO TO 10
END

*EX$$
,. EXIT
tC

6-38

The TECO command EX$$ causes the file to be ended and the contents of the buffer to be read
onto your disk area. It then returns control to the monitor.

MAKE TESTIT calls in TECO to open a file for the FORTRAN testing program. The program calls
the subroutine to get random numbers. It then averages a specified number of random numbers
and, since the random numbers are confined to the range (0,1), the average should be close to
0.5 if the numbers are truly random.

The TECO insert command ( I ) causes TECO to insert the text of the program up to the two
ALTMODEs into the buffer.

The command HT$$ causes the whole buffer to be typed onto your Te Ie type • This is usefu I to
check for typing mistakes.

EX$$ causes the file to be closed and read onto your disk area. It then returns control to the
monitor.

6-39

.EXECUTE TESTIT,RANDOM

FORTRAN:
TESTIT
********
1
FORI"'IAT(' COMPuTE THE AVERAGE OF " 5X, , •
********
" t
********
M-7 UNTERMIN~TED HOLLERITH STRING
********
9PSEUDO-RANDOM NUMBERS')
********
t
********
S-l SYNTAX.
MAIN.
ERRORS DETECTED: 2
? TOT~L ERRORS DETECTED: 2
FORTAA'\T: RANDOM
LOADING
LOADER 5K CORE
?EXEGUTION DELETED
EXIT
tC

.TECO TESTIT
*S5X, , • $$
*2R8< 1 ~=$C>$$
39
46
13

10
9

57
80
*f2lLCD0L-TT$$
1
FORMAT(' COMPU"tE THE AVERAGE OF ',5X, '.
9PSEUDO-RANDOM NUMBERS')

*EG$$
FORTRAN:
LOADING

TEST!T

LOADER 5K CORE
EXECUTION
COMPU'rE THE AVERAGE OF 00010.PSEUDO-RANDOM NUMBERS

6-40

Type EXEOJTE TESTIT ,RANDOM to call in the FORTRAN IV compiler to create binary machinelanguage files (these will be given the extension. REL). The EXECUTE command also causes the
two relocatable binary files to be loaded and then executed, if there are no compiler detected
errors:

The FORTRAN compiler has detected errors in the main (testing) program. It types out the lines
the errors occur in and an arrow at the particular point the error is detected. The total errors
for the main program are then typed out. The compiler then translates the file RANDOM and does
not detect any errors. The total core requirement for loading is then typed out. The execution
is deleted since there were compiler detected errors. Control is then returned to the monitor.

The error messages returned by the FORTRAN compiler seem to indicate that there may be an
illegal character in one or both of the two lines which were typed out by the compiler. To check
this assumption, type TECO TESTIT which opens the already existing file TESTIT for editing.
This command has the added effect of renaming the file, as it was before editing, TESTIT.BAK .•
The first command string to TECO searches for the characters 5X, I • • The second string causes
the decimal equivalents of the ASCII code of eight consecutive characters, starting with the
character

,to be typed on the Teletype. In this way, it should be possible to see if there is

a character among these eight (even a non-printing one) that should not be there.

The 32 is a space, and for this Iine to be a continuation line it shou Id not be there. Type the
TECO command string shown to delete the space and type the corrected lines.

The command EG$$ causes TECO to perform the functions of an EX$$ and then to execute the
last compile class command given to the monitor. In this case, it was EXECUTE TESTlT,RANDOM.
Since RANDOM has not been changed, it is not recompiled.

Execution of the program is begun and it types the line COMPUTE THE AVERAGE OF
.. PSEUDO-RANDOM NUMBERS. The program will then space over to the blank spaces and wait
for you to enter the number of random numbers it is to average. In this case 10 random numbers
are averaged. Strike the return key after the number has been entered, and the program should
give you the average and type the first Iine again.

6-41

INTEGER DIVIDE CHECK

PC=000267

INTEGER DIVIDE CHECK

PC=000267

INTEGER OVERFLOW

PC=000276

INTEGER OVERFI.,.DW

PC=000276

IS:
0.0000000
COMPUTE THE AVERAGE OF fC

.DEBUG ICREF/COMPILE

FORTRAN:
FORTRAN:
LOADING

.PSEUDO-RANDOM NUMBERS

TESTIT(~~M)~RANDOM(~~M)

TESTIT
RA.:\TDOM

LOADER 7K CORE
EXECUTION

XXX

.SAVE DSK TEST
J>B SAVED
fC

.CREF

6-42

The INTEGER DIVIDE CHECK

messages occur when the seconds portion of the time used in the

program is an even multiple of 10. This causes IT(2) to be 0 and the divide check results when
the program attempts to divide by IT(2). When this happens, the result is as if the divide never
occurred, thus the results obtained are still accurate.

The INTEGER OVERFLOW messages occur when RNUMB is multiplied by MAGIC (MAGIC

5 15). The fact that these overflows occur does not affect the resu Its, since the purpose is just
to obtain a random number. Both the INTEGER DIVIDE CHECK and INTEGER OVERFLOW
messages are suppressed after they are outputted twice.

The average is returned as 0 when it shou Id be close to 0.5. There must be another bug in the
program.
ConlTol-C

When the program requests the number of random numbers to average, type

(t C)

to return to the monitor.

The DEBUG/CREF/COMPILE TESTIT("M),RANDOM("M) command does several different
operations. First it loads DDT along with the two programs to make it possible to debug with
DDT. The /CREF causes a cross-referenced listing to be produced to help in finding the bug.
/COMPILE must be used for forced compilation of the programs. Ordinarily the source files
are compiled only if they have a creation time newer than the binary machine-language files.
The /COMPI LE (called a switch) overrides this feature and ensures the creation of the listing
files. If it was not used the CREF files would not be ,produced. Tlie (, ,M) causes the listings
to contain the MACRO expansion code which is sometimes helpful in debugging •

..
After the monitor types EXECUTION, it transfers control to DDT. This happens because DEBUG
was used instead of EX ECUTE.

Strike the RU BOUT (or DELETE) key to make certain that DDT was entered. In DDT, the
RUBOUT key echoes (typ,es back) as XXX. Now type

tc to return

to the monitor to get the

listings.

So that DDT can be reentered with the greatest possible ease, it is necessary to save the core
area on the disk. If this is not done, another DEBUG command must be given. The command
SAVE DSK TEST writes a copy of the core area on the disk and gives it the filename TEST. SAV.
The monitor types JOB SAVED and leaves the Teletype in monitor mode.
Type CREF to print the cross-reference listings on the line printer.

6-43

• GET DSK TEST
JOB SETUP
tC
.DDT

T.... 4P+4$2B
$$F
$G
COMPUTE THE AVERAGE OF 00010.PSEUDO-RANDOM NUMBERS
$lB»4? R/
~17105693E~33
INTEGER OVERFLOW
PC=003552
$lB»4P R/
.26502884E-34
INTEGER
$1 B»4P
$1B»4?
$1B»4P
$1B»4P
$1 B»4P
$1B»4P
$1 B»4P

OVERFLOW
PC=0213552
R/
.12697389E-33
R/
.18615497E-33
R/
.17992393E-33
R/
• ~ 7408278E-33
R/
.15958281E-33
R/
.37201131E-34
R/
.16486226E-33

INTEGER DIVIDE CHECK
PC=f2l03543
$1B»4P R/
.14481467!J:-33
$2B»4P+4
T/
.13711563E-32
IS:
f2l.f2l0f2l0f2l0f2l
COMPUTE ;HE AVERAGE OF tC

.PSEUDO-RANDOM NUMBERS

.DDT
$B
RANDOM$:
RNUMB .... 2P+4$$1B
$$C
$G

6-44

•

GET DSK TEST loads the core image from the disk into core. The monitor types JOB SETUP and
returns the Teletype to monitor mode.

The command DDT is typed to' reenter the program in DDT. After this command is executed
it is as if the monitor had just typed EXECUTION and transferred control to DDT. It is now
possible to debug the program wi th the aid of DDT and the listings from the line printer.

MAIN .$: opens the symbol table for the FORTRAN main program, in this case TESTIT.

DDT

responds to each command with a TAB. By examining the listings carefully, it is possible to find
a place to stop the program to find out what some of the random numbers are it is getting from
the subroutine. Location 4P (assigned by the compiler) is the correct point to examine the random numbers. The command R,,4P$$lB tells DDT to type the contents of R (address of the random number) at location 4P, assign this as the first breakpoint, and continue program execution
without stopping. If only one ALTMODE ( $) were used, the program would stop after typing"the
contents of R.

At location 4P+4, the total of the random numbers can be examined by typing out the contents
of T. The command T, ,4P+4$2B instructs DDT to type the contents of T at location 4P+4,
assign this as the se-cond breakpoint, and stop the program after the typeout. $$F tells DDT to
output the contents of the specified locations as floating point numbers. The $G then starts
execution of the program.

The ten random numbers are extremely small and not even close to the range of zero to one.
This explains why an average of zero was r~turned. The calculated average was too small to
print using an F format. The bug must be somewhere in the random number generating subroutine.
After DDT types the total, type $P to proceed with the program. When it asks for the number of
random numbers, type

t C to return to the monitor.

Reenter DDT by typing the command DDT. Open the symbol table for the random number
generating routine by typing RANDOM$: . $B is typed to clear the previous breakpoints. To
examine the random numbers produced by RANDOM, type RNUMB,,2P+4$$lB. This tells DDT
to type the contents of RNUMB at location 2P+4, assign this as the first breakpoint, and continue
the program execution without stopping. This should simply produce random digits in address
RNUMB. Type $$C to cause DDT to type the numbers as octal constants. $G starts execution of
the program.

6-45

COMPUTE THE AVERAGE OF f21f2lf211f21~PSEUDO-RANDOM NUMBERS
INTEGER OVERFLOW '
$1B»2P+4'
RNUMBI

PC=f21f213552
11213231 ~ ~ 730141

PC=f21f213552
INTEGER OVERFLOW
$1B»2P+4
RNUMBI 353364~~63f21365
$1B»2P+4
RNUMBI 2032n 151761
$1B»2P+4
RNUMBI 273526-~~272275
$lB»2P+4
RNUMBI 10 5623n 3341211 5
$1B»2P+4
RNUMBI '52227n 117021
$1B»2P+4
RNUMBI 136431,,262241
$1B»2P+4
RNUMBI 317344~ ~ 31212511
$1B»2P+4
RNUMBI 366123~~235f2165
$1B»2P+4
RNUMBI 254721~~447775
IS:
121.121121121121121121121
COMPUTE THE AVERAGE OF tC

.PSEUDO-RANDOM NUMBERS

.DDT
T" 2P+10$$1 B
$G
COMPUTE THE AVERAGE OF f21f2lf2l1f21.PSEUDO-RANDOM NUMBERS
INTEGER OVERFLOW

PC=f21f213552

INTEGER OVERFLOW
$1B»2P+1121
TI
$1B»2P+10
'FI
$1B»2P+1121
TI
$lB»2P+10
TI
$1B»2P+lf21
TI
$1B»2P,+10
TI
$1B»2P+1121
TI
$1B»2P+10
TI

PC=f212!3552
204f213~ ~ 354047

INTEGER DIVIDE CHECK

PC=01213543

$1B»2P+1121
$1B»2P+10

2f21316~~622373

20240~~644566

2eJ402~~262376
2eJ142~~231053

20755n 531405 ,

2eJ300~, 643450 '
20126" 233254
20254~~522723
20315~ ~

121.0000000
IS:
COMPUTE THE AVER~GE OF tC

115224

.PSEUDO-RANDOM NUMBERS

.DDT
CONST.I

2000f21,~0

20012100,,0

20012100,,0
$B
$G

COMPUTE THE AVERAGE OF f210010.PSEUDO-RANDOM NUMBERS
INTEGER OVERFLOW

PC=003552

INTEGER OVERFLOW

PC=003552

IS:
0.5106965
COMPUTE THE AVERAGE OF 0121100.PSEUDO-RANDOM NUMBERS
IS:
121.5007578
COMPUTE THE AVERAGE OF tC

.PSEUDO-RANDOM NUMBERS

6-46

The numbers appear to be random. The bug must be farther on in the program. Type

t C to

return to the monitor.

Type DDT to return to DDT. It is

unn~cessary

to open the symbol table of RANDOM since it

was opened the previous time DDT was used. The command T,,2P+10$$lB causes DDT to type
the contents of T at location 2P+1O, assign this as breakpoint one, and continue execution without stopping. It is not necessary to clear the breakpoints since breakpoint one has been
reassigned. T at location 2P+ 10 shou Id contain the unnormalized random number. Each number
should begin with 200, as that is the exponent used. Type $G to start the program.

The bug is here! Each number beg ins with 020 instead of 200; therefore, a zero ,must have been
omitted in the exponent in the program. Type

t C to return

to the mon itor and reenter' DDT by

typing DDT.

Type CONST./ to examine the contents of that location. DDT types 20000,,0. There should
be another zero in the left half of the word. Type 200000"

to correct the error. DDT changes

the contents of CONST. to the numbers just typed. Next type ./ to again examine the contents
of CONST.

DDT responds with the corrected value. $B clears the breakpoints and $G starts

the program.

The answer is close to 0.5 for 10 random numbers and closer for 100 random numbers. The
program is correct. \

6-47

.TECO

R~NDOM

*S"2$-T$$
C
THE EXPONENT TO 0 (EXCESS 200).
I = ( RN(JMB 1256 ) • (fR. "2*10 $0L TU
I = ( RNUMB 1256 ) .OR. "200000000000
*EX$$
EXIT
tC

.DIR/F
J

DIRECTORY 27,560

1020

25-FEB-70

AANDOM.BAK
TESTIT.B~K

TESTIT.REL
AANDOM.REL
TEST IT
TESTIT.CRF
AANDOM. CRF
TEST • S~V
AA!'-1DOM
.K
CONFIRM: I
AANDOM.BAK

<055>
2. BLKS
1 • BLKS
<055>
2. BLKS
<055>
TESTIT.REL
2. BLKS
AANDOM.REL
<055>
1 • BLKS
TESTIT
<055>
:S
<055>
4. BLKS
TESTIT.CRF
DELEITED
<055>
AANDOM.CRF
6. BLKS
DELETED
TEST .S~V
<055>
45. ·BLKS
<0'55>
2. BLKS
RA.!'-1DOM
:S
JOB 7, USER [27,560] LOGGED OFF TTY3
1023
DELETED 7 FILES (62. DISK BLOCKS)
~VED 2 FILES (INCLUDING UFD, 5. DISK BLOCKS)
RUNTIME 121 MIN .. 26.52 SEC
TESTIT.B~K

25-FEB-70

The command TECO RANDOM opens the already existing file RANDOM for editing. The old
file is renamed RANDOM.BAK. The command string 5"2$-T$$ causes TECO to search for the
characters "2 which are unique in the program'and are located at the beginning of the octal
constant used to insert the exponent. TECO then types the previous line and the current Iine up
to the posit-ion following the characters searched for. TECO signals its readiness for another
command string by typing an asterisk. The second command string inserts a zero and types the
corrected line. The EX$$ causes the file to be closed and read onto your disk area with the
corrections in eluded. Control is then returned to the monitor.

Type DIR/F to obtain a directory of your disk area. The

IF causes a shortened form of the

directory to be printed. The length of each fi Ie and the creation date are omitted.

The two files with extensions .BAK are back-up files'. They contain the files, specified by
file names, as they were before ed iting was done with TECO. The . REL fi les are the binary
machine-IQnguage files created by the FORTRAN compiler. The files with the extension .CRF
are the CREF listing files.

Type K (abbreviation for KJOB) to log off the system. When the monitor types CONFIRM: ,
respond with an I to individually save or delete your files. The two source files are saved by

typing an 5, the .CRF fi les are automatically deleted by the system, and the other files are
deleted by typing only a carriag~ return. The system then responds with the rest of the logout
information.

6-49

Book 7

Advanced
Monitor
Commands

ADVANCED
MONITOR COMMANDS

The !.ystern controls many peripheral devices, such as Teletypes, magnetic tape drives, DECtape
drives, card readers and punches, line printers, papertape readers and punches, and disks. The
monitor is responsible both for allocating these peripheral devices, as well as other system
resources (e.g., core memory), and for maintaining a pool of such available resources from
which you can draw.

Each device controlled by the system has a physical name associated with it. The physical
name is unique. It consists of three letters and zero to three numerals specifying a unit number.
The following table lists the physical names associated with various peripheral devices.
Tobie 7-1
Peripheral Devices

Device

Physical Name

Teletype

TTYO, TTY 1, • • • , TTY77

Console Teletype

CTY

Paper Tape Reader

PTR

Paper Tape Punch

PTP

Plotter

PLT

Line Printer

LPT

Card Reader

CDR

Card Punch

COP

DECtape

DTAO, DTAI, ••• , DTA7

Magnetic Tape

MTAO, MTAI, ••• , MTA7

Disk

DSK

You may also give each device a logical device name. T.he logical device name is an alias,
and the device can be referred to either by this alias or by the physical name. The logical

•

7-3

name consists of one to six alphanumeric characters of your choice-. Tne reason for logical
device names is thot in writing a program you may use arbitrarily selected device nomes
(logical device names) that can be assigned to the most conven ient physical devices at runtime.
However, care should be exercised in assigning logical device names because these names have
priority over physical device names. For example, if a DECtape is a~gned the logical name
DSK, then all of your programs attempting to use the disk via the physical name DSK end up
using the DECtape instead. It is wise not to give .any device the logical name DSK because
certain monitor commands (such as the COMPILE com~ands) make extensive use of special
features that the disk has but other devices do not ha've. The following examples show the use
of logical and physical device na~es •

.!. ASSIGN DTA,ABC )

Assign a DECtape the logical name ABC.

.!. ASSIGN MTAl,XYZ )

Assign !JICgnetic tape drive #1 the logical
name XYZ •

.!.ASSIGN PTR, FOO )

Assign the papertape reader the logical
name FOO.

In order to use most peripheral devices, you must assign the desired device to your ,job. You
may assign a device either by a program or from the console. The first kind of assignment
occurs when you write a program that uses a particular device. When the program begins using
the device, it is assigned to you on a temporary basis and released from you when your program
has finished with it. The second kind of assignment occurs when you explicitly assign the
device by means of the ASSIGN monitor command. This is a permanent assignment that is

effect until the device is released by a DEASSIGN or FINISH monitor command or by your
logging off the system.

When you assign a device to your job, the monitor associates your job number with that device.
This means that no other user may use the device while you are u,.sing it. The only exception is
the dis~, which is accessible by all users. When you assign the disk, you are allocated a
fraction of the disk, not the'entire unit. When you deassign a device or kill your job, the
device is returned to the monitor's pool of qvailable resources.

7.1
7.1.1

COMMANDS TO ALLOCATE SYSTEM RESOURCES
The ASSIGN Command

The ASSIGN command is used to assign a peripheral
device on a permanent basis for
the duration,
,
,
. '
,

of your job or until you explicitly deassign it. This command must ha~e as an argument the
legal physical device nome (see Table 7-1) of the device you wish to assign.

For example, if

•

7-4
\

you want to assign a 0 ECtape drive to your job, type

.!. ASSIGN DTA)

The monitor responds with the message
DT An ASSI GN ED

where n is the unit number of the DECtape drive assigned to your job. If all drives are in use,
the monitor responds with

NO SUCH DEVICE

and you must wait until a drive becomes available. You may assign a specific DECtape drive
as follows:

• ASSI GN DTA3 )

The mOllitor responds with

DTA3 ASSIGNED

if the drive is available, or

ALREADY ASSIGNED TO JOB n

if job n is using DECtape drive #3.

The ASSIGN command may also have, as an optional argument, a logical device name following the physical device name. The logical device name may be used in place of the physical
device name in all references to the device. For example, if you want to use DECtape drive
#1 and have it named SAMPLE, type the command

.!. ASSI GN DT A I SAMPLE )

If DECtape driye #1 is free, the monitor responds with
DTAI ASSIGNED

7-5

and stores the logical name you typed. You may then refer to ffifl the contents of the specified source files to be typed on the line
printer. Headings at the top of each page tell the page number, the name of the file, and the
date of printing. You may list fi les from disk or 0 ECtape • For example, the command

.:.. LIST TEST .F4 )

causes your disk file TEST .F4 to be listed on the line printer. You may list multiple files by
separating the fi lenames by commas. For example, if you want to list three fi les, S.t\MPLE.BAS,
FILEX.F4,MAIN .F4, from DECtape drive #4, type the command
.:.. LIST DTA4: SAMPLE. BAS, FI LEX. F4~MAIN .F4)

The asterisk convention discussed in Book 2 may' be used with this command. For example,
.:.. LIST *.F4 )

7-9

causes all files with the filename extension. F4 to be listed.
"

7.3.2

The CREF Command

The CREF command is used "to list a certain type of file called a cross-reference file. This
command is an invaluable aid in program debugging. If a COMPilE, lOAD, EXECUTE, or
DEBUG command string (see Book 2) has a /CREF switch, the command string generates an
expanded listing that includes ( 1,) the original code as it appears in the file, (2) the octal
values the code represents, (3) the relative locations into which the octal values go,
( 4) a list of all the symbols your program uses, and (5) the numbers of the lines on which
each symbol appeats. This is called a cross-reference "'Sting. To pri"nt this. listing file, you
must call in a special cross-reference lister with the CREF command. All the cross-reference
listing files you have generated since the last CREFcommand ar~ printed on the line printer.
The file containing the names of the cross-reference listing files is then deleted so that subsequent CREF commands will not list them again.

7.3.3

The DIRECTORY Command

When a DTAn: argument is specified with the DIRECTORY command, the directory of DECtape n
is typed on the Teletype. (See Book 2 for a discussion of the DIRECTORY command when no
argument is·specified.) For example, the command

. .:. DIRECTORY DT A2 )

types the directory of DECtape drive 62 on the Teletype.

Besides having optional device arguments, this command has two switch options. The first
switch option is

/F.

Including /F in the command string causes the short form of the directory

to be listed on the Teletype. The short form of the directory consists of the names of your
files and the length of each file in PDP-10 disk blocks. (The long form of the directory also
lists the creation dates of each file.)

The second switch option is fl. Including

/L in

the

command string causes the output of the directory to go to t~e line printer rather than to the
Teletype. For example, the command

• DIRECTORY /l )

lists your'directory of your d iskarea on the line printer. The line printer is assigned to you on
a temporary basis and is released when the output is finished.

7-10

7.4

COMMANDS TO MANIPULATE CORE IMAGES

By using one of the following commands, you can load core image files (see Book 2 for the
definition of a core image file) from disk, DECtapes, and magnetic tapes into core and then
later save the core images. These files can be retrieved and controlled from the user's console.
Files on disk and DECtape are called by filename, and if you have any files on magnetic tape,
you must position the tape to the beginning of the file.

7.4.1

The SAVE Command

The SAVE command causes your current core image to be saved on the specified device with
the specified filename. This command must be followed by severa I arguments. First, you must
tell the monitor the device on which you want to save the core image. A colon may follow the
device name. Second, you must give a name to the core image file.
sion js not specified, the monitor designates one.

If the filename exten-

You may specify the amount, of core in

which you want your file saved by specifying a decimal number to represent the number of 1K
blocks. For example, if you want to save your core image on DECtape drive #2, give it the
name SALES, and allow 12K of core for storage, type

. SAVE DTA2: SALES 12 )

A file called SALES is created and your core image is stored in it. If you list your DECtape
directory, the length of the file is slightly over 12,OOOworcls. ':Afteryou use this command,

you cannot continue executing the program. The program can be restarted only from the beginning.
7.4.2

The RUN Command

The RUN command allows you to run programs you previously saved on the disk, DECtape, or
magnetic tape. This command reads the core image file from a storage device and starts its
execution. You must specify the device containing the core image file and the name of that
file. The file must have been saved previously with a SAVE command. If the file is no,t a
saved program, the monitor responds with an error message. If the core image file you want
to execute is on another user's disk area, you must specify his project-programmer number,
enclosed in square brackets. Again, you may specify the amount of core to be assigned to the
program if different from the minimum core needed to load the program or from the core
argument of the SAVE command.

7-11

7.4.3

The R Command

The R,~l1lmand is a specia1 form of the RUN command. This command runs programs (or CUSPs)'
that are part of the system, rather than programs that are your own. The R command is the
usual way to run a OJ SP that does not have a direct mon itor command associated with it;
For example, the only way to run BASIC and AID is by the commands

• R BASIC)
and

• RAID)

A device name or a project programmer number may not be specified for this command.

7.4.4

The GET Command

The GET command is the same as the RUN command except that it does not stqrt the program;
it merely generates a core image and exits. Thl\! monitor types

JOB SETUP

and is ready to accept another command.

7.5
7.5.1

COMMAI'JDS.TO START A PROGRAM
The START Command

The START command begins execution of the program at its starting address, the location

sp'~cified within the file, and is valid only if you have a core image. This command allows
you to specify another starting address by typing the octal address after the command.
Normally, to start a program, type

• START )

but to start a program at the specified octal location 347, type

• START 347 )

A GET command followed by a START command is equivalent to a RUN command.
t

,.:..,j

"!: ":

7-12

7.5.2

The HALT ( t C) Command

Typing

tc stops your program and takes you back to the monitor. The program "remembers"

at what pC)int it was interrupted so that it may subsequently be continued. After typing t C,
you may type any commands that do not affect the status of your program (e.g., PJOB,
DA YTIME, RESOURCES) and still be able to continue the execution of the program with a
CONTINUE command.

However, contin~ing is impossible if you issue any command that runs

a new program, such as a RUN or R command.

7.5.3

The CONTINUE Command

If you stop your program by a HALT (tC) command, you may resume execution from the point
at which it was interrupted by typing the CONTINUE command.

You may continue the

program only if you exit by typing control - C. If the program exited on an error condition
of some sort, the mon itor does not let you continue. It types

CAN IT CONTINUE

if you try. However, you may continue your program if it has halted and given the typeout

HALT AT USER n

7.6

COMMANDS TO GET INFORMATION FROM THE SYSTEM.

7.6.1 - The RESOURCES Command
The RESOURCES command types out a list of all the available devices (except Teletypes) and
the number of free blocks on the disk. A disk block is 128 PDP-10 words in length. For
example,

• RESOURCES )
22100. BLKS, PTYI,CDR,PTR,MTA 1,COP, PLT,

At the time of this command, there were 22100 free disk blocks available in addition to six
devices.

7.6.2

The SYSTAT Command

The SYSTAT command produces a summary of the current status of the system and may be typed
without logging in. I,:,cluded in the summary is a list of the jobs currently logged in, along

7-13

with their protect-programmer numbers, program names being 'run, and runtime. The following
is a partial example of SYSTAT.

~re inform~'ti~~' is contained

in this program and can be

obtained by running SYSTAT.

~1:26:4~,

UPTIME
JOB

WHO

WHERE

WHAT

SIZE

STATE

RUNTIME

1
2
3
4
5
6
7
8
9

** , **

PIP
MACRO
MACRO

13,575

TTY2~

lK
4K
12K
lK
15K
lK'
3K
lK
lK
lK
2K
lK
lK
2K
2K
2K
2K
lK
lK
3K

tc SW

4JO,633

DET
TTY4
TTY3
TTY6

~~:12:~1
~~:~1:22
~JO:J05:J05
JO~:~~:32
JO~:~JO:19
~JO:~JO:52
~~:~JO:2~
~~:~~:24
~~:~JO:58
~~:ll:ll
~~:~~:39

2,5
11,554
j~~637

TTY24
TTYI
1~2
TTY27
** , **
2~,521
TTX'13
2~,623
TTY23
1,2
TTY2
TTY33
** , **
TTY14
** , **
DET
** , **
lJ04,334 TTY43
7~,54
TTY15

11
12
13
14
15
16
17
18
19
20
21
22
23
24

7;J

38% NULL TIME = IDLE+LOST = 26% + 12%

4~,65

TTYl~

4JO,64

TTY7
DET
TTY21
DET
TTY37
TTY5
DET

** , **

11', 7~

** , **

11,131
13,12

** , **

~IP

COBOL
DEVCHK
OPFILE
LOGOUT
SYSTAT
PIP
PRINTR
LOGIN
LOGOUT
UFILE
TECO
STACK
TECO
PRINT
SYSTAT
MONGEN
CHKPRT ~K
'HMAC
6K
BATCH ·4K
PLEASE lK

TT
TT SW
TT SW
IO
MQ
tc SW
AU
IO
SL
MQ
tC SW
tc SW
TT SW
RN

~~:JO~:~JO
~JO:~2:25

~~:~~:~9
~~:JO~:~~

~~:~1:33
~~:~2:42
~JO:~JO:12

~~:~~:~~
~~:~~:>n
~~:~~:JOI

TT SW
SL
tc SW

~~:~~:42
~~:~~:58

TT
~C

~~:~~:~1

ADDITIONAL·MONITOR COMMANDS

In order to present the complete set of monitor commands, the following must be, included.

These commands
are speciahun control and system administration commands and are discussed
,
,

in the PDP-10 Reference Handbook, Communicating With the NIonitor, Chapter 2.

Table 7-2
Additional Monitor Commands
Command
DDT
, '- "

Explanation
" This comma~ !.sused in debug9ir:'9 programs and allows DDT
~ -to assume, control o(the execution of your program in
'
various ways. See the PO P-lO Reference Handbook,
Communicatina with the Monitor for further information.

Table 7-2 (Cont.)

Command

Explanation

REENTER

Similar to the DDT command. This command causes the
program to start at an alternate specified entry point.
The alternate entry point must be set by you or your
program.

This command allows you to examine locations in your
core area. The argument adr is required the first time you
use this command. By specifying an address, the contents
of that location are typed. If an argument is not specified,
the contents of the location following the previously
spec i fied address are typed out.

This command allows you to deposit information in your
core area. You must specify octal values to be deposited
in the left half and right half of the location. The address
of the location in which information is to be deposited
may be specified. If the address is not specified, the
information is deposited in the last location examined or
the last location in which information was deposited.
Th is command is the same as the SAVE command except that
the program will be sharable when it is loaded with the
. GET command. To indicate sharabiI ity , the high segment
is written with the extension .SHR. A subsequent GET
causes the high segment to be sharable.

SSAVE

CSTART
CCONT

These commands are identical to the START and CONT
commands except that you are able to continue talking
to the monitor. The START and CONT allow you to
communicate only with the CUSP that is in execution.
Monitor commands may now be executed while the job is
running.

SCHEDULE n

Thi$ command is legal only from the operator's console.
It changes the scheduled use of the system depending on n,
where n is:
.
o =regular time-sharing
1 =no further logins allowed
2 =no further logins allowed from remote
Teletypes

ASSIGN SYS:dev
II

DETACH dev

This command changes the system device to device
devil. The user must be logged in under [1, n or [1,2] •

This command assigns the device "dey" to job 0, thus
making it unavailable. The user must be logged in
under [ 1, 1 ] •

7-15

Table 7-2 (Cor-t.)

Explanation

Command

7.8

ATTACH dev

This command returns a detached device to the monitor's
pool of available resources. The user must be logged in
under [1, 1] •

CTEST

This command is used to test extensions made to the
COMPIL CUSP.

MONITOR ERROR MESSAGES

The following table contains a summary of the error messages the system can issue. The
convention used in the summary is that
dev

represents any legal device name.

file.ext

represents any legal filename and filename extension.

adr

represents a user address.

represents a job number or device unit number

Table 7-3
Monitor Diagnostic Messages

Message
The type in is 'typed back
followed by? )

Meaning
The mon itor encountered an incorrect character,
such as a letter in a numeric argument. The
incorrect character appears immediately before'
the?
For example, •
.:.. CORE ABC)
CORE A? )

ADDRESS CHECK FOR
DEVICE dev AT USER
adr

The monitor checked a user address and found it
to be too large or too small; in other words, the
address lies outside the bounds of your program.

ALREADY ASSIGNED
TO JOB n

1he device is already assigned to another user's
job (job n).

BAD DIRECTORY FOR
DEVICE DTAn

The system cannot read or write the DECtape
directory without getting some kind of error.
Many times this error occurs when you try to
write on a write-locked tape or use a virgin tape.

7-16

Table 7-3 (Cent)
Meaning

Message
BUSY

The console addressed is not communicating with the
monitor or is not positioned at the I eft margin.
(The operatorls console is never busy.)

CAN IT ATTACH
TO JOB

The project-programmer number specified is not
that of the owner of the desired job.

CANIT CONTINUE

The job was terminated due to a monitor detected
error and cannot be contlnued.

COMMAND ERROR

General catch-all error response for the COMPILE
commands. The syntax of the command is in
error and the command cannot be deciphered •

dey: ASSIGNED

The device has been successfully assigned to
your job.

DEVICE CAN IT BE
REASSIGNED

A userls Teletype cannot be reassigned or an
attempt was made to reassign a device that your
job is sti II using.

DEVICE dev OK?

The device is temporarily disobled. The line
printer may be turned off or out of paper. For
mag tapes, there may be no tape mounted or
the switch is in LOCAL. You should correct the
situation and then proceed (retry the operation)
by typing CONTINUE.

DEVICE dev
WASNIT ASSIGNED

The device isnlt currently assigned to your job
and cannot be deassigned or reassigned by your
job.

DEVICE NOT
AVAILABLE

Specified d~vice could not be initialized because
someone else is using it.

DIRECTORY RJLL

The directory of the device is full and no more
fi les can be added.

DISK NOT
AVAILABLE

The device DSK: could not be initialized.

ERROR IN JOB n

A fatal error occurred in your job or in the
monitor while servicing your job. This
typeout usually precedes a I-line description
of the error.

EXECUTION
DELETED

A program is prevented from being executed because
of errors detected during assembI y,- compilation,
or loading. Load ing is performed, but the Loader
exits to the monitor without starting execution .

...

. 7-17

Table 7-3 (Cont.)
Meaning

Message

file

FILE IN USE OR
PROTECTED

could not be entered
A temporary command
in your UFO (user's file directory).

HALT AT USER adr

Your program executed a HALT instruction at
adr. Typing CONTINUE resumes execution at
the effective address of the HALT instruction.

HUN G 0 EYIC E dev

If a device does not respond within a certain
period of time when it is referen ced, the system
decides that the device is not functioning and
outputs thi s message.

ILLEGAL DATA MODE
FOR 0 EYICE dev
AT USER adr
-

The data mode specified for a device in your
program is i"egal, such as dump mode for
Teletype.

ILLEGAL UUO AT
USER adr

An i"egal UUO was executed at user location
adr.

ILL INST. AT
USER adr

An illegal operation code was encountered in
your program.

ILL MEMREF AT
USER adr

An illegal memory reference was made by your
program at adr or adr + 1.

lNCORRECT RETRIEVAL
IN FORMATION

The retrieval poil1ters for a file are not in the
correct format; the fi Ie is unreadable.

INPUT DEVICE dev
CANNOT DO OUTPUT

Output was attempted on a device that can only
do input, such as the card reader.

INPUT ERROR

I/O error occurred while reading a temporary
command file from the disk. File should be
rewritten.

?INVALID ENTRYTRY AGAIN

An ill~gal project-programmer number or password
was entered and did not match identification in
system.

I/O TO UNASSIGNED
CHANNEL AT USER adr

An attempt was made to do an OUTPUT, INPUT,
OUT, or IN fo a device that your program has not
initialized.

JOB NEVER WAS
INITIATED

An attempt was made to attach to a job that has
not been in itia lized •

JOB SAVED

The output is completed.

LINKAGE ERROR

I/O error occurred while reading a CUSP from
device SYS:

7-18

Table 7-3 (Cont.)

Meaning

Message
LOGICAL NAME
ALREADY IN USE
DEVICE dev
ASSIGNED

You previously assigned this logical name to
another device. The device is assigned but
the logical name is not.

A command that requires you to be logged in
has been typed to the monitor; it cannot be
accepted until you log in.

?
LOO KU P AND ENTER
HAVE DIFFERENT
NAMES

An attempt was made to read and write a file
on the disk. However, the LOOKUP and
ENTER UUO's have specified different names
on the same user channel. This message does
not indicate a DECtape error.

MASS STORAGE
DEVICE FULL

The storage disk is full. Users must delete
unneeded files before the system can proceed •

NESTING TOO DEEP

The @ construction exceeds a depth of nine
and may be due to a loop of @ command
files.

nK OF CORE
NEEDED

There is insuffic.ient free core to load the file.

n 1K BLOCKS OF
CORE NEEDED

The user's current core allocation is less than
the contents of JOBFF.

NON-EX MEM AT
USER adr

Usually due to an error in the monitor.

NON-RECOVERABLE
DISC READ ERROR;

The monitor encountered an error while reading
or writing a critical block in the disk file
structure (e.g., the MFD or the SAT table).
If th is condition persists, the disk must be
reloaded using FAILSAFE, after the standard
location for the MFD and SAT table has been
changed using the monitor once-only dialogue.

N ON -RECOVERABLE
DISC WRITE ERROR;

NO CORE ASSIGNED

No core was allocated when the GET command
was given and no core argument was specified
in the GET.

NO START ADR

Starting· address or reenter address is zero
because you failed to specify the address.

NO SUCH DEVICE

The device name does not exist or all devices
of this type are in use.

7-19

Table 7-3 (Cont.)

Message

Meaning

NO SUCH FILEfile .ext

Specified file could not be found. May be a source
file or a file required for operation of the COMPILE
commands.
'

NOT A DUMP FI LE

The file is not a core image file.

NOT A JOB

The job number is not assigned to any currently
runn ing job.

NOT ENOUGH CORE

System cannot supply enough core to use as
buffers or to read in 'a OJSP.

NOT ENOUGH FREE
CORE IN MONITOR

The monitor has run out of free core for assigning
disk'data blocks and monitor buffers.

NOT FOUND

The program file requested could not be found
on the system device or the specified device.

OUT OF BOUNDS

The specified adr is not in your core area, or
the high segment is write-protected and you do
not have privileges to the file which initialized the
high segment.

OUTPUT DEVICE dey
CANNOT DO INPUT

An attempt was made to input from an output
device, such as input from the line printer.

OUTPUT ERROR

I/O error occurred while writing a temporary
command file on disk.

PC EXCEED S MEMORY
BOUND AT USER adr

Your program made an illegal transfer outside
its bounds.

PROCESSOR CON FLICT

Use of + construction has resulted in a mixture
of source languages.

PLEASE KJOB OR
DETACH

Attempt was made to attach a job when you
already have a job initialized at that Teletype.

SWAP READ ERROR

A consistent checksum error has been encountered
when checksumming locations JOBDAC through
JOBDAC+74 of the Job Data Area during swapping.

TOO FEW ARGUMENTS . A command has been typed, but necessary
arguments are missing.
'
TOO MANY NAMES
or
TOO MANY SWITCHES

Command string complexity exceeds table space
in the COMPIL CUSP.

7-20

Table

7-3 (Cont)

Message
TRANSMISSION
ERROR

. TTYn ALREADY
ATTACHED

Mean mg
Duril'lg a SAVE, GET, or RUN command, the system received parity errors from the device, or
was unable to read your file in some other way.
This can be as simple as trying to write on a
write-locked tape.
Job number is erroneous and is attached to
anot her conso Ie, or another user is attached
to the job.

UN RECOGN I ZABLE
SWITCH

An ambiguous or undefined word followed a
slash (/).

UUO AT USER adr

This message accompanies many error messages and
indicates the location of the UUO that was the
last instruction your program executed before the
error occurred .

•

7-21

Book 8

Utility Programs . '
BATCH
CHAIN
LINED

TECD

BATCH

CONTENTS
CHAPTER 1
CHAPTER 2

8-7

INTRODUCTION
BATCH PROCESSING UNDER THE PDP-I0 MONITORS

2.1

Description

8-9

2.2

Batch Equipment Requirements

8-11

2.3

Object Job Status

8-12

2.4

User-Control Levels

8-13

CHAPTER 3

PROGRAMMER CONTROL OF THE PDP-lO BATCH PROCESSOR

3.1

Control Cards Acceptable as Batch Input

8-16

3.1.1

Control Card Notation

8-16

3.1.2

Control Card Descriptions

8-16

3.2

Loading User Programs

8-28

CHAPTER 4

DRIVER (A CORE DUMP PROGRAM)

4.1

General Description

8-29

4.2

Equipment Requirements

8-29

4.3

Implementation of Driver

8-30

4.4

Using Drivei'

8-30

APPENDIX A

BATCH EXAMPLES

8-33

APPENDIX B

TABLES

8-41
ILLUSTRATIONS

2-1

Batch Processing within the PDP-I0 Time-Sharing System

8-10

2-2

Lines of Control and Communication Between Batch and the
Batch-Controlled Object Job

8-11

Sample Control Cards for Three Jobs Processed by Batch

8-38

A-I

TABLES
3-1

Batch User Diagnostic Messages

8-28

B-1

Batch Control Cards

8-41

8-5

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

CHAPTER 1
INTRODUCTION

The PDP-10 Batch Processor (Batch), runlling under any of the PDP-10 Monitors, supervises the sequentia I execution of a, seri es of jobs. In a ti me-sharing environment, Batch performs this function as one
of the users of the system, thus allowing normal access by other users. Batch maintains constant communication with the operator and allows him to interrupt, skip, repeat, or prematurely terminate one or
more of the jobs in the series at any time. Chapter 2 contains a general description of Batch operation.
Chapter 3 describes the Batch control cards that must be present in the input to Batch. The
Appendicescontain supplementary information on Batch, including examples, and control card
and Teletype command summaries.

Two programs are used in conjunction with Batch-Stack and Driver. Stack is used to transfer job files
to the Batch input device and stack them there for subsequent input to Batch, transfer output job files
created by a Batch run from the Batch output device to some other device (usually the line printer), list
job file directories, delete job files, and list directories with selective file deletion or transfer.
As described in Chapter 4, the DRIVER provides a core dump of the user's core area.

8-7

CHAPTER 2
BATCH PROCESSING UNDER
THE PDP-10 MONITORS

2.1

DESCRIPTIO N

The PDP-10 Batch Processor" Batch, is a sl!bsystem which exists as one of many Commonly Used Systems
Programs (cusps) in the PDP-lO System Library. Batch is called in by the operator from his console
Teletype by the Monitor command "R BATCH" in the same manner as F40 (the FORTRAN Compiler),
Macro-lO (the Macro Assembler), or PIP (the Peripheral Interchange Program), or any of the other
cusps.

The Batch Processor is not an integral part of the Monitor and therefore C?ccupies no core storage

when it is not being run. There is only one version of Batch; this version runs under all Monitors.
Batch is a command interpreter and job supervisor; it does not contain its own versions of assemblers,
compilers or looders. Rather, the PDP-10 Batch Processor calls in and controls the execution of the
same standard cusps that an

on-lin~

user would utilize in unbatched execution of jobs from a console

Teletype. The input/output handler of the Batch Processor uses Programmed Operators (UUOs) which
trap to the Monitor; thus, the actual

I/o is handled by routines that exist within the

Monitor, thereby

enabling Batch to be run as a time-shared job in only 3K of core.
When Batch is being run from a user's console Teletype (TTY) as a time-shared job, with a job number
n, it sequentially initializes and executes a series of time-shared jobs (with job numbers m1, m2 , etc.)
in parallel with itself. Batch accomplishes this by utilizing a "simulated Teletype" (caded a pseudoTeletype (PlY». A PTY is a mechanism by which one job (a control job) can control another job (an
object job). Batch uses a PTY to type its commands to the object job. Thus, the Batch control job
runs concurrently with the time-shared, batch-processed object job. Since the Monitor "sees" the
control job (which is running Batch) and the object job (which is being run by Batch) as two separate
and distinct time-shared jobs, memory protection and relocation ensures the complete protection of the
Batch Processor area of core as well as that of the Time-Sharing Monitor. 1 Consequently, there is no

lThis holds tn:e only if the hardware configuration includes the memory protection and relocation
package, i.e., a time-sharing system only.

8-9

way in which an error in a user program being run under Batch can inadvertently i~terfere with the
Batch Processor itself. The fact that the two jobs are being run in perallel by the Time-Sharing Monitor
makes it possible for the operator to communicate directly with Batch via his console Teletype without
any interruption of the job being run by the Batch Processor; i.e., that portion of Batch which interprets console commands can operate independently from that portion which controls the execution of
the object job (unless, of course, the console command specifically requests an interruption or termination of the current user's job being run). See Figure 2-2.
MONItOR

CONSOLE
COMMAND
INTERPRETER

1
I
I

I
I

SYSTEM
SUPERVISOR

PROGRAM
(USER
JOB)
EXECUTOR

I·

INPUT/OUTPUT
HANDLER

1
I

USER JOBS
(CORE)

USE A

JOB 1
PIP2

CONSOLES

•
F4

SYSTEM DEVICE
(CUSP'S)

MACRO-lO
LOADER
BATCH
DUMP

JOB 2
BATCH

,. --..,
I

L ___

PIP
EDITOR. ETC

JOB 6
F4

I
~

Ffgure 2-1 Batch Processing within the
PDP-10 Time-Sharing System

8-10

CONTROL JOB

BATCH

CONSOLE
COMMAND
INTERPRETER

OPERATORS
CONSOLE

.----

INPUT
STREAM
INTERPRETER

(

I-f--I

1 i
OBJECT
JOB
EXECUTOR

8
'

l7J
OUTPUT
DEVICE

THREE SllITES
OF AN OBJECT
• JOB

BPTEMP

r'-

--.

08JECT JOB WHILE
UNDER BATCH
CONTROL

r5
Figure 2-2

2.2

INPUTI
OUTPUT
HANOLER

SYS)

A'~r
.

f---+

BATCH
INPUT
DE\I1CE

OBJECT JOB WHILE
UNDER CUSP
CONTROL

OBJECT JOB WHI LE
UNOER USER
PROGRAM CONTROL

Lines of Control and Communication Between Batch
and the Batch-Controlled Object Job

BATCH EQUIPMENT REQUIREMENTS

The minimum utilities required for batch processing within a PDP-10 system are: one Batch input device
(contair:ts the input 'stack of jobs to be run), one Batch output device (for any assembler or compiler listings), one scratch device (BPTEMP}l, the shared system device (SYS; contains the systems programs),
3K of core for the Batch program, and sufficient core available to Ba~ch to run the required cusps or
i

d~vice

1This scratch
can be accessed by programs running under Batch by use of the device name
BPTEMP:. Assume that it is file-structured.

8-11

specified user prog,rams. Th~ input device may be any device'capable of inptJf~itiiin;the insfdll~tlcin's
sYstem (card reader, magnetic tape, DECtape, paper tape reader, or disk). The Batch output, or listing device, may be any output device within the PDP-lO system configuration (line printer, paper tape
punch, magnetic tape, DECtape, or disk); in a time-sharing system, a console Teletype other than the
operator's can be usedas the listing device. The scratch device can be any retrievable device (magnetic tape, DECtape, or disk) and is assigned to the control job with the logical name BPTEMP before
Batch is started. The system device (logical name, SYS) is a directory device specified at system-build
time, and shared by all system users; it is kept write protected and cannot be uniquely assigned to any
one job, although any job can initialize and input from it. Because of the disk fi Ie structure in

th~

PDP-10 systems, a disk may be initialized as "different" devices concurrently; therefore, in a system
which includes a disk in its configuration, Batch may be run with that disk as its input, output, scratch
and system device, all initialized at the same time. Other devices, including this disk, that a particulCl1" job may require must be assigned by control cards in the Batch input stream.
The traditional approach to Batch processing is that all Batch control cards relating to a job to be run
appear together with the job on the Batch input device, and the Batch output messages directly concerning the job appear with the job's output on the Batch output device. Other messages may go to the ..
operator's console. In this mode of operation, the user's job should 'address the Batch input device and
Batch output device; these

devi~es

may be assigned as any device and the user's job will still run with-

out modification.
Ho~ever,

there is no restriction which states that the user must operate in this way. The Batch control

cards and the user's job (e.g., program, data, etc.) may be placed on two or more separate devices.
In most of the discussions in this manual, the first mode of operation is implied, but in actuality only
the Batch control cards must appear on the Batch input device, and only the Batch messages concerning
the user's job must appear on the Batch output device.

2.3

OBJECT JOB STATUS

Each object job comprises a file in the input stack. Each such job is separately logged in by Batch,
and at the endo~ each job, Batc;h performs a KJ6B. The job number assigned by the system to the
object job is typed out fo,llowing the typeol,lt of that job's $JOB card.
The object job , il1 which all job execution is done, is a Iway~,'in one of three possible, ~tates determi,ned
by where control of the object -job resides (see Figure 2-2); uti lization of the above-mentioned devi-ces
varies between each of'these stotes. The object job is under sole Botch control whenever job execution

8-12

is being controlled; i.e., whenever Batch is bringing a cusp into the object job's core area, whenever
compilations, assemblies, or other

proc~sses

are initialized or terminated, or whenever a postmortem

dump is performed. All control-card command execution is done while the object job is under Batch
control. Batch can always bring the object job back to its own control, regardless of the object job's
state.
When a system program, such as the FORTRAN Compi ler, has been started as the time-shared object job
by Batch, that program is in control of the job. The compiler may ask for input from the Batch input
device, do output to the Batch output device, or perform I/O to devices specified on the control card
that initialized its execution. Relocatable binary files produced by the assembler and compiler, or any
other intermediate files, are placed on the scratch device, BPTEMP, for subsequent input for another
process -- usually a loading process prior to running the now executable user program.
When a user program is executed (execution automatically follows compilation or assembly unless the
~

control card includes a command to suppress execution or there has been an error whi Ie compiling or
assembling), the object job is running under that program's control. The program can perform input
and output on the Batch input and output devices or on any device previously assigned by a control card.
When a user program e~its normally (with a CAll EXID, control reverts to Batch which then processes
the next control card request; when the exit is,due to a monitor-detected error, Batch will execute a
postmortem core dump, if requested, by calling most of the dump routine from the system device. If
the previously specified maximum running time for the user program is exceeded, control also reverts to
Batch.

Ultimate control of the object job always remains with Batch, since it can interrupt the execution of
any program which is being run at any time. Batch does the timing of user programs being executed,
and interprets commands that the operator may type on the console. These commands could interrupt,
terminate, or atter the execution of a series of user jobs, or they could specify new parameters to Batch
without interruption of the existing sequence, or even without slowing down object-job execution.

2.4

USER-CONTROL lEVELS

There are two levels of control that a user exercises over Batch; these levels are determined by the form
of the commands input'to Batch. Thl'lse commands are either in the form of "control cards" (see Chapter
3) which are prepared and arranged before Batch run time, or they are console commands typed to
Batch at ruh time;' . The remainder of this section is primarily of interest to the programmer and
discusses the fever of control that is exercised over the processor by various types of control-card
commands.

8-13

-',;

CHAPTER 3
PROGRAMMER CONTROL OF THE
PDP-I0 BATCH PROCESSOR

The programmer controls the execution of his job by Batch through control cards which he prepares prior
to run time. A control card is hereby defined as any ASCII string of characters from any legal input
device, where that string is terminated by the ASCII characters, RETURN and LINE-FEED, and initialized with an ASCII $ (dollar sign) as its first character. We shall refer to control cards as if they were
cards, and refer to positions on these cards as columns. If the input device happens to be a card reader,
the end of the card itself determines the termination of the ASCII character string; however, in every
case (except the KEY card), column 1 must contain the dollar sign.
The format of control cards requires that the control card type be identified by its first word, which
must begin in column 2; this card type is usually an instruction or category of commands which mayor

may not take a series of arguments. The fields of the various arguments are delimited by spaces (except
for the name field on the $JOB card, which must be delimited by a comma, since it may contain space~)
and they need not be delimited by.specific columns; leading spaces before arguments are ignored by
Bat :h, so absolute positioning is flexible - the relative positioning of arguments, however, must be as
specified below.

If a directory device is used as the Batch input device, each user's job is assumed to be a separate file
with a name, IJOBxy .abc, where xy represents the ASCII characters 01 through 99 and .abc represents
any desired extension (omission of .abc implies a null extension). "xy" must run consecutively, with
no missing numbers between the first job (IJOB01) and the last job (IJOBnn). Stack "stacks" files on
a directory device, giving them consecutive names as just described (see Chapter 5). Batch runs jobs
in the input stack as follows. First, Batch searches for the job IJOBOl and initializes it. At the end
of IJOBOl ,. Batch searches for IJOB02, etc.

B~tch

continues operating in this sequential manner unti I

after running· IJOBn I a LOOKUP on IJOBn+l fai Is; at this point, Batch assumes that it has reached the
end of the input stack and types "END OF BATCH."

8-15

When Batch is executed with a directory device QS its output
device,
Batch. - creates
filenames in the
,,1_, ,
"'.
., ,
•

•

, :.

1,'

• '

~ ~, •

(_~

form OJOBxy.abc, where the xy.abc string in the output files always corresponds to that of the
IJO Bxy •abc fil es •

3.1

CONTROL CARDS ACCEPTABLE AS BATCH INPUT

3.1.1

Control Card Notation

In the following control-card command descriptions, these notation conventions are used.
Parameters in uppercase letters indicate the use of that particular ASCII string in the field indicated on
the control card; e.g., NOGO suppresses program execution.
Lowercase letters indicate an ASCII string to be substituted; e.g., "name" indicates a variable name.
Lowercase terms with II as last character indicate a quantitative argument; e.g., "timell " indicates
maximum execution time.
Parentheses ( ) indicate that the enclosed argument is optional.
Braces {

3.1.2

3.1.2.1

} indicate a choice of formats.

Control Card Descriptions

$JOB Card - The $JOB card must be the first card for a given user's application, or user job.

The user job may consist of any number of specific tasks, compilations, assemblies or executions which
are placed prior to the $EOJ (end of job) card, wnich terminates the job, causing Batch to look for the
next $JOB card in the stack. The format of the $JOB card is as follows.

1
$JOB name, corell timell projll ,prog# (NOGO) (DUMP)
I,

name

User's name or other information; must be delimited by a comma and cannot exceed 25
,

characters, inc Iudi ng blanks.
"

if'

'.~

,;,

If"" ,
!)I'

8-16

•

,
,..;..,

,'"

core II

This quantity is the user's estimate of the maximum number of blocks (1024 10 , or 20008
words per block) of core memory required to process his job. This quantity is expressed
in decimal. This estimate must include the 1K of locations reserved by the Monitor as
the job-data area in every runable user program, and also the 1K locations required
by the core dump DRIVER which is loaded by Batch starting at user location 140.
All programs and/or cusps within a user job will be run in the amount of core requested
on the $JOB card, whether that particular program or cusp requires it or not; this
is necessary to prevent another time-shared user from acquiring core needed to complete
a specific Batch user job.

time ll

This quantity is the user's estimate of the maximum amount of time (in seconds) that his
job should require to run to completion. This figure should reflect use of processor
I,

time only, since input/output is handled by the Monitor; furthermore, if the environment is time-sharing, only the running time of the user is measured by Batch, not the
real-time processor use of any other time-shared jobs. At program run time, if Batch
finds that the specified time has been exceeded, a message is typed to the operator on
the Batch console teletype, MAX TIME EXCEEDED; however, the user job continues
uninterrupted for 8 seconds before skipping to the next user job.
During this period, the operator may type TIMEOK to extend the program's execution
until its normal exit (or until the operator terminates it with a console command, see
Chapter 4).
projll

The projll, prog# ar~ applicabl,e only in systems that have a LOGIN feature; this includes all systems with a mass storage device (disk or drum) in their configuration. The
1

project number of a user is the first part of the number that he types when logging in
for on-line utilization of the PDP-l0 system. The project-programmer number sequence
identifies the user file directory (UFO) of that particular user on the disk. Once Batch
has logged in the user under his number, all references to the disk with unspecified

UFO by any part of the user's program or by $ASSIGN card will be a reference through
that user's own file directory. The projll can be connected to the progll with a comma
'(ASCII code =054) or a slash (ASCII code =057).
prog ll

This argument is the second part of the project-programmer number; every user of a
system should have his own unique programmer number; the project number is usually
common to several programmers. The significance of the project-programmer number in
a disk system is treated in more detail in the PDP-l0 Time-Sharing Monitors manual.
8-17

. If the argument NOGOls included after thev~riable arg(,ments on t~e $JbB card I the

NOGO

object program produced by assembly and load or compi lation and load will not be
executed; this feature might be used in conjunction with a $SAVE or $SSAVEcards in
case the user wishes to run the program on-line at some later time.

If the character string DUMP is included on the $JOB card, a postmortem dump is per-

DUMP

formed on the user core image following any object program termination other than a
CALL EXIT. If the DUMP argument is not specified, however, the operator may still
initialize" a core dump by typing the DUMP command on his console Teletype at any
time (e.g., upon receiving a MAX TIME EXCEEDED message).

3.1.2.2 KEY Card - The KEY card must be the second card in the user job on systems that have a
LOGIN feature. The key is a string of six or less ASCII characters and is associated with the previously mentioned project-progra·mmer number. To be logged in, the key must be correct; otherwise,
the user's job will not be executed by BATCH. The formot of the KEY card is as follows:
1
key

NOTE
The ASCII dollar sign ($) is not used as the first
character on this card.
Examples of the $JOB card and KEY card combination:
1
$JOB EXAMPLE, 206099,99 NOGO
PASWRD
$JOB EXAMPLE2, 21 59 100,100 DUMP
SECRET

3.1.2.3

$ASSIGN Card - The $ASSIGN card is required if the user wishes to reference any device

other than the Batch input and outPlJt device. or SYS, the system devi<;e. If the user w~mts to perform
I/O on

the

~at~~ input/output devices, regardless

Qf what these devices are assignec!to by the operator

at run time, he does not use the $ASSIGN card; instead he performs

I/o

wi.th ACCEPT and TYPE state-

ments in FORTRAN, or with "TTY" initialized as his input and output device if his source program is in

8-18

Macro. A user program may also use the Batch scratch device, BPTEMP, without an $ASSIGN card; in
fact, the symbolic unit (or logical name) specified on an $ASSIGN card can be any logical name except BPTEMP and SYS. With the exception of DSK, the physical device specified cannot define a device already specified as the Batch input or Batch output device (see "NOTES," 4.1.3).
The function of the $ASSIGN card is to set up a correspondence between a symbolic unit used in the
user's program and a particular physical device designated at run time; if the device is a tape, it also
associates the label appearing on the physical tape with the logical name and the tape drive. The
format of the '$ASSIGN card is as follows.

1
$ASSIGN label symu (PROTECT) (NOREW)
label

This is the argument by which the user specifies the physical device he wants to reference
in his program by the logical name, symu; it also specifies the physical device that subsequent control cards wi II reference as symu •

If label is a nonsharable physical device (e.g., CDR, LPT) and is not avai lable at user
run time, Batch will type a message, "USER NEEDS DEVICE label." to the operator and
then wait for a response before proceeding. The operator should attempt to assign the
required device to Batch, perhaps after waiting for the current user of the device to
finish with it and release it. When the operator types "CONT", Batch will attempt to
INIT the device. If this attempt succeeds, Batch will reassign the device to the object
job and continue execution. If Batch cannot INIT the device, it will print an error
message on the output device and skip to the next user's job.

If the user assigns a sharable physical device (e.g., DTA, MTA), the label must begin
with either D (for DECtape) 1 or M (for magtape) followed by some word or number that
identifies the reel to be mounted. For example, the serial number might be used to
indicate to the operator which of the tapes given him by the user should be mounted at
this time. A label beginning with a D or M will cause Batch to type "MOUNT TAPE
label WRITE PROTECTED" or "MOUNT TAPE label WRITE ENABLED" (the presence or
absence of the PROTECT argument determines which of these two messages is typed);
The operator then mounts the specified tape' on an available drive and types the device
name and numl:>er on the console. (NOTE: The drive selected must not be that of either
the Batch input or Batch output device.)
1 However, note that the label "DSK II assigns disk to the symu.

8-19

$ASSI~~ TAP~IN D1984 PROTECt

This $ASSIGN c~~d cou~es'the
typeouts at wn time.

f~lIowir1g ;

MOUNT TAPE D1984 WRITE PROTECTED

(Operator mounts DECtape with serial number of 1984 on an avail(jJble DECtape
drive, for example, drive 5)

Operator types in device name and
number, followed by'a colon.

DTA5: )

Batch responds with message indicating
that device was successfully initialized.

If, for some reason, the drive on which the operator has just mounted the tape is not
available (i .e., it is assigned to another time-shared job), the message "physdev NOT
AVAILABLE" (where physdev is the physical device typed in) is typed to the operator
followed immediately by the "MOUNT TAPE" message previously described. As soon
as successful assignment is made, Batch types "OK" to the operator and waits for his
"CONTINUE" command before resuming processing. If no drives are available or if
the operator wishes to cease processing of the iob, "END" can be typed to abort the
job.
symu

This argument can consist of six or fewer alphanumeric characters (no spaces or
punctuation' can appear in this string). This is the symbolic unit which must be the
name that the user's program employs to reference the device.

PROTECT

This argument is described under '~Iabel" above.

NOREW

This argument causes magtape to bypass rewind.

The $ASSIGN control card
$ASSIGN label symu
is equivalent to the Monitor command
.:.ASSIGN label symu
if symu is equal to DSK or does not begin with an ASCII D or M. In the latter case (D or M), the
operator must provide Batch with an actual DECtape drive or magtape drive.

~-20

3.1.2.4

$TAPE Card - The $TAPE card causes Batch to dynamically perform certain device-dependent

operations on DECtapes or magnetic tapes that have previously been assigned a symbolic-unit name with
an $ASSIGN card. The control card format is as follows.

1
$TAPE symu op 1 op2 op3
symu

This logical symbolic unit must have been specified with an $ASSIGN card; if it was
not, the message "UNIT symu NOT ASSIGNED, CARD IGNORED" is output on the
Batch listing device, where symu is the unassigned logical nQme which was specified
on the $TAPE card. If symu was assigned to a nontape device, the operations specified
will be no-ops, but no message will be pri nted •

opn

This argument may be any of the following 2-character tape operation codes; the
operations are executed in the order in which they appear on the card and their
number may be variable. Operations that do not pertain to the device specified
(e.g., zero directory command for magnetic tape) are considered to be no-ops.

3.1.2.5

Zero directory of DECtape symu.

Advance one file on 'magnetic tape symu.

Rewind magneti c tape symu to load point, or rewind DECtape
to end zone at front of tape.

Backspace magnetic tape symu one file.

Advance magnetic tape symu to logical end of tape (double end
of file).

$MAC, $F4, and $CBl Cards - The $MAC card executes a Macro-lO assembly; the $F4 card

executes a FORTRAN compilation at the user's source program; similarly, the $CBl card executes a
COBOL compilation of the user's source program. Then'(if execution is not suspended), the users
program is loaded and executed with the timing control specified on the $JOB card. The action that
Batch takes with the relocatable binary program produced by either assembly or compilation is independent of whether the compiler or assembler produced it. The format of.the cards is identical;
and the conditions under which the relocatable binary program is to be handled by Batch may be specified on other control cards 'regardless of whether the source program was FORTRAN, Macro-lO, or
COBOL. The format of the cards is as follows.

{~MAC}

prgname (B: symu2)

(l: symu3)

$F4
$CBl'

(S: symu1)
}
{ (S: symu I: prgname 1,prgname2, .. '.

..•• symux:pr~namey)
8-21

, •

prgname

•

.... '.~'

~..

~ ~ ( ' -1

•-

'This argument is ci program name of six or less charactEmi. If the 'control" card has speci'fied any directory output device, this will be the name of the file whi'ch will be ~ro
duced by the compilation or assembly. If a directory output device has been specified
and no name is given here, the name TEMP will be assigned. If NOGO was specified
on the $JOB card, the file produced by assembly or compilation will not be passed to
the Loader.

B:
L:
$:

These optional arguments specify that the user wishes to specify his own source, binary
or listing device, ~espectively. The symu following the B, L, or S'must have been
a~igned

previously with a $ASSIGN card. The first of the "S" format above assumes

the file prgname if symu1 is a directory device. The second of the two "S" formats
above describes the case in which a file other ,than prgname or several source files are
to be compiled or assembled into one bi·nary program. B:* or L:* indicates that binary
output or I isting is to be suppressed.
If no source device is specified, the Batch input device is assumed: if no listing device
is specified, the Batch output device is assumed; and if no binary device has been
specified, the intermediate relocatable binary file is output ~n the Batch scratch tape,
BTEMP, from which it is loaded by tlie Loader prior to execution (note that BPTEMP is
zeroed foltowing each job). Since the Macro-10 Assembler is two-pass, whenever the
source is unspecified, the following file is copied from the Batch input devi ce onto
BPTEMP prior to.assembly; in this case, if some binary device, has not been specified 1 ,
Batch will request that the operator mount additional scratch device(s).
,

Note. that "TTY" specified as source or listing device results in the source or listing being input or output on the Batch input or output device.

3.1 .2.6

$CREF Card - The $CREF card performs all the functions of the $MAC card and, in addition,

produces a cross-reference assembly listing. It is provided for the user who wishes to obtai n a special
cross-reference listing of hi~ Batch assembly. In the Macro listing produced, there is a decimal sequence number printed leftmost on each line of the output, regardless of whether thaf line is an, instruction, comment, or even blank. At the end of the listing",after the symbol table, every symbol referenced in the progra~ is listed alphabetically; each ~ymbo' heads a horiiontal list ~f sequence numbers
which identify every line in which th~ given symbol is referenced.
1Specification could be by $BI N card prior to this card.
I

8-22

,~,

Note that, according to the following format description of the $CREF card, the I isting produced is
printed on the Batch output device.

1
$CREF

B:
S:

prgname

(B:symu2)

(

(S:symul)
"\
(S:symu1 :prgnam 1, prgnam2, ••• ,symux:prgnam3~

Since the cross-reference procedure requires an intermediate "scratch" listing device,
Batch utilizes BPTEMP for this purpose. Since the $MAC card already requires a binary
device (in addition to BPTEMP) if no source device is specified, the $CREF card requires
that if neither a binary nor a source device is specified, the operator will be requested
to mount two additional scratch devices at assembly time.

3.1.2.7

$lDR Card - The $LDR card will cause the Loader to load relocatable binary files from a

device previously assigned with an $ASSIGN card or from the system device SYS or from BPTEMP. The
format for this card is as follows. Note that every program which has been asse~bled or complied (via
$MAC,$F4, $CBL and $CREF cards) is automatically loaded. Thus, the $LDR card should be used only for
programs which already exist in binary format and have not been assembled or compiled during this
Batch run.

1
$LDR symu: prgnam 1, prgname2,. • •

(LIB)

symu

Argument is described above.

prgnam

These must be the file names of relocatable binary files; they are specified only if
symu is a directory device.

LIB

If this string appears, every program on the file is 10Qded in library search mode
(see description of Loader, PDP-10 System User's Guide).

3.1.2.8 $EXLDR Card
Card format:

1
$EXLDR (MAP)
This card is optional, and is to be used only when no more source programs follow. When this card is
read by Batch, the Loader is brought into core and is used to load alt programs previously compiled
or assembled, or previously specified by $LDR cards.

8-23

MAP
Any $LDR cards that follow the $EXLDR card do not bring the Loader in again, but continue to toad
with the Loader that is already in the user's area.
If the $EXLDR card is missing, the Loader is coiled and loading is triggered by the $EOJ or $EOF card.

3.1.2.9

$BIN Card

Card format:

1
$BIN symu
The logical name, symu (previously specified with an $ASSIGN card), specifies an

symu

assigned device which becomes the permanent output device for all relocatable binary
files. Once this card has been read, all files normally written by Botch on BPTEMP
are written on the specified device.

NOTE

3.1 .2.10

Make certain that the device is not write protected when the $ASSIGN card specifying it is
read.

$SAVE Card and $SSAVE Card

Card format:

1
$SA VE symu:prgname (coreD)
$SSAVE symu:prgname (coreD)
These cards cause Batch to save the core image of the user's area on the,symu device specified in the
argument field; if the device has a directory, the saved file is assigned the name "prgname.

The

constraints on the symu device are the same as for the $BIN card above; i. e., it must not be write
protected. The $SAVE card and the $SSAVE card serve the same function except tnat the $SSAVE
cause the stored program to be sharable.

-8-:24

coreN

This argument specifies the number of 1K core-image locations which Batch is to save
on the specified device; however, if the program in core requires more space than
specified in the argument, it will be saved in the amount of space required. This argument takes precedence over the core argument specified on the $JOB card for the
specific execution of the $SAVE (or $SSAVE card) card only, with all following operaations being executed in the amount of core specified on the $JOB card. If no coren
argument is specified on the $SAVE(or $SSAVE card} card, the program is saved according to Monitor conventions.

3.1.2.11

$RUN Card

Card format:

$RUN symu:prgname
This card causes Batch to read in and execute the program "prgname" from the previously assigned symu;
this device may be write protected. The device can also be SYS or BPTEMP.

Note that BTEMP is zero-

ed at the end of each job.
This must be a previously saved .SAV file or a system cusp. If the program "prgname"

prgname

expects input from TTY, these desired prgname inputs must be on the Batch input device,
following the $RUN card; they should not have dollar signs in column 1. In this case,
an $EOF card should be used to terminate the prgname input stream.

NOTE
Programs which run in DDT submode where communication
between Batch and the program run by Batch is via Teletype
(in DDT submode) cannot be specified (e.g., TECO, DDT).

3 .1 .2 • 12

$G ET Card

Card format:

$GET symu:prgname

8-25

"
This card causes Batch to read in the program "prgname" from the previously a~}gn~ sYil'iu. The dr~u
ments and functions of this car9 are similar to those of the $RUN card in all respects except that the
program is not executed.

3.1.2.13

$START Card

Card format: '
1
$START

The $START card causes Batch to initiate execution of a program that has been called in with the previous $GET card, or that has been I inked by the loader.

3.1.2.14

$EOF Card - This card has no argument field.

The $EOF card creates an internal end-of-file to a preceding input stream on the Batch input device.
If NOGO was not specified on the $JOB card, the $EOF card triggers the execution of programs that
have been loaded in core, or before execution triggers the loading'of programs that have been assembled or compiled previously under control of $MAC, $F4, $CBL or $CREF cards. If the previously
compiled or loaded programs require data from the Batch input device (ACCEPT statements or INPUT
UUOs in Macro from TTY), the data must appear on the cards immediately following the $EOF card
on the Batch input device. '

3.1 .2.15

$EOJ Card - This card has no argument field.

The $EOJ card specifies the end of a user's job. If no $EOF card has been issued previously, the $EOJ
card triggers the same actions as for as loading and execution of programs by Batch as the $EOF card.
The $EOJ card, however, specifies the end of the'inpllt stream for the current job."

NOTE
This card is mandatory for the end of the job; however, ifan
end of file (EOF) on the "input device occurs (an EOF appears
after each input job, exc;ept when the,'Batch input device is,
card or paper tape), Batch simulates the $EOJ card.

8-26

3.1.2.16

$DUMP Card

Card format:

1
$DUMP
The $DUMP card insert~ at any point in the user's data specifies that a dump is to be taken when the
job reaches this point.

3.1.2.17 $* Card - Write to operator and wait for reply.
Card format:

1
$* comment

...

Columns 4 through 80 of this card are typed on the operator's console, and Batch waits for operator
action, e.g., CONT or END.

3.1.2.18

$** Card - Write to operator without reply.

Card format:

$** comment
Columns 4 through 80 of this card are typed on the operator's console, and Batch continues without
operator intervention.

3.1.2.19

$PAUSECard

Card format:
1
$PAUSE

The $PAUSE card suspends Batch operation until operator intervention •

8-27

-3.2 LOADING USER

PROG~MS

Batch will run Loader whenever it encounters a $EXLDR, $EOF, $EOJ, $SSAVE or $SAVE control card.
Batch loads programs in the order they were encountered on the $LDR, $F~, $CBL and $MAC cards, so
that programs which previously existed in bInary form may be loaded prior to (that is, into numerically
lower addresses than)"programs which have been translated during this Batch run.
If loading was initiated by a $EXLDR card, Batch will then load any programs specified by $LDR cards
and finish loading when it encounters a $EOF, $EOJ, $SAVE or $SSAVE card.
Table 3-1
Batch User Diagnosti c Messages
Message

Meaning

BEGIN EXECUTION

$EOJ card has been processed.

CAN ONLY COpy 1 FILE ONTO DISK

Cannot copy onto BPTEMP for MACRO
assembly.

CAN'T COMPILE OR ASSEMBLE AFTER A
$EXLDR CARD

The input deck is out of order.

DRIVER NOT LOADED - CAN'T DUMP
******J08 ABORTED

The input job was terminated during
-runtime by operation intervention.

JOB CARD BAD

A $J08 card field has been omitted or is
in improper format.

MAX TIME EXCEEDED - JOB KILLED

Job has exceeded time on job cards.

EX~CUTIO N

An error or a NOGO has resulted in no
execution of a previously loaded program.

NO LOAD - PROGRAM NOT SAVED

Trying to load a non-savJ!d program.

******NOJ AVAILABLE

Batch has received a "1" from the monitor
on a $ASSIGN card indicating the device
is not available.

SCRATCH DEVICE DIRECTORY FULL

Could not el)ter a file name into the
directory •

UNIT UUU NOT ASSIGNED, CARD IGNORED

The unit named on the card has not been
specified on a $ASSIGN card.

UNRECOGNIZABLE CARD, IGNORED

An illegal control card has been introduced
into the Batch stream.

UNRECOGNIZABLE FIELD ON CARD,
CARD IGNORED

A field on the card is in improper format.

8-28

CHAPTER 4
DRIVER (A CORE DUMP PROGRAM)

4.1

GENERAL DESCRIPTION

Driver is a PDP-l0 system program used in conjunction with the Batch Processor (BATCH).
The major function of Driver is to provide a dump of the user's core area, when the Batch Processor encounters a $DUMP card in the Batch input deck, a DUMP option on the job card, or a DUMP command
typed in by the Batch operator.
Driver performs all of the following functions when it is invoked. These functions are performed sequentially as listed.

(1)

A dump of the ACs in both octal and decimal is performed.

(2)

A dump of selected monitor status information, obtained by utilization of the GETTAB
UUO is performed. The standard Driver outpus the job status word (JBrs TS), job
relocation and protection (JBTADR), high segment table (JBTSGN), and the user
program name (JBTPRG).

(3)

A dump of specific job data locations is performed. The standard Driver outputs the
following job information in this format.

JOBUUO
JOBBLT
JOBUSY
JOBCNI
JOBVER

(4)

JOB41
JOBHCU
JOBSA
JOBTPC

JOB ERR
JOBDDT
JOBFF
JOBOPC

JOBENB
JOBHRL
JOBREN
JOBCHN

JOBREL
JOBSYM
JOBAPR
JOBCOR

A dump from the end of Driver up to JOBFF in octal, SIXBIT, and ASCII is performed •

...
NOTE
Because Driver is written as a series of MACRO
calls, it is relatively simple for each installation
to modify or extend the information output on the
dump. For further information, consult the Driver
source fiI e •
.

8-29

4.2 EQUIPMENT REQUIREMENTS
The Batch Processor operator's console is required for control of Driver. Driver requires one output
device (usually the line printer) although intermediary output devices, such as MTA, can be used.

4.~

IMPLEMENTATION OF DRIVER

The $EXLDR card automatically loods Driver into core before any user programs. 1 When a dump is
requested (either by the $DUMP card or by operator intervention) the Batch Processor uses the E
(EXAMINE) command to look at location 140. If location 140 contains "DRIVER" in SIXBIT, an ST
(STARn 141 is used to invoke the dump. lf location 140 contains a value other than SIXBIT "DRIVER",
the Batch Processor outputs a diagnostic to the user's output, and continues with the Batch note job
stream.

4.4

USING DRIVER

Once invoked by either the $DUMP card or by operator intervention, Driver performs a core dump of
the Batch job drea without any operator intervention; no further operator actions are required for this
Batch job.

--...

1 If the $EXLDR card is omitted, Driver can be loaded with a $LDR card or a $RUN SYS LOADER card.

8-30

••••••••• *
ACS
00-07

~0000000A00. 777~00004371 e00e11~02166

1~.17

~00000~0~012 0~0~0~000042

04'0@~~00012

~0"07
1~~17

*'
*10

*2360438
+52344 9 1402

-16774919
.34

CORE OIJMP ••••••••••

OCT'~

000000006457 00~000007247 000000000000 777250001247 0~060~0~
0 4 0332471016 0e~000~000~6 0~4555002367 777754004235 77775~000632
DECMAL
+J375
*3751
.0
"90173785
.100663306
.4352274956 +6
+&32"4743
.524067'
~6291~46

MON I TOR ST AT,US 1N~O
JBTSTS 44000'0~0~06 J8T,OR 007777104~02 ~BTSGN 000000000000 J8TPRG L~AnER

._-----_._----- .

JOB DATA INF'O
JOBUUO 000404007255 JOB41 26400e002107 J09ERR 000000000000 JOBENB 0~0000000000 JOBR£L 000000007777
JORBLT 3100000~0J01 JOA~CU 000~~~~0~~~0 JOBD~T 00000~000~~~ JOq~RL 0~0~0~0~0~0~ J09SVM 77725~0~7250
JOeU5Y 000~000?7250 J08SA ~04271eZ1?5' JOarr 00000~004371 JOPBEN 0~0~00000e00 JO~APR 0e000~070000
JOBeNI 0000000~0~00 J08TPC 000~~~00~~~t JOBOPC 31000e0e1e52 JOBC~N 0~1056000000 J08C~R 00427112100000
JOBVEB 00000~000~17
------ ---------_.
-~---~

AOOR

00
I

OCUL.

~-~-

_ _ _ _ _ S! X8j..:.T_ __

ASCII

9101050 4406000003wa 449170000121000 25400000UJ52 26670011104033 .t"&
10'
5. (J6W -II'~
~ ___ ~___ ~ ___ .1
~01054 0150000~0~0~ 254e11l0~01052 3?144~0~106' 200000003260 .IH
5. fJI,' (W0
I~.'
*
42
X'
~01060 2~20000~3262 607440000010 254f131110~106' 23314000327~ ~
IRP\. (5' (W~!' IX. •• YAR'
JuL __
~01064 202147000001 200140003272 202147000002 135140003340 .~1~
101~ li01G
"*1' ". , Fa
J pa
4 p,
9101070 27U40003~40 205000350700 2~200r/10~3034 !>52J543001i!0~.Jt111.__ll.~Ji.....!...!_~ 8(~"C
I', IS
Il. • ......l.......__..t __
11101074 5r554~0~0700 554~13000090 3~6~0~25400~ 254000~01110 .~~. 'M~*
SP 5~ 5. 1( • • Q6 .r x l ' X.
$,
1"011£'10 37000i1101!'09113 55'0030000010 336NH'00000:J 2?lU2l0i/!00373 *L- .M'"
IP
0( jr •• )
~ ..1_II__ --1.L __
"'011~4 270000000013 202540003033 20254~0"'3334 35'~00"'0000~.'
.11'5' A105' 1(-'
.',
v
V NI
•
0'101110 5500200010"'13 542000~03!l134 20125400"3035 63~4400llHl_!.M ill
.UII S(2!5. e,su IB_.i!
XI! ___ '1 .. L ___ Q..L_
0101114 4760e"'0"'3~3~ 5412'000"'0~e 4"'360~0~3017 62144!l110~00~ .r,p ~)L.~
_) A/R.,(
*
v.
,x 02
"'01120 54144"'000(11l1lfA 403040000006 5~52400C'100(/H" 2011'100"'00013 *1 ,.
~8'"
&f!J.
"',
. . 'X2
*e
Q.
.....L __ _
0"1124 20210(l'10~3~32 13 4100000013 311540003034 254000"'01177 .A1 I I . '
.9 •• 8<5,
,~ • • n
M
26.
7'
V, 0113 0 62010 IU! '" 010" 6 4 '" 1Ol0 '" 0 00 4" 2 0 014 ~ 00 0 0 !lI2 _231140",," !lI.aL!tHL_L.I.L __ ~_"_J..a.--'.Jt-...tD.. __ ..H______ . _ U
_L _
~011~4 1351440~147111 25'~23"'01511 663'4i11011'01!'0j 2540"'0001142 *'IM IX5'~ ~IV<'
I~'
18 •• A *
$LR
•
1001140200200003332202200003333 2'510?0CH1"'2'" 2211;"""'''0012 .(?I"
1102 1171
02((11 .. ,
M H t'.L.I~l'_'__ f~
001144 27004"'''002102 25'~~0~01123 671?4~000001 621440000001 .7 ~ "~. 13W.' IB,- I. '.
•
IN.
02
•
L'l011~0 2V1!IJ4001'llIr1100 25'0"'0001123 2 6 174V'0(IJi!0(U i!61740000013~ ___ -'-l.
)36" 16" ... _Ltt_. _:'Ln. 112 _ ....t2. __ .t__ _
001154 607440000~02 ~0360000"'0~1 2540000~1166 627440000001 .~\~ "8)
15. IVR\. :_ .AR
~X
+
,[R
"'01160 254l"0A0r.1164 201112\40003333 202(-14<10,,333' 3"4(210f1lA000Z'0 .". IT21" 11~0. 1(8.
• .+
__ ~.JL....Ji1
001164 20254(l'1003~34 202540"'03033 20104~e00001" 34460~"'01123 .~5. 1(05' 8,,,,( • . '1021;""0002 274740003343 *61~ 11M
8(6(
"le' Ie. " Jil. _ _~~ I
Q.
0012"4 6614'0100000 20054000333' 621.40000001 ~2l344"0100P0 .v,~( 0~- I(P,. 1'('1 • 'L2
~D2
~R
t
U1210 2540000"'1.63 20Ul1!I0003060 25100I1!!lIe'3077 2542lQl0002H'3 .", • 50 L sp" 8.-5, u. ,.
__ ~___._--1.t __
r01214 373 91 17777777 25'~00"01220 2'4'43e03343 25400~001117 _'8/~.~5~ .07G' ,C5. II • • )~.
HI
O.
I001220 200557000a00 344600001117 6614402"'''''00 6214'0000"~1 .~XQ
(f
I/V •• 0 ~"
1*' X Q
t~2
D2
•
001224 254e0"0~1123 260140001346 2607400 0 1 7 21 254000001120 *5. '36 1 • • r6" 115. 10...
II
S.
~.
(.
V~123~ 2010401~02e4 6214400001r1 66144~0~101~ 62144ee00001 ,re, "SR,.
IV •• e B"
I •• " A02
L.2
02
•
~012~4 322e400?1120 55~1~000303~ 275113~00000 2211000000~' .,0' )0MI
8(71.
2)
X• • 4~ (l
ISX Ii
,
~01240 325440m01252 13400m0m0013 36210~0011ZZ 60744000100~ II~~ .J.p
.>1 ).P\, ( • '52 lJ
(0 iAB ....JL ___ _

.0.

NOTE
SIXBn output is enclosed between asterisks (*)
ASCII output is enclosed between up-arrows (t).

APPENDIX A
BATCH EXAMPLES

This appendix contains a collection of examples showing the use of Batch control cards and operational
procedures .
Example 1

$JOB
BATCH1,
10 20 100,101
DEMOI
$1'4
TEMP
(F"ORTRAN PROGRAM STATEMENTS)
$EOF"
CI NPUT DATA)
$EOJ

On running the above sequence of cards under control of Batch, the following actions occur.
a. The contents of the $JOB card, followed by the job number assigned by the system to
the object job, is printed on the operator IS Teletype.

a file, TEMP.REL, on BPTEMP.

The FORTRAN compiler produces

The $EOF card triggers the loading of TEMP. REL and starts the job.

The $EOJ card marks the end of the job and the end of the input data.

Example 2

10 10 100,101
BATCH2,
$JOB
DEMOI
DOUT
$ASS IGN DTAI
PROGRM
$1'4
DIMENSION
11(1000)
DTA 1 = LOGICAL DEVICE NO.9
C
INTEGER G
DATA G/9/
DO
1
J=I, 1000
II ( J ) = J
F"ILE = 4HF"ILE
CALL OF"ILE (G,F"ILE)

8-33

WR IrE

(G)

END FILE G
STOP
END
$EOJ

o.n running the above job, the followi ng actions occur.
a. The contents of the $Jo.B card, followed by the assigned job number, is printed on the
operator's' Teletype.
b.

The message
Mo.UNT TAPE Do.UT WRITE ENABLED

is printed on the operator's Teletype. The operator can specify the actual DECtape (Do.UT)
drive on which he'has mounted a DECtape reel by typing
. -

Batch replies with
OJ<

*
and, when user types Co.NTINUE, proceeds with the running of the job.
c. The Fo.RTRAN compiler p~duces a file, PRo.GRM.REL, on BPTEMP, and the $Eo.J
card performs the functions of the $EQF card (triggers the loading of PRo.GRM. REL and
starts the job).
d.

The execution of the program wi II create a

fj Ie,

FILE. DAT , on DECtape Do.UT.

Example 3
In the preceding examples, the storage map produced by the Loader was written on the output device.
This map can be suppressed by using the following sequence of control cards.
$JOB
DEMOl
$ASS IGN
$F'4

BATCH3 "

DREL
MAIN

DTA

(FORTRAN PROGRAM STATEMENTS)
$LDR DTA:SUBRl"SUBR2
$EXLDR NOMAP
$EOI="

CINPUT DATA)
$EOJ

8-34

The DECtape DREL containing the .REL files SUBR1 and SUBR2 will be requested by Batch.
MOU~T

TAPE DREL

W~ITE

ENABLED

After the compilation, the Loader is brought in and executed by the $EXLDR card. Note that the file
MAIN.REL is not specified, as doing so would result in multiply defined symbols. The option NOMAP
on the $EXLDR card suppresses the writing out of the storage map. The $EOF card begins the execution
of the loaded program. The $EOJ card terminates the input data and the job.
Example 4
To save a program on a DECtape, the following sequence of control cards can be used.
$JOB
DEMOI
$ASS I GN
$1"4.

BATCH ..

DSAV
PROG

DTA

(rORTRAN PROGRAM STATEMENTS)
$SAVE
$EOJ

DTA:rORSAV

Ch!lnging DSAV on the $ASSIGN card to DSK would result in savtng the job on the disk in the user's
(100,101) disk area.
Example 5
To suppress the printing of the Macro code generated by the FORTRAN compiler, the following sequence
of control cards can be used.
$JOB
BATCH
12
100 .. 101
DEMOI
$RUN
SYS:r40
BPTEMP:COMP .. TTY:/M~TTY:
(FORTRAN PROGRAM STATEMENTS)
$LDR.
BPTEMP:COMP
$EXLDR NOMAP
$EOr
(INPUT DATA)
$EOJ

8-35

The following facts should be noted •
. a.
b.

S.wit~h 1M suppresses the printing of the Macro code.

BPTEMP may·be·used without

assignin~

it.

c. COMP must. be specified on. the $ LOR card, because the compi lation is not done
under control of a $F4 card.
d.

The $EOF card begins execution of the loaded program.

Example 6
The use of the Macro-10 assembler by means of the $MAC or $CREF card is completely-analogous to
the use of the $F4 card.
If one wants to run the assembler by means of a"$RUN card, it should be noted that the assembler
makes two passes and, consequently I the source statements must be entered twice; this introduces
a problem where card input is involved. However, by means of PIP (Peripheral Interchange Program),
this problem can be alleviated. The control cards used are given below.

$JOB
DEMOI
$RUN

BATCH6..

100 .. 101

SYS:PIP

BPTEMP:SOURCE~TTY:

(MACRO PROGRAM STATEMENTS)
$EOF'
$TAPE BPTEMP MW
$RUN
SYS:MACRO
BPTEMP:MACBIN .. TTY:~BPTEMP:SOURCE
$EOJ
.

Example 7,
This example shows the combination of a FORTRAN program and a Macro-l0 program in one job.

$JOB
DEMOI

BATCH7 ..

$1"4
DIMENSION KK(40)
ACCEPT I .. KK
DO 2 1=1 .. 40
K=KKCI>
2
1

CALL MACROCK .. L>
TYPE 3 .. K.. L
STOP
F'ORMATC4012 )
F'ORMAT C1 X .. 2 17)
END

, 8-36

$EOF
$MAC

SUB

ENTRY MACRO
MACRO:

MOVEM
MOVE
LSH
MOVEM
MOVE
JRA
SAVE:

l~SAVE

;LOAD K

1~@(16)

1~ 1

;STORE 2*K IN L

1~@1(16)

l~SAVE
16~2Cl6)

END
~p
$EXLDR
$EOF
0102 ••••••••••••••••••••••••••••••• ·.···········3940
$EOJ

Example 8
This' example contains a diagram of sample control cards for three jobs to be executed under Batch
(see Figure A-l) and a sample dialogue produced on the operator's console Teletype while these three
jobs are being run.
FolJowing this is the dialogue on the operator's console Teletype produced while the batch in Figure
A-l is run. Underlined strings indicate computer typeouts.

8-37

MACRO-l0 SOURCE PROGRAM

$EOJ

$ SAVE
$ ELXDR

DSK NAMDDT

NOMAP

10-0477

Figure A-l

Sample Control Cards for Three Jobs Processed by Batch

8-38

.ASS I GN MTA 1 BPTEMP
:R BATCH ~
*IN CDR:~
iOUT LPT: ~
!SK 0 ~

$JOB JOHN DOE,
RUNN I NG JOB 3

(Operator assigns scratch device)
(Monitor command to run Batch)
(Card reader input)
(Line printer output)
(Skip 0 jobs; start with first)

33,44

(Compilation and Execution)
RUN TIME - 32 SECS.
$JOB JOE DOAKES,
8

DUMP

($JOB card always printed on TTY)
47,11 NOGO

- RUNNING JOB 3
MOUNT TAPE 01984 WRITE PROTECTED
DTA3~

DTA3 NOT AVAILABLE
MOUNT TAPE 01984 WRITE PROTECTED
DTA5~

OK
(Operator mounts tape before typing CO NT command)
!CONT ~
CONTINUING
(Execution suppressed)
RUN TIME - 0 SECS.
$JOB fOGGY BOTTOM, ~ 70 50,50 DUMP
RUNNING JOB 5
PLEASE MOUNT A SCRATCH TAPE
DTA4~

(Operator mounts tape, write enabl ed, before typi ng
CONT)
!,CONn
CONTINUING
PLEASE MOUNT A SCRATCH TAPE

(Batch needs 2 extra tapes)

MTA0~

OK
!CONT~

(Operator mounts magnetic tape number 0 write enabled)

CONTINUING
MAX. TIME E~CEEDED

(Program execution exceeded time limit; e.g., infinite loop)

DUMP ~

(Operator commands core dump on output device,
LPT, and termination of user job)

RUN TIME - 67 SECS.
END Of BATCH

(At this point operator can run another batch or exit
with a CTRL C command)

8-39

APPENDIX B
TABLES

Table B-1
Batch Control Cards
Format

Function

$ASSIGN label symu (PROTECn (NOREW)

To reference any devices other than the Batch
input and output device or system (SYS) device
(see 3.1.2.3).

$BIN symu

To specify the previously assigned device to be
used to output all relocatable binary files (see
3.1.2.9).

$CBL prgname (B:symu2) (L:symu3) (S:symul)

Executes a COBOL compilation of user's source
program and executes the resultant object program with timing control specified in the $JOB
card (3. 1. 2 .9) •

$CREF prgname (B:symu2) (S:symul)

To cause the assembly of a Macro-10 symbolic
program and the generation of a special crossreference listing (see 3.1.2.6).

$DUMP

Inserted at any point in the user's data to produce
dump at this point (3.1.2. 16t.

$EOF

Creates an internal end of file to a preceding
input stream on the Batch input device and
triggers the running of programs loaded into core
and the running of programs assembled (or complied) but not yet loaded (see 3.1.2. 14).

$EOJ

Signals the end of the user's job. If no $EOF
card precedes the $EOJ card, the $EOJ card
triggers the loading and running actions described above (see 3.1.2.15).

$EXLDR (MAP)

Used only when no more source programs follow;
brings the loader into core and loads all programs
previously assembled or compiled or specified by
preceding $LDR cards (see 3.1.2.8).

8-41

Table, B-1 (Cont)
Batch Control Cards
Function

Format
$F4 prgname (B:symu2) (L:symu3)
(S:symu1)

Executes a FORTRAN compilation of the user's
source program and executes the resultant object
program with 'the timing control specified in the
$JOB card (See 3.1.2.4).

$GET symu: prgname

Directs Batch to load the program "prgname"
from the previously assigned sym~. Similar to
-$RUN card except that the loaded program is
not executed (see 3. 1 .2. 12).

$JOB name, corel time# proj# , prog#
(NOGO) (DUMP)

The fitst card of a user job. All compilations,
executions, and other tasks requested between
this card and an $EOJ card are considered to be
part of this job (see 3.1.2.1) •

Key

Must follow $JOB card (3.1.2.2) and password
associated with Project Programmer number.

$LDR symu:prgname 1 , prgnam2, ••• (LIB)

Calls the loader: to load relocatable binary files
from a device previously assigned by a $ASSIGN
card or from the system device or from BPTEMP
(see 3. 1 .2. 7) •

$MAC prgname (B:symu2) (L:symu3)
(S:symu1)

Executes a Macro-l0 assembly of the user's
source program and executes the resultant object
program with the timing control specified'in the
$JOB card (see 3.1.2.5).

$PAUSE

Suspends Batch until operator intervention
(3 • 1. 2. 19).

$RUN symu:prgname

Directs Batch to load the program "prgname"
from the previously assigned symu (or SYS or
BPTEMP) and then execute it (see 3.1 .2.11) •

$SAVE symu:prgname (corJi)
$SSAVE symu: prgname (core#)

Directs Batch to save the core image of the user's
area on the symu device specified and, if symu is
a directory device, assign the name "prgname"
(see 3.1.2.10). SSAVE card marks the"prgname"
as shareable.

•

$START

Causes Batch to initiate execution of a program
, which has been called in with previous $GET
card, or which has been linked by loader,
(3.1.2.13).

8-42

Table B":l (Cont)
Batch Control Cards
Function

Format
$ TAPE symu op f op2 op3 •.•
DZ - Zero DECtape directory.
MA - Advance mag tape on file •.
MW - Rewind mag tape to load point.
MB - Backspace mag tape one fiI e.
MT - Advance mag tape to logical end
of tape.

Directs Batch to dynamically perform certain
device-dependent operations on DECtapes or
magnetic tapes which have previously been
assigned a symbolic-unit name with an $ASSIGN
card (see 3.1.2.3).

$*comment

Comment Card. Directs Batch to type out contents of columns 4 through 80 of this card and
wait for operator to type CONTINUE or END
(see 3.1.2.17).

$**comment

Comment Card. Directs Batch to type out contents of columns 4 through 80 of this card; Batch
continues without operator intervention (3.1.2.18).

8-43

CHAIN

ABSTRACT

The CHAIN Program is the prime component of a system that allows users to deal with FORTRAN
IV programming applications which would produce programs too large to fit or to load into the
amount of core avai lab Ie. Special switches in the LOAD ER allow the user to create CHAIN
files, consisting of complete programs and subroutines, which can be read into core and executed as they are needed.

CHAIN itself, a subroutine called by the user, provides a standard-

ized method of reading the successive segments of coding (CHAIN files) into core and linking
them to the programs already residing in core.

PDP-10 CHAIN JOB IMPLEMENTATION

A COMMON area in lower core is set aside for the transmission of data between successive
CHAIN files. This area in lower core is known as the Permanent Resident Area, and remains
in core at all times. The Permanent Resident Area contains CHAIN and part of LIMO and may
contain any number of Macro- 10 programs followed by the FORTRAN IV BLOCK OAT A program
which defines COMMON. The BLOCK OAT A program defines the end of the Permanent
Resident Area. There can be only one BLOCK DATA program in any CHAIN job.

o
CHAIN
Any number
or MACRO-lO
programs

by~

Defined
FORTRAN IV
BLOCK DATA
program

Permanent
Resident
Area

COMMON
MACRO-lO &
FORTRAN IV
programs

Segment
Read-In
Area

. For any CHAIN job the Permanent Resident Area assumes a fixed length. This are~ is unaffected by the process of reading in successive CHAIN files. The Macro-l0 programs

8-47

residing in the Pemianent Resident Area should be programs used by more than one CHAIN file
(e.g., DDT or CHAIN). The remainder of core, above the Permanent Resident Area, is known
as the Segment Read-in Area. It is in this area that various, CHAIN files are read into core and
executed. The Segment Read-in Area may dontain a mixture of FORTRAN IV and Macro-lO
programs. Within this area the user may define a Removable Resident Area. This area is
directJy above the Permanent Resident Area. It may contain any number of Macro-lO programs
fo "owed by one FORTRAN IV program. When the user makes a ca" to CHAIN, he may
specify that the next CHAIN file be read'in either directly after the Permanent Resident Area
or directly after the Removable Resident Area. Thus the user may leave his Removable
Resident in core while several CHA IN files are being read in and executed, and'then he may
read over it with another file.

A CHAIN job beginning in this state:

o
•

Permanent
Resident
Area

Removable
Resident
FORTRAN IV
& Macro-10
programs

Reads in a new CHAIN file and becomes

o
Permanent
Resident
Area

Unchanged

Removable
Resident
CHAIN 1

Then reads a CHAIN file that overlays the Removable Resident and becomes:

8-48

o
Permanent
Resident
Area

}

Unchanged,

~4--4

CHAIN2

Then reads in a CHAIN file that restores the Removable Resident:

o
Permanent
Resident
Area
Removable
Resident
~-

Unchanged

- --

FORTRAN IV
& Macro-tO
programs
CHAIN file just read in (CHAIN3)

Arrows point to that location in core which is the lower bound into which the file has just been
read.

By reading successive CHAIN files into the area above the Removabl,e Resident, the Removable
Resident may be kept in core as long as desired. The Removable Resident may be removed at
any time by reading a CHAIN file into core immediately above the Permanent Resident Area.
The Removable Resident may be restored at any time by reading a new CHAIN file containing a
copy of the-Removable Resident into core immediately above the Permanent Resident Area.

LOADING CHAIN

CHAIN will be loaded from SYS by the Loader. This loading must be followed by a library
search of lIB40 before the loading of block data so that', essential Macro programs are loaded
in the PRA.

8-49

· 4.

CALLING SEQUENCE

The call to CHAIN is of the form:
CALL CHAIN (TYPE, DEVICE, FILE)

where:

TYPE

=0 reads the next CHAIN

file, into core immediately above the' Permanent

Resident Area (COMMON).
TYPE == I reads the next CHAIN file into core immediately above the FORTRAN IV
program which marks the end of the Removable Resident.
w~ere:

DEVICE = I, 2, ••• is an I/O device numbe~ corresponding 'to the device where'the
CHAIN file may be found. For example, when reading a CHAIN file from the disk,
DEVICE

= I.

NOTE:

CHAIN files may be stored in DSK, MTA, or DTA only.

FILE = I, 2, ••• is the number of the magnetic tape file where the CHAIN file is

where:

located.
or:

FILE =0 tells CHAIN to read the next file from the selected magnetic tape.

or:

FILE

= 'ASCII

NOTE:

filename ' if the CHAIN file is to be read from DTA or DSK.

File names are limited to five or fewer letters according to the FORTRAN IV
convention.

EXAMPLE:

If a CHAIN, job wishes to read in a CHAIN file named SEG4 from the disk, and

it wishes to read that file into the area above the Removable Resident, the,call to CHAIN
would be:

CALL,CHAIN (l,l,'SEG41)

CREATION OF CHAIN FILES

Using LOAD ER 1, the creation of CHAIN fi les is a two-step operation.

First, one uses LOADER to create an image of core as it will look y.then the CHAIN file being
created is r:ead in at run time. For instance, consider th~ CHAIN job illust rated below:

Version 5 I or later of the LOAD ER is necessary.

I '

8-50

o
MAC 1

- - - - CHAIN

I- -

Permanent
Resident
Area

MAC2

I- - -

LlB40
ROUTINES

~--

COMMON
Segment
Reed-In
Area

Removable Resident

RESID
MAC6

F41

Stage I

Temporary Programs

A call to CHAIN of the form CALL CHAIN(l, 1,'CHN1') would produce:

o
MAC1

- MAC2
- - --

I- - - -

CHAIN

~------

LlB40
ROUTINES
1--.-._COMMON
RESID
F42
-- -- }cHNloCHN
MAC3
Stage II
A call to CHAIN of the form CALL CHAIN(O,I,'CHN2') wo~ld produce:

o
MAC 1
I-- -

---

MAC2

1------

CHAIN
1-----LlB40
ROUTINES

I-- -- -

COMMON
F45

} CHN2.CHN

Stage \1-1

8-51

The first step in the creation of the file CHN 1 would be to input to LOADER all the REL files

corresponding to the programs which will be in core at STAGE III; 'n this case, the command to
LOADER would be:

*DSK:MAC1,MAC2,CHAIN/FDSK:COMMON,RESID/FDSK:F42,MAC3

where F42 and MAC3 constitute the basis of the CHAIN file to be created. The /F switch is
used to force .the loading of library programs so that they will be placed in lower core where
they can be properly and permanently linked to the resident programs which call them. Commas
must not follow a/Fswitch because the LOADER tries to load L1B40 twice.

Second, a command is given that will cause the remaining library routines to be loaded and the
completed CHAIN file, consisting of everything above the Removable Resident, to be written
out onto the specified output device. In the case of the example above, the command might be:

*DSK:CHN l-/R $

where "DSK:CHN 1-" instructs LOADER to write the CHAIN file named CHN 1.CHN

01)

the

disk. /R instructs LOADER that the CHAIN file consists of everything above the Removable
I

Resident, and $ (ALTMOD E key) instructs LOADER to first load the necessary Ilbrary
.

routines, and then write out the CHAIN file.
NOTE: LOADER puts all library ,routines referenced only by the
programs in a CHAIN file into core above the last user program
MAC3 in the example), and they Qre written out as part of the
CHAIN file.

Similarly, the CHAIN file CHN2 would have been created by giving to LOADER the command:

*DSK:MACI,MAC2, CHAIN/FDSK:COMMON, F45

•

where F45 (and the library routines it references) constitutes the body of the CHAIN file.
subsequent command: .

*DSK:CHN2-/C $

. would instruct LOADER to do the necessary library search- and write out the CHAIN file
CHN2.CHN starting with the program after COMMON.

8-52

The

The original core image in a CHAIN job (see Stage I above) is a LOADER"created SAV mode
core image. In this case, it would be created by using the LOADER command string:

*DS,K:MAC1,MAC2,CHAIN/FDSK:COMMON,RESID/FDSK:MAC6,F41 $

In summary, when one creates CHAIN files or the original core image used in a CHAIN job,
the Permanent Resident Area must be constructed in exactly the same way each time LOADER
is run. The same rule applies to the creation of Removable Residents, when they exist. To
this end, the

IF switch of the

LOADER should be used to force the uniform loading of library

routines referenced by programs in the Permanent Resident Area (PRA) or in the Removable

IF switch should be given immediately after the last program in the PRA
When an IF switch is set, LOADER loads the previously specified file, then

Resident (RRj. The
and the RR.t

enters library search mode and scans the FORTRAN library loading the required programs only.
The

IF switch terminates a

specification; therefore, it must not be followed by a comma as this

also terminates a specification causing the LOADER to load the last file specified again.
Also note, that the user must explicitly load CHAIN into his PRA.
6.

PROGRAMMING CONSIDERATIONS

a. When a call to CHAIN inuccessful, a new CHAIN file will be read in and execution begins
af the 'starting address of the CHAIN 'file which has just been inputted. ~his starting address
is governed by the usual LOADER rules and switches. This allows the user to specify different
starting addresses for each link that he loads. As part of its binary output, the FORTRAN IV
Compiler produces a starting address for each moin program that it compiles, and this information is used by LOADER to tell where to start a loaded program at run time. Similarly, the
END statement in a Macro-lO program can be used to specify a starting address. When loading
more than one program, LOADER accepts the starting address of the last program loaded which
has a starting address as the starting address of the whole group of programs unless the

switch to LOADER is used. (See LOADER writeup for details .)

b. CHAIN releases all I/O devices in use at the time the call to CHAIN is made. Thus

I/o

started by the programs of one CHAIN file cannot Be completed by the programs of another
CHAIN file. In utilizing file-oriented devices, data must be organized into separate files
for each CHAIN link. It is recommended that the user release all channels after the return
from CHAIN. (This is done automatically by the first FORTRAN main program in each CHAIN
file. )
1 The library program loaded after the FORTRAN IV program which defines the end of the RR
will be written out as part of the created CHAIN file.

8-53

c. When using the optiona I Removable Resident, ~the length of the Removable Resident may
not be changed during a particular CHAIN job. If a Removable Resident is removed and then
replaced, it must be replaced by a Removable Resident of the same length. f

d. It is not necessary that all CHAIN files be the same size. However, the user must assign
to his job enough core to accommodate the largest CHAIN file.

While CHAIN is loading a new link, three errors may occur:

I. The device specified in the call to CHAIN is not available. This causes the message:
DEVICE xxx NOT AVAILABLE - CHAIN

followed by a call to EXIT.

2. The filename specified with DECtape or disk input could not be found. This cal,lses the
messag.e:

FILE xxx NOT FOUND - CHAIN

•
followed bya call to EXIT.

3. An input error occurred while loading the actual dump file. Since CHAIN performs this
input from the accumulators, its space is limited.

If a read error has

occurre~,

CHAIN will execute a "Halt" instruction in 10catioA 14, and the

Monitor will print a message on the Teletype .

•
7. PROGRAM DESCRIPTION
When CHAIN is called, it does a RELEASE on all I/O devices. If the specified input device
is magnetic tape, the tape is positioned as specified in the call to CHAIN, otherwise a
LOOKUP is done on the appropriate directory device. A CHAIN file contains an image of
the appropriate portion of upper core. It also contains five preceding words which update
information in the JOBDATA area (JOB4I, JOBSA, JOBSYM, JOBDDT, and length of
CHAIN file). Thus five words at the end of the BLOCK DATA area (CO!",MON) or the
Removable Resident are used while the new CHAIN file is being read into core. The actual
input of the new CHAIN file is done by a portion of coding placed in the accumulators by
CHAIN. This coding in the accumulator$ does the input of the CHAIN .file, updates J0B41,

8-54

JOBSA, JOBSYM, and JOBDDT and length of CHAIN file, and restores the five words to the
area just below the CHAIN file that has been read in. Control is then transferred to the
starting address for the CHAIN file just read in. However, the contents of all accumulators
except 17 are altered by CHAIN.

When CHAIN is called, it does not know the length of the incoming CHAIN file. This lack of
information forces CHAIN to INPUT the file into the whole of available core. This lengthens
the time required to complete the reading of a CHAIN ftle-which is stored on DECtape or disk
and which is smaller than the amount of core available. This happens because input from these
devices is not completed until sufficient data is transmitted to fill the amount of core specified
with the INPUT commands1•

It is to the user's advantage to load all CHAIN files into core

images of approximately equal length so as to minimize the time required to input CHAIN files
from DSK or DTA.

With this version of CHAIN (V 50) and LOADER(V5.1), the removable resident area, when used,
must remain a constant length. It is not possible to read in a link that destroys the original
removable resident and then read in another link that replaces the removable resident with one
of a different length. This will be fixed in further versions of CHAlN and LOADER by preserving
one more word from the Job Data Area, JOBCHN.

1 However, after input is complete, CHAIN kn.ows how much data should have been read and
checks for too little data transferred.

8-55

LINED

LINED
A LINE EDITOR FOR PDP-lO DISK FILES

LINED is a line editor for disk files. It is used to create and edit source program files which are
written on disk in ASCII code with line sequence numbers appended. LINED has the ability to
reference any line at any time without the user having to close and reopen the file.

LINED

is a reentrant program and loads in 2K pure and 2K impure segments of core.

NOTE
In this document, computer typeouts are indicated by underscoring.
The symbol) represents the RETURN key. The symbol
represents the ALTMODE key.

(!)

MONITOR COMMANDS

The MONITOR commands CREATE and EDIT may be used to select a file for editing with
LINED. A temporary disk file, called DDDEDT .TMP, is created for passing the commands to
, LINED.

1.1

The CREATE Command

The CREATE command calls in LINED a'ld opens the specified new disk file for editing. The
CREATE command is of the form:
• CREATE filename.ext )

1.2

The ED IT Command

The EDIT command calls in LINED and opens the specified existing disk file for editing. The
EDIT command is of the form:
.!. EDIT filename.ext )

LINED COMMANDS

LINED indicates its readiness to receive commands by typing an asterisk. At this time LINED

8-59

is said to be in command mode. The user may then type in the followi~9 LINED commands.

2.1 .Inserting or Replacing a Line
•.

* Innmn
nnnn
nnnxx

aaaa ••.••• a

Insert or replace the following typed Itne at line number
nnnnn of the currently open file; nnnnn can be specified as
a line sequence number or a. point (.), or it can be omitted
entire Iy. A point refers to the last Iine which was typed,
or the last I ine de leted, or the last Iine inserted. If
nnnnn is omitted, it is assumed to be 10.

When LI N ED has typed a Iine sequence number" the program enters text mode. In the text mode,
characters typed by the user are understood to be text for the insertion. Following the user's
typein of the line to be inserted, LINED types out the next sequential line number
(nnnnn+l0) following which the user presses the ALTMODE key (sometimes labeled PREFIX or
ESC) to terminate the insert process and retum to LINED command level.

If there already exists a line at nnnnn, it will be replaced. A single quote following the line
number indicates that insertion at this line number will cause the existing line to be replaced.

2.2

Inserting Multiple Lines
*Innnnn, iiiii
nnnnn

aaaaa •••••• eI

nnnxx

bbbbb •••••• b

nnnyy

Insert the following typed lines, beg inn ing at line number
nnmn (which can be specified as either a line number or a
point) of the currently open file. Each time a line is
entered, nnnnn is increased by the specified increment,
iiiii:
If iiiii is omitted, it is assumed to be 10 (if
iiiii has never been specified previously), or the
previous increment specified.

*
If nnnnn is omitted, it is assumed to be 10, and the result becomes the Iine number of the next
insertion. Type ALTMODE on the line following the last insertion to return to LINED command
mode. LIN ED then awaits another command.

A double quote following a line number indicates that the increment specified for the current
insert instruction has resulted in an existing line being skipped.

2.3

Deleting a Line
* Dnnnnn

Delete a line number nnnnn from the currently open filei
nnnnn can be specified as either a line sequence number or
a point )

8-60

2.4

Deleting Multiple Lines
* Dmmmmm, nnnnn

2.5

Printine a Line
*Pnnnnn

2.6

Print lines mmmmm through nnnnn of the currently open file;
mmmmm must be less than nnnnn. Either mmmmm or nnnnn may
be specified as a point as long as mmmmm is less than nnnnn.

Closing the Current Fi Ie

2.8

Print line nnnnn on the user's Teletype; nnnnn can be specified
as either a line sequence number or a point. Typing ALTMODE
following a typeout wi" cause the next sequential line to be
printed.

Printing Multiple Lines
* Pmmmmm, nnnnn

2.7

Delete lines mmmmm through nnnnn from the currently open file;
mmmmm must be less than nnnnn. Either mmmmm or nnnnn may
be specified as a point as long as mmmmm is less than nnnnn.

Closes the current file and returns to LINED command mode.
At this point, the user may either open another file or type
t C to return to Monitor level to assemble, list, and/or save
his file on a permanent storage device (e.g., DECtape).

Examples of Command Sequence
Example 1
. CREATE FILEA

RUN LINED AND OPEN FILE FILEA

*I1,fJ
"J,fJ,fJ1,fJ HE PROGRAM
,fJJj.fJ2,fJ IS INSERTED
~3,fJ HERE

BEGIN INSERTING LINES AT LINE NUMBER
1,fJ INCREMENTING BY 1,fJ.
"

RETURN CONTROL TO LINED COMMAND
MODE BY TYPING ($). CLOSE FILE FILEA
BY TYPING AN E. '1'YPING A
t C RETURNS TO THE MONITOR COMMAND LEVEL.

. 8-61

Example 2

• EDIT FILEA

RUN LINED AND OPEN EXISTING FILE
rlLEA
PRINT LINES 10 THROUGH 30
PR,INTOUT

*Pl,fJ,3,fJ
THE PROGRAM
,fJ,fJ,fJ2,fJ ISINS ERTE 0
,fJ~3,fJ HERE
*12,fJ
~~,fJ IS PLACED
,fJ,fJ,fJ3,fJ
*D3,fJ
*P 1,fJ, 3,fJ
J~I,fJ THE PROGRAM
,fJ,fJ~,fJ IS PLACED
*E
~tc
~,fJ,fJl,fJ

INSERT LINE 20

DelETE LINE 30
PRINT LINES 10 THROUGH 30
PRINTOUT
TYPE E TO CLOSE FILE FILEA
TYPING A
t C RETURNS JOB TO MONITOR
CONTROL LEVEL.

AUXILIARY COMMANDS

These Auxiliary Commands provide an alternate method of calling LINED and opening files.
In most cases, auxiliary commands can be replaced by the monitor instructions CREATE and
ED IT (Section 1).
3.1

R LINED

LINED can be called in from the system device by typing
.R LINED)

*
\

LINED responds with an asterisk to indicate its readiness to receive a command.
3.2

Initializing a File for Processing
S filename •ext )
S filename .ext

Select an existing disk file,filename.ext,
for ed iting •

Select (create) a new disk file for editing,
call ing it filename .ext.

LINED CONVENTIONS AND RESTRICTIONS-

The following conventions and restrictions should be noted.
a. Files are written with the installation standard protection. See Book 1 for explanation of
protected files.
• 8-62

b. When in insert mode, typing ALTMODE following the printout of the next insertion line
sequence number causes a returned to LINED command level. Typing ALTMODE to
terminate a line of text to be inserted causes the text line to be ignored.

,a,af/11,.O

f/1f/1f/12f/1

LINE OF TEXT

Returns to LINED command level

*
¢f/1¢I,a

LINE OF TEXT

Line is ignored

*
c. LINED assumes that all blocks in a disk file have an integral number of lines (i.e., each
block begins with a sequence number and no line is split between blocks). This will always
be the case with files which'have been created,and edited only with LINED; however, if
sequence numbers have been removed, say by TECO, they may be restored by using PI P
switch /A (see PDP-IO Reference Handbook.)

d. LINED files can be resequenced using PIP switch jA (see PDP-IO Reference Handbook).

e. Line number 0 is illegal and cannot be used.

f. Lines can be edited in any order; however, editing lines by ascending line numbers reduces
file access time.

ERROR HANDLING

When an error is detected, LIN ED types a message and returns the user to' LIN ED command leve I
(indicated by the output of an * on the Teletype).

Some errors are fatal and cause control to

retum to the monitor. Error messages .for LIN ED are given in Table 1.
Table I
LIN ED' Error Messages

Meaning

Message
?FAU*

Filename Already in Use. The filename specified for a
newly created file already exists on the disk. Retype command correctl y •

?ILC*

I L1egal Command. Illegal syntax or other error in command
string.

8-63

Table 1 (C~nt.)
Message

Meaning

?NCF*

Not Current File. The filename in,an "S filename"
command could not be found on the disk.

?NFO*

No File Open. No "S filename" command preceded this
command st ring.

?NlN*

Nonexistent Line Number. A Print or De lete command
refers to a nonexistent Iine sequence number.
NOTE
The follow ing are internal system errors.

?CCl*

CCl error. Error while referencing CCl comand file.

?COR*

No core available for data segment. ,

?DCPI

Device directory full.

?DDE*

Device Data Error.

?UNA*

Unit Not Avai lab Ie. The disk is not avai lab Ie.

Read or write failure On disk.

6. IMPLEMENTATION
The following explanation is intended to help the user to understand how LINED works so that he
may use it more effective Iy.

Lines of text are stored in a 100O-Word working buffer. Each line has a I-word header containing two items. The left half contains the sequence nUl)1ber of the line, and the right half con-'
tains the number of words (including the word contain ing the I ine header) needed to store the
line of text. Thus, to find the beginning of the next line of text, it is necessary to simply take
the address of the current line header and add the word count of the current line.

Several pointer words are used to keep track of the lines in the working buffer. WRTLST contains
the sequence number of the highest line in the buffer. SN contains the sequence number of the
line currentl y being hand led in a command.

When LI NED discovers that SN is greater than WRTLST, it knows that the Iine be ing sought has
already passed through the working buffer. This line is not directly accessible, because there
is no way to read a disk file backwards. Consequently, it is necessary for LINED to close the
file and then reopen it. This process of going from the current position of the file to the end of
the file, from there to the beginning of'the file, and finally to the line being sought is

8-64

accompl ished as fo I lows:

To close the file, all remaining text must be passed through the working buffer to the
temporary output file (called ###L1N. TMP). This is done by giving the subroutine FNDLIN
(which finds a line whose sequence number is SN) the highest possible s~uence number -

99999.
b.

Next, the original file is renamed to ###TMP .TMP, the temporary output file is renamed to
the original filename and the original file (###YMP. TMP) is renamed to name. BAK (same
name as original with an extension of BAK).

FNDLIN is then given the sequence number being sought, and LINED continues with the
original command.

8-65

TEeo

CHAPTER 1
INTRODUCTION TO TECO

TECO, a very powerful text editor, enables the advanced PDP-l0 user to edit any ASCII text
with a minimum of effort. All editing can be accomplished by using on Iy a few simple commands;
or the user may select any of a large set of s~phisticated commands such as character string
searching, command repetition, conditional commands, programmed editing, and text block
movement. In this description of TECO only the basic commands are described. If the user requires information about the more advanced uses of TECO, he can refer to the TECO section of
the PDP-IO Reference Handbook.

TECO is a character'::'oriented editor. One or more characters in aline' can be modified without
retyping the rest of the line. Any sort of document can be edited: programs written in FORTRAN,
COBOL, MACRO-lO, or any other language; memoranda; specifications; and other types of
arbitrarily formatted text. TE.cO does not require that line numbers or any other extraneous
;

information be associated with the text.

1.1

GENERAL OPERATING PROCEDURE

TECO operates on ASCII data files. A file is an ordered set of data on some peripheral device.
In the case of TECO, a data file is some type of document. An input file may be a named file
on disk or DECtape, a file on magnetic tape, a deck of punched cards, or a punched paper tape.
An output file can be written onto any of these same devices. The input file for a given editing
operation is the file to which the user wishes to make changes. If the user is using TECO to
create a new file, there is no input file. The output file is either the newly created file or
the edited version of the input file. An output file is not required if the user wishes merely to
examine a file without making any changes.

In general, the process of editing proceeds as follows. The user first specifies the file he wishes
to edit and t hen reads in a "page II of text. A page is normally an amount of text that is intended for a single sheet of paper. Form feeds are used to separate a document into pages.
Ol input, TECO interprets form feeds as end-of-page indicators. It is not required, however,

8-69

that a clocument be so divide~ into pages.

If a form feed is not encountered, TEGO simply reads

as much text as will reasonably fit into its editing buffer. For the purposes of this document,
the word page is used to mean the segment of text in TECO's editing buffer.

---

When a page has been read into the buffer, the user can modify this text by using the various
editing commands. When he has finished editing the page, he outputs it ~nd reads in the next
page.

This process continues until, after the last page has been output, the user closes the

output file. If there are several pages where no editing is required, there are commands which
may be used to skim over them.

1.2

INITIALIZATION

. The two main uses of TECO are (I) to create a new disk file, and ( 2) to edit an existing
disk file. These are the only uses of TECO described in this document. In particular, the use
of TECO with devices other than disk is not described. The beginner can get around this
limitation by using PIP to transfer files to and from disk. (Refer to Book 6 in the PDP-IO
Reference Handbook for information about PI P.)

The two main uses of TECO are so common that there are direct monitor commands to initialize
TECO for executing them. The command

• MAKE

filename .ext )

is used to initialize TECO for creating a new disk file. Filename.ext is the name that the user
gives to the new file. The filename can be from one to six alphanumeric c.hciract,ers. This is
followed (optionally) by a period ( • ) and a filename extension of from one'to three alphanumeric
cha·racters. The most commonly used filename extensions are:

.F4
.CBL
.MAC

for FORTRAN source programs
for COBOL source programs
for MACRO-IO source programs

The MAKE command opens a new disk file to receive output from TECO and gives it the name
specified by the user.

Once the file has been opened it is then actually created by' using the

insert and output commands, which are explained in sections 2.5 and 2.6 of this document.
The command
• TECO

filename .ext )

8-70.

is used to initialize TECO for editing an existing disk file, named filename ,ext, The filename
and filename extension must be exact I y th~ same as those- of the file that is to be ed ited, The
TECO command opens the specified file for input by TECO and opens a new file, with a temporary name, for output of the edited version. When output of the new version is completed, the
original version of the file is automatically renamed filename.BAK, a~d the newly edited version
is given the name of the original file. The filename extension .BAK is used for backup files.

After TECO has been initialized for a particular job, it responds by typing an asterisk ( *) •
The asterisk indicates that TECO is ready to accept commands; it is typed at the beginning of
TECO·s operation and at the completion of exeEution of every command string.

Examples:
This command initializes TECO for creation
of a new disk file called EARNNG.F4.
The extension • F4 is used because the
file is to be a FORTRAN source file.

• MAKE EARNNG.F4)

• TECO

This command initializes TECO for editing
the existing disk file L1B40.MAC. At the
completion of editing, TECO automatically
changes the name of the original version of
LlB40.MAC to L1B40.BAK and gives the
name L1B40.MAC to the new version,

L1B40.MAC)

NOTE
The TECO command cannot be used to edit a file which has the
filename extension .BAK.- To edit a backup file the user must
first rename the backup file, For example, to edit the file
L1B40.BAK the user should proceed as follows:
• RENAME lIB40.0LD=LlB40.BAK)
.TECO

LI B40. OLD ) _

1.3

SPECIAL SYMBOLS USED IN THIS DOCUMENT

Symbol

)

The argument is "SOMETHING". "

As shown in the above example, the altmode used to

termi~ate

an alphanumeric argument may

also serve as one of the two altmodes necessary to terminate a command string. Any ASCII
character except null, altmode, and rubout may be included in an alphanumeric argument.

8-74

•

CHAPTER 2

TECO COMMAN OS

2.1

INPUT COMMANDS

The Y (yank) command first clears the ed iting buffer and then reads the next page of the input
file into the buffer.

A single Y command is automatically performed by the command

• TECO

filename.ext)

so that when editing with this command the first page of the input file is automatically read in
before TECO prints the first asterisk •

•

The Y command may be used to delete entire pages of a file, since the editing buffer is completely cleared before the input is performed.

The A (append) command reads in the next page of the input file without clearing the
current contents of the ed iting buffer.

This command is used to combine several pages of a

document. When the A command is used, the form feed separating the page already in the
buffer and the page to be read in is removed. Thus after the A command the two pages are
combin!!d into one.

If the editing buffer does not have enough room to accommodate an A command which has been
given, TECO automatically expands its buffer and then executes the A command. The user is
notified of this action by a message of the following form
\

[3K CORE]

If sufficient core is not available to allow buffer expansion, the user is notified by an error
message.

8-75

NOTE
On either an A,or a Y command the form feed terminating the
_page to be read in is not actually read into the buffer. It is
removed on input and a single form feed is appended to theend of the buffer when the buffer is output.

Examples:
• TECO REPORT.CBl)

This command deletes the entire contents of
the buffer and then reads in the next page of
the input file.

Read the next two pages of the input file into
the buffer, combining them with the page
already in the buffer.

~A
[4K CORE]

2.2

This command, as part of the process of
initializing TECO for editing the disk file
REPORT .CBl, automatically clears the
buffer and then reads in the first page of the
file.

The buffer is expanded as required by the A
co mmand • In most case s th is message need be
of no concern to the user. It is important only
if the system is low on core and does not have
swapping capabil ity •

BUFFER POINTER POSITIONING

Since TECO is a character-oriented editor, it is very important that the user understand the
concept of the buffer pointer. The position of the buffer po inter determines the effect of
many of the editing commands. For example, insertion and deletion always take place at the
current position of the buffer pointer.

The buffer pointer is simply a movable position indicator. It is always 'positioned between

two characters in, the editing buffer, or before the first character in the buffer, or after the
last character in the buffer. It is never positioned" on .. a particular character, but rather
before or after the character. The pointer may be moved forward or backward over any
number of characters.
The J command moves the buffer pointer to the beginning of the buffer, i. e ., to the position
immed iate Iy before the first character in the buffer.

The ZJ command moves the pointer to the end of the buffer, i.e., to the position following

. '

8-76

the last character in the buffer.

The C command advances the pointer over one character in the buffer. The C command may be
preceded by a (decimal) numeric argument. The command nC moves the pointer forward over n
characters. (The pointer cannot be advanced beyond the end of the buffer.)

The R command moves the pointer backward over one character in the buffer. This command may
also be preceded by a numeric argument. The command nR moves the pointer backward over n
characters. (The pointer cannot be moved backward beyond the beginn ing of the buffer.)

The L command is used to advance the buffer pointer or move it backward, on a line-by-Iine
basis. The L command takes a numeric argument, wh ich may be positive, negative, or zero,
and is understood to be one (1) if omitted.

The action of the L command with various arguments is best explained in a more concrete way.
Suppose the buffer pointer is positioned at the beginning of line b, or at some position within
line b.

The command L, or 1L, advances the pointer to the beginn ing of line b+ 1, i.e., to the position
following the line feed which terminates line b.

The command nL, where n > 0, advances the pointer to th~ beginning of line b+n.

The command OL moves the pointer to the beginning of line b. If the pointer is already at the
beginning of line b, nothing happens.

The command -L moves the pointer back to the beginning of line b-1.

The command -nL moves the pointer back to the beginning of line b-n.

NOTE
After execution of a Y command, the buffer pointer is always
positioned before the first character in the buffer. (The Y
command automatically executes an implicit J command.)
The A command does not change the position of the buffer
pointer.
In examples, the position of the buffer pointer is often
represented in this manual by the symbol t just below
the I ine of text.

&-77

Examples:
.: J3L (J)(J)

,The J commend moves the pointer to the beginning
of the first line in the buffer • The 3L command
then moves it to the beg inn ing 0 fthe fourth line.

*
':ZJ-2L Q)(J)

This moves the pointer to the beginning of the
next to last line in the buffer.
-

Advance the pointer to the position following
the fourth character in the next line.

OL moves the pointer back to the beginning of
the line it is currently on. Then 2R maves it back
over the carriage return-line feed pair which
terminates the preceding line.

In th is example of text stored in the buffer, the
position of the buffer pointer is shown to be
between B end C.

2.3

TEXT TYPE-OUT

Various parts of the text in the buffer can be typed out for examination. This is done by use of
.

the T command. Just what is typed out depends on the position of the buffer pointer and the
argument given. The ~T command never' moves the buffer pointer.

The command T types out everything from the buffer pointer through the next line feed. Thus, if
the pointer is at the beginning of a line, the command T causes that line to be typed out. If the
pointer is in the middle of a line, T causes the portion of the line fOllowing the pointer to be
typed.

The command nT ( n > 0) is used to type out n lines, i.e., everytliing from the buffer pointer
through the nth line feed following it.

The command OT types out everything from the beginning of the current line u'p to the buffer
pointer. This is useful for determining the position of the pointer.

The command HT types out the entire contents of the: buffer.

The user, especially one new to TECO, should use the T command often, to make sure the
buffer pointer is where he thinks it is.

8-78

During execution of any T command, the user may stop the Teletype output by typing the
(control 0) character.

This command causes TECO to finish execution of the command string,

omitting all further type-out. The

to command does not carryover to the next command string.

Examples:

.: OlT ClXD
ENTI RE LIN E TYPED

*
.: OTT (00)
ENTIRE LINE TYPED

.: 2T

0, deletes
the n characters immediately following the pointer. The commands -D and -nD delete
the character or the n characters, respectively, which immediate Iy precede the buffer pointer.

Lines are deleted using the K command. The K command may be preceded by a numeric
argument I which is understood to be 1, if omitted. The command n K (n> 0) de letes everything from the current Position of the pointer through the nth line-feed character following the
pointer. The command H K deletes the entire contents of the buffer.

At the conclusion of a D or K command the buffer pointer is positioned between the characters
which precede and follow the deletion.

8-79

Exa!"ples:
The editing buffer contains the following three lines of text,
and the pointer is positioned between the G and H.
ABCDEF~t·iIJKLM:) ~

NOPQRSTUVWXYZ ) ~
1234567890) ~

~ 4D (00)

Delete HIJ K •

-~* -D (00)

Delete G.

*
~ -3D

(00)

Delete EFG.

*
Delete HIJ KLM) but do not delete the line
feed at the end of the first line.

Delete HIJKLM) ~ •
Since the carriage return and line feed at the
end of the first line are deleted, the text in the
buffer after this command would be:
ABCDEFGNOPQRSTUVWXYZ) ~ ,
1234567890) ~

~ 2KlOD

axJ)

:: OlK G)G)

*
:: l2K axJ)

This would leave the buffer containing only
ABCDEFG) ~ •
.
This is the command string that is required to
kill (delete) the entire first line.
This kills the last two lines.

*
Kill the entire buffer.

*
2.5

INSERTION COMMAND

The only insertion command is the I command.' The ASCII text that is to be inserted into the
buffer is typed immediately after the letter I. ,The text to be i!,serted is terminated by an
altmode.

Any ASCII character except null, altmode, and rubout may be included 'in the text to be
inserted. Specifically, spaces, tabs, carriage returns, form feeds, Iine feeds, and control

~80

characters are all allowed. If a carriage return is typed in an insertion, it is automatically
followed by a I ine feed.

The text to be inserted is placed in the buffer at the position of the buffer pointer, i.e., between
the characters. At the conclusion of the insertion command

the buffer pointer is positioned

at the end of the insertion.

Any number of lines may be inserted with a single I command. For the user's protection, however, no more than 10 to 20 I ines should be inserted with each I command.

Examples:
If the buffer contains ABCDlF) ~ with the pointer between D and E, the command

.: IXYZ G)G)

produces' ABCD XYZj- F ) ~

*
produces

ABCD) ~

!F)~

*
*I~

produces

G)(j)

ABCD +
EF) +

*
produces

AABCD~f) ~

.: I( FORM)

(00)
*

* JILINE ONE)
LINE TWO)
LINE THREE)

This command is used to separate the page in
the buffer into two pages. Both pages, however,
remain in the buffer. They are not actually
separated until output.

This example shows insertion of several lines of
text at the beg inn ing of the Duffer.

(00)
*

8-81

This is the command string used to.delete the
tail of a line without removing the carriage
return-I ine feed at the end of the line. If the
buffer contains

This command will produce

2.6

OUTPUT COMMANDS

The command P causes ( 1) the entire contents of the editing buffer to be output to the output
file and ( 2 ) an impl icit Y command to be performed which reads in the ne~t page of the input
file. This command is used after editing of a given page is complete and the user is ready to
move on to the next page.

The P command may be used with a posit~ve numeric argument to skim over several pages.
Specifically, the nP command causes the n consecutive pages of the input file, starting with
the page in the ed iting buffer;, to be output, and then the n+lst

page to be yanked in.

The PW command merely outputs the page currently in the editing buffer. It does not clear the
buffer, it does not read in any more text, and it does not move the buffer pointer. This
command is used when creating a new file.

It is also used to output the last page of a file.

I f the buffer is empty, the PW and P commands have no effect.
The EF command must be used to close the output file after all output to it is complete. EF is
normally used after the PW command which outputs the last page of the file.

Examples:

.: PWE F

2.7

If, for example, page 6 of a document is in the
ed iting buffer, this command causes pages 6
through 13 of the document to be output,
one after the other, and then reads in page 14.

SPECIAL EXIT COMMANDS

The EX command is used to conclude an editing job with a minimum of effort. Its use is best
shown by an example.

Suppose the user is editing a 30-page file and suppose that the last actual change to the file
is made on page 10. At this point the user gives the command
.: EX (J)(J)
.!.

In this case the action performed by TECO is equivalent to the command string 20PPWEF, with
an automatic return to the mon itor at the end. Thus, the action of TECO is ( 1) to rapid Iy
move a" the rest of the input file on to the output file, (2) close thE! output file, and
( 3) to return control to the monitor.

The EG command is even more efficient. This command performs exactly the same functions
as the EX command, but after that it causes re-execution of the last COMPILE, LOAD,
EXEOJTE, or DEBUG command attempted before TECO was called.

For example, suppose the user gives the command

.!.

COMPILE PLOT. F4)

to request compilation of a FORTRAN source program, but the compiler discovers error,S in the
code. The user would then call TECO to correct these errors:

• TECO PLOT. F4)

*
When" all the errors are edited, the user exits from TECO with the command

.: EG

GXi)

8-83

This causes'the COMPILE commarld

to be executed again on the me PLOT. F4, after TECO has

finished output of the file,

Any TECO job may be aborted by using the standard return-to-monitor command:

tC t C

(contro'l C typed twice). However, ·if this command is typed before the output file is
closed, the output file is lost.

If no input or output operations are in progress a single

is sufficient to exit from TECO to

the mOnitor. In such a case, the user may reenter TECO without destroying the job he was
previously executing. This is illustrated in the following example •

.!.

TECO

SOURCE,MAC) A TECO job is started •

.: ICOMMENTS (jX1)
The user exits to perform a few simple monitor
commands.
.

.: tc
.• DEASSIGN LPT)
• DAYTIME)

24-FEB-70

• REf)

*
2.8

10:34
The user reenters TECO. The previous buffer
is still intact,

SEARCH COMMAND S

In many cases the simplest wc,y to position the buffer pointer is by using a character string
search. A search command causes TECO to sc"an through the text ~ntil a specified 'string of
characters is

fou~,

and then to position the po inter at the end

th is string. There are two

main search commands.,

The S command is used to search for a character string within the editing buffer. The string to
b~

searched for is specified as an alphanumerical argument following the S command. This

argument must be terminated by an altmode. The character string to be searched for may contain any ASCII character except null, altmode, or rubout.

The S command may be preceded by a numerical argument n > 1. This argument is used to
search for the nth occurrence of a character string. Thus a 2S

comma~d

searches for the

second occurrence 'of the part,icular character string, skipping the first occurrence. If n)s
omitted, n =1 is assumed.

8-84

Execution of the S command begins at the position of the buffer pointer and continues t,o the end
of the buffer. If the specified character string is not found in this range, an error message is
printed and the buffer po inter is set to the beginn ing of rhe buffer.

Examples:
This causes the pointer to be positioned after the
B in the first occurrence of the string
A - tab - B past the current position of the
pointer.

*
~ J 2SN AME

ax1)

* S20)
TAG:
TAG:

OTT (j)G)

FORMA T( 1X, WORD ')

~1~WORD2~

Here the user wishes to insert "~WO RD 2"
after "WORD". He wisely types out the line
to make sure he is at the right place, before
inserting "WORD2" •

*
The other principle search command is the N command. The difference is that an S search
ends at the end of the current buffer, whereas an N search does not. An N search begins like
an S search, but if the character string is not found in the current buffer, an automatic P
command is executed. The current page is outputted, the next page read in, and the search
continued on the new page. This process continues until either the string is found or the
input file is exhausted.

8-85

'If the .N.'search does find the specified character string, the pointer is positioned at its end •
Inlle string is not found, an error message is generated. In this case the user caused himself
a fair' amount of delay. If an N search fails, the user must close the file with an. EX command,
then reopen it and try the N search ,again with a character string that can be found. The user
is strongly urged to be careful when typing search character'strings. Remember also that a
search string must be terminated with an altmode.

Example:
~ NSTRIN G - 3D (J)(J)

Her.e the user meant to search for the character
string" STRING", and to delete the last th'ree
characters of tile st ring. However, he forgot
to terminate the search string with an altmode
and this caused the unsotisfied search request
errormessoge (?35 ).

?35

* EX (J)(D
• TECO fi lena me .ext )
~ NSTRING (1)- 3D axJ)

8-86

CHAPTER 3

ERROR MESSAGES
When TEce encounters an illegal command or a command that for any other reason cannot be
executed, a numeric error message is printed on the user's Teletype. Such messages are of the
form 1nn where nn is a two-d igit decimal integer that refers to the following table of error
messages.

When an error message is generated, the command to which it refers is not executed, the
'remainder of the command string is ignored, and TECe returns to the id Ie state by typing an
asterisk and awaiting a new command string.

The novice user is especially warned that there are a great many TECe commands that have not
been described in this introductory material. Almost every letter of the alphabet and many of
the special characters have meanings as TECe commands. Hence, the user should be careful
when typing command strings. The beginner should probably stick to relatively short command
strings.

In the following table, all TECO error messages ore listed, even though som@! of them refer to
the more advanced commands not described in this manual. Error messages referring to the
advanced commands will probably be encountered by the user of this introductory material only
if he has typed an unintended command letter.

The complete set of TECO commands is fully described in the TECO section of the PDP-lO
Reference Handbook.

Since most editing can be done using only the basic commands covered

in this introductory material, most users should be able to get along without the more advanced description for some time. The novice should gain complete mastery of the basic commands before attempting to use any of the advanced commands.

8-87

· Table 3)" 1
TECO Error Messages
nn
1

Meaning

where n=O is illegal.

8-89

Appendices
Index

A Bibliography of PDP·tO Programming Documents

APRIL, 1970

To solve several customer problems, the POp-to Product Line has initiated a new documentation system. POP-tO software
information is now being printed in two handbooks and a series of notebooks. The handbooks and the notetiooks will contain
essentially the same material; the notebooks, however, will be updated more frequently with insertable pages.
Two handbooks "PDP-IO Timesharing Handbook" and PDP-lO Reference Handbook" now duplicate software manuals. These
handbooks are easy to handle and store, and to assure availability, they are printed in large quantities. Revision and reprinting of the handbooks is done every six months. Customers will receive twenty copies of each handbook with the signing of
the pur9hase order for the POP-tO and twenty more copies with the delivery of the machine.
Each customer will also receive, free of charge, two copies of the PDP-IO software note~ooks--a multiple volume set of
manuals in the BY.! by II" format. The notebooks are printed on high quality paper allowing the customer to effectively
reproduce the material. Tec;:hnical accuracy is maintained with quarterly update pages to the notebooks.
Since most PDP-IO software information is presently included in the handbook, it is no longer necessary to print separate
manuals. Therefore, except when information is not contained in the handbooks, individual manuals can no longer be ordered.
This Bookshelf serves to indicate in which handbook manuals are now located. If the manuals are not located in either handbook, the order number and price are given.
.
Available manuals and additional copies of the handbooks may be obtained from Digital Sales Offices or by sending a written
request (with check or money order) to Program Library, Digital Equipment Corporation, Maynard.
AID (Algebraic Interpretive Dialogue)
A 'hands-on' guide to the use of AID at the Teletype. AID,
a PDP-IO version of JOS81, is an on-line system which provides each user with a personal computing service utilizing
a conversational algebraic language. This manual describes
the use of the Teletype, the syntax and general rules governing the AID language, and each of the AID commands, with
appropriate examples. Contained in PDP-lO Time-sharing
Handbook.

PDP·tO Reference Handbook
This handbook is a comprehensive volume of information
for experienced programmers, systems analysts, and engineers who are interested in writing and operating assemblylanguage programs in the PDP-lO tillie-sharing environment.
Included in the handbook are four manuals (System Reference Manual, MACRO-lO Assembler, Time-Sharing Monitors, and DDT-IO), editor programs (Editor, LINED and
TECO), and utility programs (LOADER, PIP and
TENDMP). A sample LOGIN procedure, a convenient
summary of monitor commands, and a comprehensive index/ glossary make this handbook a valuable reference for
the person interested in assembly-language programming.
Order No. AIW
$5.00

Single·User Monitor System
Revision September, t969
A complete guide to the use of the Single-User Monitor,
which performs fast job-to-job sequencing, provides II 0
service for all standard devices, and is upward compatible
with the Time-Sharing systems.
Order No. DEC-IO-MKZA-D
$2.00

PDP·tO Timesharing Handbook
This is a tutorial document intended primarily for students,
scientists, engineers, and financial analysts who have no experience in programming. It contains an introduction to
timesharing and an explanation of the elementary and advanced monitor commands. Included are the three reference manuals BASIC, AID, and FORTRAN, as well as
procedural descriptions of Batch, CHAIN, LINED, and
TECO. The four demonstration programs in Book 6 enhance the tutorial aspect of the handbook.
Order No. AKW
$5.00

Batch Processor (Batch) and Job Stacker (Stack)
An indexed manual containing all information required to
prepare and run user jobs under control of the Batch Processor in either a single-user or time-sharing environment.
(Batch supervises the sequential execution of a series of jobs
with a minimum of operator attention, yet allows the operator to interrupt, skip, repeat, or prematurely terminate one
or more of the jobs in the series at any time.) Job Stacker
is used in conjunction with Batch to (I) transfer job files to
the Batch input device and stack them there for subsequent
input to Batch, (2) transfer Batch output job files from the
Batch output device to some other device, (3) list job file
directories, (4) delete job files, and (5) list directories with
selective file deletion or transfer. Contained in PDP-IO
Time-Sharing Handbook.

PDP· to System Reference Manual
An indexed programmer's handbook that describes the PDP10 processor and the basic instruction repertoire. Following
an introduction to the PDP-I0's central processor structure,
general word format, memory characteristics, and assembler
source-programming conventions, this manual presents the
specific instruction format, mnemonic and octal op codes,
functions, timing formulas, and examples of each of the
basic instructions. Several helpful appendices, including
mnemonic op code tables, al~orithms and timing charts,
complete the manual. Contamed in PDP-IO Reference
Handbook.

System User's Guide
Revision August, 1969
A fact-filled operations guide designed for handy reference
at the user's Teletype. Contains the basics of Teletype usage
and complete operating procedures for all Commonly Used
Systems Programs (CUSPs). Includes complete write-ups on
DECtape Editor, BASIC, LINED, and Linking Loader. A
typical chapter includes a brief descriptioo of the program,
its operating environment, initialization procedures, command string formats, special switches, diagnostic messages,
and indepth examples. The' manual is tab-indexed for the
user's convenience.
Order No. DEC-lO-NGCC-D
$10.00

Time-Sharing Monitors:
A complete guide to the use of the PDP-lO's two powerful,
real-time, mUltiprogramming, time-sharing Monitors. All
Monitors schedule multiple-user time sharing of the system,
allocate facilities to programs, accept input from and direct
output to all system 1/ 0 devices, and relocate and protect
user programs in storage. This manual details user ip.teraction with the Monitors, from botIi a programming and operating viewpoint, and contains several quick-reference tables
of commonly used Monitor commands and parameters, as
well as examples of user coding. Contained in PDP-lO
Reference Handbook.

1JOSS is a trademark and service mark of the RAND Corporation for its computer program and services using that
program.

A-l

PIP (Peripheral Interchange Program)
Explains how PIP is used 'to transfer data files between
standard peripheral devices. Shows .llow command strings
are written, describes switches available for optional functions, techniques for handling file directories, error messages
and other features. Contained in PDP-IO Reference Handbook.

COBOL LANGUAGE
August, 1969
A reference ~ manual designed to aid the user in writing
COBOL programs for the PDP-IO. Each COBOL language
element is accorded a detailed treatment that explains and
demonstrates its use in a variety of programming contexts.
The four major divisions of a COBOL program and their
conventional formats are clearly described and. effectively
illustrated. Other subjects given extended coverage in this
manual are the COBOL library, COBOL reserved words,
and the CALL procedure. Each chapter contains numerous
examples of the efficient use of the components of a COBOL
program. Indexed.
Order No. DEC-lO-KCIA-D
$6.00
FORTRAN IV
This manual describes statements and features of FORTRAN IV on the PDP-IO. Includes descriptions of library·
functions, calling library subroutines from the Science
Library, and the FORTRAN IV operating System. An appendix contains language differences for those using the
small (5.5K) PDP-lO FORTRAN Compiler. Contained in
PDP-IO Time-Sharing Handbook.
Science Library and Fortran Utility Subprograms
Revision March, 1969
A general reference manual covering Science Library arithmetic function and utility subprograms and FORTRAN IV
nonmathematical utility subprograms. A functional description followed by the calling sequence, list of external sub'programs called, entry points, and subprogram length, is
given for each subprogram. In addition, the type of argument(s) and result, a description of the algorithm used, and
a discussion of the accuracy of the algorithm are given for
each function. Appendices contain information on error
analyses, double-precision format and input conversion, a
bibliography, and average run times. l
Order No. DEC-IO-SFLE-D
$4.00

MACRO-I0 Assembler
The programmer's reference manual for the PDP-IO assembly system. Explains format of statements, use of
pseUdo-operations, and coding of macro instructions which
make MACRO-IO one of the most powerful assemblers
available. Contained in PDP-IO Reference Handbook.
PDp·tO Reference Card
Revision November, 1969
. A handy pocket-sized guide to instruction mnemonics, hardware and software (Monitor system) word formats, and instruction codes.
Order No. DEC-IO-JOOB-D
$0.25
DDT·I0 (Dynamic Debugging Technique)
This reference manual describes the dynamic debugging program used for on-line checkout and testing of MACRO-IO
and FORTRAN programs. The commands .of DDT are
grouped so that they can be used easily and effectively by
both the uninitiated user and the experienced programmer.
Included in the appendices is an informative summary of all
DDT functions. Contained in PDP-lO Reference Handbook.
The following supplementary documents are also available
from the Program Library.

TECO (Text Editor and Corrector)
,
I
. Minor Revision, August, 1969
This programmer's reference manual describes the powerful
context editor for the PDP-IO. Editing is done on a character,
line or variable character string basis. Describes more than
30 commands for inserting, deleting, appending, searching
for, and displaying text. Contained in PDP-IO Reference
Handbook.
BASIC
A valuable guide to the BASIC® commands needed for a
efficient expression of scientific, business, and educational
problems. The manual contains complete tutorial explanations of these additional features: (1) matrix computations;
(2) alphanumeric information handling; (3) program control and storage facilities; (4) program editing capabilities;
(5) formatting of Teletype output; and (6) documentation
and debugging aids. Contained in PDP-IO Time-Sharing
Handbook.

® Registered: Trustees of Dartmouth College

A-2

PDP-lO DECtape Copy
Program (COPy)

DEC-IO-RPTA-D

1.00

FORTRAN IV Software
Maintenance Memos
Linking Loader V.27

'DEC-IO-KFIA-D
DEC-IO-LLZA-D

1.00
1.00

FORTRAN IV Utility Subprograms (RELEAS,
MAGDEN, BUFFER,
IFILE, and OFILE)

DEC-lO-FIYB-D

1.00

S680I-DC68A Data Line
Scanner for PDP-IO

DEC-IO-FWVA-D

1.00

Program Logic Manual
for the PDP-IO
Time-Sharing
Monitors

DEC-IO-MRZA-D-(L)

4.00

APPENDIX B

PDP-l0 SOFTWARE

Table B-1 lists PDP-l0 system programs and the documentation pertaining to them. For a
description of each of the documents, refer to the Bookshelf in Appendix A of this handbook.

Table B-1
PO P-l 0 Software
Software

Documentation

Document Order No.

PDP-l0 Timesharing Handbook (Book 4)

AKW

PDP-l0 Software Notebook

DEC-l0-SYZA-D

System User's Guide

DEC-l0-NGCC-D

PDP-l0 Timesharing Handbook (Book 3)

AKW

PDP-l0 Software Notebook

o EC-lO-SVZA-D

PDP-l0 Timesharing Hardbook (Book 8)

AKW

PDP-l0 Software Notebook

DEC-lo-SYZA-D

PDP-l0 Referenc.e Handbook (Book 6)

AIW

PDP-l0 Software Notebook

DEC-l0-SYZA-D

System User's Guide

DEC-l0-NGCC-D

PDP-l0 Timesharing Handbook (Book 8)

AKW

PDP-l0 Software Notebook

DEC-IO-SYZA-D

CHKPNT

Pf)~-10 Software No.tebook
(System Manager's Guide)

DEC-lO-SYZA-O

COBOL

COBOL language

DEC-l0-KC lA-D

PDP-l0 Software Notebook

DEC-IO-SYZA-D

AID

BASIC

Batch

BINCOM

CHAIN

B-1

..
Table 8-1 (Cont.)
,

SoftwQr~:'

'.
,PDP-I0 Reference Handbook (Book 2)

COMPIL

AIW

PO'P-lO Software Notebook

DEC-I0-SYZA-D

PDP-lO DECtape Copy Program '(COPY)

DEC-I O-RPT A-D

PDP-lO Software Notebook

DEC-I0-SYZA-D

PDP-I0 Reference Handbook (Book 5)

AIW

PDP-lO Software Notebook

DEC-I0-SYZA-D

PDP-I0 Reference Handbook. (Book 5)

AIW

PDP-I0 Software Notebook

DEC-I O-SYZA-D

System User·s Guide

DEC-I0-NGCC-D

PDP-I0 Timesharing Handbook (Book 8)

AKW

PDP-lO Software Notebook

DEC-I0-SYZA-D

DSKLST

PDP-I0 Software Notebook
(S'ystem Manager·s Guide)

DEC-I0-SYZA-D

EDITOR

PDP-I0 Reference Handbook (Book 4)

COpy

CREF

DDT

DRIVER

.' AIW

PDP-I0 Software Notebook

DEC-I0-SYZA-D

~----------T-----------------------~------T-----------~----~

FAILSAFE

PDP-lO Software Notebook
(System Manager·s Guide)

DEC-I0-SYZA-D

FILDDT

PDP-I0 Software Notebook
(System Manager·s Guide)

DEC-I0-SYZA-D

FORTRAN

PDP-lO Timesharing Handbook (Book 5)

AKW

PDP-I0 Software Notebook

. DEC-I0-SYZA-D

System Userrs Guide'
",;,'}t

DEC-I0-NGCC-f)
"

.•• i

1",-

,,',

FUDGE2

PDP-lO Reference Handbook (,Bbok :6)
PDP-I0 Software Notebook

B-2

,'"

'.'

. AIW':
DEC-I0-SYZA-D

Table 8-1 (Cont.)
Software
GL08

LINED

LOADER

LOGOUT

Documentation

Document Order No.

PDP-l0 Reference Handbook (Book 6)

AIW

PDP-lO Software Notebook

DEC-l0-SYZA-D

PDP-l0 Reference Handbook (Book 4)

AIW

PDP-l0 Timesharing Handbook (Book 8)

PDP-l0 Software Notebook

DEC-l0-SYZA-D

PDP-lO Reference Handbook (Book 3 )

AIW

PDP-l0 Software Notebook

oEC-l0-SYZA-D

PDP-lO Reference Handbook (Book 3)

AIW

PDP-l0 Software Notebook
(System Manager's Guide)

DEC-l0-SYZA-D

PDP-lO Reference Handbook (Book 3)

AIW

PDP-l0 Software Notebook
{System Manager's Guide)

DEC-lO-SYZA-D

.
MACRO

PDP- to Reference Handbook (Book 2)

AIW

PDP-lO Software Notebook

DEC-lO-SYZA-D

System User's Guide

DEC- JO-NGCC-D

.
MONEY

PO P-lO Software Notebook
(System Manager's Guide)

DEC-lO-SYZA-D

MONGEN

PDP- JO Software Notebook
(System Manager!s Guide)

DEC- JO-SYZA-D

MONITOR

PDP-lO Reference Handbook (Book 3)

AIW

PDP-lO Software Notebook

DEC-lO-SYZA-D

PO P-l 0 Reference Handbook (Book 3)

AIW

PDP-lO Software Notebook

DEC-lO-SYZA-D

PIP

8-3

Table 8-1 (Cont.)
Software

Document Order No.

Documentation

PIP1

PDP-10 Reference Handbook (Book 3)

AIW

PDP-10 Software Notebook

DEC-10-SYZA-D

PRINT
<

PRINTR

DEC-10-SYZA-D

PDP-10 Software Notebook
($ystem Manager's Guide)

DEC-10-SYZA-D
,

REACT

PDP-IO Software Notebook
(System Manager's Guide)

DEC-10-SYZA-D

SRCCOM

PDP- 10 Reference Handbook (Book 6)

AIW

PDP-10 Software Notebook

DEC-lO-SYZA-D

System User's Gu ide

DEC-10-NGCC-D

STACk

PDP-10 Software Notebook

SYSTAT

PDP-10 Reference Handbook (Book 3)

AIW

PDP-10 Software Notebook

DEC-1 O-SYZA-D

PDP-10 Reference Handbook (Book 4)

AIW

PD,P-10 Timesharing Handbook (Book 8)

System User's Guide

DEC-10-NGCC-D

PDP-10 Software Notebook

DEC-l0-SYZA-D

PDP-10
Reference Handbook (Book 6)
,

AIW

PDP-lO Software Notebook

DEC-10-SYZA-D

TECO

PD P-1 0 Software Notebook
(System Manager's Guide)

TENDMP

DEC-l0-SYZA-D

''''

8-4

INDEX
Page numbers refer to the book and the page number
~ithin the book; i.e., 3-42 is the 42nd page of Book 3.

A command, TECO, 8-75
A format, 5-44
ABS function, 3-14, 3-73
Absolute value, 3-14, 3-73, 4-10, 4-23
ACCEPT stat~ment, 5-58, 5-77
Access time, 1-10
Access to BASI C, 3-29, 3-32
Accumulator conventions, 5-111
Accuracy of AID, 4-11
Addition, 4-10, 4-23
Adjustable dimensions, 5-63
Allocating system resources
ASSIGN monitor command, 7-4
CORE monitor command, 7-8
DEASSIGN monitor command, 7-6
FINISH monitor command, 7-7
REASSIGN monitor command, 7-7
Alphanumeric fields, 5-44
AlPHI. routine, 5-84
AlPHO. routine, 5-84
AlTMODE key, 2-20
Argument, FORTRAN, definition, 5-24
Arithmetic error conditions,
FORTRAN, 5-121
Arithmetic Formulas, AID, -4-19, 4-78
Arithmetic function definition
statEm ent 5-71, 5-79
Arithmetic operations, BASIC, 3-13
Arithmetic operations on complex
numbers, FORTRAN, 5-21
Arithmetic statement, ,FORTRAN, 5-29
Array dimensioning, 5-22, 5-62
Arrays, 4-21, 5-22
ASCII character set, 5-125
ASCII mode
DECtape , 5- 128
disk, 5-128
magnetic tape, 5-131
$Assign Card, Batch control card, 8-20
PROTECT, 8-20, 8-21

ASSIGN monitor command, 7-4
ASSIGN statement, 5-32, 5-77
ASSIGN SYS monitor command, 7-15
Assigned GO TO statement, 5-32, 5-77
Asterisk convention, 2-11
Asynchronous design, 1-6
ATN function, 3-14, 3-73
ATIACH monitor command, 7-8, 7-16
Augmented matrix, 6-11

Background job, 7-8
BACKSPACE statement, 5-39, 5-59,
5-77
Batch
diagnostic messages, 8-28
equipment requirements, 8-11
examples, 8-33, 8-39
introduction, 8-7
processing under PDP-I0 monitors, 8-7
processor, 8-7
Batch control cards
'Tape, 8-21
$*Cald, 8-27
$**Card, 8-28
$ ASSIGN Card, 8-20
$ BIN, e-24
$ CBl, 8-il
$ CREF, 8-23
$DUMP, 8-27
$ EOF, 8-26
$ EOJ, 8-26
$EXCDR, 8-23
$ F4, 8-21
$ GET, 8-25
$JOB, 8-16
KEY, 8-18
$LDR, 8-23
$MAC, 8-21

Index-l

(".: A-" ',' ';
Clock, 1-5
Closed subroutines, 5-71.
.
COBOL compilation,' 8-21.
Coding form, FORTRAN, 5-16, ':'
Command
"
",
direct, definition,' 4-10
indirect, definition, 4-10
Command summary, AID, 4-80
Comment line, FORTRAN; 5-16
COMMON area, CHAIN, 8-47
Common block, FORTRAN, 5-64
COMMON statement, 5-64, 5-66, 5-78
Common storage, FORTRAN, 5-64
COMPILE monitor c~mmand, 2-13
Complex constants, FORTRAN, 5-20
Complex fields, 5-46
Complex subexpression, 5-25
COMPLEX, type declaration
statement, 5-68, 5-78
Compound expressions, FORTRAN
logical, 5-28
numeric, 5-24
Compute bound, 1-6
Computed GO TO statement, 5-31, 5-77
Conditional expressions, 4-32, 4-78
Conditional GO TO statement
see IF-THEN
Constants, FORTRAN
complex, 5-20
double precision, 5-20
integer, 5-19
literal, 5-21
logical, 5-21
octal, 5-20
real, 5-19
Context switching, 1-5
CONTINUE monitor command, 3;'32,
4-10, 7-13
CONTINUE statement, 5-36, 5-77
Control commands, BASIC, 3 -65
Control statements, FORTRAN, 5-31, 5-77
CALL, 5-75
CONTfNUE, 5-36
DO, 5-34
END, 5-37
GO TO, 5-31
IF, 5-32
PAUSE, 5-36
RETU RN , 5-75
STOP, 5-37
CONTROL-C, 2-18, 3-31, 3-:66., .4-9
CONTROL-F, 2-20, 4-11, 4-12 .
Core image ~ 2-3, 2-13'
,
CORE monitor command, 7-8

$ PAUSE, 8 - 2 i ' - '
$ RUN, 8-2S
$ SAVE, 8-24
$ SSAVE, 8-24
$ START, 8-26
Batch processing, 1-3
$ BIN Card, Batch control card, 8-24
Binary ,mode
DECtape, 5- 128
disk, 5-128
magnetic tape, 5-131
BINWR. routine, 5-85
Blank common, 5-64
Blank fields, 5-49
Blank records, 5-47
BLOCK DATA statement, 5-68, 5-76
BLOCK DATA subprogram, 5-76
Block identifier, 5-64
Block name, 5-64
Block of words, 1-10
Boolean expressions, 4-11,4-20,4-31
Brackets, AID, 4-10, 4-23
BTEMP, 8-11, 8-12, 8-19
Buffer pointer positioning, TECO, ,8-76
'Buffer sizes of peripheral devices, 5-127
BU FFE R subroutine, 5-90

C TECO command" 8-77
CALL statement, 5-75, 5-77
CANCEL command, 4-37; 4-80
$*Card, Batch control card, 8-27
$**Card, Batch control card, 8-28
Card notation, Batch,
# , 8-16
braces, 8-16
lower case letters, 8- 16
parameters, 8- 16
parentheses, 8- 16
Cards acceptable as Batch input
card description, 8-16
card notation, 8-16
Carriage control, FORTRAN, 5-45, 5-48
$ CBL Card, Batch control card, 8-21.
CCONT monitor command, 7-15
CHAIN calling sequence, 8-50
Chain files, 5-90, 8-47
CHAIN job implementation, 8-47
CHAIN program description, 8-54
CHAIN programming considerations, 8-53
CHAIN subroutine, 5-90, 8-47
CHAN G,E instruct jon , 3-61, 3-63
Character set, AID, 4-85
Character set, ASOI, 5-125
Character set, FORTRAN, 5-17

Index-2

''1';

Correcting typing errors
AID, 4-13
BASI C, 3-30,,3-31, 3-34
Monitor, 2-19
'TECO, 8-73
Cremer's method, 6-13
CREATE monitor command, 2-7, 8-59
Creating files
CREATE monitor command, 2-7
MAKE monitor command, 2':'9
Creation of CHAIN files, 8-50
$CREF card, Batch control card, 8-23
cross reference assembly listing, 8-23
CREF monitor command, 7-10
Cross-reference listing, 7-10, 8-23
COS function, 3-14,3-73
C?sine, 3-14, 3-73
COT function, 3-14, 3-73
Cotangent, 3-14, 3-73
CSTART monitor command, 7-15
CTEST mon itor command, 7-16

o format, 5-40, 5-44
o LINED command, 8-61
o monitor command, 7-15
o TECO command, 8-79
Data block, 3-16, 3-61
Data file capability, BASIC, 3-67, 3-73
Data line multiplexor, 1-8
Data line scanner, 1-8
Data record, 5-53Data set, 1-8
DATA statement, BASIC, 3-11,3-12,3-13,
3-16, 3-71
DATA statement, FORTRAN, 5-66, 5-78
Data specification statements, 5-61
DATA, 5-66, 5-78
BLOCK DATA, 5-68, 5-76
Data specification subprogram, 5-68
Data transm iss ion statements, 5-39, 5-77
ACCEPT, 5-58
o ECOD E, 5-59
EN COD E, 5 -59
PRINT, 5-53
PUNCH, 5-54
READ, 5-56
REREAD, 5-57
TYPE, 5-54
WRITE, 5-54
DATA; UUO, 5-85
DATE subroutine, 5-90
DAYTIME monitor command, 2-16
DDT monitor command, 7-14

Index-3

DDT submode, 8..25
DEASSIGN monitor command, 7-6
DEBUG monitor command, 2-14
Debugging programs
DEBUG monitor command, 2-14
in Basic, 3-34
DECODE statement, 5-59, 5-77
DECtape usage, 5-128
DEC. UUO, 5-86
Oedicated system, 1-4
DEF function, 3-40, 3-74
Defensive software, 1-12
DEFINE ALE statement, 5-55
Defined function, 3-41, 3-74
Defined locations, 5-111
DELETE, AID command, 4-39, 4-80
DELETE, BASIC command, 3-65
D ELET E, monitor command, 2-12
Deletion commands, TECO, 8-79
DEMAN 0 command, 4-18, 4-41, 4-80
Demonstration programs
curve-fitting, 6-8
random-number generator, 6-36
remaindering, 6-26
sum of squares, 6-4
DET function, 3-55, 3-74
DETACH,monitor command, 7-8, 7-15
Device assignments, 5-128
Device control statements, 5-58, 5-77
BACK SPACE, 5-59
END FILE, 5-59
REWIND, 5-59
SKIP RECORD, 5-59
UNLOAD, 5-59
Device table, FORTRAN, 5-129
DEVTB., , 5-129
Diagnostic messages
AID, 4-87
BASIC, 3-75
BATCH, 8-28
FORTRAN, 5-116
monitor, 7-16
LINED, 8-63
TECO, 8-87
Diagnostic software, 1-1 2
DIM statement, BASIC, 3-26, 3-28,
3-52, 3-74
DIMENSION statement, FORTRAN,
5-62, 5-78
adjustable dimension, 5-63
Dimensioning, BASIC, 3-26, 3-28,
3-52, 3-54
Direct command, definition, 4-10
Direct steps, 4-15

Directory format'
, long format, 2-11
short format, 7-10
DIRECtORY, monitorcommond,2-11,7-1O
DIRT. rOutine, 5-84
.,
J
DISCARD command, 4-45, 4-80, 4-84
Disk usage, 5-128
Division, 4-10, 4-23
DO command, 4-18, 4-34, 4-46, 4-80
DO statement, 5-34, 5-77
DON E command, 4-51, 4-80
DOUBLE PRECISION, type declaration
statement, 5-68, 5-78
Double precision constants,
FORTRAN, 5-20
Double word, FORTRAN, 5-25, 5-27
DOUBT. routine, 5-84
Driver
equipment requirements, 8-30
general description, 8-29
implementation, 8-30
use of, 8-30
Dual memory protection and
relocation, 1-8
Dummy arguments, AID, 4-20
Dummy arguments, FORTRAN, 5-72, 5-73
Dummy identifiers, 5-71, 5-72
DUMP, 8-27, 8-29, 8-31
DUMP subroutine, 5-91
$ DUMP card, Batch control card, 8-27

E format, 5-40, 5-44
E, LIN ED command, 8-61
E( monitor command, 7-15
Edit commands, BASIC, 3-65
EDIT, monitor comman<;l, 4-9, 8-59
Ed iting files
EDIT monitor command, 2-9
TECO monitor command, 2-10
EF, TECO command, 8-82
EG, TECO command, 8-83
ENC. UUO~ 5-86
ENCODEstatement, 5-59
END OF FILE statement, 5-59
END statement, BASIC, 3-11, 3-19, 3-72
END I statement, FORTRAN, '5-37
Entering a BASIC program, 3-30, 3-32
$EOF card, Batch c.ontrol card, 8-26
EOF1 subroutine, 5-91
EOFC subroutine, 5-91
$ EOJ card, Batch control card, 8-26
Equipment requirement$ fpr BATCH, 8-11
EQUIVALENCE statement, 5-65, 5-66

Errors, BASIC .
grammaticq,l, 3-34.
logical, 3:"34
fRRSET subroutine, 5",:,91
EX, IECO commqnd, 8-83
Examples, BATCH, . 8-33, 8-'39
Examples, LIN ED., 8-61
EXECUTE, monitor command, 2-14
Executing a BASIC program, 3-31, 3-33,
3-35
Executing programs
EXECUTE monitor commqnd, 2-14
Executive mode, 1-9
Executive program, 1-5
Exit commands, TECO, 8-83,
EXIT subroutine, 5-91 '
$EXLDR card, Batch control card, 8-23
map', 8-23
EXP function, 3-14, 3-73
Exponentiotion, 4-10,4-23
Expression, definition, 4-10, 4-78
Expressions, FORTRAN
logical, 5-26
numeric, 5-24
EXTERNAL statement, 5-76
External storage, defi,nition, 4-78
External subprograms, 5-71
c

F format, 5-40-5-44
$F4 card, Batch control card, 8-21
Field delimiters, 5-43
Field specifications, 5-40
Field width~ 5-40,-5-44
FILE command, AID, 4-53, 4-81, 4-84
File, definition, 4-78
File protection, 1-11Filename extension, 2-6
Filenames, 2-6
Files, 2-6
FI LES command, Basic, 3-67, 3-73
Filing system, 1-10
FIN. UUO, 5-85
FINISH, monitor command, 7-7
FLIRT. routine, 5-84
flOUT. routine, 5-84
FN EN 0 statement, 3-40
FOR statement, Basic, 3-22, 3-23, 3-71
FORM command, 4-54, 4-81
Form, definition, 4-78
FORMAT statement, 5-39
alphanumeric fields, 5-44
blank fields,' 5-49
.
complex fields, 5-46'
logical fields, 5-43

Index-4
~--. i

mixed fields, 5-45
multiple records, 5-46
numeric fields, 5-40
variable field width, 5-43
Formats stored as data, 5-47
Formula, 4-19, 4-78
FORSE. , 5-83
FORMA T processing, 5-83
I/O device control, 5-84
UUO dispatching, 5-84
FORTRAN compilation, 8-21
FORTRAN compiler diagnostics
command errors, 5-116
compilation errors, 5-117
FORTRAN compiler switches, 5-115
FORTRAN library functions, 5-86
FORTRAN library subprograms, 5-71,
5-86, 5-90
FORTRAN library subroutines, 5-90
FORTRAN operating system, 5-83
FORSE. , 5-83
I/O conversion routines, 5-84
FORTRAN UU01s, 5-85
FORTRAN program and MACRO subprogram
linkage, example of, 5-97
FORTRAN UU01s, 5-85
Function, definition, 5-24
Function identifier, 5-24, 5-72
FUNCTION statement, 5-72
FUNCTION subprogr(lms, 5-72
FUNCTION statement, 5-72
Function subprogram linkage,
example of, 5-96
Function type, 5-24, 5-73
Function value, 5-24
Functions, AID
argument, 4-26
cosine, 4-26
digit part, 4-26
exponent part 4-28.
exponential, 4-26
first, 4-26, 4-34
fraction part, 4-26
integer part, 4-26
logarithm, natural, 4-27
maximum, 4-27, 4-34
minimum, 4-27, 4-34
product, 4-27, 4-34
signum, 4-27
sine, 4-27
square root, 4-27
sum, 4-27, 4-34
truth value, 4-28, 4-32
Functions, Bcisic, 3-14, 3-27, 3-54,
3-55, 3-73

G format, 5-40-5-44

$ GET card, Batch control card, 8-25
GET monitor command, 7-12
Getting information from the mOnitor
DAYTIME monitor command, 2-16
PJOB monitor command, 2-16
RESOURCES monitor command, 7-13
SYSTAT monitor command, 7-13
TIME monrtor command, 2-16
Getting on the system, 2-4
Glossary of AID terms, 4-78
GO command, 4-57, 4-81
GO TO statement, Basic, 3-11, 3-18,
3-71
GO TO statement, FORTRAN
assigned, 5-32, 5-77
computed, 5-31, 5-77
uncond itional, 5-31, 5-77
GOSUB statement, 3-41, 3-72

H-conversion, 5-45
HALT monitor command, 1-10
Hierarchy
of logical operators, 5-28
of numeric operators, 5-26, 5-28
of relational operators, 5-28
Hilbert matrix, 3-56

I format, 5-40-5-44
I LIN ED command, 8-60
I TECO command , 8-80
IBUFF call, 5-90
Identifiers, 4-10, 4-17, 4-78
indexed, 4-21
Identity matrix, 3-52, 3-72
IF clause, 4-59, 4-81
IF END statement, Basic', 3-70, 3-73
I F statement, FO RTRAN
logical, 5-33, 5-77
numerical, 5-33, 5-77
IF - THEN statement, Basic, 3-10,'
3-18, 3-71 '
I FI LE subroutine, 5-91
III subrout ine, 5-02
Immediate storage, definition, 4-78
IMPLICIT statement, 5-68, 5-78
Impure code,rr=7
IN. UUO, 5-85
Indexed identifiers, 4-21
Indirect command, definition, 4,-10
Ind irect steps, 4-15

Index-5

'~~NF.~lJUOi,-5"'!85\!.

m ';',.

~(.I '''l'

LET command, AID, 4-19, 4.;,.6()i-'I~:;~Hr
LET command; ,-Basic:,"'3.-10,- 3.. -16, '3-71
L1B40, 5...i.S3' ," i--":'~'-~
')';"::
LINE ~ommand,' ;4-~}·-'4-<'82 ~;.,',::
Line continuation fie Id, 5-15"'~ ·,i·' ,
Line format, 5- 15
' '. '
Line numbers, Basic, 3-10, 3-12~ 3~31
Line spacing, 5-48
LINED
a uxi Iiary commands, 8-62
command level, 8-60
commands, 8-59
conventions and restrictions, 8-62
error, 8-63
examples, 8-61, 6-62
implementation, 8-64
monitor commands, 8-59
text mode, 8-60
LINT. routine, 5-84
LI ST, Basic command, 3-65
LIST, monitor command, 7-9
Lists, Basic, 3-25
Literal constants, FORTRAN, 5-21
LOAD, monitor command, 2-14
Loading CHAIN, 8-49
Load ing programs
DEBUG, monitor command, 2-14
EXECUTE, monitor command, 2-14
LOAD, monitor command, 2-14
Locations
defined, 5-111
required, 5-111
LOG, Basic function, 3-14, 3-73
LOGICAL, type declaration statement, 5-68, 5-79
Logical constants, 5-21 .
Logical device names, 7~3
Logical expressions; 5-26
Logical fields, 5-43
Logical I F statement, 5-33, 5-77
Logical operators, 5-27, 5-28
LOGIN, monitor command, 2-4
Login procedure, 2-4
Loops, 3-21
nested, 3-23
LOUT. routine, 5-84

,1/,

Input commands, TECO ,-_ 8-75 - Input file, TEeO ,_ ::·8-69", IN PUT stat~nt ,~.8I!rsi'C-r 3.,.48" 3...72 --~
data file, 3-69, 3""73
Input/output control, 1-9
Input/oufput processor, 1-6
Insertion command, TECO, 8-80
Instruction set, PDP-lO, 5-132
INT function, 3-37, 3-73
Integer constants, 5-19
Integer function, 3-37, 3-73
INTEGER, type declaration statement, 5-68, 5-79
Intelligent terminal, 1-14
Interaction, 1-3
Internal subprograms, 5-71
Interrupting execution of a
Basic program, 3-31, 3-35
INTI. routine, 5-84
INTO. routine, 5-84
I/O bound, 1-6
I/O conversion routines, 5-84
I/O list, 5-52
I/O records, 5-53
Item-list, definition, 4-78
Iterative clauses, 4-34

J TECO command, 8-76
$ JOB card ,Batch control card, 8-16
DUMP, 8-18
NOGO, 8-18

K TE CO command, 8-79
KEY card, Batch contro I card, 8-18
KJ 0 B mon itor command, 4- 17, 4- 10

L format, 5-43
L TECO command, 8-77
Latency optimization, 1-10
$ LOR cQl'C\, Batch control card, 8-23
LIB, 8-23
Loader,
8-23
Least squares, 6-9
Leaving the monitor
KJOB monito~ command, 2-17,
3-32, 3-33
LEGAL subrQutine" 5-92,
LENGTH command, 3-65

$ MAC card, 8-21
MACRO main programs, 5-103
MACRO subprograms, 5-95
example, 6-26 .
MAGDEN subroutine,- 5-92
Magneti c tape usage, 5- 130

Index-6

Natural logarithm functions, 3-14, 3-73
. n-dimensional arrays, simulation of, 3-57
NEW Basic command, 3-29, 3-65
.
NEXT Basic command, 3-22, 3-23, 3-71
NLI. UUO, 5-85
NLO. UUO, 5-86
NMLST. routine, 5-85
Nonexecutable statements
" FORMA T statement, 5-39
NAME LI ST statement, 5-49
Normal exit of a DO stat~ment, 5-34
NUM Basic function, 3-54, 3-74
Numbers, Basic, 3-15
Numeric expressions, 5-24
Numeric fields, 5-40
repetition of, 5-46
repetition of groups, 5-46
Numeric IF statement, 5-33, 5-77
Numeric operations, 5-26
Nu"meric operators, 5-24

Magnitude
of double precision constants, 5-20
of integer constants, 5-19
of real constants, 5-19
Main memory, 1-5
MAKE,monitor command, 2-7, 8-70
Manipulating core images
GET , monitor command, 7-12
R, monitor command, 7-12
RUN, monitor command, 7-11
SAVE, monitor command, 7-11'
Manipulating files
DELETE, monitor command, 2-12
DIRECTORY, monitor command, 2-11
RENAME, mon itor corrimand, 2-12
TYPE, monitor command,· 2-11
Manipulating Teletype assignment
ATIACH, monitor command, 7-8
DETACH, monitor command, 7-8
TALK, monitor command, 7-8
Master File Directory, 1-10
Mathematical operators,
absolute value, 4-10, 4-23
addition, 4-10, 4-23
brackets, 4-10, 4-23
division, 4-10, 4-23
exponentiation, 4-10, 4-23
multiplication, 4-10, 4-23
parentheses, 4-10, 4-23
subtraction, 4-10, 4-23
Matrices, 3-51
Memory blocks, 1-6
Memory protection and relocation,
Batch, 8-9
Memory protection register, 1-5
MFD,I-10
Mixed fields, 5-45
Modem, 1-8
Modularity, 1-12
Monitor, 1-5
Monitor calls, 1-) 0
Monitor mode, 1-9
Monitor overhead, 1-7
MTOP. UUO, 5-85
Multiple record formats, 5-46
termination of, 5-47
Multiplication, 4-10, 4-23
Multiprocessor configurations, 1-14
"Multiprogramming, 1-5

o format,

5-40-5-44

OBUFF call, 5-90
Octal constants, 5-20
OCTI. routine, 5-85
OCTO. routine, 5-85
OFILE subroutine, 5-92
OLD Basic command, 3-29, 3-65
ON-GO TO, Basic, 3-19, 3-72
On-I ine, 1-9
Open subroutines, 5-71
Operating system, 1-5
Operating system diagnostics,
FORTRAN, 5-120
Operators
logical, 5-27
numeric, 5-24
priorities of, .5-28
re laHonal, 5-27
Order of precedence, 4-10, 4-23
our . UUO, 5-85·
OUTF. UUO, 5-85
Output commands, TECO, 8-82
Output file, TECO, 8-69
Overlapped 1/0,1-10
Overlay, 1-8

P LINED command, 8-61
P n:::o command, 8-82
PAGE command, 4-63, 4-82
Page, TECO, 8-69
Parentheses, 4-10, 4-23

N, TECO command, 8-85
NAMELI ST statement, 5-39, 5-49, 5-79
input data, 5-50
output data, 5-51
Index-7

,.:"

APb'&7("J4.ii'l5;j,~7&~ ,'>t:P

•. J,

j '~f' '(,,>1'1<, ,,2
$ PAUSE 'card~ Batch ,cantroJ card, ,,8-27
PAUSE statement, ,F0RT-AAN.; _5..36, :5..77
PDUMP subroutine, 5:-92,« ',' , <
Peripheral deviees, ;,,7..3 '
Perman'ent device assignment
ASSIGN monitor command, 7-4
Permanent resident area (CHAIN), 8-47
Physical device names, 7-3
PJOB mon itor command, 2-16 ,
Precision
of double-precision constants, 5-20
of real constants, 5-19
PRIN T statement, Basic, 3- 11, 3-17,
3-45, 3-71
PRINT statement, FORTRAN, 5-53, 5-77
Printable characters, 3-62
Priorities of operators, 5-28
Priority interrupt system, 1-5
Private device, 1-10
Program names, 3-30
Programmed operators, 1-10
Programming phases, 2-3
Propositions, 4-20, 4-31
PseudQ-Teletype (PTY), 8-9
Public device, 1-10
PUNCH statement, 5-54, 5-78
Pure code, 1-7
PW,
command, 8-~2

RECALL ;Gbmmaitd, 4-65; 4-82,,'4..~.
Record, it -.\'0 '
REENTER;' ,monitor comman.d, 4,..10"',7-15
Re-entrarit software,! l":(,,,., "> ; <; ,
, Relational opefators,7-27
",
Relational symbols, 3-15'
RHEAS subroutine, 5-92
Reliability, 1-3.1.. '
Relocatable b'inary program, 2-3, 2-13
REM statement, 3-49, 3-72
Remembered arguments, 2-10
Removable resident area (CHAIN), 8-48
Removable storage device, 1::-11
RENAME, Basic command; 3-65
RENAME, monitor command, 2-12
Repetition
of field specifications, 5-46
of groups, 5-46
REPLACE command, 3-65
Replacement operator, 5-29
Requesting line printer output
CREF, monitor command, 7-10
DIRECTORY, monitor command, 7-10
LIST, monitor command, 7-?
Required locations, 5-111
REREAD statement, 5-57, 5-78
RERED. UUO, 5-85
RESEOUENCE command, 3-66
RESET TIMER command, 4-66, 4-82
RESET. UUO, 5-85
RESOURCES, monitor command, 7-13
RESTORE command, 3-49, 3-61, 3-72
data file, 3-69, 3-73
RETURN key, 2-19
RETURN statement, Basic, 3-41, 3-72
RETURN statement, FORTRAN, 5-75,5-77
REWIND statement, 5-59, 5-78
RND function, 3-38, 3-72
Round robin operation, H
RTB. UUO, 5-85
RUBOUT key, 2-19, 3-30, 3-35
Rules of form, AID, 4-11
RUN, Basic command, 3-13, 3-31, 3-65
$ RUN card, Batch control card, 8-25
RUN, mon itor command; 7-11
RUNNH command, 3-31, 3-65

nco

Queue, 1-6
QUIT command, 4-64, 4-82

R command, TECO, 8-77
R monitor command, 7-12
RAID, 4-9
R LIN ED, 8-62
Random access of records
READ, 5-57, 5-78
WRITE, 5-55, 5-78
Random number generator, example, 6-36
Randon numbers, 3-38, 3-73
RANDOMIZE statement, 3':'39, 3-73
Range of a DO statement', 5-34
READ statement, Basic, 3-10, 3-11,
3-16, 3-71
READ statement, FORTRAN, 5-56, 5-78
Real constants, 5-19
REAL, type declaration statement,
5-68, 5-79
REASSIGN, monitor command, 7-7

S, LINED command, 8-62,,'
S, TECO command, 8..$4
',',
$SAVE card, Batch control card, 8,..24,
SAVE, monitor command, 3-3&'i3~,7-11
SAVRAN subroutine, 5.,.92
Scalar variables, 5-22

Index-8

Subprogram linkage, exampie ,'5....96, 5-104
SUBROU·TlNE statement, 5-74
Subroutine subprograms, 5-74
CALL statement,· 5-75
RETURN statement, 5-75
SUBROUTINE Statement, 5-(4
Subroutines, 3-41
nested, 3-42
SU BSCRI PT INTEGER, type
declaration statement, 5-68, 5-79
Subscripts, 3-25, 3-28
Subtraction, 4-10, 4-23
Swapping, 1-5
Symbiont operation, 1-12
Symbolic logic, 5-26
SYS, 8-11, 8-12
SYSTAT, monitor command, 7-13
example, 7-14
SYSTEM command, 3-66
System device, 8-11, 8-12

Scale factor, 5-19, 5-20, 5-42
SCHEDULE, monitor command, 7-15'
Scheduling algorithm, 1-6
SCRATCH command, 3-66
data fi Ie; 3 -68, 3:"73
Search commands, TECO, 8-84
Secondary memory, t-S
Segment read-in area (CHAIN), 8-48
SET command, 4-17, 4-67, 4-82
SETRAN subroutine, 5-92
SON function, 3-40, 3-74
Shared system dev ice, 8-11
Sign function, 3-~, 3-74
SIN function, 3-14, 3-73
Sine, 3-14, 3-73
SIZE argument, 4-78
~KIP RECORD statement, 5-59,5-78
SLIST. UUO, 5-85
SLITE subroutine, 5-93
Slow peripherals, 1-11
Source progr'am definition, 2-3
Spacing, 5-48
Specification statements, 5-61, 5-78
data specification, 5-66
storage specification, 5-62
type declaration, 5-68
Spooling, 1-12
SOR function, 3-14, 3-73
$ SSAVE card, Batch control card, 8-24
SSAV E, monitor command, 7-15
SSWTCH subroutine, 5-93
Standard processor, 2-13
$ START card, Batch contro I card, 8-26
START, monitor command) 7-12
Starting a core image program
CONTINUE, monitor command, 7-13
HALT, monitor command, 7-13
START, monitor command, 7-12
Statement field, 5-16
Statement number field, 5-15
Statement numbers, S-15
Statements, 3-10
ST EP instruction, 3-22, 3-24
Steps, 4-15, 4-79
STOP command, AID, 4-68, 4-82
STOP command, Basic, 3-49, 3-72
STOP statement, FORTRAN, 5-37, 5-77
Storage specification statements, 5-62
COMMON, 5-64
DIMENSION, 5-62
EQUIVALENCE, 5-65
Stored formats,· 5-47
Strings, Basic, 3"'59
SubproQram calling seqlJenceS, 5-95

T format, 5-48
T, TEeO command, 8-Z8
Tab, horizontal, 3-47, 5-15
Tables, Basic, 3-25
TALK, monitor command, '7-8
#TAPE, Batch control card, 8-21
TAN function, 3-14, 3-73 '
TECO command arguments, 8-74
TECO command string syntax, 8-72
T ECO error me.ssage s, 8-87, 8-88
TECO general operating procedure, 8-69
TECO initialization, 8-70
TECO, mon itor command, 2- 10, 8-70
TECO special symbols, 8-71
TECO text type-out, 8-78
Te letype conso les, 4-12
Teletype control characters, 2-18
Teletype special keys
ALTMODE key, 2-20
RETURN key, 2-19
RUBOUT key, 2-19
Temporary device assignment, 7-4
Termination of a program, 5-37
TIME, AID command, 4-79
TIME, monitor command, 2-16
Time quantum, 1-4
Time slice, 1-4
TIME subroutine, 5-93
TIMER argument, 4-79
Timesharing, 1-4
TO command, 4-69, 4-82

Index-9

Translating programs
_
COMPILE, mon itor command, '2-13
Trappir)g" ,1... 9 ~ .:,.:.
TYPE, AID command, 4-71, 4-83·
Type de~laration statements, 5-68
TYPE,!TIonitor command, 2-11
TYPE statement, FORTRAN, 5-54, 5-78

stop, 4-68, 4-82
to, 4-69, 4-82
type', .1~,1}!jA-8fl" ,',
use, 4-75, 4-83, 4-84

WEAVE, 3-66
Wor:d format, PD P-1 0., 5-126
WRITE statement, Basic, 3-:-68, 3-73
WRITE statement , FORTRAN, 5-54" 5-78
WTB. UUO, 5-85
.

UFO, 1-10
Unconditional GO TO statement, 5-31,
5-77
Un it records, 5-40
UN LOAD statement, 5-59, 5-78
USE command, 4-75, 4-83, 4-84
User control levels, Batch
console commands, 8-13
control cards, 8-13
User-defined functions, 4-~0, 4-29
User directories, 2-11
User mode, 1-9
User's Fi Ie Directory, 1-10

X format, 5 -49

Y, TECO command I 8-75

Variable field width, 5-43
Variables, AID, 4-10, 4-17, 4-79
Variables, Basic
alphanumeric string, 3-59
numeric, 3-15
subscripted, 3-25
Variables, FORTRAN
array, 5-22
scalar, 5-22
Vectors, 3-51
Verbs, AID
cance I, 4-37, 4-80
de lete, 4-39, 4-80
demand, 4-18, 4-41, 4-80
discard, 4-45, 4-8Q, 4-84
do, 4-18, 4-34, 4-46, 4-80
done, 4-51, 4-80
file, 4-53, 4-81, 4-84
form, 4-54, 4-81
go, 4-57, 4-81
if clause, 4-59, 4-81
let, 4-19, 4:"60, 4-81
line; 4-62,4-82
page, 4063, 4-82
qu it, 4-64, 4-82
recall, 4-65, 4-82, 4-84
reset timer, 4-66, 4-82
set, 4-17,4-67, 4-82

Index-10

DIGITAL EQUIPMENT CORPORATION

WORLD-WIDE SALES AND SERVICE

MAIN OFFICE AND PLANT
146 MaIO Street, Maynard, Massachusetts, USA. 01754 • Telephone From Metropolitan Boston 646-8600' Elsewhere' (617)-897-51J1 • TWX. 710-347-{)212 Cable' DIGITAL MAYN Telex 94-8457

UNITED STATES
NORTHEAST

MID·ATLANTIC-SOUTHEAST (cont,)

CENTRAL (cont,)

REG/OhiAL OFFICE'
15 Lunda Street, W.lth.m, M.ss.chusetta 02154
Telephone' (617)-891-1006
TWX.710-324-0919

DURHAM/CHAPEL HILL
2704 Chapel Hill Boulev.rd
Durham, North Carol me 27707
Telephone (919)-489-3347
TWX 510-927-0912
HUNTSVILLE

ST. LOUIS
Suite 110,115 Progress Pky .. Maryland Heights,

WALTHAM
15 Lund. Street, Walth.m, M••••chu.etts 02154
Telephone (617)-891-6310/6315
TWX. 710-324-0919
CAMBRIDGE/BOSTON
899 Ma," Street, Cambridge, Massachu.ett.02139
TWX: 710-320-1167
Telephone: (617)-491-6130
ROCHESTER
130 Aliens Creek Road, Roche.ter, New York 14618
Telephone (716)-461-1700
TWX 710-599-3211
CONNECTICUT
1 Prestige Drive, Meriden, Connecticut 06450

Telephone: (203)-237-8441

TWX: 710-461-{)Q54

MID·ATLANTIC-SOUTHEAST
REGIONAL OFFICE:
U.S. Route I, Princeton, New Jer.ey 08540
Telephone (609)-452-9150
TWX. 510-685-2338
NEW YORK
95 Cedar Lane, Englewood, New Jersey 07631
Telephone. (201)-871-4984, (212)-584-5955, (212)-736-0447
TWX· 710-991-9721
NEW JERSEY
1259 Route 48, Parsippany, New Jersey 07054
Telephone: (201)-33S.3300
TWX: 71D-987-8319
PRINCETON
Route One and Emmons Drive,
Prmceton. Np,w Jersey 08540
Telephone: (609)-452-2940
TWX: 510-685-2337
LONG ISLAND
1919 Middle Country Road
Centere.ch, L I., New York 11720
Telephone: (516)-585-5410
TWX: 510-228-6505
PHILADELPHIA
1100 We.t Valley Roed, W.yne, Pennsylvanl. 19087
Telephone (215)-687-1405
TWX: 510-668-4461

Suite 41 -

Holiday Office Center

3322 Memorial Parkway S W , Huntsville, Ala, 35801
Telephone (205)-881-7730
TWX: 810-726-2122
ORLANDO
SUite 232, 8990 Lake Ellenor Drive, Orlando, Flo 32809
Telephone (305)-651-4450
TWX 810-856-{)180
ATLANTA
Suite 116, 1700 Commerce Drive, N.W ..
Atlanta, Georgia 30318
Telephone: (404)-351-2822
TWX: 810-751-3251
KNOXVILLE
5731 Lyons View Pike, S W , Knoxville, Tenn. 37919
Telephone. (615)-588-6571
TWX· 810-583-{)\23

CENTRAL
REGIONAL OFFICE.
1850 Frontage Road, Northbrook, illinOIS 60062
Telephone (312)-498-2580
TWX 9\0-666-0655
PITTSBURGH
400 Penn Center Boulevard,
Pittsburgh, Pennsylvania 15235
Telephone' (412)-243-6500
TWX· 710-797-3657
CHICAGO
1850 Frontage Road, Northbrook, illinois 60062
Telephone (312)-498-2500
TWX 910-686-0655
ANN ARBOR
230 Huron View Boulevard. Ann Arbor. Michigan 48103
Telephone (313)-761-1150
TWX 8\0-223-8053
INDIANAPOLIS
21 Beachway Drive - SUite G
IndianapoliS, Indiana 48224
Telephone (317)-243-8341
TWX 810-341-3436
MINNEAPOLIS
15016 Mlnnetonk. Industrial Ro.d
Minnetonka, Minnesota 55343

MISSOUri

63043

Telephone: (314)-872-7520

TWX: 910-764-0831

DAYTON
3101 Ketter,"g Blvd., Dayton, Ohio 45439
Telephone: (513)-299-7377
TWX: 810-459-1676
DALLAS

8855 North Stemmons Freeway. SUite 204
Dallas. Texas 75247

Telephone (214)-636-4860

TWX· 910-661-4000

HOUSTON
3417 Milam Street, Suite A, Houston, Texas 77002
Telephone: (713)-524-2961
TWX: 910-881-1651

WEST
REGIONAL OFFICE·
580 San Antonio Road, Palo Alto, California 84308
Telephone: (415)-328-0400
TWX: 910-373-1286
ANAHEIM
801 E. Ball Road, Anaheim, California 92805
Telephone: (714)-776-6932 or (213)-625-7669
TWX: 910-591-1188
WEST LOS ANGELES
2002 Cotner Avenue. Los Angeles. California 90025
Telephone. (213)-479-3791
TWX 910-342-6999
SAN FRANCISCO

sao San AntoniO Road. Palo Alto.

California 94306

Telephone: (415)-328-5840
TWX: .910-373-1266
ALBUQUERQUE
8303 Indian School Road, N.E,
Albuquerque, N M. 87110
Telephone: (505)-296-5411
TWX· 910-989-0614
DENVER
2305 South Colorado Blvd., Suite #5
Denver, Colorado 60222
Telephone· 303-757-3332
TWX, 910-931-2650
SEATTLE
1521 l30th N.E , Bellevue, W.shlngton 96004
Telephone (208)-454-4058
TWX 910-443-2306
SALT LAKE CITY
.
431 South 3rd East, Salt Lake City, Utah 84111
Telephone. (801)-328-9838
TWX 910-925-5834

WASHINGTON
Executive Bulldlng7100 B.ltlmore Ave., College Park, Meryland 20740
Telephone: (301)-779-1100
TWX: 710-826-9662

Telephone: (612)-935-1744
TWX: 910-576-2818
CLEVELAND
Park HIli Bldg, 35104 Euclid Ave.
Willoughby, Ohio 44094
Telephone: (216)-946-6484
TWX: 810-427-2808

CANADA

ENGLAND

ITALY

D,glt.1 Equipment of Cenada, Ltd.
CANADIAN HEADQUARTERS
150 Ros.mond Street, C.rleton Place, Ont.rlo
Telephone: (613)-257-2615
TWX: 610-581-1651

Digital Equipment Co_ Ltd,
READING
ArkWright Road, Reading, Berkshire, England
Telex. 84327
Telephone: Reading 65131
MANCHESTER

MILAN
Corso Garibaldi, 49, 20121 Milano, Italy
Telephone 872 746, 672694,872 394 Telex 33615

6 Upper Precinct. Worsley

AUSTRALIA

Manchester, England m285az
Te,lephone.06I-790-4591/2
Telex: 666666

Digital Equipment Austr.lia Ply. Ltd_
SYDNEY
75 Alexander Slreet, Crows Nest, N.S.W. 2065. Austrelia

INTERNATIONAL

OTTAWA
.
120 Holland Street, Ott.w.3, Ontario
TWX 610-582-8907
Telephone: (613)-725-2193
TORONTO
230 Lakeshore Road East, Port Credit, OntariO

Telephone: (416)-278-6111

TWX: 610-492-4306

MONTREAL
9675 Cote de Llesse Ro.d
Dorv.I, Quebec, Canada 760
Telephone 514-636-9393
TWX· 610-422-4124
EDMONTON
5531-103 Street

Bilton House. Uxbridge Road. Ealing. London W 5

Telephone. 01-579-2781

Telex 22371

FRANCE
EqUipement Digital SA R.L.
PARIS
233 Rue de Charenton, P.rls 12, Fr.nce
Telex 21339
Telephone 344-76-07

BENELUX

Edmonton. Alberta. Canada

Telephone: (403)-434-9333

LONDON

TWX. 610-831-2248

EUROPEAN HEADQUARTERS
Digital EqUipment Corporation International-Europe

81 Route De L' Alre
1227 Carouge / Geneva. Switzerland
Telephone: 42 79 50
Telex. 22 683

Digital EqUipment N.V_
(serv,"g Belgium, Luxembourg, and The Netherlands)
THE HAGUE
Konlng,"negracht 65, The Hague, Netherlands
Telex: 32533
Telephone: 835960

SWEDEN
Digital Equipment Aktlebolag
STOCKHOLM

GERMANY

Vretenvagen 2. 8-171 54 Solna. Sweden

Dlglt.' Equipment GmbH
COLOGNE
5 Koeln, Blsmarckstrasse 7, West Germany
Telephone 52 21 81.. Telex 668-2289
Telegram: Flip Chip Koeln

Telephone 08 98 13 90
Telex 17050
Cable' Digital Stockholm

MUNICH
8000 Muenchen 19. Leonrodstrasse 58

Telephone 516 30 54

Telex 524226

SWITZERLAND
Digital EqUipment Corporation S A.

GENEVA
81 Route De L'Aire
1227 Carouge / Geneva, Switzerland
Telex: 22 663
Telephone. 42 79 50

,,"

Digital EqUipment SpA

Telephone 439-2566

Telex 20740

Cable: Digital, Sydney
MELBOURNE
.J!! Park Street, South Melbourna, Victoria, 3205
-'1 elephone 69-6142
Telex 30700
WESTERN AUSTRALIA
643 Murray Street
West Perth. Western Australia 6005

Telephone 21-4993

Telex 92140

BRISBANI!
139 Merlvale Street, South Brisbane
Queensland. Australia 4101

Telephone 44047

Telex 40616

JAPAN
TOKYO
Rlkel Tredlng Co., Ltd (s.le8 only)
Kozato-Kalkan Bldg,
No, 18-14, Nlshlshlmbashl l-chome
Mlnato-Ku,Tokyo, Japan
Telephone: 5915248
Telex: 7814206
Digital Equipment Corporation International
(engineering and services)

Fukuyoshlcho Bulld,"g, No 2-6, Roppongl 2-Chome,
Mmato-Ku, Tokyo
Telex No. 0242-2850
Telephone 565-3624

•

TO THE READER OF THE PDP-lO TIMESHARING HANDBOOK
We at Digital want to improve the quality and
usefulness of our publications. However, we cannot achieve this goal by ourselves. We need your
collaboration: your corrections, your observations,

your critical evaluations. Will you please provide
us with such constructive information by filling out
this questionnaire and mailing it hack to us?

1. (a) Is the handbook a useful document? ................................... DYES
(b) If you answer is YES, tell us what features make it useful.

FOLD

D NO

2. (a) Is the text clear and readily understandable? ............................. DYES D NO
(b) If your answer is NO, cite the paragraphs, chapters, or sections that are unclear or difficult to
understand.

3. (a) Are you pleased with the organization of the handbook? ................ DYES
(b) Should the organization be changed? ................................... DYES
( c ) What changes do you suggest?

D NO
D NO

4. (a) Should the organization of individual chapters or books be changed? ...... DYES
(b) If your answer is YES, give us your suggestions.

D NO

5. (a) Should more demonstration programs be added when the handbook is revised? DYES

D NO

FOLD

(b) What kind of programs would you like to see added?

6. (a) Should more utility programs be added when the handbook is revised? .....
(b) Give us your suggestions.

YES

7. (a) Should anything be deleted from the handbook when it is revised? .........
(b) If your answer is YES, give us your suggestions.

YES

- FOLD

8. List any further suggestions you have for the improvement of this handbook.

•

FOLD

FIRST CLASS
PERMIT NO. 33
MAYNARD, MASS.

BUSINESS REPLY MAIL
NO POSTAGE STAMP NECESSARY
IF MAILED IN THE UNITED STATES

Postage will be paid by:
PDP·10 Software WrltiRg Groap
ProgrammiRg Depaflmellt
Digital EflUipment CorpentioR
Maynard, Massachasetts 01754

STAPLE

SAMPLE
LOGIN PROCEDURE
Make contact with your computer facility by whatever means the facility has estabilshed (e.g., acoustic coupler, telephone, or data phone).

+
Tum the little plastic knob on the right-hand side
of the Teletype to ON.

Type
C on the Teletype (i.e., hold down the
CTRL key while striking C). This establishes communication with the Time-Sharing Monitor. The
Monitor signifies its readiness to accept commands
by responding with a period (.).

Type LOGIN, or LOG, followed by a carriage return. The system will respond with an informative
message like the following:
JOBn NAME OF SYSTEM

#
JOB n is the job number the system has just assigned to you. NAME OF SYSTEM is usually the
Monitor name and version number.
~

Type your project-programmer numbers after the
number sign, followed by a carriage return.

+
The time-sharing system will then type
PASSWORD:

+
Type your secret password followed by a carriage
return. The system will keep the password secret
by not printing it on the paper.

If the project-programmer numbers and the pass-

word match the project-programmer numbers and
password stored in the system accounting file, the
system responds with the time, date, TTY number,
C, and a period.
Example:
1301 8-May 70 TTY23

+
Now the time-shraing system is ready to accept any
commands you wish to type in. You may direct it
to load and start a program from the System Library (.R prog), start a program already loaded in
core (.START), or perform any of a variety of
other operations. (See inside of back cover for a
summary of Time-Sharing Monitor commands.)

1,
2,
3,
4,

-5.
6.
7,
8,
9,

102X •
0·09·50

~470

• AKW

COllSole Teletype
Central Processor
·16K, 1.0 ~sec Memory
16K, 1.0 ~sec Memory
16K, 1,0 ~sec Memory
Data Channel
Swapping Disk Control
Swapping Disk
Disk Pack Unit*

10,
11,
12,
13,
14.
15,
16.
17,
18.

Disk Pack Unit·"
Line Printer
Card Reader
Magnetic Tape Transport
Magnetic Tape Transport
Magnetic Tape Control
Communications System
Line Printer/ Card Reader Control
DECtape Control and 3 DECtape Units

PRINTED IN U,S.A.

Source Exif Data:
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EXIF Metadata provided by EXIF.tools

1970_PDP 10_Timesharing_Handbook 1970 PDP 10 Timesharing Handbook

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