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Document:	02 timesharing
Order Number:	XX-BD67C-69
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Pages:	34
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_53_

DEC-10-MTWB-D

decsusteric

GETTING STARTED
WITH TIMESHARING

digital equipment corporation - maynard.

massachusetts

_54..

TIMESHARING

1st Printing June 1971

2nd Printing July 1972

Copyright © 1971, 1972 by Digital Equipment Corporation
The material in this manual is for information purposes and is subject to change without notice.

The following are trademarks of Digital Equip-

ment Corporation, Maynard, Massachusetts:
DEC

PDP

DIGITAL

COMPUTER LAB

FLIP CHIP

FOCAL

_55._

CONTENTS

TIMESHARING

Files

Creating Files

The CREATE Command

The MAKE Command

Editing Files

Manipulating Files

The DIRECT Command

The TYPE Command

The DELETE Command

The RENAME Command

Translating, Loading, Executing, Debugging Programs

The COMPILE Command .

The LOAD Command

The EXECUTE Command

The DEBUG Command

Getting Information from the System

The PJOB Command

The DAYTIME Command

The TIME Command

Leaving the System

The KJOB Command

How to Live with the Terminal

Control =C

The RETURN Key

The RUBOUT Key

Control =U~

The ALTMODE Key

Control -O

Peripheral Devices

Commands to Allocate System Resources

The ASSIGN Command

—

The TECO Command

)

The EDIT Command

—

éefl'ing on the System

*O*O\O*O*O:O*Omm\lNVNO\O\O\OO\OUIMUIUTAAAQJ&CON—O
O
h
W
N
O
- o w N
O B W N — 0o
N
O M DO MM -o oo

Page

_56_

TIMESHARING

CONTENTS (Cont)

The DEASSIGN Command

The DISMOUNT Command

The REASSIGN Command

The FINISH Command

The CORE Command

Commands to Manipulate Terminals

The SEND Command

80
81

N
W

The ATTACH Command

Commands to Request Line Printer Output

The PRINT Command

The CREF Command

The DIRECT Command

Commands to Manipulate Core Images

The SAVE Command

The RUN Command

The R Command

‘b‘

The GET Command

Commands to Start a Program

The START Command

The HALT (1C) Command

The CONTINUE Command

Additional Commands to Get Information from the

—

(821

The DETACH Command

—

The MOUNT Command

Page

System

The RESCURCES Command

The SYSTAT Command

TABLES

Title

Table No.
1

Peripheral Devices

Page

-57

TIMESHARING

FOREWORD

Getting Started With Timesharing is a simplified guide intended
for the beginning timesharing user of

the DECsystem-10.

This document presents an overall view of the timesharing use of

does not describe every command available to the user.

COMMANDS (DEC-10-MRDC-D) is the complete reference
document for
it should be referred to for any additional. information.

the System, but

DECsystem-10 OPERATING SYSTEM

the command repertoire, and

TIMESHARING

_58_

-59 -

TIMESHARING

Programs are typed directlZ into the computer by means of the terminal.

By typing in programs, you

establish communication with other programs already resident in the computer.

The first resident pro-

gram you communicate with is the monitor, the most important program in the
computer.

The monitor

is the master program that plays an important role in the efficient operation of the computer.

Just as

the terminal is your link with the computer, the monitor is your link with the programs within
the com-

puter.

The monitor has many functions to perform,’ like keeping a record of what each user is doing and de-

ciding what user should be serviced next and for how long. The one function of the monitor that is of
greatest concern at this point is that the monitor retrieves any resident programs that you need.

retrieval happens only if the monitor "understands” what is expected of it.

This

The commands to the mon-

itor which are explained in the following sections are sufficient for the terminal to be the device

which information is inputted into the system and by which the system outputs its results.

See section 9.0 for d discussion on How to Live With

the Terminal.

1.0

GETTING ON THE SYSTEM

In order to gain access to the timesharing system, you must say hello to the
system by "logging in".

The first move is to make contact with the computer facility by whatever means

lished (e.g., acoustic coupler, telephone, or dataphone).
switch)
on the lower right-hand side of the terminulf
LOCAL (tuming clockwise).

the facility has estab-

Next, notice the plastic knob (the power

This knob has three positions:

ON, OFF, and

When the knob is in the LOCAL position, the terminal is like a typewriter; -

it is not communicating with the system at all. The knob must be turned to the ON
pésifion in order

to establish communication with the computer. When the terminal is turned ON, type a 1C (depress
the CTRL key and type C).

This action establishes communication with the monitor.

We wish to express appreciation to Stanford University for the use of their

The monitor

Stanford A-1 Project User's

Manual, Chapter 1, SAILON No. 54, as a guide in writing the material
in this section.

- 60 -

TIMESHARING

signifies its readiness to accept commands by responding with a period (.). All the commands discussed
in this document can only be typed to the monitor. They are operative when the monitor has typed a

period, signifying that it is waiting for a command.

The first program the monitor should call in for you is the LOGIN program. This is accomplished by

typing LOGIN followed by a carriage-retum (depress the RETURN key). All commands to the monitor

should be termmated with a carnage-retum When the monitor"sees" a carriage-retum, it knows that
a c%mmand has been typed and it begins to execute the command.

In the text, underscoring is used to designate terminal output.
A carriage-retum is designated by a ) .

By typing LOGIN, you cause the monitor to read the LOGIN program from the disk info core memory

and it is this program that is now in control of your terminal. Before the LOGIN program is called in,
the monitor assigns you a job number for system bookkeeping purposes. The system responds with an
information message similar to the following.
JOB 17

SS@218A

TTY34
_

In the first line, the system has assigned your job number (17) and has glven both the name of the monttor and its version number and the number of your terminal line. The version number changes whenever

a change, or patch, is incorporated into the monitor. In the second line, the number sign (*), which
is typed out by the LOGIN program, signifies that it wants your identification.

The standard identification code is in the form of project numbers and programmer numbers, but individual installations may have different codes. The numbers, or whatever code each instullafion uses,
are assigned to each user by the installation. The LOGIN program watts for you to type in your project
number and your programmer number, separated by a comma and terminated with a carriage-return,
o
following the number sign.
S JoB 17

)
#27,400

55621 8A

TTY34

ca-

An alternate method of typing in your project number and prégrammer number is to type your identifi

retion on the same line as the LOGIN command and to follow it with a camriage retum. The system
For
sponds with the information message, and the LOGIN program does not type out the number sign.
A
exdffiple,
)
SLOGIN 27,400
JoB

Ss@21sA

TTY34

- 61 -

The LOGIN program needs one more item to
requests in the next line by asking for your
JOB

SSH218A

complete its analysis of your identification.

This it

password.

TTY34

#27,400

PASSWORD 3

TIMESHARING

Type in your password, which is also assigned by

the installation, followed by a carriage-retum.

maintain password security, the LOGIN progra
m does not print the passwor

If the identification typed in matches the identif
the LOGIN program signifies its acceptance by

ication stored in the accounting file in the monitor

responding with the time, date, day of the week,

the

messag® of the day (if any), and a period.

LJO0GIN )
Jog

5502184

#2775 400

PASSWORD ¢

TTY34

2LOGIN 27,409 )
JOB

PASSWORD:

1950
4-MpaY-T1
WED
TYPE SYS:SCHED FOR SYSTEM
SCHEDULE
_

1050

5Sp218A

TTY3 4

4-MAY=71 ' WED

TYPE SYS:SCHED FOR SYSTEM
SCHEDULE
-

This typeout indicates that the LOGIN program has exited and returned control to'the monitor.
have successfully logged in and may now have the monitor call in other programs

for you.

You

If the iden-

tification typed in does not match the identification in the accountin

g file, the monitor types out the

error message

ZINVALID

ENTRY~-TRY

AGAIN

If this error message occurs, type in the correct project-programmer
numbers and password.

2.0

FILES

When you want to run a program, first type in the program and
decide on a name for it.
is stored on the disk with the specified name.

The program

Then translate the progiram by ca|||ngina trans1afor

and giving it the name of the program you wish to translate.

A program, or data, is stored on the disk in files. If a program is being
typed in to a text editor {(for
example, TECO), the editor is busy accepting the characters being

typed in and generating a disk file

&For them. Then, when the program is to be translated, the translator reads this file just created and
generates a relocatable bmary file.

Since you may have many files and the other users on the computer

may have files, there must be a method for keeping all of these files
separate.

Thisis accomplished by

-62 -

TIMESHARING

ct and programmer

giving each user a unique ofea_on the disk. This area is identified by your proje

a
numbers. For example, if your project and programmer numbers are 27,400, you have
.
that name. Each file you create goes fo your disk area and must be uniquely

named

disk area by

name, the fileFiles are named with a certain convention, the same as a person is named. The firstindica
tes what group
name, is the actual name of the fi le, and the last name, the filename extension, by a period.
ted
the file is associated with. The filename and the filename extension are separa

are ignored. The
Filenames are from one to six letters or digits. All letters or digits after the sixth
to indicate the type of filename extension is from one to three letters or digits. It is generally used

ions.

information in the file. The following are examples of standard filename extens
.TMP

Temporary file

.MAC
.F4
.BAS
.ALG
.CBL
-REL

Source file in MACRO language
Source file in FORTRAN 1V language
Source file in BASIC language
Source file in ALGOL language
Source file in COBOL language
Relocatable binary file

.SAV

A saved core image

Since files are identified by the complete name and the project and programmer numbers, two

users

may use the same filename as long as they have different project and programmer numbers; the files
ons.
would be distinct and separate. The following are examples of filenames with filename extensi
A FORTRAN file named MAIN
MAIN.F4
SAMPLE.BAS A BASIC file named SAMPLE

TEST1.TMP
NAME.REL

A temporary file named TEST1
A relocatable bin(isy file named NAME

3.0 CREATING FILES

the
The two commands mentioned in this section use two editors to create a new disk file. One of
editors is LINED, a line-oriented editor, and the other is TECO, the Text Editor and Corrector (refer
d re=
to the LINED and TECO documents in the DECsystem=10 Software Notebooks). Each comman
created
quires a filename as its argument and should have a filename extension. A new file may be
with either of these commands, depending on the editor desired.

- 63 -

3.1

TIMESHARING

The CREATE Command

The CREATE command is used only to create a new disk file. When this command is executed, the
monitor calls in LINED to initialize a disk file with the specified name and to accept input from the

terminal. At this point, begin to type in your program; line by line. LINED types a line number at
the beginning of each line so that later a reference to a given line may be made in order to make cor-

rections,

Below is a sample program using the commands discussed so far.
1C

Establish communication with the monitor.

Type C while depressing the CTRL key.
SLOGIN

27,400
)

Begin the login procedure and type in your

identification.
JOB

SS@218A

ITY34

The job number assigned, followed by the

monitor name and version and the terminal

line number. The LOGIN program requests
identification (project number and programmer number) if it was not typed on the same
line as the LOGIN command.

PASSWORD @

‘

The LOGIN program requests password.
Type it in; it is not printed.

1050

4-MAY=T1

TYPE SYS:SCHED

SYSTEM SCHEDULE

WED

FOR

—

If identification matches identification

stored in the system, the monitor responds

with the time, date, day of the week, message of the day, and a period.

CREATE

MAIN.Fz

)

A new file on the disk is to be created and
called MAIN.F4.

The extension .F4 is used

because the program is to be a FORTRAN

source file.

LINED is called in to create

~ the file.

Response from LINED signifying it is ready
to accept commands.

A command to LINED to insert line numbers
starting with 10 and incrementing by 10

(refer to the LINED document).

20210

apaze.

20939

TYPE 53 )

Type in your FORTRAN PROGRAM.

FORMAT (" THIS IS MY PROGRAM' ) )
END )

000 40

- The (§) (altmode) is a command to LINED

to end the insert.

On the terminal this key

is labeled ALT, ESC, or PREFIX.
X

Response from LINED signifying it is ready
to accept another command.

Fo)

- A command to LINED to end the creation of
the file.

- 64 -

TIMESHARING
¥

Response from LINED indicating readiness to

accept a command.
10

Retum to the monitor.

The monitor now has control of the program.

The three LINED commands (I, (@, E) shown in the examples are fully discussed in the LINED
document.

3.2

The MAKE Command

This command can also be used to open a new disk file for creation.
mand in that TECO is used instead of LINED,
Notebooks).

It differs from the CREATE com-~

(TECO is discussed in the DECsystem-10 Software

Otherwise, the CREATE and MAKE commands operate in the same manner.

JMAKE

FILEAF4 )

*1 (Text input)

§¢

FX %%

EXIT

The altmode ($) and the EX command are commands to TECO and are explained in the TECO document.

4.0

EDITING FILES

After creating a text file, you may wish to modify, or edit, it.
an existing file to be opened for changes.
calls in TECO.

The following two commands cause

One command (EDIT) calls in LINED, and the other (TECO)

In general, the editor used to create the file should be used for editing.

Each com-

mand requires, as its argument, the same filename and filename extension used to create the file.

4.1

The EDIT Command

The EDIT command causes LINED to be called in and, as the name implies, signifies that you wish to

edit the specified file.

LINED responds with an asterisk and waits for input.

be an already existing sequence-numbered file on the disk.
MAIN.F4 was created.

The file specified must

For example, in Paragraph 3.1, the file

If the command

SEDIT MAIMF4 )

is given to edit the file, the computer responds with an error message (assuming that there was no file
named MAIM.F4).

The command

-65sFDIT

TIMESHARING

MAINGF4
)

causes the right file to be opened for edifinrg.

4.2

The TECO Command

The TECO command is similar to the EDIT command

except that it causes the TECO program to open an

already existing file on the disk for editing purposes.
sTECO

* (editing)

The command sequence

FILEA.F4)

*FX‘?‘F

causes TECO to open FILEA.F4 for editing and close the file upon
out of the original file.

~al

completion, creating a backup file

Whenever one of the commands used to create or edit

a fileis executed, this

command with its arguments (filename and filenam

e extension)is "remembered" in a femporary file

the disk.

Because of this, the file last edited may be recalled

filename specified again.

for the next edit without having the

For example, if the command

«CRFATF PROGI .MAC )

is executed, then you may type the command

SEDIT)
instead of

SEDIT

PROG1.MAC
)

assuming that no other CREATE, TECO, MAKE, or
EDIT command that changed the filename was used

m-bel‘ween. As mentioned before, if a command tries to edit
a file that has

not been created, an error

message is given.

5.0 MANIPULATING FILES
You may have many files saved on your disk area.
area, refer to Paragraph 14.1.)

The list of your files, along with lists of other users'
files, is kept on

the disk in what are called user directories.
saved a particular file.

Version 23 TECO

(For discussion on how fo save a file on your disk

Suppose you cannot remember if you have created and

The next command helps in just that type of situatio

July 1972

- 66 -

TIMESHARING
5.1

The DIRECT Command

The
The DIRECT command requests from the monitor a Iisfir‘\g of the directory of your disk area.
file in the num-

monitor responds by typing on the terminal the names of your files, the length of each
file was
ber of DECsystem=10 disk blocks written (a block is 128, words), and the date on which each
indithat
code
a
is
created. The protection associated with each file is also output. This protection
the
cates which users are allowed to access your files. It is automatically assigned when you create ion.

file. Refer to DECsystem=10 Monitor Calls (DEC-10-MRRB-D) for an explanation of file protect

Names of files not explicitly created by you may show up in the directory. These files were created
as intermediate files for storage by programs you may have used. For example, in translating a file,
the translator generates a file with the same filename but with a filename extension of .REL. This
file contains the relocatable binary translation of the source file. You may also notice filenames with
the filename extension of .TMP. This extension signifies a temporary file created and used by different system programs.

5.2

The TYPE Command

By listing your directory on the terminal, you know the names of the files on your disk area. But what
if you have forgotten the information contained in a particular file? The TYPE command causes the
contents of source files specified in your command string fo be typed on your terminal. For example,
the command

TYPE

MAINGF4 )

F4 to be typed on the terminal. Multiple files separated by commas may be
causes the file MAI. N
specified in one command string, and only source files, not binary files, may be listed.

This command allows the "asterisk construction” to be used. This means that the filename or the fileFor
name extension may be replaced with an asterisk to mean any filename or filename extension.
example, the command

JIYPE

FILEB.* )

causes all files named FILEB, regardless of filename extensions, to be typed. The command
JYPF

#eVAC )

causes all files with the filename extension of .MAC to be typed. The command
STYPE *o% )
causes all files to be typed.

- 67 5.3

TIMESHARING

The DELETE Command

Having finished with a file, you may

files may be deleted in one command

erase it from your disk area with the

DELETE command.

string by separating the files with comma

2DELETE

LINEAR )

SDELETE

CHANGE.F4,

Multiple

For example,

and

are both legal commands.

S$INE.REL
)

The asterisk convention discussed

DELETE command.

5.4

in section 5.2 may also be used with

the

The RENAME Command

The names of one or moretfiles on your disk area
filename on the right and the new

may be changed with the RENAME command.

filename on the left are separated

ing more than one file, each pair
of filenames (new=old)

+RENAME

by an equal (=) sign.

is separated by commas.

ILEZ2.F4=FILELl.F4 )

no longer appears in your directory;

L to SALES.CBL and file FILE1.F4

to FILE2.F4.

The old filename

instead the new filenames appear conta

The asterisk convention may again

RENAME

For example, the

SALES «CBL=GROSS CBLSF

- changes the name of file GROSS.CB

as in the old files.

The old

In renam-

ining exactly the same data

be used.

For example, the command

ko F4=2% )

causes all files with no filename
extension to have the exten

sion .F4.

6.0

TRANSLATING, -LOADING,\EX

ECUTING, DEBUGGING PROGRAMS

As this point you know how to get on
and how to list your source file on
after it has been translated into
into core memory.

6.1

the system, how to create and edit
a source file

the terminal.

The program has not been executed.

the binary machine language under

of q program,
This only happens

More often than not the program
must be debug

standable to the computer and loade

ged.

The COMPILE Command

This command has as its argument

one or more filenames separated by

to be processed (translated) if neces

sary by the appropriate processor

commas.

It causes each command

(translator).

It is considered

necessary to process a file
if no .REL file of the sourc
e file exists, or if the .REL
file was created

- 68 -

TIMESHARING

tion is done.
before the last time the source file was edited. If the .REL file is up-to-date, no transla
ing shows
The appropriate processor is determined by examining the extension of the file. The follow
which processor is used for various extensiong.
.MAC

MACRO assembler

.F4

FORTRAN 1V compiler

ALG

ALGOL compiler

.CBL

COBOL compiler

.REL

No processing is done

other than above,

“Standard processor"

or null

standard
The standard processor is used to translate programs with null or nonstandard extensions. The
use of various
processor is FORTRAN at the beginning of the command string, but may be changed by
is not necessary to indiswitches (refer to DECsystem-10 Operating System Commands). Althoughrditproces
sor can be disregarded
cate the extension of a file in the COMPILE command string, the standa
if all source files are kept with the appropriate extension.

with
When the appropriate translator has translated the source file, there is a file on your disk areatranslator
the
the filename extension .REL and the same filename as the source file. This file is where
The program is
stores the results of its translation and is called the relocatable binary of the program.
is used for storage
now translated into binary machine language, but is still on the disk. Since the disk
y to form a core

and not for execution, a copy of the binary program must be loaded into core memor

image. The core memory of the computer is used for execution; it is like a scratch pad.
command does not generate a core image, but the following three commands
6.2

do.

The COMPILE

The LOAD Command

on causes the
The LOAD command performs the same operations as the COMPILE command and in additi
together,
LOADER to be run. The LOADER is a program that takes the specified REL files, links them
and generates a core image. The LOAD command does not cause execution of the

program.

6.3 The EXECUTE Command

the loaded
This command performs the functions of the LOAD command and also begins execution of in core memis now
programs, if no translation or loading errors are detected. The compiled program
program is
ory and running, and what happens next depends on the program. More than likely, the
ging.
not returning the correct answers, and you now enter the magic world of program

debug

- 69 -

6.4

TIMESHARING

The DEBUG Command

This command prepares for the debugging of a program in éddifion to performing the functions of the
COMPILE and LOAD commands.

DDT, the Dynamic Debugging Technique program (refer to the DDT

manual, DEC-10-CDDE-D), is loaded into core memory first, followed by the program.

pletion of loading, DDT is started rather than the program.

Upon com-

A command to DDT may then be issued to

begin the program execution. This command should be used by the experienced programmer familiar
with DDT. The above four commands have extended command forms discussed in DECsystem-10
Operating System Commands.

The following is an example showing the compilation and execution of a FORTRAN main program
and

subroutine. The login procedure is not shown.
CREATE MAIN.F4 )

CREATE a disk file.

* )

Command to LINED to begin inserting on
line 10, incrementing by 10.

0N 10
anp2n

TYPE 69 )
69

FORMAT

Statements of the FORTRAN main program.

THIS

70030

CALL $uBl )

29040

END

N8B 50

)

THE

MAIN

PROGRAM')

)

Altmode ends the insert.

LINED command to end the edit.

*1C

Retum to the monitor.

;CéEATE: PROG«F4 )

Create a disk file for the subroutine.

*1 )

Begin inserting at line 10 incrementing by
10.

20010

SUBROUTINE

00020

TYPE

20830

SUBR )

105
)

FORMAT

Pne 40

RETURN )

29050

THIS

IS THF

SUBKOUTINE')

Altmode ends the insert.

AE )

LINED command to end the edit.

*tC
+EXECUTE

Statements of the FORTRAN Subroutine.

Retum to monitor.
MAINF4,PRCGF4 J

FORTRAN s

MAIN.F4

FORTRAN:

PROG
«F 4

Request execution of the programs created.
_

LOAD ING

FORTRAN reports its progress.

TIMESHARING

- 70 nerrnE1

UNDEF INED GLOBALS

SuB1

neB152

There is no subroutine named SUBI.

LOADER

CORE

This includes the space for the loader.

?EXECUTION DELETED

No execution was done.

EXIT

EDIT )

Ask to edit PROG .F4, filename need not be

10,20 )

Type lines 00010 and 00020 on the terminal .

mentioned since it was the last file named.

HA1D

SUBROUT INE

nAB20

TYPE

SUBR

105

Insert a new line 10.

0o )
PA01H°

SUBROUTINE SUBL )

wou20"

Terminate the insert.

End the edit.

*E )
*1C

EXECUTE MAINF4,PROG.F4 )

Request execution.

FORTRAN ¢

Only the subroutine is recompiled since

PKOG.F4

only it has been edited.

Both MAIN and PROG are loaded.

LOAD ING
LOADER

CORE

EXECUTION

THIS

1S THE MAIN PROGRAM

THIS

CPU

TIME:

THFE

Execution begins.

SUBRKOUTINE

.93

EXECUTION

SEC.

ERRORS

ELAPSED

TIME:

@13

SEC.

DETECTED

EXIT

Execution ends.

.
—

7.0

GETTING INFORMATION FROM THE SYSTEM

There are several monitor commands that are used to obtain information from the system. Three commands usefu!l at this point are discussed in this section, and additional commands are discussed in Paragraph 16.0.

-71 -

7.1

TIMESHARING

The PJOB Command

If you have forgotten the job number assigned to you at LOGIN time, you may use the PJOB command
to obtain it.

The system responds to this command by typing out your assigned job number.

For ex~-

ample,

SPJOB )
17

7.2

The DAYTIME Command

This command gives the date followed by the time of day.

The time is presented in the following for-

mat:

hh:mm:ss

where hh represents the hours, mm represents the minutes, and ss represents the seconds. For example,
SDAYTIME )

17-MAY-T71

7.3

14:37:35

The TIME Command

The TIME command produces three lines of typeout.
last TIME command was typed.

The first line is the total running time since the

The second line is the total rynning time since you logged in.

third line is used for accounting purposes.

The

The time is presented in the following format:

hh:mm.ss

where hh represents the hours, mm the minutes, and ss the seconds to the nearest hundreth.

For ex~

ample,

STIME
)
52445
02:29.95
KILO-CQORE-SEC=57

In the first two lines, you are told that you have been running 52.45 seconds since the last time you
typed the TIME command, and a total of 2 minutes and 29.95 seconds since you logged in.

The third

line of typeout is used by your installation for accounting and is the integrated product of running
time and core size.

Refer to DECsystem=~10 Operating System Commands.

TIMESHARING

8.0

-72 -

LEAVING THE SYSTEM

Now that you know how to log into the system and create and run a program, you might be wondering
how you leave the system.

You have to tell the system you are leaving, and you do this by the KJOB

command .

8.1

The KJOB Command

The KJOB command is your way of saying goodbye to the system. "Many things happen when you type
the command.
user.

The job number assigned to you is released and your terminal is now free for another

An automatic TIME command is performed.

In addition, if you have any files on your disk area,

the monitor responds with
CONFIRM:
and you have several options available to you.

By typing H and a carriage return after the CONFIRM:

message, the monitor lists the options available.

For example, the following typeout occurs by re-

sponding to the CONFIRM: message with H and a carriage return.
IN

RESPONSE

PERFORM

DELETE

(ASKS

ARE

CONFIRM:,TYPE

ALGORITHM
ALL

YOU

SURE?s

TRY

TYPE

INDIVIDUALLY

TEXT
NAME

FILE

OUT

QUOTA

LCGGGED

REPORT

SAVE

THE

FILE

ALL

UNPRESERVED

LIST

PRESERVE

-3

PRESERVE

REPORT

SAVE

SAME

ALL

LIST

SUPPRESS
LETTER

THOSE

CONFIRM
NOTE:

MO«
FILE

EXCEPT

TEMP

ALL

FILE

ONE

SAVE

FILES
OF:

THIS

EKPGS

FILE

STRUCTURE

WHEN

DELETED

LISTING

FILES

FOLLOWED

SPECIFIED
TYPED
IS5

NO.

UWRITTEN

PRESERVED

OUT

GUOTA>

THEN

REPEAT

FILE

PROTECTION

FILES

AUTOMATICALLY

SIZE

WITH

DSK

FILES

BLCOCKS

)

TEMP

FILES

TYPE

AND

LOGGED

EXCEPT

OUT»,

PRESENT

OUT

WILL

FILE

OVER

WITH

LOGGED

FILES

THIS

OVER

BUT

ALL

FILE

STILL

FILES

QUOTA

FILE

THE

WHAT

DELETE

OUT

CR)

STRUCTURE

THE

TYPED

BDFHIKLPOSUWX
LOGGED

CETERMINE

FILE

OF:

BELOW

LEAVING

ONLY

TYPE

FAST

X = cCwnoTrr
X

EACH

SKIP

BELOW

LOGOUT

THIS

ONE

GET

FILES

AFTER

WILL

GQUOTA

PRESERVE

ALREADY

PRESERVED

‘
WHEN

FILES

DELETED

SPACE

AND

AFFECTED

LIST

THE

FILE

STRUCTURES

COMMAND.

ALSO

AGAIN.
OF

BLOCKS

(DIRECTORY
ITS

ACCESS

ALLOCATED

WHICH

COMMAND)
.
CODE

CONF IRM:

1890

MAY

LARGER

THAN

THF

TIMESHARING

-73 -

You may now use the options available. If K was used as the option, the following is a sample of
what is output to your terminal .

JOB 33, USER [27s256041] LGGGED OFF TTY34

DELETED ALL 2 FILES (3. DISK BLOCKS)
RUNTIME D

MINs

1317 28-MAY=-T1
'

88.29 SEC

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 (27,3213 LOGGED OFF TTY17

"RUNTIVE 0 MINs @029 SEC

9.0

1317 20-MAY-T1

‘

HOW TO LIVE WITH THE TERMINAL

On the terminal, there is a special key marked CTRL called the Control Key. If this key is held down
and a character key is depressed, the terminal types what is known as a control 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 terminal, but cause special functions to
occur, as described in the following sections.

There are several other special keys that are recognized by the system. The system constantly monitors
the typed characters and, most of the time, sends the characters to the program being executed. The

important characters not passed to the program are also explained in the following sections. (Refer to
DECsystem=10 Monitor Calls for more explanations of special characters.)

9.1

Control = C

Control - C (1C) interrupts the program that is currently running and takes you back to the monitor.
- The monitor responds fo a control = C by typing a period on your terminal, and you may then type an-

other monitor command. For example, suppose you are running a program in BASIC, and yéu now
decide you want to leave BASIC and run a program in AID. When BASIC requests input from your
terminal 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 terminal (i.e., the program is in the middle of execution) when you type control - C,

the program is not stopped immediately. In this cdse, type control - C' twice in a row to stop the

execution of the program and return control to the monitor. If you wish 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

TIMESHARING

-74 -

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 communi-

cating 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.

9.2

The RETURN Key

This key causes two operations to be performed:

(1) a carriage-return and (2) an automatic line-feed.

This means that the typing element returns to the beginning of the line (carriage-re

turn) and that the

paper is advanced one line (line~feed).

Commands to the monitor are terminated by depressing this

key.

9.3

The RUBOUT Key

The RUBOUT key permits correction of typing errors.
ter typed to be deleted.

Depressing this key once causes the last charac-

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.

does RUBOUT function if the program has already processed the characters

The monitor types the deleted characters, delimited by backslashes.

you wish to delete.

For example, if you were typing

CREATE and go as far as CRAT, you can correct the error by typing two

letters.

Nor

RUBOUTS and then the correct

The typeout would be

CRAT\TA\EATE
Notice that you typed only two RUBOUTS, but \TA\ was printed.
but in reverse order.

9.4

This shows the deleted characters,

(Note that when using TECO, deleted characters are not enclosed in
backslashes.)

Control - U

Control = U (1U) is used if you have completely mistyped the current line and
wish
Once you type a carriage-return, the command is read by the computer, and
no longer be used on that line.

to start over again.

line-editing features can

Control - U causes the deletion of the entire line, back to the last

carriage-return, line-feed, or altmode. The system responds with a carriage-return, line-feed
so you
may start again.

=75 9.5

TIMESHARING

The ALTMODE Key

The ALTMODE key, which is IaBeled ALTMODE, ESC, or PREFIX, is used as a command terminator
for several programs, including TECO and LINED.

Since the ALTMODE is a nonprinting character,

the terminal prints an ALTMODE as a dollar sign ($).

9.6

Control -O

Control - O (1O) tells the computer to sfippress terminal output. For example, if you issue a command
to type out 100 lines of text and then decide that you do not want the
typeout, type

stop the output.

10.0

control - O to

Another command may then be typed as if the typeout had terminated normally.

PERIPHERAL DEVICES

The system controls many peripheral devices, such as terminals , 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.

Table 1
Peripheral Devices

Device

Physical Name

Terminal

TTYO, Y, ..., 11Y77 -

Console TTY

CTY

Paper Tape Reader

PTR

Paper Tape lech

PTP

Plotter

PLT

Line Printer

LPT

Card Reader

CDR

Card Punch

cbpP

DECtape

DTAO, DTAL, ..., DTA7

Magnetic Tape

MTAO, MTAI, ..., MTA7

Disk
Display

‘

DSK
DIS

TIMESHARING

-76 -

You may also give each device a logical device name. The logical device name is an alias, and the
device can be referred to either by this alias or by the physical name. The logical name consists of
one to six alphanumeric characters of your choice. The reason for logical device names is that in

writing a program you may use arbitrarily selected device names (logical device names) that can be
assigned to the most convenient 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 assigned the logical name D3K, 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 de-

vice the logical name DSK because certain monitor commands (such as the COMPILE commands) make
extensive use of special features that the disk has but other devices do not have. The following examples show the use of logical and physical device names.

-ASSIGN DTA ABC)

Assign a DECtape the logical name ABC.

<ASSIGN MTAl XYz)

Assign magnetic tape drive #1 the logical name

ASSIGN PTR F0O )

Assign the papertape reader the logical name

XYZ.

FOO.

In order to use most peripheral devices, you must assign the desired device to your job. You may as-

sign 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 or MOUNT
monitor command. This is a permanent assignment that is in effect until the device is released by a
DEASSIGN, DISMOUNT, 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 using it. The only exception is the disk,

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 available resources.

Under- normal circumstances, the spooling mechanism built into the system is used to output to slowspeed devices. Spooling is the method by which output to these devices (usually the line printer, card
punch, paper tape punch, and plotter) is placed on the disk first and then output to the device at a later
time. This method of using a device saves you time because you do not have to wait for the device to
be freed if it is being used by another user nor do you have to wait for your files to be output before you

5.05 Monitor

July 1972

-77 -

TIMESHARING

can perform another operation. Once your files have been placed on the disk, you can do another task,
such as running a program or leaving the system by killing your job.

After you leave the system

(KJOB), your files will be output whenever the device you requested to output them is available.

The spooling of files to the line prinfer is described in Paragraph 13.0. Refer to the DECsystem=10
Operating System Commands manual for a discussion of spooling to other devices.

11.0

COMMANDS TO ALLOCATE SYSTEM RESOURCES

11.1

The ASSIGN Command

The ASSIGN command is used fo assign a peripheral device on a permanent basis for the duration of
your job or until you explicitly deassign it.

This command must have os an argument the legal physical

device name (see Table 1) of the device you wish to assign.

For example, if you want to assign a

DECtape drive to your job, type
<ASSIGN DTA)
The monitor responds with the message
DTAn

ASSIGNED

where n is the unit number of the DECtape drive assigned to your job.

If all drives are in use, the

monitor responds with
ASSIGNED

JOBS'Nn,

N2,

and you must wait until a drive becomes available.

cen

You may assign a specific DECtape drive as fol-

lows:

+ASSIGN DTA3)
The monitor responds with
DTA3

ASSIGNED

if the drive is available, or

ALREADY ASSIGNED TC 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 iogical 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
sASSIGN DTAl

SAMPLE )

If DECtape drive #1 is Freé, the monitor responds with
DTA1

5.05 Monitor

ASSIGNED

July 1972

TIMESHARING

-78 -

and stores the logical name you typed. You may then refer to the DECtape by the name SAMPLE until
you explicitly release the device, assign the name SAMPLE to another device, or kill your job.

Logical names can be very useful. Suppose you write a program that uses DECtape drive #5 and refers
to it by its physical name (DTAS). When you run your program, you find that DECtape drive #3 is the
only drive available. Instead of rewriting your program to use DECtape drive #3, type
)
«ASSIGN DTA3 DTAS

Thereafter, whenever your program refers to DTA5, it is actually referring to DTA3. Since logical
device names are strictly your own, they are different from the logical names of other users. The
following is an example using physical and logical device names.

<ASSIGN DTA NAME J

Assign a DECtape drive the logical name

DEVICE DTA4 ASSIGNED

DECtape drive ¥4 has been assigned.

NAME.

Find another DECtape drive; assign the

.ASSIGN DTA LINE )

logical name LINE.

» e All DECtape drives are in use.
ASSIGNED TO JOBS Nys N,

SASSIGN PTP,NAME
)
ZLOGICAL

NAME

WAS

DEVICE PTP ASSIGNED

Reserve paper tape punch.

USEs

Paper tape punch is assigned and NAME

now refers to PTP.

Request DECtape drive #3 and give it the

+ASSIGN DTA3 LINE p)

logical name LINE.

ALREADY ASSIGNED TO JOB7

11.2

Another user (job 7) has DTA3.

The MOUNT Command-

The MOUNT command is similar to the ASSIGN command in that it is used to assign a peripheral device to your job. However, unlike the ASSIGN command, it requests operator intervention. This is
useful for users who cannot place their devices on the computer because they are too far away. These
users are called remote users because they are connected to the computer via communications lines.
For example, if you have DECtapes at the location of the computer (commonly called the central site)
but are using the computer remotely, you can use the MOUNT command to assign a DECtape drive and
to have the operator place the DECtape on the drive.

This command must have as an argument the legal physical device name (see Table 1) of the device you
wish to assign and may have a logical device name. These arguments are the same as in the ASSIGN

command. In addition, switches can be used to specify items to be considered by the operator. Only
the following three switches are applicable in this manual; the remainder are described in

DECsystem=-10 Operating System Commands

Specifies that the volume is read only and

/RONLY or /WLOCK

5.05 Monitor

that it cannot be written on.

July 1972

-79 -

/VID:name

’

TIMESHARING

Specifies the name used to identify the

volume (storage medium) to the opera
tor,
The name can be in one of two forms:

1) any string of 25 characters or less

con-

taining only letters, digits, perio
ds, and

hyphens or 2) any string of 25 chara
or less enclosed in single quotes.

cters

The

string cannot contain break chara
cters
or single quotes.

/WENABL

Specifies that the volume is enabled for

writing.

This condition

is assumed if

no switches appear in the MOUN
T command string.
.

11.3 The DEASSIGN Command
The DEASSIGN command is used to

release one or more devices currently

This command may have as an argum

the specified devices are released.

ent a physical or logical device

associated with your job,

name.

If an argument is given,
If an argument is not specified, all
devices assigned to your job

are released. When devices are released,
they are retur

ned to the monitor's pool of available re~

sources for use by other users.

The DEASSIGN command does
not

your job may have for devices.

11.4

affect any temporary assignment

The DISMOUNT Command

The DISMOUNT command is simila

r to the DEASSIGN command becau
se it is used to return devices to
In addition, it notifies the operator
to remove the volume (storage mediu
m) from the device (i.e., DECtape from a DECta
pe drive, cards from a card réode
r, and so forth), This command
takes a physical device name as an
argument. The device must have
been previously assigned with the
ASSIGN or MOUNT command.
The switch /REMOVE follows the
device name in order to tell the
the monitor.

operator to physically remov

e the volume from the device.

«DISMOUNT

DTA4:/REMOVE )

notifies the operator to deassign

11.5

For example, -

DTA4 and remove the tape from

the drive.

you to give a device assigned to

you to another user without havin

The REASSIGN Command

The REASSIGN command allows
device returned to the monitor's

pool of available resources.

command: the name of the device being reassigned

the device.

For example, suppose you have finish

10 wants it.

Type the command
:REASSIGN

:DEASSIGN

5.05 Monitor
TM

this

and the job number of the user who is receiving

ed with DECtape. drive #6 and the perso

DTA6

This deassigns DECtape drive #6

g the

Two arguments are required with

n who is job

19 )

from your job and assigns it to job

10, just as if you had typed

DTA6
)

July 1972

- 80 -

TIMESHARING
and job 10 had typed

)
ASSIGN DTA6

igned.

immediately thereafter. All devices except the job's terminal can be reass
11.6 The FINISH Command

program that is being executed while preservThe FINISH command is used to prematurely termiisnatenotaused,
part or all of the output file may be lost.
and
ing as much output as possible. If this comma physi
or logical device name, in which case any input
The FINISH command may be followed by that cal
e is terminated. If no device is specified, inor output currently in progress in relation to devic
to your job. The monitor responds to this command
put or output is terminated on all devices assignedsing
the device for use by others.
by terminating output, closing the file, and relea

an assembly listing of a program on your disk area
This command could be used if you were generating
of the listing, not the entire listing. Type
and decided that you wanted only the first part
1C

SFINISH DSK )

and the monitor completes the writing of your listing and releases

the disk.

11.7 The CORE Command

and is
nt of core assigned to your job. The commthat
The CORE command allows you to modify thetheamou
er of 1K blocks (1024 word blocks) you s
followed by a decimal number representingon. Fortotalexamnumb
ple, if you want the program to have 8K block
want the program to have from this point
of core, type

«CORE 8 )

and there is
if available. If you request additional core
and the monitor gives the program 8K blockans, error
by the
message. If the CORE command is follks owed
none available, the monitor responds with
‘core.
because you are requesting 0K bloc ofnumb
decimal number 0, your program disappearsandfromis core
out (1) the total er of
comm omitted, the monitor types
" If the decimal number following the
of core not assigned to
1K blocks you have, (2) the maximum you can request, and (3) the amount
any user.

12.0 COMMANDS TO MANIPULATE TERMINALS
The SEND Command

and
a line of text to another terminal inthethemesssystageem.follTheowedcomm
The SEND command allows you to send
the
by
to which you are sending
is typed followed by the number of themesstermageinalis print
ed on the receiving terminal and is preceded by
message and a carriage return. This
12.1

- 81 -

the number of your terminal.

TIMESHARING

If the receiver of the message is busy, that is, his
terminal is not commu-~

nicating with the monitor, you receive the
message BUSY and your message

sending a message to an operator, the receivin
g terminal is never busy.

12.2

is not sent.

If you are

The DETACH Command

The DETACH command causes your terminal to be
trol another job.

disconnected from your program and released to conThis means that, while your program is disconn
ected, you may log in again, receive

a new job number, and do something else.

be a detached job.

The job that was disassociated from your terminal

This means that it is not under control of any user's

console.

is said to

If your detached job

attempts to type something to the terminal, it is stopped
, for there is no terminal attached to it.
12.3

The ATTACH Command

The ATTACH command allows you to attach a console
of the job to which you wish to attach.

to a detached job.

You must specify the number

If you are the owner of the detached job, your console
is im-

mediately detached from your current. ]'ob and attache

d to your detached job.

executed, the console is in communication with
the monitor.

After this command is

[f the job you just attached to happens

to be running, type CONTINUE without affecting the status
of the job.

If you are not the owner of the detached job, you must also specify the

the owner.

The project-programmer number must be enclosed in square

this command to work.

project-programmer number of

brackets (e.g., [27,4001) for
If the job whose job number you typed is already attached
to a terminal, you

cannot attach and the monitor responds with
?TTYn

ALREADY

ATTACHED

where n is the number of the terminal attached to the

job.

attached to a job at any time.

13.0

Observe that only one terminal can be

COMMANDS TO REQUEST LINE PRINTER OUTPUT

In Paragraph 5.2, the TYPE command for listing source
files on your terminal
tion, there are three commands that may be used
to list

mechanism.

13.1

was discussed.

In addi-

files on the line printer via the spooling

The PRINT Command -

The PRINT command is used to list disk files on the line printer

via the spboling mechanism.

command takes a filename, or many filenames separate
d by commas, as an argument.

also be used with the PRINT command.
ones are mentioned below.

/COPIES:n

This

Switches can

Although many switches are available, on ly a few pertinent

The remainder are discussed in DECsystem=-10
Operating System Commands.

Specifies the number of copies that you

want of the file.

less than 64.

This number must be

If this switch is not given,

one copy is produced,

5.05 Monitor

July 1972

-82 -

TIMESHARING

/LIMIT:n

Specifies the maximum number of ispages
not

/SPACING:DOUBLE

be double,
Specifies that the output. will
If the /SPACING

you want printed. [f this switch
given, the maximum number is 200 pages.

single, or triple spaced output is

/SPACING:SINGLE

switch is not given, the

/SPACING:TRIPLE

single-spaced.

All files remain in your disk area except for temporary files; these files are deleted aofter

they are

printed.

13.2

The CREF Command

d
The CREF command is used to list a certain type of file called a cross-reference file. This command string
comman
is an invaluable aid in program debugging. If a COMPILE, LOAD EXECUTE, or DEBUG listing
that
ed
expand
(rjefc-;r to Paragraph 6.0) has a /CREF switch, the command string generates an
(3)
includes (1) the original code as it appears in the file, (2) the octal values the code represents,uses,
the relative locations into which the octal values go, (4) o list of all the symbols your

program

e listing.
and (5) the numbers of the lines on which each symbol appears. This is called a cross-referenc
CREF command. All
To print this listing file, you must call in a special cross-reference lister with the are
on the
the cross-reference listing files you have generated since the last CREF commuand printed so that
line printer. The file containing the names of the cross—reference listing files is then deleted
subsequent CREF commands will not list them again.
13.3. The DIRECT Command

the directory of DECtape n is typed
When a DTAn: argument is specified with the DIRECT command,
the DIRECT command when no argument
on the terminal. (Refer to Paragraph 5.1 for a discussion of
is specified.) For example, the command
<DIRECTORY DTA23)

types the directory of DECtape drive ¥2 on the terminal.

options. One switch
Besides having optional device arguments, this command has several switch
form of the directory to be listed
option is /F. Including /F in the command string causes the short
your files. (The long form
on the terminal. The short form of the directory consists of the names ofAnoth
er switch option is /L.
file.)
of the directory also lists the creation dates and lengths of each
r rather
Including /L in the command string causes the output of the directory to go to the line printe
than to the terminal. For example, the command
SDIRECTORY /L )

lists your directory of your disk area on the line printer. The line printer is

temporary basis and is released when the output is finished.

5.05 Monitor

assigned to you on a

July 1972

-83 14,0

TIMESHARING

COMMANDS TO MANIPULATE CORE IMAGES

By using one of the following commands, you can load core image files (refer to Paragraph 6.1 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.

14.1

The SAVE Command

The SAVE command causes your current core image fo be saved on the specified device with the
specified filename. This command must be followed by several arguments. First, you must tell the
monitor the device on which you want to save the core image. A colon must follow the device name.
Second, you must give a name to the core image file. If the filename extension is not specified, the

monitor designates one. 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 fo 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 12,000 words. Affer you use this command, you cannot continue
executing the program. The program can be restarted only from the beginning.
14.2 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 not 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.
14.3

The R Command

The R command is a special form of the RUN command. This command runs programs that are part of
the system, rather than programs that are your own. The R command is the usual way to run a system
program that does not have a direct monitor command associated with it. For example, the only way
to run BASIC and AID is by the commands

)
R BASIC

TIMESHARING

-84 -

and

2R AID )
A device name or a project programmer number may not be specified for this command.

14.4

The GET Command

The GET command is the same as the RUN command except that it does not start the program; it merely
generates a core image and exits.
JOB

The monitor types

SETUP

and is ready to accept another command.

15.0

COMMANDS TO START A PROGRAM

15.1

The START Command

The START command begins execution.
of the program at its starting address, the location specified

within the file, and is valid only if you have a core image.

This command allows you to specify an-

other starting address by typing the octal address ofter the command.

Normally, to start a program,

type

.START )

but to start a program at the specified octal location 347, type

SSTART 347 )
A GET command followed by a START command is equivalent to a RUN command.

15.2

The HALT ( t C) Command

Typing 1C stops your program and takes you back to the monitor.

The program ''remembers' at what

point it was interrupted so that it may subsequently be continued.

After typing tC, you may type any

commands that do not affect the status of your program (e.g., PJOB, DAYTIME, RESOURCES) and
still be able to continue the execution of the program with a CONTINUE command.

However, con-

tinuing is impossible if you issue any command that runs a new program, such as a RUN or R command.

15.3

The CONTINUE Command

If you stop your program by a HALT (1C) command, you may resume execution from the point at which
it was interrupted by typing the CONTINUE command.

exit by typing control = C.

not let you continue.
CAN'T

You may continue the program only if you

If the program exited on an error condition of some sort, the monitor does

It types
CONTINUE

_85..

if you try.

TIMESHARING

However, you may continue your program if it has halted and
given the
HALT AT

typeout

USER
n

16.0

ADDITIONAL COMMANDS TO GET INFORMATION FROM THE SYSTEM

16.1

The RESOURCES Command

The RESOURCES command types out a list of all the available devices (except terminals)
minal.

For example,

on your ter-

*RESOURCES )
PTY1,CDR,PTRsMTA1sCDP,PLT

At i'he_fime of this command, there were six devices available.
16.2

The SYSTAT Command

The SYSTAT command produces a summary of the

logging in.

current status of the system and may be typed without

Included in the summary is a list of the jobs current

ly logged in, along with their project-

programmer numbers, program names being run, and
runtime., The following typeout is
a partial exam-

ple of SYSTAT output.

More information is contained in this program and

can be obtained by running

SYSTAT.

S5p224D

STATUS

UPTIME

5:18:56,

JOBS

USE

247
OUT

DOF

37.

1:34:02 PeMe ON 11-MAY-T71

TIME

1942

IDLE

LOGGED

INs

DETACHED

LOST

WHO

LINE#

WHAT
.

{CPR]

[CPR].
LOPR]

OMOUNT

2+4

SwW

OMOUNT

2+4

CDRSTK

1:01

JOB
VRN
UT S W
-

SYSTEM #2 AT

SIZE(K)

STATE

{OPR1

BATCON

4+
4

LPTSPL

3+4

{OPR]

5:39

PTPSPL

2+3

[OPR]

CHKPNT

SwW

1+5PY

MSCOPE

LGPR]

LOoPR]

TYLOST

2+5

10,16

DIRECT

1+3

2:31

3+SPY

DAEMON

T+SPY

{OPR]

OPSER

142

20574

DIRECT

1+3

40565

TECO

2+3

10,566

BATCON

11,131

B+4

DIRECT

143

10,77

SwW

MONLOD

12+2

LOPR1

FAILSA

19,63
[(SELF]

16,34
MEANS

LOCKED

CORRESPONDS

FD5224

SYSTAT

4+5PY

KJoB
-

6+4

CORE

TTY42+NN

S5YSDPY

58:15

fOPR1]

PNN

L[OPR]

ok
y ko

TIME

Sw
SW

RUN

45:09

TIMESHARING

..86_