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MAINDEC-08-D2G

December 1965

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Document:	maindec-08-d2ga-d
Order Number:	MAINDEC-08-D2G
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Pages:	10
Original Filename:	https://svn.so-much-stuff.com/svn/trunk/pdp8/src/dec/maindec-08-d2g/maindec-08-d2ga-d.pdf

OCR Text

MAINDEC-08-D2GA-D

IDENTIFICATION

Product Code:

MAINDEC-08-D2GA-D

Product Name:

PDP-8 High Speed Punch Test

Da+e Crea+ed:

May 12,1965

Maintainer:

Diagnostic Group

Author:

M. Horovitz

Previous Code:

MAINDEC 817

U
PDP-a
LIE=F]AF]Y

•.-I

MAINDEC-08-D2GA-D

ABSTRACT

This program consist.s of two separate tests.

The first causes the High Speed Punch I.o produce

a tape containing a sequence of "pseudo-random" character codes.

This tape is checked for accuracy

using either the high-speed reader or the Teletype reader.
In +he second +es[, +he charac+er code represented by the setting of SR4.1 I is punched re-

peatedly.

The switch setting may be changed while the test is running.
The interrupt system is also test.ed.

REQUIREMENTS

Storage
The test program occupies memory locations 0001 -0163 and requires that the RIM loader be

in locations 7756-7776.
Equipment

Standard PDP-8 wit.h Teletype Keyboard/Printer
High-Speed Tape Punch and Control

(Optional) High-Speed Tape Reader and Control Type 750

USAGE

3.I

Loading
The RIM Loader must be in memory.

Turn off the Teletype reader
Se+ the SWITCH REGISTER +o 7756; press LOAD ADDRESS, then START.

Place the RIM program tape in the Teletype reader, and turn on the reader.

When the program has been loaded, stop the computer, I.urn off the reader, and remove
t.he tape .

3.2

Switch Se+tings

SWo

Down (off).

SWo

Up (on).

punched tape.

`,~'`

Causes program to punch the tes"ape.

Terminates punching and conditions the program to begin checking the

MAINDEC-08-D2GA-D

Start Up and/or Entry

3.3

With the progi.am in memory, set the SWITCH REGISTER to the desired starting address as
follows:

0020

Entry when using the high-speed reader for checking.

0021

Entrywhen using the Telerype reader for checking.

0022

Start:ng address of the sw:tch Reg:ster Test.

Press LOAD ADDRESS .

Put SWo down .
(For SR punch test) Place the desired character code in SR4_I 1 .
Press START.

As long as SWo is down, the punch will continue i.o produce a pseudo-random sequence.

soon as the switch is raised, the punching stops, a length of blank +railer is produced, and the program
halts.

At this point, the C(MA) will be 0041.

the reader chosen to do the checking.

Remove the punched tape from the bin and place it in

The blank leader must be posifioned a[ the read heads so that

the checking program will not miss the first character punched.

If using the high-speed reader, turn on reader power, place the guide arm down, and press
CONTINUE.

The Teletype reader must be off.

When using the Telefype reader, with the rape in place press CONTINUE, then turn on the

reader.

The checking program will cont.inue until an error occurs or until the blank frailer is en-

countered .

3.4

Errors

Stop
EI

C (MA)
0011

Cause of S+op
The PLS instruction did not clear the punch flag.

Less

likely, the PSF instruction skipped even though the flag
was clear.

0002

A€purious interrupt occurred.

Less likely, the PSF in-

struct.ion failed to skip when +he flag was set.
E3

0117

As an error stop, this occurs when an incorrect character
has been read from the tape. The erroneous code is displayed in the AC .

E3A

0123

After the preceding error, the AC displays the correct
code .

lJ
2

MAINDEC-08-D2GA-D

Cause of Stop
As a legitimate halt, this signals that the program has
reached the blank +railer. This is the FINAL STOP.
0041

Legitimate halt.

This slop occurs after the trailer has

been punched, to allow the operator to remove the punched
tape and place it in the reader.
There are no halts :n the SR Punch Test program.

3.5

Recovery from Such Errors

Recovery Procedure
To resume punching, press CONTINUE.

If the interrupt has failed, terminate the Punch Test.
to determine cause.

Record the C(AC).

Run Instruction Test 2A

Press CONTINUE to reach the next halt.

Record the C(AC) and compare it with the previous C(AC) .
on rape.

`-.

3 .5 .I

Check the. character

To resume testing, press CONTINUE.

Other Stops -When the program halts a+ A, remove the punched tape from the punch bin and

place it in the reader I.o be used for checking.

Then follow the procedure described in paragraph 3.^3

to begin the checking of the tape.

RESTRICTIONS

If the computer has any input/output devices other than the Teletype keyboard/printer with
reader and punch, the Type 750 High-Speed Reader, and the Type 75A High-Speed Punch, be sure that

+hese devices are turned off .

If there is any chance that one of them may have been left active, insert

a "clear status" instruction for that device in one of +he two loca+ions reserved for this purpose:
or 0154.

0153

This is in a subrou+ine +ha+ clears all +he clev:ce flags befoi.e s+ar+:ng +he punch program.

DESCRIPTION

This program tests +he performance of the high-speed punch in producing a random sequence

of-characters.

The program begins by punching a length of blank leader.

It then punches a sequence

of "pseudo-random" numbers (see METHODS) until the operator places SWo up.
nates +he Punch Test, produces a length of blank trailer, and stops.

L,
3

At this point it termi-

MAINDEC-08-D2GA-D

The operator removes the tape and places it in the reader.
scans the tape until the first nonzero character appears.

The next part of the program

It then checks the ''random" sequence for errors.

The checking continues until an error occurs, or until the first blank character appears, signaling the

end of the test section and the beginning of the frailer.

A separate section of the test program aHows the operator using an oscilloscope to examine

the wave forms generated by the punch when punching a single character.
location 0022.

The start of this test is at

The program punches the character code corresponding t.o the setting of switches 4-11.

The operator can, of course, change +hese se++ings a+ will .

When a single character is punched, the tape can be examined visually for proper spacing

between lines as well as for accuracy.

METHODS

6.1

Discussion

The sequence of characters punched on the test tape is determined by a random number generating subroutine.

The sequence is initialized by two random number seeds,12338 and 76228.

The

reading program checks the punched sequence by comparing each character with the number generated
by the same subroutine .

6. 2

AIgorithm(s)

The algorithm for generating the sequence of pseudo-random numbers follows.
All numbers given are octal integers.

RN designates the number that is punched.

RN=O is

not permitted .

RT2Of=7fff[|

Rlo = 1233;

Rln+I = 4(Rln) + R2n

R2n+1 = 4[4(Rln+1) + R2 ]

RNn = (Rl n+I ^377)
If RNn = 0, then RNn+i = RNn
n = 0'

I, 2' .....

•U

MAINDEC-08-D2GA-LA
7.

PROGRAM LISTING

/POP-8

HIGH

SPEED PUNcli TEST

/PUNCH TEST

SIJBROUTINES

PSF

E2'

HLT
JMP

/ERROR:

.FAILED 0R

/PUNCH

SuBROUTINE

SPuRI0LIS

INTER.r{!Ji'T

PUN

PLS
ION

PSF

/TEST

SKP CLA
HLT

/CLEAR--G0 0N

JMF)
®®15

6811

©©14

6©51

FisF
KSF

8©15

6956

KRB

CTl,

FOR

CLEARED

FLAG

/ERROR:

PUNCH FLAG NOT CLEARED
/OR PSF SKIPPED 0N ZERO FLAG
/WAIT FOR INTERRIJPT

/CONSTANTS TABLE

PL:3

*2©
BD2fo-

/INITIAL ENTRY POINTS
/FOR HIGH SPEED READER

5Z]27

Ei821

5864

0G22

7694

ij825

6826

¢a24

6©21

8b25
b$26

5924
5822

/FOR
/FOR

8827

l{EYB0ARD READER
PljNCH TEST USING

/SETUP T0

lJSE

/CONTAINS

RFC

LOW,

/SETUP TO

USE

HIGH

SWITCHES

SPEED

READER

ub 5 id
too 5 1

INSTRUCTION

b%32
8®35
®B54

1®14

S.835

5975

®©36

1®15

3@57
884©

318©
5®41

rdb4 I

76®2.

/START

0F TEST

Lj®42

4145

/CLEAR

I-0

bb45
gb44

1155
3161

/INITIALlzE

0£.45

1155

8£46

5162

KEYBOARD

REAi3ER

PROGRAMS

FLAGS
RANDopri

NUMBER

¢kj47

76©4

Bzi5¢
S¢51

771©
51®2

/TEST SW-@
/ON--READ PUNCHED

TAPE

©®52

4©65

/OFF--BEGIN

TEST

PuNCH

®®55

8054
'J055

L,,

/TERMINATE PUNCH TEST?
/NO--GET ANOTH.ER NUMBER
/YES--PUNCH BLANK TRAILEFi

®E56
gc; 5 7

/STOP

RouTINE

MAINDEC-08-D2GA-LA

8®60

JMS

RNUM

/GET

ffl ff 6 I

JMS

PUN

/PUNCH

ONE

NUMBER

8862

JMPC

©®63

/TAPE

FEED

©©64

CLA

'4Lt65

TAD

C`T2+2

©@66

DCA

TEN

•8®67

JMS

PUN

®07®

ISZ

TEN

®871

JMP

®¢72

JMP

8k' 7 5
©u74

/COUNTER

SUBROUTINE

(2®®

LINES)

.-2
I

FEED
/READ

SIJBROUTINES

FOR

CHECKING

CLA

/(OR

KSF)

RRB

/(NO

EFF`ECT

RFC

/(OFi

KRB)

kju 7 5

F3SF

¢ L' 7 6

JMP

bu77
d i b` S
RE " u "

JMP

.-I

KEYBOAFiD

READ

READER)

RPT

RFC

JMS

WITH

/ENTRY

FOR

RPT

SNA

/SKIP OVER BLANK LEADER
/STORE CHARACTER READ

JMP
DCA

JMS
CIA

/GET

TAD

/(LOGICAL 0R)
/TEST RESULT OF OR
/ERRO,i:
AC NOT ZERO

SZA
JMP

JMS
JMP
El16

TAD

i, I I 7

HLT

/OK:

TEN

NUMBER

READ

/ERROR

/ERROR:

/OR END

8128

1161

8125
0124

5114

7492

E3A,

--`

CHARACTER

CONTAINS

0F TAPE:

CHAR

FINAL

PUNCHED

HALT.

/AC CONTAINS CORRECT CHAR
/READ NEXT CHARACTER
E

I)12 6

CLL

jl27

TAD

/FiANDOM

D I 5 I)

RTL

8151

TAD

L3152

DCA

8135

TAD

bl54
bl55

RTL

8156
8157

F3TL

DOA

FiAN2

3 I 4 LJ

TAD

RANI

2)141

AND

CT2+5

6142

•SNA

IAC
JMP I

®144

COMPARISON

720B

dl2l

•Lj 1 2 5

FOR

TAD

NUMBER

GENERATOR

RAN2

/TRIJNCATE
/TEST FOR
/IF ZERO,

RNUM

NO. TO 8 BITS
ZERO NO.
CHANGE T01

•`v`

-G
MAINDEC-08-D2GA-LA

8146
0 i `4 7
0158

RRB

PCF
TCF

NOP

8152
8156

NOP
KCC

gl54

JMP

/CLEAR I-0

/FOR

USER'S

FLAGS SR

SPECIAL

DEVICES

CLEF
/CONSTANTS TABLE 2
/FIRST RANDOM NUMBER SEED
/SECOND RN SEED
/CHAR COUNTER FOR TAPE FEED

/RN

CLEF
CTI

GT2
D

ERR
EI

E2
E3
E3A
FEED
HIGH
LOW

PUN
R
RANI

RAN2
RNUM

RPT

S2
TEN

MASK

+.f

MAINDEC-08-D2GA-D

FLOW CHART

i-,-

EEH
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