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DIGITAL-8-6-U

December 1965

10 pages

Original

0.2MB

Document:	digital-8-6-u-d
Order Number:	DIGITAL-8-6-U
Revision:
Pages:	10
Original Filename:	https://svn.so-much-stuff.com/svn/trunk/pdp8/src/dec/digital-8-6-u/digital-8-6-u-d.pdf

OCR Text

IDENTIFICATION

1.1

Dig ita I-8-6- U- Sym

1.2

Octal Memory Dump

1.3

March 17, 1965

IPDP-8/
LIBRARY

D i g ita I-8-6-U-Sym
Page 2

ABS TRAC T

This routine w i l l read the console switches twice to obtain the upper and lower
limits o f an area o f memory, then type on the Teletype an absolute address plus the octal contents of the first four words specified and repeat this u n t i l the block i s exhausted, a t which time
the user may repeat the operation.

REQUIREMENTS

3.1

Storage

This routine requires 77 core locations.
3.3

Equipment
Basic PDP-8 w i t h ASR 33.

USAGE

4.1

This routine i s loaded with the Binary Loader. (See Digital-8-2-U-Rim
\

for a

complete discussion o f the Binary Loader and i t s use.)

4.2

Cal Iing Sequence
None.

4.3

I t cannot be called as a subroutine.

Switch Settings

The switch register is used to enter the starting address. It i s also used to enter
two delimiting addresses which define the area o f memory to be typed.

4.4

Start Up/Entry
Assuming the program i s i n memory, proceed as follows:

4.4.1

Set the starting address in the switch register and press the LOAD ADDRESS key.

4.4.2

Set the low address into the switch register and press the START key.

The computer w i l l halt. Set the high address into the switch register and press
4.4.3
the CONTINUE key.

4.4.4

I isted .

Typeout w i l l occur and the computer w i l l halt when the designated block has been

To type another block, set the low address into the switch register and press the
4.4.5
CONTINUE key.

4.4.6

Repeat step 4.4.3 above.

Dig ita I-8-6-U-Sym
Page 3

DESCRl PTlON

6.1

Discussion
Reference to the Flow Charts (Section 11.1) w i l l illustrate the following discussion.

Three inner subroutines are used. These are tagged TYPN, CRLF, and PNUM.
Respectively, these subroutines cause a d i g i t to be typed, cause a carriage return followed by
a line feed to be typed, and control the typeout of a 4-digit octal number, i.e., either a
memory address or data stored i n a single word i n memory. PNUM i s illustrated w i t h a flow
chart. The other two subroutines are composed o f a few instructions only.
M a i n routine flow i s as follows. After initialization, a carriage return line feed
i s typed. Next, the starting address followed by several spaces i s typed. A loop i s next entered
to type the contents of four memory locations (if four remain to be typed). If during the latter
loop the routine finds i t has processed the last memory location, the loop exits, a carriage
return line feed i s typed, and a JMP to ODUM executed.

If after typing the contents o f four successive addresses there remains more data
to be typed, a JMP to DUM2 repeats the process.

6.2

Example

The O c t a l Dump routine was used to dump itself as follows:
Address

7400
7404
7410
7414
7420
7424
7430
7434
7440
7444
7450
7454
7460
7464
7470
7474
7500
7504
7510
7514

Four Data Words

7200
7404
5213
3260
1265
2247
466 1
2257
5200
5243
7200
424 1
7774
0240
1265
7004
0313
2310
0000
0260

7404
7040
2260
4247
3247
5222
1264
521 1
7433
7200
1263
5647
7466
7774
3310
7006
1314
5274
0000

3256
1256
5226
1256
1264
7200
424 1
4247
6046
564 1
424 1
7456
0212
743 1
1311
331 1
4712
7200
744 1

7402
3257
1265
466 1
424 1
1656
2256
7402
6041
0000
1262
774 1
0215
331 1
7004
1311
131 1
5666
0007

Digital-8-6-U-Sym
Page 4

FORMAT

8.1

External Data
See the example in Section 6.2.

EXECUTION TIME
This routine i s entirely output limited.

10.

PROGRAM

10.4

Program Listing

7400
740 1
7402
7403
7404
7405
7406
7407
7410
741 1
7412
7413
7414
7415
7416
7417
7420
742 1
7422
7423
7424
7425
7426
7427
7430
743 1
7432
7433

7200
7404
3256
7402
7404
7040
1256
3257
5213
2260
5226
1265
3260
4247
1256
466 1
1265
3247
1264
424 1
2247
5222
7200
1656
466 1
1264
424 1
2256

*7400
ODUM,

DUM2,

DUM3,

CLA
OSR
DCA LOCK
HLT
OSR
CMA
TAD LOCK
DCA LIM
JMP .+3
ISZ LPCN
JMP DUM3
TAD CONS+3
DCA LPCN
JMS CRLF
TAD LOCK
JMS I PRlN
TAD CONS+3
DCA CRLF
TAD CONS+2
JMS TYPN
ISZ CRLF
JMP .-3
CLA
TAD I LOCK
JMS I P R l N
TAD CONS+2
JMS TYPN
ISZ LOCK

/GET LOWER LIMIT
/GET UPPER LIMIT

/INITIALIZE RANGE COUNTER
/END OF LINE
/-4
/RESET ITEM COUNTER
/CARR. RET. AND LINE FEED
/INTER-COM.
/-4

TO PNUM

/240 (SPACE)

/INTER-COM.
/240 (SPACE)

TO PNUM

/INDEX LOCATION POINTER

Digi ta I -8-6-U-S ym
Page 5
7434
7435
7436
7437
7440
744 1
7442
7443
7444
7445
7446
7447
7450
745 1
7452
7453
7454
7455
7456
7457
7460
746 1
7462
7463
7464
7465
7466
7467
7470
747 1
7472
7473
7474
7475
7476
7477
7500
7501
7502
7503
7504
7505

2257
521 1
4247
7402
5200
0000
6046
6041
5243
7200
564 1
0000
7200
1263
424 1
1262
424 1
5647
0000
0000
0000
7466
0212
0215
0240
7774
0000
331 1
1265
3310
131 1
7004
7004
7006
331 1
131 1
0313
1314
471 2
131 1
231 0
5274

ISZ LIM

TYPN,

CRLF,

LOCK ,
LIM,
LPC N,
PRIN,
CONS,

PNUM,

PNU2,

JMP DUM2
JMS CRLF
H LT
JMP ODUM
0
TLS
TS F
JMP .-1
CLA
JMP I TYPN
0
CLA
TAD CONS+l
JMS TYPN
TAD CONS
JMS TYPN
JMP I CRLF
0
0
0
PNUM
212
215
240
7774
0
DCA PTEM
TAD CONS+3
DCA DCN
TAD PTEM
RAL
RAL
RTL
DCA PTEM
TAD PTEM
AND PCON
TAD PCON+l
JMS I TDlT
TAD PTEM
ISZ DCN
JMP PNU2

/END OF RANGE

/GO AGAIN
/TYPE CHARACTER SUBROUTINE

/CR AND LF SUBROUTINE
/215 (CARR. RET.)
/212 (LINE FEED)

/INTER-COM.
/CONSTANTS

TO PNUM

/PRINT NUMBER SUBROUTINE
/-4
/INITIALIZE DIGIT COUNTER

/7
/260
/TYPN (TYPE A DIGIT)

Digitu I-8-6-U-Sym
Page 6

7506
7507
7510
751 1
7512
7513
7514
CONS
CRLF
DC N
DUM2
DUM3
LIM
LOCK
LPC N
ODUM
PCON
PNUM
PNU2
PRI N
PTEM
TD I T
TYPN

7200
5666
0000
0000
744 1
0007
0260
7462
7447
7510
741 1
7426
7457
7456
7460
7400
7513
7466
7474
746 1
751 1
7512
744 1

DCN,
PTEM,
TD I T,

CLA
JMP I PNUM
0
0
TYPN
7
26 0

/DIGIT COUNTER
/C o NSTA NTS

Digi ta I -8-6-U-Sym
Page 7

11.

DIAGRAMS

11.1

Flow Charts

11.1.1

Main Flow

eJ ,
ENTER

ODUM

INITIALIZE

YES&

TEST LINE

TYPE CR LF

1
LOAD ADDRESS

TYPE DATA

e
TYPE SPACE

cr'
TYPE SPACE

Digi ta 1-8-6-U-Sym
Page 8

11.1.2

PNUM Subroutine

ENTER

PNUM

e3
EXTRACT DIGIT

5FORM CHARACTER

TEST 4
DIGITS
YES

RETURN