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DIGITAL-8-35-S

December 1965

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Document:	digital-8-35-s-d1
Order Number:	DIGITAL-8-35-S
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Pages:	18
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OCR Text

IDENTIFICATION
I .I

Digital-8-35-S-A

I .2

680 5-Bit Character Assembly Subroutines

I .3

November I 7, I965

PDP

8
LIBRARY

Digital-8-35-S-A
Page i
2

ABSTRACT

These subroutines concentrate Teletype data by assembling serial-bit data into 5-bit characters
They also add start

and presenting the user with data similar to that obtained by using a 630 and scanner.

and stop bits to 5-bit characters and transmit them in serial-bit fashion.

Full duplex lines are assumed, but

the subroutines can operate with half duplex if the user handles the expected echo.
3.

REQUIREMENTS

3 l

Storage

The subroutines as presently coded occupy 400 octal locations plus space for internal buffer—
of
the
ing
input and output characters and for the TTI instructions. In addition, space is used in memory
0
and
a limited number of autoindex registers are used as
page
explained below. Within the limits described,
the program can be placed anywhere in the first 4K of PDP-8 memory.

The total amount of memory used,

including the autoindex registers and the locations in page 0, is as follows:

4358

where n is the number of teletype lines to the next even multiple of eight lines if the number of lines is
not already an

even

multiple of eight.

Subprogra ms and/or Subroutines

3 2
.

Digital-8-35-S-B
680 8-Bit Character Assembly Subroutines for reference or when the user's requirements

include a mixture of 5-bit and 8-bit lines.
3.3

Equipment
Minimum configuration PDP-8
680 Data Communication

System hardware

1 to l28 5-bit Teletype lines

3.4

Miscellaneous
The tag TTSBGN must be defined as the address of the start of the Teletype subroutines.
be defined as anywhere in memory, but must be equivalent to the start of a PDP-8
memory page.

3.4.]
can

3.4.2

3.4.3

Teletype

Four autoindex

registers called T5AXl

T5AX2, T5AX3, and T5AX4 must be defined.

The tag TT5PGO must be defined as the start of an area in
constants can be stored.

An area of

memory page 0 where the necessary

268 registers must be reserved.

3.4.4

The tag T5OBF must be defined as the start of the area reserved for
outputting the Teletype
characters. It must be equal in length to the number of lines (even multiple of 8) attached to the
particular set of subroutines. It can be anywhere in memory and need not start at the
beginning of a
memory

page.

3.4.5

The tag T5OBF2 must be defined as an area equal in length to T5OBF.
the
buffering
output characters to allow maximum output rate.

3.4.6

numbers.

It is used for double-

The tag T5|BF must be defined as the area for storing
incoming Teletype characters and line
It must be equal in length to twice the number of lines attached to the
set of subroutines.

particular

Digital-8-35-S-A
Page 2
The tag T5|N must be defined as the start of the area used by the subroutines for generating
the appropriate number of TTI instructions. It must be equal in length to three times the number of lines

3.4.7

plus one register.

Here again it need not be defined as the start of a memory page.

3.4.8

The tag TTCHAR must be defined as a single register in page 0.

3.4.9

In the interrupt service routine the Following set or sets of instructions must appear:

/SK|P ON CLOCK FLAG
/TEST FOR NEXT INTERRUPT CAUSE
/JUMP TO APPROPRIATE CLOCK INTERRUPT ROUTINE

T5SKP
SKP
.

JMP T5D|S

Because of the speed necessary for Teletype handling, the checks for clock interrupts should be the first ones

interrupt service interrogation loop; the link bit and accumulator contents should not be saved prior
to interrogation of the appropriate clock flag.
If necessary for other interrupts, the link and accumulator
contents should be saved only after all clock interrupts have been checked.
in the

Clock lOT's

3.4.10

The lOT's to test the clock for a 1 state, turn the clock on, and turn the clock off must be

given the correct octal definitions:

Mnemonic

Clock l

Clock 2

Clock 3

Clock 4

T5S KP

642i

643i

644i

645i

TT5ON

6424

6434

6444

6454

TT5OFF

6422

6432

6442

6452

USAGE

4.2

Calling Sequence
The pseudo command T5|N|T must be executed before the instruction TT5ON and also before

either of the other pseudo commands T5SOF or T5S|R is executed (See Sections 4.4.l ,

4.4.2, and 4.4.3

for definitions of the pseudo commands.)

Switch Settings

4.3

None

Start up and/or Entry

4.4

Three pseudo commands for using this set of subroutines are provided to the main program

They

are

defined as

iumps to subroutines and their definitions and

instructions are included in the package.

These are the only commands necessary in the main program for gathering and outputting the Teletype

characters.

The user should note that no subroutines are included for packing or unpacking the characters

by word or even line number.
4.4.l

Teletype Initialize (T5lNlT)
This command (which must be used only once in the main program) assumes that the user

enters with

the number of lines in the accumulator and that the register following the initialize command

Digital-8-35-S-A
Page 3
contains the first line number for this type of Teletype line.
areas,

counters, and pointers,

4.4.2

This subroutine initializes all of the buffer

and generates the proper number of TTI instructions.

Skip if Output Free (T5SOF)

This instruction skips the next register in memory and transmits the character contained in
does
register TTCHAR if the indicated output line is free. If the output line is not free, the instruction
that the line number over which the character is to be transmitted be
The instruction
not

skip.

requires

The pseudo command takes 24 psec minimum
The accumulator is cleared when exiting from the command.

in the accumulator at the time the instruction is issued.

time, and 42 psec maximum time.
4.4.3

Skip if Input Ready (T5SIR)

This instruction skips the next location in memory and returns with the line number in the
accumulator and the character placed at TTCHAR if an input character is available. If no character is
and the contents of the accumulator equal —l
Only the low
available, the instruction does not

skip

additional bits representing the stop codes
The user should note that the bit structure of the character is reversed
are also present in the character.
from DEC's standard Teletype code. (For example, the character 0 does not appear as l5 in the low order
order 5 bits of the character at TTCHAR should be used,

5 bits, but as 26.

This special consideration may be important if the user is setting up any necessary con—

version tables.)

available,

If no character is available, l5 psec are used by the pseudo instructions; if a character is
37.5 psec are used; and if the end of the storage area is reached, a maximum of 48 psec are

used by the instruction.
5.

RESTRICTIONS

5 .l

Status Active Registers
The autoindex registers defined as T5AXI ,

T5AX2, T5AX3, and T5AX4 must not be disturbed

after the pseudo Operation T5INIT.
6.

DESCRIPTION

6 .l

Discussion

These subroutines are designed to accumulate 5-bit Teletype characters to and from multiple

Teletype lines connected to a PDP-8.

They handle input data in serial-bit format and present the user

with character and line identification.

The user presents the routines with line identification and chara-

cter format data and they transmit the information in serial-bit format.

Most of the PDP—8 memory is available for data buffering and for packing.
tion of the time,

however,

is used mainly in buffering the Teletype lines themselves.

A large propor-

Assuming only

minor data handling is necessary before transmission (possibly to a larger computer), present estimates
indicate that the user could handle I28 5-bit lines at 50 baud. Exact timing information is shown in

The user should note that the programming described involves the handling of the Teletype
lines only and does not include any packing or unpacking of words, lines, or messages. The main program
Section 9.

communicates with the Teletype subroutines via a group of pseudo commands which are described fully in
Section 4.4 with examples of their usage in Section 6.2.

If the user's requirements include mixed speeds of 5-bit lines, these subroutines must be dupli-

cated for each line speed.

Or, if a mixture of 5-bit and 8-bit lines is required, it is necessary that the
8-Bit Character Assembly Subroutines (Digital—8-35-S-B) be included with the user's programs and the
5-Bit Character Assembly Subroutines.

Digital-8—35-S-A
Page 4
6.2

Examples and/or Applications

6.2.I

To initialize the subroutines, coding similar to the following should appear in the user's

program:

TAD

/GET NUMBER OF LINES.
/|NITIALIZE SUBROUTINES.
/STARTING LINE NUMBER.
/ENABLE INTERRUPTS.
/TURN ON CLOCK.

NUMLIN

T5INIT
SLN

ION

TT5ON
To output a character,

6.2.2

TAD

CHARAC

DCA

TTCHAR

TAD

LINE NO

coding similar to the following should appear:

T5SOF
JMP

/GET OUTPUT CHARACTER.
/FOR OUTPUT SUBROUTINE.
/GET LINE NUMBER.
/OUTPUT, SKIP IF FREE.
/OUTPUT NOT FREE.
/CHARACTER ACCEPTED, CONTINUE.

OUTNA

CONTINUE

To test for an input character available,

6.2.3

/CHECK FOR INPUT.
/WAIT FOR A CHARACTER.‘
/SAVE LINE NUMBER.
/GET CHARACTER INPUT.
/37, CLEAR STOP BIT.

TSSIR
JMP

.-I

DCA

SAVLIN

TAD

TTCHAR

AND

THREE7

coding similar to the following should appear:

METHODS

7.I

Discussion

7.I .I

Input Character Assembly
The 5-Bit Character Assembly Interrupt Subroutine executes a TTI instruction for each line

selected every clock interrupt.

The program then scans one fourth of the TTI character

assembly words

When an assembled input character is found, the program shifts off
stores the character and line number in the input buffer, zeros the TTI status word and re-

for fully assembled input characters.
the start bit,
sets the
acter

character assembly word to 0400.

assembly word is zero.

Note that bit 3 is initially set to a I and the rest of the char-

As the input character is assembled bit by bit, the character assembly word

is shifted one position to the right for the start bit, each data bit, and the stop bit.
was

When the bit that

initially in the character assembly word can be set into the link by a RTR, the character is fully

assembled.
7.I .2

Output Character Handling

Initially, the pseudo operation T5SOF adds start and stop bits to the output characters and
places the characters in the second output buffer (T5OBF2). Eventually, the interrupt subroutine transfers
the characters from the second output buffer to the first output buffer (T5OBF). In the interrupt subroutine,
the program outputs on one eighth of the lines selected every clock

the program outputs a data bit every eight clock interrupts.
is zero, there is no output on that line.

interrupt. That is, for any one line

If the first output buffer location for a line

After 56 clock interrupts (7 bit times), the program halts the outeach
of
and
the
next
utilizes
four interrupts (one half bit time) to scan one fourth of the second
put process

Digital-8-35—S-A
Page 5
buffer location for a line is zero,
output buffer for new output characters. Again, if the second output
there is no output. When a location is found that is non-zero, the character is placed in the first output
buffer and the second output buffer location is set to zero.
8.

FORMAT

8.1

Input Data (T5SIR)
If the pseudo operation T5S|R skips, the input data is the following format:

8.1.1

The accumulator contains the line number.

8.l .2

The lower five bits of the register TTCHAR contain the input character.

(See NOTE in

Section 8.3)
8.3

Output Data (TSSOF)
The user presents the pseudo operation T5SOF with output characters in the following format:

8.3.1

The lower five bits of the register TTCHAR contain the output character.

8.3.2

The accumulator contains the number of the line on which the character is to be output.

NOTE:

As mentioned in Section 4.4.3, the bit structure of the 5—bit codes
These subroutines present the user with this reversed

is reversed from standard.

code and similarly expect the user to present them with the

reversed code.

EXECUTION TIME
9.1

Minimum

9.2

Maximum

9.3

Average

The table below indicates the percentages of machine time used for two Speeds of 5-bit
systems and is as accurate as presently possible. Any additional features which may be required for the

Teletype handling would add appreciably to the times shown:
TIMING TABLE

Numbers indicate the percentage of available machine time used in the average case.

No. of Lines

5-Bit 50 Baud

5-Bit 75 Baud

20.0%

30.0%

35 1%

52 7%

50.3%

75.5%

I 28

65 5%

98 3%

Digital-8-35-S-A
Page 6
9.4

Timing Equations

9.4.1

50 Baud Rate

Where
11 .85n + 120 psec.

9.4.2

the number of lines, the 5-bit subroutines
Clock flags (at 50 baud) occur every 2500 psec.
n

require an average time of

75 Baud Rate
The percentages for 75 baud are merely 1 .5 x 50 baud rate.

Clock flags occur every

1667 psec.

10.

PROGRAM

10.3

List of Items and Pseudo Commands

10.3.1

List of Items
Start of

TT5BGN

subroutine, must be equated to the start of a page.

Area includes 2 pages.

10.3.2

T5AX1

Autoindex register.

T5AX2

Autoindex register.

T5AX3

Autoindex register.

T5AX4

Autoindex register.

TT5PGO

Start of constant

T5OBF

Start of output buffer (Length

TSOBF

Start of second output buffer (Length

T5|BF

Start of input buffer (Length

T5|N

Start of TTI area (Length

TTCHAR

Character area page 0 (Single register).

area

in page 0.

n).
=

n).

2n).

3n +

11).

List of Pseudo Operations

Operation

Meaning

Times (User's)
Min.

TSINIT

Initialize

N.A.

TSSOF

Skip if output free

TSSIR

Skip if input ready

Av.

37.5

Max.

42
48

Digital-8-35-S-A
Page 7
10.4

Program Listing
/TYPE 68O TELETYPE LINE MULTIPLEXER
/CHARAC TER ASSEMBLY ROUTINE
5 BIT
/LMH
910/15/65
TTI:6402
TTO:64O 4
TTCL=64 11
TTRL=64 14
TTSL=64 12
TT5ON:6 424
IT5OFF:6422
T5SKP:6 421
TTINCR:6401

/TELETYPE INPUT COMMAND
/TELETYPE OUTPUT COMMAND
/CLEAR LINE REGISTER
/READ LINE REGISTER
/SET LINE REGISTER, CLR AC
/TURN CLOCK ON
/TURN CLOCK OFF
/SKIP ON CLOCK FLAG
/INCREMENT LINE REGISTER

/65O LINE MULTIPLEXER
/LIST OF ITEMS
TSIBF27 2OO
T5OBF227000
TSOBF266OO
T5IN=56OO
TT5PGO=145
T5AX121 O
T5AX2=1 1
T5AX321 2
T5AX4:1 6
TT5BGN252OO
TTCHAR: 177
*TI5PGO
O145
3146
O147
O15O
O151
O152

OOOO
7177
OOOO
54OO
5425
5447

O155
O154
O155

66OO
7774
OOOO

O156
O157
316O
O161
O162
O165

OOOO
O177
7000
OOOO
OOOO
777O

Ol64
O165

56OO
7776

Ol66

O4OO

@167
Ol7O
3171
3172
Ol75
O174
O175
9176

66OO
5221
OOOO
6577
5267

5561

5221
7000

TBINFL,
ISBFK,
ISNL,
TSSOUT,
T551N,
T560,
TSOUTK,
TSCNTI,
TSCNTZ,
ISCNTS,
TSKIO,
ISKSS,
ISCNTS,
ISCNTS,
TBKZ,
T5K5,
ISKi,
ISKS,
I5K7,
15KB,

ISKS,
ISKSA,
ISKSB,
TSKSC,
T5K9D,
TSKSE,

/INPUT READY FLAG
/TO RESET INPUT BUFFER POINTER
O
/-NUMBER OF LINES
TSOUTS
/SKIP IF OUTPUT FREE
T5INS
/SKIP IF INPUT READY
T5GOS
/INITIALIZE ROUTINE
TSOBF
/POINTER TO IST OUTPUT BUFFER
-4
/HOLDS MAJOR LOOP COUNTER
O
/MINOR LOOP COUNTER
O
/COUNTER FOR INPUT BUFFER
177
/FOR ANDING
TSOBF2
/2ND OUTPUT BUFFER
O
/OUTPUT COUNTER
l7 BIT COUNTER
O
-1O
/TO RESET BIT COUNTER
T51 N
/RESET INPUT TTI POINTER
-2
/FOR SUBTRACTION
AOO
/IO RESET 5 BIT ASSEMBLY WORD
TSOBF
/K FOR 1$I OUTPUT BUFFER
TSCOM
/TO ENTER COMMON ROUTINE
O
/LINE NUMBER -1
TSOBF-l
/FOR CLEARING
T5CM1A
/TO AVOID OUTPUTTING
JMP T5CM1O /TO SET OUTPUT BUFFER FROM DOUBLE
TSCOM
/FOR NORMAL RETURN
NOP
/TO DO INPUT ONLY
O

TSIBF-l

BUFFER

Digital-8-35-S-A
Page 8
*TTSBGN

/MULTIPLE LEVEL

INTERRUPT

/ALLOWS MULTIPLE LEVEL
/AND UNLIMITED

5230

2566

ISZ

T5LC

5201

5216
5567
7216
5572
1600

JMP
DCA
RAR
DCA

T5DIS5
TSSA

TAD

5571
6414
5572
6424
6821
1171
6415
5564

DCA

5282

5285
5254
5225
5296
5207

5210
5211
5212

5215
5214
5215

T5DIS,

/
/

/GET

T5SVO
TTRL
DCA T5SVLN

6951

INTERRUPT
IT5ON
ION

522%

5409

JNP

5221
5222
5225
5224
5225
5226

1575
5155
1575

5227
5252
5251

5551
6405
5555

5252
5255
5254

2155
2155
5225

JMP

5255
5256

6414
5575

DCA

5257

1574
5155
2013

/2ND

LEVEL

TSDIS5,

5240
5241

5242
5245
5244
5245
5246

5247
525%

/SAVE LINK
INTERRUPT ADDRESS

SAVE
-

SET

FROM

JMP T5COM8
TTO+1
DCA 1 z TSOUTK
z Isourx
z T5CNI2
TSCOME

ISZ
ISZ

TSCOMI,

TTRL
T5LN

140

7220

Ismwcb
DCA T5CNT2
1
52 T5AX1
ISCJNz,
[AD I z T5AX1
/
CLL RIR
SZL
JMP Iscams
CLA

7229

Iscoms,

NOP

141%
745%
5526

ISZ z TSAXI
ISZ T5LN2
ISZ ISCNTZ

201%

5251
5252
5255

2576
2155

5254
5255
5256

2154
551%
1164

/-NO. OF LINES/8
/MINOR LOOP COUNTER
/LINE NUMBER

TSCOM,

TSCNIA,

7112

ADDRESS
/READ LINE NUMBER
/SAVE LINE NUMBER
/TO CLEAR CLOCK FLAG ONLY
/RE-ENABLE PROGRAM INTERRUPT
/SIARTING LINE-1
/SET LINE REGISTER, CLR AC
LINE REGISTER, CLR AC

/CLEAR CLOCK FLAG
/RE-ENABLE PROGRAM INTERRUPT
/RETURN TO THE MAIN PROGRAM”

INPUT TII LOOP
TAD T5MNC
DCA z Tscurz
TAD T5LN
/ SET
TTSL+1
TAD I z TSOUTK
T5COM2,
SNA

/RETURN

6415
1555
745G

ROUTINE

TTSL+1
I Z T5K5

JMP

THIS

LEVEL COUNTER
/2ND LEVEL INTERRUPT
SAVE ACCUMULATOR

TTSON
ION
TAD T5K9

T5DIS2,

LINK

T5SVLK
O

5216
5217

6424

ROUTINE

INTERRUPT

5241

T5COM4,

JMP

TSCOMZ

ISZ

T5CNT1
T5COM5
sts

JMP
TAD

LINE NUMBER
/OUTPUT WORD
/CHARACTER AVAILABLE

/NOTHING TO TRANSMIT
/INCREMENT AND TRANSMIT
/RESTORE CHARACTER
/UPDATE OUTPUT POINTER
/ARE ONE-EIGHTH OF LINES DOE
/CHECK NEXT OUTPUT LINE
/READ LINE NUMBER
/SAVE LINE NUMBER
/NO OF LINES/4
/MINOR LOOP COUNTER
/
ADVANCE FOR NEXT INPUT
/CHARACTER ASSEMBLY WORD
PUT BIT 1% IN LINK
/CHARACTER NOT COMPLETED
/STORE CHARACTER
/CLEAR AC FOR TAU

/OR JMP T5CM16
/UPDATE FOR NEXT INPUT LINE
UPDATE LINE NUMBER
/ARE ONE-FOURTH OF LINES
/CHECK NEXT LINE
/HAVE ALL INPUT LINES BEEN
/RESET AND DISMISS
/T51N

Digital-8-35-S-A
Page 9
DCA Z T5AX1
Z T5K9

/RESET TTI POINTER
LINE-1
LINE
/RESET LINE NUMBER

5257
262
5261

5212
1171
7221

5262
5265

5576
1577

DCA
TAD

5264

5154
2161
5512
1165
5161
1171
5575
2162
5555
1165

DCA T5CN11
ISZ Z T5CNT5
JMP T5COM5
TAD Z T5K5
DCA Z T5CN15
TAD Z T5K9
DCA TSLN
ISZ Z TSCNTS
JMP T5COM9
TAD T5K4

5162
2161
1172

DCA Z T5CNT6
ISZ Z T5CNT5
TAD Z T5K9A
DCA Z T5AX4
TAD Z T5K56
DCA T5OUTK
TAD Z TSKSB
DCA Z T5K8
TAD Z T5K9C
DCA T5COM5
IOF

/INPUT CHECK COUNTER
/HAVE ALL OUTPUT LINES BEEN
/RESET AND DISMISS
/-2
/RESET COUNTER
/START LINE-1
/RESET LINE NUMBER
/ENDING 7TH BIT?
/NO RESET NORMALLY
/-12
/RESET COUNTER
/ADD 1 T0 COUNTER
/TSOBF-1
/OUTPUT POINTER
/TSOBF2
/2ND BUFFER POINTER
/SPECIAL ADDRESS, TSCMIA
/RESET ADDRESS
/JMP TSCMLO
/SET TO DO OUTPUT
/TURN OFF INTERRUPT

STA

/-1

5265

5266
5267
5272
5271
5272
5275
5274
5275
5276
5277
5522
5521
5522
5525

1162
5155

‘5526
5527
5512
5511
5512
5515
5514

1566
5566
1566

5515
5516
5517

7722
5212
1572

5522
5521
5522

6415
1572
7124
1567
6221

5525
5524
5525

IA C

5215

1175
5172
1174
5247
6222
7242

5524
5525

TAD

T5COM5,

7112
7212

5552
5551
5552
5555
5554

5411
1576

T5LC
T5LC
TAD T5LC
SMA CLA
JMP T5DISZ
TAD TSSVLN
TTSL+1
TAD TSSVLK
CLL RAL
TAD

TSSA

ION
JMP

I
C

T5COM6,

T55V2
LL RTR

FIRST

/-4

/LEVEL COUNTER
/RESTORE LEVEL COUNTER
/LEVEL COUNTER
/RESTORE AC, ETC.
/CHECK INPUT AGAIN, ETC.
/LINE NUMBER
/SET LINE REGISTER, CLR AC
/PICK UP LINK
/RESTORE LINK
/RESTORE AC
/RE-ENABLE PROGRAM INTERRUPT
/RETURN TO THE MAIN PROGRAM
/ REMOVE START CODE

RTI \

5555

5411
1212
1165
5212

DCA
TAD
DCA
TAD
TAD
DCA

5556
5557
5542

5412
1166
5412

DCA
TAD
DCA

5541
5542
5545

2145
2156
5247

ISZ
ISZ
JMP

5544
5545

1146
5211

5546
5547
5552

5156
5247

1147

TAD
DCA

5771

5526
5527

/SET
T5LN2
T5K2A

'/START

T5COM7,

I Z T5AX2
T5LN2
Z T5AX2
T5AX1
T5K5

NHNHNNH

T5AX1
Z T5AX1
T5K6

Z T5AX1
T5INFL
T5CN15
T5COM5

Z T5BFK
Z T5AX2
TAD T5NL
DCA Z T5CNT5
JMP T5COM5
TAD
DCA

/STORE CHARACTER
/LINE NUMBER
/STORE LINE NUMBER
/TTI POINTER
/-2
/RESET POINTER
/ZERO STATUS AND COUNTER
/wORO TO RESTORE ASSEMBLY NB
/RESET CHARACTER ASSEMBLY wB
/SET INPUT READY FLAG
/HAS END OF BUFFER BEEN READ
/CONTINUE
/TSIBF-l
/RESET INPUT BUFFER ADDRESS
/-NUMBER OF LINES
/RESET LENGTH COUNTER
/CONTINUE

Digital-8-35—S-A
Page 10
5551

6401

I5CUM3,

5552
5555
5554

5252
1167
5155

I5COM9,

5555
5556

1175
5170

5557

1176

5560
5561
5562

5507
1555
5415

5565
5564
5565

5555
2155
5250

5566

7777

5567
5570
5571

0000
0000

5572
5575
5574
5575
5576

0000
0000
0000
0000

5577

7774

T5CM10,

TTINCR
JMP TSCOMI
TAD z T5K7
DCA z TSOUTK
TAD z I5K9D
DCA z T5K8
TAD z T5K9£
JMP TSCOMS-l
T AD 1 z
DCA I z T5AX4
DCA 1 TSOUTK
ISZ T5DUTK
JMP ISCOM5+1

TSOUTK

/INCREMENT LINE NUMBER
/CONTINUE
/T5OBF
/RESET OUTPUT POINTER
/NORMAL ADDRESS, T5COM
/RESET ADDRESS
/NOP
/CONTINUE
/2ND BUFFER CHARACTER
/STORE IN 1$T BUFFER
/CLEAR 2ND BUFFER
/UPDATE POINTER
/CONTINUE

/CONSTANTS

0000

T5Lc,
T5SA,
TSSVLK,
TSSVO,
TSSVLN,
TSMNC,
ISMNCZ,
T5LN,
f5LN2,
TsxaA,

/INTERRUPT LEVEL COUNTER
/SAVE ACCUMULATOR
/SAVE LINK
/SAVE PROGRAM COUNTER
/SAVE LINE NUMBER
/-NO OF LINES/B
/-NO OF LINES/4
/LINE NUMBER FOR OUTPUT
/LINE NUMBER FOR INPUT
/TO RESET MAJOR LOOP COUNTER

-1
D
D
D
D
D
D
D
D
-4

/PSEUDU-OPERATIONS
*TTSBGN+200

/SKIP IF OUTPUT IS FREE AND TRANSMIT CHARACTER AT
/DON'T SKIP LINE NUMBER MUST BE IN AC. 24US MIN.,
T5SOF:JMS 1 z TSSOUT
5400
5401

5402

5405
5404
5405
5406

5407
5410
5411
5412

5415
5414
5415

5416
5417
5420
5421
5422

0000
0157
1217
1160
5220
1620
7640
5600
1177
0221
1222
7104
5620
2200
5600
0000
0000
0057

0040

5425
5424

0000
6002

5425

7240

TSOUTS,

42US

MAX.

AND
TAD

T5SL,
TswA,
T5Kll,
T5K12,

TTCHAR,

2 T5K1D
TSSL

TAD z T5K56
DCA TswA
TAD T TswA
SZA CLA
JMP I TSOUIS
TAD z TTCHAR
AND T5Kll
TAD T5K12
CLL RAL
DCA 1 TswA
ISZ ISOUTS
JMP 1 Tsours
D
D
57
40

/177
/-STARTING LINE NUMBER
/OUTPUT BUFFER ADDRESS
/WORK AREA
/OUTPUT CHARACTER
/SKIP IF FREE
/EXIT
/PICK UP CHARACTER
/5 BITS ONLY
/140 FOR STOP CODE
/CHEATE START CODE
/STORE CHARACTER IN TABLE
/INDEX EXIT

/EXIT
/-STARTING LINE
/WORK AREA
/FOR 5 BIT CODE
/FOR STOP CODE

NUMBER

/SKIP IF CHARACTER AVAILABLE AND RETURN WITH LINE
OTHERWISE DO NOT SKIP
/CHAR AT TTCHAR.
/15us MIN., 48US MAX., 57.5US NORMAL IF READY
T5SIR:JMS I z TSSIN
D
T5INS,
IOF
7/ SET AC FOR TAD-l
CLA CMA

NUMBER

ING

Digital-8-35-S-A
Page 11
5426
5427
5455

5451
5452
5455

5454
~5455
5456
5457
5445
5441
5442
5445
5444
5445
5446

1145
751%
5244
5145
2246
5243
1147
5246
1146
5612
1412
5177
1412
2225
6021
5625
993%

ANPUT FLAG COUNTER-l
TSINFL
/SOMETHING AVAILABLE
T5INON
DCA Z TSINFL
/RESTORE FLAG COUNTER
ISZ T5CNT4
/END OF BUFFER?
START
JMP .+5
/GET CHARACTER
TAD Z T5NL
/-NUMBER OF LINES
DCA TSCNT4
/RESET COUNTER
TAD Z TSBFK
/BUFFER ADDRESS-1
DCA Z T5AX5
/RESET ADDRESS
TAD I Z T5AX5
/PICK UP CHARACTER
DCA Z TTCHAR
/STORE CHARACTER
TAD I Z T5AX5
/PICK UP LINE NO.
ISZ 151N6
/INDEX EXIT
1
ON
151N0N,
JMP 1 151N6
/EXIT
5
/-NUMBER OF LINES
150N14,
/INITIALIZATION ROUTINE
/ENTER WITH NUMBER OF LINES IN AC
TAD
SPA
JMP

T5INIT
IST LINE

/FORMAT
/

TSINITzJMS
5447

OOOO

5455

@555

AND

5451
5452
5455

5147
1147
@556

DCA
TAD
AND

5454
5455
5456

7642
1557
1147

5457
5465
5461
5462
5465

O56D
7041
5147
1147
5156
1561

5464

NO.

1560

15K14

z 15NL
z 15NL
15x15
SZA CLA
TAD T5K16
TAD z 15NL
AND 15x17
CIA
DCA z 15NL
1AD z 15NL
DCA z T5CNT5
140 15K25
DCA z 154x1
TAD 15K21

5465
5466
5467

5010
1562
5011

_DCA

5475
5471

1AD
DCA

15K57

5472
5475
5474
5475
5476
5477
5555

1575
5012
1147
5246
1565
541%
541%
1166
541%

5551
5552
5555

5411
5412
2246

5554
5555

15Ax2

15AX5
TAD z TSNL

T5G02,

DCA
TAD
DCA

T5CNT4
15x22
1 z 154x1
DCA 1 z 15Ax1
1A0 z T5K6
DCA 1 z 15Ax1
DCA
DCA

15Ax2
154x5

5274
1564

JMP
TAD

5556

5410

15602
15K24
1 z 15Ax1

5557

1147
7G12

DCA
1AD z
RTR

5515

-B

15006,

T5601,

ISZ

1 z
1 z
150N14

15NL
-

/577
/N0.
/NO.

OF
OF

LINES
LINES

/MULTIPLE OF 8
/15
/N0. OF LINES
/575
/TWO'S COMP. NUMBER OF LINES
/-N, CONSTANT
/-N
COUNTER
/T51N-1
/TO STORE TTI TABLE
/TSOBF-1
/TO CLEAR OUTPUT AREA

/TBOBF2-1
/TO CLEAR

DOUBLE BUFFER

/-N
/FOR COUNTING
/TTI+INCR
/STORE TTI

/CLEAR STATUS WORD
/ASSEMBLY RESET WORD
/RESET ASSEMBLY WORD
/ZERO OUTPUT WORD
/CLEAR DOUBLE BUFFER
/COUNTER
/DO NEXT LINE
/JMP I Z T5K8
/STORE FINAL JUMP
/-N
/-N/4

Digital-8—35-S-A
Page 12
5511

7OIO

RAR

5512
5515

0565
1566

ANJ
TAO

T5K25
T5K26

/776B,

MAKE

5514
5515
5516

5767
1767
1767

DCA
TAD
TAU

I
I
I

T5K27
T5K¢7
T5K27

/T5MNC
/T5MNC
/T5NNC

'N/4

5517
552%
5521
5522

5774

DCA

I5K58

/T5MNC2

724C
5246
1146

STA
DCA

5525
5524

5011
157%
5154

5525
5526
5527
5553

1165
5161

5551
5552
5555

531%

5554
5555
5556

5557
5546
5541
5542
5545
5544
5545
5546
5547

T5CNT4
TAD Z T5BFK
DCA Z T 5AX2
TAD T5K28
DCA Z T5CNT1
TAD Z T5K5
DCA Z T5CNT5
TAD Z T5K5

1164

5162

5553
5551
5552
5555
5554

1175
517%

5555

$577
OOO7

NEGATIVE

/-1
/SET CNTR TO SKIP 151
/TSIBF-l
INPUT BUFFER POINTER

/SET

TIME

/-4

/MAJOR

LOOP

COUNTER

/-2

DCA Z T5OUIK
STA
TAU I T5GOS
DCA Z T5K9
TAD Z T5K9
CMA
DCA TSSL
DCA Z T5INFL
STA
DCA I T5K55
ISZ TSGOS
TAD T5K55A
DCA
TSCNT6
TAD
T5KSD
DCA
T5K8
TAU
T5K9E
DCA
T5K4O
JMP
T5605

577

/FOR

19
57C

/POB
/FOR
/FOR

Z TSAXI
T5K7

HNN

1176
5775
5647

NUMBER

/OUTPUT COUNTER
/T5IN+1
/SET TTI POINTER
/T508F
/SET OUTPUT BUFFER POINTER
/-1
/STAHTING LINE NUMBER
/STARTINO LINE NO-l
/STARTING LINE -1
/MAKE NEGATIVE
/-S TAHTI NO LINE NUMBER
/CLEAR INPUT FLAG COUNTER
/-1
/T5LC, RESET INTERRUPT LEVEI
/INDEX EXIT
/-7
/SET SPECIAL 5-BIT COUNTER
/T5COM
/TII RETURN
/NOP
/TSCOM5
/EXIT

DCA
TAD

1167
5155
724%
1647
5171
1171
734$
5217
5145
724%
5771
2247
1572

/-N/8
/17

/CONSTANTS
5556
5557
556C
5561
5562
5565

5564
5565
5566

5567

557U
5571
5572
5575
5574
5575

OOIO
@573
5577

6577
6405
5573

@317
7762
5575
7774
5566
7771

6777
5574
5247

I5K14,
T5Kl5,
I5K16,
T5K17,
TSKZG,
TSKZI,
T5K22,
T5K24,
TSKZS,
15K36,
T5K27,
TSKZB,
I5h55,

T5IN -1

T5OBF-1
TTI+1
JMP I Z
17
7763
T5MN C
-4

I5LC

T5K8

/FOR

ANDING
EVEN MULTIPLE
EVEN MULTIPLE
EVEN MULTIPLE
STORING TTI'S
OUTPUT AREA

/FOR

FINAL JUMP

/POB
/FOR

-N/B
MAKINO

/POB

-N/B

/POB
xPOB

MAJOR LOOP COUNTER
INTERRUPI LEVEL COUNTER
5-BIT COUNTER
DOUBLE BUEPEB
-N/4
SWITCH

B
8
B

III

IBKOBA

-7

/PON

I5K57,

TSOBPz-I
T5MN C2
T5COM5

/FON
xPON
/FJd

I5K53,
15K4Z,

OF
OF
OF

NEGATIVE

Digital-8—35-S-A
Page
I I

DIAGRAMS

II .1

Flow Charts

ENTER

TSDIS

TSDISB
2ND
LEVEL INT

YES

CLR CLOCK
ION

SAVE AC LINK
LINE NUMBER
EXIT ADDRESS

CLEAR CLOCK
ION SET STARTING
LINE NUMBER
MULTIPLE EXIT DUE TO
7 1/2 CHARACTER TIME

[

TEST 5 an"
INPUT LINES EXIT
JMP IZTSK

SET

T5CM1A

TSIN

SET MIN LOOP

\ 0”

COUNTER = 1/4
# LINES

UNE

RECmTER

T5COMO
OUTPUT

CHARACTER
AVALABLE
?

YES

T5COM8
INCREMENT UNE
REGSTER

TRANSMTT

&
SAVE

REST OF

CHARACTER

|NCREMENT
UNE REmSTER

T5COMI
UPDATE OUTPUT

POINTER

1/8 OF

LINES

DONE

Digital-8-35-S-A

T5COM2
IS
INPUT CHAR
FULLY

YES

ASSEMBLED

2
NO

T5COM6
REMOVE
START CODE

CLA

&
8

TSCMIO

TSCOMS

NOP 0R
TSCMIO

JMP

PICK UP OUTPUT
2ND BUFF R
PUT IT IN IST AND
CLR 2ND BUFFER

IL
STORE CHARACTER
AND LINE NUMBER
.

I
ADVANCE
INPUT POINTERS
AND LINE NO.

I
INCREMENT 2ND
BUFFER POINTER

TESTED
OF LINES
FOR INPUT

ZERO STATUS AND
COUNTER LOAD SET
CHAR ASSEM FLAG

RESET BUFFER
ADDRESS AND
INDEX INPUT

YES

END

SET INPUT
READY FLAG

OFINPUT
BUFFER

1/4

YES
T5COM4
HAVE
ALL LINES
BEEN CHECKED
FOR INPUT
P

LD AC WITH
A NOP

RESET TTI POINTER
LINE NUMBER AND
INPUT CHECK

RESET T5K8
TO T5COM

HAVE
ALL OUTPUT

LINES BEEN
CHECKED

LD AC WITH

T5CMIO

T5COM9
RESET OUTPUT
BUFFER POINTER

RESET T5K8
TO TSCMIA

(T5CNT6)=-IO
RESET T5CNT5
TO -2

ENmNG
7TH an

RESET T5CNT6
TSCNT + 1

AX4 = OBF -1
T50UTK=OBF2

RESET OUTPUT
BUFFER POINTER

Digital-8-35-S-A
Page 15

DCA
T5COM3

T5COM5
IOF

INT

LEVEL

COUNTER-1

INTERRUPT
LEVEL S TO

PRogESS

RESET LINE N0
AC 5 LINK

ION

12.

REFERENCES

12.]

Other Library Programs

Digital-8-35-S-A
680 5-Bi’r Character Assembly Subroutines

AC 3 NOP OR
JMP T5CM10