burroughs B9351 User manual
Burroughs -B9351
/B9353
Input
and
Display System Technical Manual
INTRODUCTION AND OPERATION -SECTION I
Communication
Options
.
Communication
Procedures
Functional
Description .
General Description .
Glossary
of
Terms
Operation
. . . .
Physical Characteristics .
System Interface . . .
FUNCTIONAL
DETAIL
-SECTION
II
Backline
Backspace . . . .
Basic Machine Timing
Broadcast Select . . .
Character Delete
(One
Memory Position Character)
Character Generation
Character
Insert
.
Clear . . . . . .
Contention
Mode
2ontrdl
Storage Register
Core Memory Addressing .
Cursor Display . . . .
Display Sequence &
Rope
Timing
Edit
& Processor Memory Sequences
Edit
Sequence (One
Position).
Edit
Sequence
(Two
Position)
Erase.
. .
Fast
Select . . .
Fixed
Tab . . . .
Fly
back
(Retrace)
Forms
. . . .
Forward
Space
Forward
Space -
Shift
Frame
Send
. . . . .
General Description
of
B9353
System
Group
Select
Home
Keyboard
.
Line Delete
Line
Insert
Memory Timing &
Operation
New Line . . . . .
Point
to
Point
Receive .
Point
to
Point
Transmit
,Polling . . . . .
Power
on
Clear . . .
Pull
by
One Replace . . . .
Pull
by
2 Replace Character Delete (2 Memory
Position Char) · · · . · · · · · · · ·
Printed in U.S. America Revised 7-30-73
INDEX
Page No.
18
15
1
. 20
.
'.
3
. 19
..
50
53
3
. 84
45
9
so
54
93
17
6
15
12
. 25
25
. 27
63
84
. 55
. .
16
. 63
63
63
80
1
88
53
17
48
.
so
9
61
92
93
75
54
38
47
Push
by
One Replace -Cursor Over ES · · · · · · 28
Push
by
One
Replace
-(One
Memory Position Character
Replaced
by
a Two Memory Position Character)
31
Push
by
Two Replace -Cursor Over ES · 34
Put
and
Get
. . . . . 24
Reposition Cursor
Rope
Character Generator
Rope
Timing .
Select
Selective
Send
Sequential Select ·
Single Variable
Tab
Option
.
,
Synchronous
Option
Tab
Delete .
Tab
Insert . . . .
VAR
Tab
....
Variable Tab
Operation
VTAB
Set
.....
CIRCUIT DETAIL -SECTION
Ill
Deflection Amplifier
Digital-to-Analog Section
Logical Elements . . .
Memory Section . . .
Symbol Generator Section
ADJUSTMENTS -SECTION N
Control
Unit
Adjustments
. . . . . . . .
Monitor Adjustments . . . . . . . . .
MAINTENANCE PROCEDURES -SECTION V
Fault
Isolation Procedure . . . . . . . .
INSTALLATION PROCEDURES -SECTION VI
Interunit
Cabling . . . .
Special Wiring and Cabling
93
10
16
66
82
89
97
98
61
61
58
57
57
23
20
5
14
1
6
..
23
1
5
RELIABILITY IMPROVEMENT NOTICES -SECTION VII
Index
-RIN/EI-EWI-ECN
Introduction
.
RIN
File
Unit Travel Log
OPTIONAL
FEATURES
-SECTION VIII
AIC Flip/Flops
Functional
Description
Functional
Detail
General · · · · · ·
Glossary
of
Signal Names
For
Library Binder
1!.Q
for
Form
1044187
3
1
2
I
3
I
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
1
Introduction and Operation
GENERAL DESCRIPTION
Fig.
1-1
The Burroughs Input and Display Set incorporates a
keyboard for data entry and a cathode ray tube (CRT) with
a character generator for data display. The display has a
repertoire
of
66 alphanumeric and special symbols, plus
space and non-destructive cursor. The content
of
the inter-
nal storage
is
sampled, converted to stroke code, and
dis-
played
SO
to
60 times per second to produce a display
presentation with 2000 character positions arranged
as
25
lines
of
80 characters each. The memory may
be
parti-
tioned and the associated logic time-shared by up to four
separate, functionally independant CRT displays, each with
®DATA-phone
is
registered service mark
of
AT&T
Co.
Printed in U.S. America 10-12-70
an
independent keyboard. Figure
1-1
illustrates a·
single
monitor in the "Free Standing" configuration.
The data content
of
the internal storage
is
generated
or altered by a keyboard or incoming
message
or both.
All
or part
of
the content
of
storage may
be
transmitted
as
an
outgoing message upon initiation by a keyboard. A multi-
wire direct system interface
is
standard. This interface
is
also
compatible with several
Bell
System data sets utilizing
either 2-wire or 4-wire private lines, or
DAT
A-phone® for
communications circuit or with a 2-wire direct circuit.
DATA-phone service
is
a data communication trans-
mission service supplied by the
Bell
System. This service
utilizes the switched telephone network and includes the
use
of the following features
of
this network:
DDD(Direct Distance Dialing)
WATS
(Wide
Area Telephone Service)
PBX
(Private Branch Exchange)
Automatic alternate routing.
PHYSICAL CHARACTERISTICS
MONITOR UNIT
The monitor unit houses the 17-inch CRT, all CRT
power, CRT driving circuits and CRT controls and status
indicators. The brightness control, the only CRT control
accessible to the operator,
is
located on the lower right side.
An
AC
power switch
is
located on the left front
of
the
monitor.
KEYBOARD UNIT
The keyboard
is
designed to comply with the touch
and geometry common to conventional office typewriters.
The keyboard
is
electrically interlocked so that no more
than one key
is
operative at a time. The keyboard unit also
includes control keys above the keyboard proper. The slope
top
case
is
designed to
be
either mounted with the control
unit and monitor unit for the free-standing composite
assembly or
as
a separate assembly.
An
option can
be
pro-
vided to permit remote keyboard operation up to 10 feet
from the monitor.
CONTROL UNIT
The control unit houses the logic circuits, memory
and power supplies. The logic circuits are separated into
replaceable circuit cards. An
AC
power switch
is
located on
the top
of
the control unit. The unit
is
intended
to
rest on
the floor.
FUNCTIONAL DESCRIPTION
This system contains a magnetic core memory with
1024 six-bit bytes. The entire memory may be associated
with a single monitor (CRT) and keyboard or the memory
may be divided into four equal sections with each section
For Form 1044187
I
Page 2 Burroughs -B9351/B9353 Input and Display Systems Technical Manual
Introduction and Operation
TABLE
I-1
PHYSICAL CHARACTERISTICS
Power: (Control Unit)
(Monitor)
Weight:
Dimensions:
Cooling:
Temperature:
Cabling:
105
to
130 volts AC, 60 Hz, 400 watts
105
to
130 volts AC, 60 Hz, 300 watts
Monitor Unit -100 pounds
Keyboard
Unit-
5
.5
pounds
Control Unit -140 pounds (including power supplies)
Height Width Depth
(inches) (inches) (inches)
Monitor
18
19.2 22
Keyboard 3.5 17.5 6.6
Control 27 19.2 14.5
Quiet, low-speed fans in Monitor and Control Unit
+59
to
+100° F (15
to
37.7°
C)
Standard
Keyboard to Monitor
4.5 ft., connector
in middle.
Monitor
to
Control
4 ft. assy. pair
Control
to
Modem
Optional
Keyboard
to
Monitor
10 ft. extension
Monitor
to
Control
20,50,100,300ft.
extensions (in pairs)
Control
to
Modem
All
interface cables are optional and must be ordered.
20, 50, 100, and 300 ft. cables available.
Control
to
Modem Expander
In addition
to
interface cables above there are also
500 and 1000 ft. cables available.
Control
to
System Direct Connect
Two wire direct connect option
Control
to
Printer
20, 50, 100, 300 ft.
cables available
NOTE: For additional cabling information,
see
Section
VI
Installation Procedures.
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
3
Introduction and Operation
or group
of
sections associated with a separate monitor and
keyboard. Each section or group
of
sections associated with
a particular keyboard
is
loaded by that keyboard or by an
incoming
message
addressed to the associated monitor. The
content
of
each section or group
of
sections
of
the memory
is
displayed on the associated monitor at a flicker-free
re-
fresh rate.
All
or part
of
the display content
of
a section or
group
of
sections
of
the memory
is
transmitted
as
an out-
going message upon command from the associated key-
board.
MEMORY
For each monitor-keyboard connected to the Input
Display System, six memory bytes are reserved for internal
functions and the remainder
of
the memory assigned to the
screen
is
available for display data. The number
of
bytes
available for display data on a monitor
is
dependent upon
the number
of
sections
of
memory assigned to the monitor
as
follows:
Number
of
Total Number
of
Number
of
Display
Sections
of
Memory Memory Bytes Data Memory Bytes
Assigned to Monitor Assigned to Monitor Assigned to Monitor
1
256
250
2 512 506
3
768
762
4
1024 1018
The display data consists
of
both graphics and format
effectors.
The first display data memory byte corresponds to
the upper left screen position.
If
this character is a graphic,
the next memory byte corresponds to the next screen posi-
tion on the line. Each graphic character in memory assigns
the next memory byte
to
the next screen position across
each line and automatically from the end
of
one line to the
beginning
of
the next line. A format effector in memory
assigns
the next memory byte to a screen position depen-
dent upon the format effector. For example, the format
effector character
NL
(new line)
assigns
the next memory
byte to the first position
of
the next line; therefore, the
.screen positions after the NL screen position do not have an
associated byte in memory. These screen positions are
referred to
as
unassigned positions. Two memory bytes
are
required for eight
of
the graphic characters,
$,%,&;'S.,
x,] ,t,
and--.
One memory byte
is
required for each screen for
the end-of-screen position. This byte
is
one
of
the six
mentioned above.
DISPLAY FORMAT
The memory data content
is
displayed on a 17-inch
CRT. Table
1-2
lists the CRT display characteristics. The
tube
is
masked to correspond to the horizontal and vertical
extremities
of
the 80-character by 25-line format, which
Printed in U.S. America 10-12-70
yields a 12-inch horizontal by 9-inch vertical, rectangular
display presentation.
Corresponding to each
of
the graphic codes stored in
memory' the appropriate graphic character
is
generated by
using up to
12
straight-line strokes to form the character. A
cursor presentation
is
also provided.
It
appears at the char-
acter position where the next keyboard or Input/Output
operation
is
to take place. The character
is
formed on the
screen
as
a set
of
horizontal
brackets,=,
that surround the
character position, such that the character
to
be edited
re-
mains viewable. Chart
1-1
shows the font
of
the Input
Dis-
play graphic character set.
CHARACTER SET
AND
CODE
Burroughs Input Display System uses a modified
limited subset
of
the USASCII, USASCII X3.4. Figures
1-2
and
1-3
designate the characters to each seven-bit character
code for receive and transmit respectively.
With the exception
of
five
character substitutions,
namely the
characters~.~'
x, ¢
and~in
lieu
of
the char-
acters !, ',
I,
/\ and - , respectively, the figures agree with
the proposed USASCII. These figures differ only in the
inclusion
of
certain characters.
Undesignated Codes
Received character codes undesignated in Figure
1-2
are undefined in the Input Display System. The character
codes undesignated in Figure
1-3
are not generated by the
Input Display System.
OPERATION
Operation may
be
considered
to
consist
of
four
phases: Composition, Send, Wait, and Receive. The modes
are independent for each keyboard.
COMPOSITION PHASE
In the composition phase, the operator may compose
a message by using the keyboard shown diagrammatically in
Figure
1-4.
The operator has complete freedom to edit and
compose information anywhere on the screen (except with
forms mode option).
The composition phase
is
ended by pressing the
SEND or PRINT keys, either
of
which evoke the Send
phase.During composition phase, the KEYBOARD
LOCK
indicator
is
OFF. Depressing the KEYBOARD key reverts
the terminal to the composition phase. The keyboard con-
sists
of
graphic, cursor movement, and control keys. Certain
of
the keys work in conjunction with the SHIFT key.
A graphic key causes the character depicted by the
keytop designation to appear at the position
of
the cursor.
If
the cursor position already displays a graphic character, it
is
replaced by the new character. The cursor moves forward
For Form 1044187
I
Page 4 Burroughs -B9351/B9353
Input
and Display Systems Technical Manual
·------------------~-------~-------------------------------------------------------------
Introduction and Operation
TABLE I-2 DISPLAY CHARACTERISTICS
Cathode Ray Tube (CRT)
Deflection Technique:
Overall Tube Size:
Phosphor Type:
Viewable Tube Area:
Brightness:
peflection
q~uitry
Writing Rate:
Flyback Time:
Character to Character Positioning Time:
Small Signal Response:
Refresh Rate:
Characters
Repertoire:
Method
of
Generation:
Max. strokes per character:
Drawing Time:
Character Size (nominal):
Character Spacing:
Line Spacing:
Stroke Brightness Compensation:
Electromagnetic
17 in. Rectangular
P4 Aluminized
9 in. high
by
12 in. wide
SO
foot-lamberts (min.)
100,000 inches/sec (max.)
42.3 microseconds
2.7 microseconds
1 MHz
SO
to
60
Hz synchronized
to
the power line
63 graphic characters, blank, cursor, group separator
(A),
record separator
(<J
),
unit separator (
E>)
Stroke type
12
0.9 microsec/stroke
0.150 in. high
by
0.115 in. wide
7 characters/in.
3.33 lines/in.
Two levels -compensated
with
residual variation
of
1.66:1
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I Page 5
Introduction and Operation
CHART 1
I
1--1
Printed
in
U.S. America 10-12-70 For Form 1044187
Page 6 Burroughs -B9351/B9353
Input
and Display Systems Technical Manual
------~--------------~~----------------------------------------~--
1n
trod
uction and Operation
CHART 1 (CONTD.)
f----i
r---+--
1------i
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I Page 7
Introduction and Operation
CHART 1 (CONTD.)
(ASTERISK)
7 I
...
---.
•-.
I \
~
7
J T
(CURSOR) (SPACE)
,,.
___
_,I (RECORD SEPARATOR)
(UNIT
SEPARATOR)
Printed
in
U.S. America 10-12-70 For Form 1044187
Page
8 Burroughs -B9351/B9353 Input and Display Systems Technical Manual
Introduction and Operation
b7
..
0 0 0 0 1 1 1 1
b6 0 0 1 1 0 0 1 1
b5
-0 1 0 1 0 1 0 1
B
b4
b3
b2
b1
~
0 1 2 3 4 5 6 7
~
....___.
.
0 0 0 0 0
NUL
OLE
SP
0 @ p "
p/POL
0 0 0 1 1 SOH > 1 A Q a
q/SEL
0 0 1 0 2
STX
..
2 B R b r/SEQ
0 0 1 1 3
ETX
II 3 c s c s/FSL
-·
0 1 0 0 4
EOT
$ 4 D T d
t/BSL
0 1 0 1 5
ENQ
NAK
% 5 E u e u
0 1 1 0 6
ACK
SYN & 6 F v f v
0 1 1 1 7
BEL/CON
ETB
~
7 G w g w
1 0 0 0 8 ( 8 H x h x
1 0 0 1 9
HT
) 9 I y i y
1 0 1 0 10
LF
* : J z j z
1 0 1 1
11
VT
ESC
+ ; K [ k {
1 1 0 0 12
FF
I < L x I I
1 1 0 1
13
CR
GS
-= M 1 m I
1 1 1 0 14
RS
> N 1 n
~
1 1 1 1 15
us
I ? 0 -0
DEL
----L------
····----'-·-
'---
NUL NUL
(CCl
SYN
SYNCHRONOUS
IDLE
(CC)
SOH
START
OF
HEADER
(CC)
ESC
ESCAPE (CC)
STX
START
OF
TEXT
(CC)
GS
GROUP
SEPARATOR
(IS)
ETX
END
OF
TEXT
(CC) GSL GROUP
SELECT**
(BCS)
HT
HORIZONTAL
TABULATION
(FE) -
FIXED
TAB
DEL
DELETE*
LF
LINE
FEED
(FE)
CR
CARRIAGE
RETURN
(FE)
VT
VERTICAL
TABULATION
(FE) -
VARIABLE
TAB
us
UNIT
SEPARATOR
(IS)
FF
FORM
FEED
(FE)
ENQ
ENQUIRY
(CC)
RS
RECORD
SEPARATOR
(IS) ETB
END
OF
TRANSMISSION
BLOCK
(CC)
EQT
END
OF
TRANSMISSION
(CCl OLE
DATA
LINK
ESCAPE (CC)
NAK
NEGATIVE
ACKNOWLEDGE
(CC) FSL
FAST
SELECT
(BCS)
ACK
ACKNOWLEDGE
(CC) BSL
BROADCAST
(BCS)
BEL
ATTENTION
SIGNAL
(CC) CON
CONTENTION
(BCS)
POL
POLL
(BCS) SEQ
SEQUENTIAL
(BCS)
SEL
SELECT
(BCS)
(CC)
COMMUNICATION
CONTROL,
(FE)
FORMAT
EFFECTOR,
(IS)
INFORMATION
SEPARATOR
(BCS)
BURROUGHS
COMMUNICATION
STANDARD
*
IN
THE
STRICT
SENSE,
DEL
IS
NOT
A
CONTROL
CHARACTER.
**ANY
CHARACTER
IN
COLUMN
2-6.
Fig.
I-2
RECEIVE CHARACTER CODES
one position.
When
a graphic key
is
operated with the
cursor in the last position
of
the line, .the cursor moves
to
the first position
of
the next line down, except that the
cursor does
not
move from the last position
of
the last line.
Graphic keys with dual·keytop designations work in
conjunction with the SHIFT key. With the SHIFT key not
depressed, the character depicted by the lower keytop
designation appears at the cursor position. With the SHIFT
key depressed the character depicted by the upper keytop
designation appears at the position
of
the cursor. Keys with
a single keytop designation are unaffected by the SHIFT
key. Keys are included to move the cursor forward or
backward a single position, or
to
the first position
of
the
next line down, the same line, the next line above, or the
top
lin~.
Some
of
these keys also have erase capability when
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
9
Introduction and Operation
~
.....
0 0 0 0 1 1 1 1
.....
0 0 1 1 0 0 1 1
0 1 0 1 0 1 0 1
6 5
B1
~u~
0 1 2 3 4 5 6 7
TS
b4 b3
b2
b1
ROWh
0 0 0 0 0
SP
0 @ p POL
0 0 0 1 1 SOH ~ 1 A Q
0 0 1 0 2
STX
,,
2 B R
0 0 1 1 3
ETX
II 3 c s
0
,.
0 0 4 EOT $ 4 D T
0 1 0 1 5
ENQ
NAK
% 5 E u
0 1 1 0 6
ACK
SYN & 6 F v
NUL
SOH
STX
ETX
ENQ
HT
VT
LF
0 1 1 1
1 0 0 0
1 0 0 1
1 0 1 0
1 0 1 1
1 1 0 0
1 1 0 1
1 1 1 0
1 1 1 1
NULL
START
OF
HEADER
(CC)
START
OF
TEXT
(CC)
END
OF
TEXT
(CC)
ENQUIRY
(CC)
7
8
9
HT
10
LF
11
VT
12
13
CR
GS
14
RS
15
us
HORIZONTAL
TABULATION
(FE) -
FIXED
TAB
VERTICAL
TABULATION
(FE) -
VARIABLE
TAB
LINE
FEED
(FE)
EOT
END
TRANSMISSION
(CC)
ACK
NAK
POL
SYN
GS
CR
us
RS
~
(
)
*
+
-
I
7 G w
8 H x
9 I y
: J z
; K [
< L x
= M ]
> N +
? 0 -
ACKNOWLEDGE
(CC)
NEGATIVE
ACKNOWLEDGE
(CC)
POLL
(BCS)
SYNCHRONOUS
IDLE
(CC)
GROUP
SEPARATOR
(IS)
CARRIAGE
RETURN
(FE)
UNIT
SEPARATOR
(IS)
RECORD
SEPARATOR
(IS)
(CC)
COMMUNICATION
CONTROL,
(FE)
FORMAT
EFFECTOR,
(IS)
INFORMATION
SEPARATOR,
(BCS)
BURROUGHS
COMMUNICATION
STANDARD
Fig.
I-3
TRANSMIT CHARACTER
CODES
used in conjunction with the SHIFT key.
In
addition, hori-
zontal tabulation
is
provided. Fixed tab stops are located in
the first position and every eighth position thereafter, i.e.,
positions
1,
9, 17, 25, 33, 41, 49, 57, 65, and 73.
A cursor movement operation which moves the
cursor to a screen position to which a memory byte
is
assigned does not alter the content
of
memory. A cursor
movement operation from an assigned position to an un-
assigned position alters the content
of
the memory
to
make
the new cursor position an assigned position, e.g., an
NL
(new line) character
is
inserted in memory when the
NEW
LINE key
is
operated
if
the first position
of
the next line
is
unassigned. The following keys are referred
to
as
cursor
movement keys:
Space
bar:-
The space bar moves the cursor forward one
position. From the last position
of
a line the cursor moves
Printed in
U.S.
America 10-12-70
to the first position
of
the next line down; except the
cursor will not
move
from the last position
of
the last line.
With the SHIFT key depressed, the space bar also
causes the
SP
(space) character to replace the character at
the cursor position before the cursor
is
moved. (In this
regard, the space bar may be considered a graphic.)
Backspace:- The
BACKSPACE
key moves the cursor
backward one position, unless the cursor
is
in the first posi-
tion
of
the first line in which case the key
is
inoperative.
When
the cursor position
is
at the first position
of
any
other line, the
BACKSPACE
key will cause the cursor to be
positioned to the last character position
of
the line above.
New
Line:-
The
NEW
LINE key moves the cursor
to
the
first position
of
the next line down. The
NEW
LINE key,
when the cursor
is
in the last line,
is
inoperative.
For Form 1044187
I
Page
10 Burroughs -B93Sl/B9353 Input and Display Systems Technical Manual
Introduction and Operation
Fig.
1-4
INPUT DISPLAY KEYBOARD
Back
Line:-
The
BACK
LINE key moves the cursor to the
first position
of
the
same
line
if
it
is
not positioned at the
first position
of
a line.
When
it
is
positioned at the first
position
of
a line, instead, the cursor
is
moved to the first
position
of
the line above. The
BACK
LINE key
is
inopera-
tive when the cursor
is
in the first position
of
the top line.
Clear/Home:- The CLEAR/HOME key moves the cursor
to
the first position
of
the top line. With the SHIFT key
also
depressed, the CLEAR/HOME key also clears the
screen.
Tab:-
With
the SHIFT key not depressed, the
TAB
key
moves the cursor to the next tab stop (fixed or variable).
If
there
is
no tab stop to right
of
the
cursor~
the cursor will
move
to the first tab stop on the next line except when the
cursor
is
in the last line. The
TAB
key
is
used
in
conjunc-
tion with a depressed SHIFT key for the Single Variable
Tab option.
Tab Insert/Delete:-
With
the SHIFT key depressed, the
TAB
INSERT causes a fixed tab character
to
be
inserted at
the cursor position. The cursor does not move.
If
the line
contains more than 72 character positions, the tab insert
function
is
inhibited.
If
the cursor
is
positioned over a tab
character, the
TAB
DELETE (SHIFT key not depressed)
causes deletion
of
the tab character and
as
a result, the
character at the next tab stop (which may
not
be
displayed)
is
moved to the cursor position and folJowing characters
move
left a corresponding number
of
positions or a full tab
stop.
Included
as
part
of
the keyboard assembly are six
control keys, the function
of
which are
as
follows:
Repeat:-
The REPEAT key causes repetition, at the rate
of
10 per second,
of
the function defined by a graphic or
format effector key that
is
operated concurrently with the
REPEAT key. Either key may
be
operated first, and repeti-
tion stops when either key
is
released.
Send:-
With
the SHIFT key not depressed, the
SEND
key
invokes Frame Send to the System Interface.
With
the
SHIFT key depressed, the SEND key invokes Selective
Send to the System Interface.
Keyboard:-
The KEYBOARD key initiates the composi-
tion phase.
Break:-
The BREAK key initiates the receive break func-
.tion.
Disconnect:- The DISCONNECT key
is
used only in con-
junction with the Data-Set interface and the switched tele-
phone network
to
initiate the disconnect or hang-up func-
tion.
Receive:- The RECEIVE key evokes the
Wait
phase.
Additionally, there are six indicators
as
follows:
Power:-
The
POWER
indicator
is
turned
ON
when the
monitor power on switch
is
activated.
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
11
Introduction and Operation
Error:-
The INPUT ERROR indicator
is
turned
ON
when
an input error
is
detected. The INPUT ERROR indicator
is
turned OFF by START
of
a receive message.
Retransmit:-
The RETRANSMIT indicator
is
turned
ON
when the system response
to
a transmitted message from
the terminal
is
a NAK,
or
an invalid character, or the
system
gives
no response at all within a specified time. The
RETRANSMIT indicator is turned OFF by depressing the
SEND key.
Receive
Alarm:-
The RECEIVE
ALARM
indicator
is
turned
ON
when the system attempts
to
send a message
to
a terminal which
is
not in
Wait
phase. The RECEIVE
ALARM
indicator
is
turned OFF when the terminal
is
placed in the
Wait
phase.
Keyboard
Lock:-
The KEYBOARD LOCK indicator
is
turned
ON
whenever the SEND, PRINT, RECEIVE keys
are activated, or a BSL, GSL, or SEQ message
is
received.
It
is
turned OFF by either the KEYBOARD switch or when-
ever the terminal ends the receive phase or terminates the
print operation.
SEND PHASE
The Send .phase may be evoked by the keyboard
.operator to send a display data message
to
the System or a
print message (option). The KEYBOARD LOCK indicator
is
ON.
Upon completion
of
sending a message the TER-
MINAL goes to
Wait
phase.
There are two types
of
display data send operations,
Selective Send and Frame Send. The text generated by
Selective Send
is
the content
of
memory corresponding
to
the display data from the cursor position to, but not includ-
ing, the first following
GS
(6) character or
to
and including
the last data character; whichever occurs first. In Frame
Send, the text
is
the content
of
memory.corresponding to
all the display data on the screen.
The operator normally either completes his composi-
tion by writing
GS
(6), then positions the cursor to the
beginning
of
his message before evoking Selective Send,
or·
he evokes Frame Send. In either case, following the Send
operation, the cursor
is
left in its original position on the
screen and the receipt
of
an
ACK
response positions the
cursor
to
either end
of
screen, or, in the case
of
Selective
Send, over the
GS(~)
character.
Each stored
NL
(new line) character
is
transmitted
as
CRLF.
WAIT
PHASE
The KEYBOARD LOCK indicator
is
ON
during the
Wait
phase. A Receive message terminates the
Wait
phase
and evokes the Receive phase.
If
the operator terminates
Printed in U.S. America 10-12-70
the
Wait
phase ·with the KEYBOARD key, the keyboard
returns to composition phase.
RECENE
PHASE
The Receive phase
is
evoked by the start
of
a receive
message addressed to the associated screen. The keyboard
is
inoperative. The INPUT ERROR indicator
is
reset at the
beginning
of
the receive message.
The terminal examines the input data bits
as
charac-
ters and places the terminal in Receive phase when STX
is
detected. The characters following are processed until ETX
or
ETB
is
detected.
If
circuit CF goes OFF before ETX
is
detected, the error
is
set and the ERROR indicator
is
turned
ON.
The System may send a message at any time. How-
ever, the System usually responds only
to
a message from
the operator. When the System sends a message to the
terminal for another reason, that message
is
termed
as
an
unsolicited message and will cause a receive alarm indicator
to
be lit. This feature
is
to
allow the system to inform the
. operator that it has traffic to send. The operator may place
the terminal in the
Wait
phase by depressing the RECEIVE
key. Broadcast, Group Select and Sequential Select
mes-
sages
(options) may be unsolicited messages which auto-
matically lock the keyboard and evoke Receive phase.
During the Receive phase, the System has control
of
the keyboard-monitor. The display data in the message may
be preceded by the
FF
(form feed) character which clears
the screen and causes subsequent message display data
to
be
loaded starting in the first display data memory byte
(which corresponds to the first display position). Other-
wise, the graphic data and format effectors load starting in
the memory location corresponding
to
the screen position
of
the cursor. At the end
of
an error-free message, the
cursor
is
left positioned after the last display character
re-
ceived. In the case
of
an input error, the cursor
is
left in the
original position before reception
of
the message.
Received data that exceeds the capacity
of
either the
screen or the memory
is
discarded. The input error
is
set
and the INPUT ERROR indicator
is
turned
ON
to indicate
such loss
of
data. The response
to
a message containing an
overflow error
is
NAK.
During the Receive phase, message integrity
is
checked by examining each character individually for cor-
rect character parity.
If
the message does not pass this test,
the input error
is
set and the INPUT ERROR indicator
is
turned ON, and a ?
is
substituted for each character in
error. The text characters that are received by the terminal
are termed
as
Graphics, Format Effectors, and Control
Characters.
Each received graphic character and some Format
Effectors are stored in the display memory.
The BREAK key
is
provided
to
signal the System
For Form 1044187
I
Page 12 Burroughs -B9351/B9353
Input
and Display Systems Technical Manual
~--------------~---------------------
CHARACTER
NUL
SYN
DEL
Introduction and Operation
TABLE
I-3
RECEIVE CHARACTER FUNCTIONS
USED
TO
FOR
THE
---------
FUNCTION
ACCOMPLISH
TIME
FILL
FOR
THE
TERMINAL
AND
TIME
AND
MEDIA
Fl
LL
SYSTEM.
ONLY
SYN
IS
EXCLUDED
FROM
BLOCK
CHECK
SUMMATION.
,____
_________
·-------+--
>
)
I g
6 7
>
D E
K L
R s
y z
GS
(4)
\ a
g h
n 0
u v
=
1
8
F
M
T
RS
STX
ETX
ETB
IESC
$
+
2'
9
@
G
N
u
x
(<1)
% & <
3 4 5
<
A B c
H I J
0 p Q
v w x
1 j
-·
us
(t>)
-----------------···--
SP
---·---------·--·-·---·--
b
<:
d e
k m
p q s
w
)(
y z
~
LF
INITIATE
HAS
BEE S ACCEPTANCE OF
CHARACTERS
AND
BLOCK
CHECK
SUM
IF
TERMINAL
N
SELECTED.
TE
RMI
NA
TES ACCEPTANCE OF
CHARACTERS.
-·-
S A
SPECIAL
CONTROL
SEQUENCE.
TABLE
INITIATE
CONT
ROL SEQUENCES.
1-4
APPLIES
DURING
SPECIAL
LOADS
C
(MAY
BE
HARACTER
INTO
MEMORY
EXCEPT
DURING
COMMUNICATION
SELECTION
USED FOR
GROUP
SELECTION
EXCEPT
FOR
GS, RS,
AND
US).
LOADS
SP (SPACE)
CHARACTER
INTO
MEMORY.
ORRESPONDING
COLUMN
4
OR
5 (UPPER CASE)
CHARACTER
INTO
MEM-
LOADS
C
ORY
EXC
SELECT!
EPT
DURING
COMMUNICATION
SELECTION
(MAY
BE USED
FOR
GROUP
ON
EXCEPT
FOR
CHARACTER
CODES
FROM
p
THROUGH-----.).
LOADS
NL
(NEW
LINE)
CHARACTER
INTO
MEMORY.
----
------------+-~·
CR
NO
FUNC
TION
IS
PERFORMED.
FF
SCREEN
AND
CAUSES
FOLLOWING
CHARACTERS
TO
BE
LOADED
START-
CLEARS
ING
AT
THE
BEGINNING
OF
MEMORY.
-------+--
-
HT
LOADSF
IXED
TAB
CHARACTER,
TF,
INTO
MEMORY.
1--------~----------+-
ARIABLE
TAB
CHARACTER,
TV,
INTO
MEMORY.
VT
LOADS
V
1~--------
-----
SOH 1NIT1ATE
S
BLOCK
CHECK
SUM.
-------------+--
IE
0 T
INITIATE
S
IDLE
OR PASSIVE
CONDITION.
1~--------
-------+--
IE
NO
INITIATE
S A RESPONSE.
ACKNOWLEDGEMENT.
---------·--
________
__:_'!'-C~-------------
-
~~~~!~-~~
INAK
NEGATIV
E
ACKNOWLEDGEMENT.
---
OLE
USED
IN
CONJUNCTION
WITH
EOT
TO
INDICATE
DISCONNECT.
1~-----------------+--
-
POL
USED
DU
RING
COMMUNICATION
SELECTION
TO
INDICATE
POLL.
--·-----
:SEL
RING
COMMUNICATION
SELECTION
TO
INDICATE
SELECTION.
USED
DU
USED
DU
SELECTIO
SEO
FSL
BSL
--·
RING
COMMUNICATION
SELECTION
TO
INDICA.:fE
SEQUENTIAL
N.
-·-·
-----···------------
RING
COMMUNICATION
SELECTION
TO
INDICATE
FAST
SELECTION.
USED
DU
USED
DU
SELECTIO
RING
COMMUNICATION
SELECTION
TO
INDICATE
BROADCAST
N.
BEL
USED
DU
RING
COMMUNICATION
SELECTION
TO
INDICATE
CONTENTION.
.
......,
--1
--·---------
··------1
!---------·---·-·--·--·------------
·-··
-------
-··
··-·-··
UNDESIGNATED
IN
TABLE
1-3
NO
FUNC
TION
IS
PERFORMED.
---
(message source)
to
terminate transmission to the terminal.
The
method
of
transmission is dependent
upon
the
type
of
System interface.
A summary
of
the receive character functions
is
shown in Table
1-3.
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
13
Introduction and Operation
Receipt
of
any graphic character, i.e., Figure I-2
columns 2 through 5, causes storage
of
that character in
memory. Note the
SP
(space)
is
considered a graphic. The
group separator, GS,
is
also treated
as
a graphic and has no
control significance in Receive phase. Characters from
columns 6 and 7, except for the last four characters in
column 7 including DEL, are translated
to
the equivalent
character in columns 4 and 5 by changing b6
to
0. Thus,
received lower case characters are displayed (and may be
later transmitted)
as
upper case characters.
Format Effectors are used
to
define the display for-
mat on graphic characters. The function
of
the format
effectors
is
as
follows:
CR (carriage return). Receipt
of
the CR character has no
effect. It
is
equivalent
to
a NUL character, except for Block
Check summation.
LP (line feed). Receipt
of
the LP character causes the NL
(new line) character to be stored in memory, and
as
a
result, the next stored character
is
displayed at the first
position
of
the next line down.
FF (form feed). Receipt
of
the FF character clears the
screen and causes the following characters
to
be loaded
starting in the first memory locations.
HT
(fixed tab). Receipt
of
the
HT
character causes the
fixed tab character, TF,
to
be stored in memory; and
as
a
result, the next stored character
is
displayed at the next
fixed tab stop.
The following are Control Characters and their re-
spective functions when encountered in a received message:
NUL, SYN, or DEL. These characters may be used
to
accomplish time fill for the terminal and time and media fill
for the System.
No
function
is
performed when these char-
acters are received. Only
SYN
is
excluded from the block
check summation.
ESC
(control sequence). Receipt
of
ESC
indicates the be-
ginning
of
a special control sequence. The special control
sequences following ESC's cause the actions indicated in
Table
I4.
A message may contain any number
of
control
sequences. Special control sequence characters which are
not defined terminate the control sequence, and no function
is
performed.
SYSTEM
OPTIONS
The basic set consists
of
three units (monitor, key-
board, and control) which are put together
to
form a free-
-standing assembly.
Although the normal display system operates from a
60 Hertz power source, a
SO
Hertz system will be available
for International use.
Printed in U.S. America 10-12-70
Character Function
Reposition Cursor (Option)
' Set Variable Tab Stop (Option)
Others Terminate
ESC
sequence
TABLE
14
SPECIAL RECEIVE CONTROL SEQUENCE
CHARACTER FUNCTION
One
of
the features
of
the display system
is
the
ability
of
the memory
to
be partitioned
as
described pre-
viously
to
accommodate the following combinations
of
keyboard-monitors and displayed characters:
2 keyboard-monitors (Control Unit II) with 506 characters
each,
2 keyboard-monitors (Control Unit II) with 250 and 762
characters,
3 keyboard-monitors (Control Unit .III) with 250, 250 and
506 char.,
4 keyboard-monitors (Control Unit IV) with 250 characters
each.
When
the keyboard-monitor combination
is
in the
free-standing configuration, the monitor plugs into the con-
trol unit with nominal 4-foot cables. However, when con-
figured
as
a multiple device, the keyboard-monitors can be
operated with up to 300 foot separation between the
monitors and the control unit. The available options are 20,
50, 100, and 300 feet. The keyboard normally plugs into
the monitor with the connection made under the monitor
assembly.
An
optional 10 foot extension cable
is
available
which will allow the keyboard
to
be operated away from
the monitor.
An optional printer interface allows the connection
of
a Teletype Model 33
TCB
page printer to the display
control unit. The memory content associated with any
monitor/keyboard may be printed at 10 characters per
second upon command
of
the associated keyboard PRINT
key or by the presence
of
B3
in the AD2 character. With
the SHIFT key not depressed, the PRINT key evokes
Frame Send
to
the Printer Interface. With the PRINT key
depressed, the PRINT key evokes Selective Send to the
Printer Interface. The message format
of
message to the
printer
is
as
follows:
CCL
A
CCL
RRF
D
RRF
2 text (from memory)
The two least significant bits
of
the AD2 character indicates
the monitor from which the text data
is
obtained. It
is
printed
as
0, 1, 2, or 3. Within text, each NL character from
memory
is
translated
to
CR, CR, LP. In addition, CR, CR,
For Form 1044187
I
Page
14 Burroughs -B93S l/B9353 Input and Display Systems Technical Manual
Introduction and Operation
LF
is
inserted following each character in position 80. Tab-
ulation should be avoided in messages
to
be printed because
the printer does not have the tabulation function. When a
receive message
is
addressed to a screen which
is
in the
process
of
being printed, the terminal will respond with a
NAK. The printer can be located up
to
a maximum distance
of
300 feet from the control unit. Optional cables available
are in lengths
of
20, 50, 100, and 300 feet.
A second option
is
available when using the printer
interface which enables a portion
of
the Input Display
System memory (250, 506, or 762 characters)
to
be used
as
a buffer between communications inputs and the printer.
The portion
of
memory
so
assigned is unavailable for
dis-
play purposes, and the Input Display System will function
exactly
as
if
a monitor-keyboard unit was assigned
to
the
printer buffer area
of
memory. Multiple buffer areas can be
assigned.
Messages
placed in the buffer area by the system
(via the use
of
the AD2 address specifying the buffer area)
may be printed via a print command from the system.
DISPLAY OPTIONS
Insert and Delete Options provide additional key-
board editing capability whereby characters and lines may
be inserted into or deleted from existing screen data. In the
case
of
inserting data, the existing data, starting
at
the inser-
tion position,
is
moved
to
the right and/or down
to
make
room for the data being inserted.
When the INSERT key
is
operated, the character
under the cursor and following characters move one posi-
tion
to
the right, a space character
is
inserted at the cursor
position and the cursor remains at the original position. The
movement
of
characters to make room for the insertion
involves all characters from the one under the cursor
to
the
first character that precedes an unused screen location, i.e.,
at
the end
of
a partially filled line or at the end
of
a tab
column. When a character
is
moved from the last position
of
a line, it moves
to
the first position
of
the following line.
Characters may be pushed from the bottom
of
the screen or
memory by an insert operation.
With the SHIFT key depressed, the INSERT key
moves the character under the cursor
to
the first position
of
the next line down and following characters to following
positions. The cursor
is
not moved.
The DELETE key deletes the character under the
cursor provided the character
is
a graphic or space. The
character to the right
of
the cursor
is
moved
to
the cursor
position and the following characters through the end
of
a
tab column or the end
of
the line are moved one position
to
the left. Character DELETE has no effect when the cursor
is
positioned over the Format Effector characters,
TF
(fixed tab),
TV
(variable tab), NL (new line), or RS (record
separator).
With the SHIFT key depressed, the DELETE key
causes erasing
of
all the characters
fiom
the cursor
to
the
end
of
the line or
RS
character, provided the cursor
is
not
positioned over the NL (new line) or
RS
character. An NL
or
RS
character
is
placed
at
the cursor position and the
cursor
is
not moved.
If
the cursor
is
positioned over an NL
character, the NL character
is
deleted and
as
a result, char-
acters from the line below fill the cursor line starting at the
cursor position. Any excess characters remain on their line,
left-justified. The leftward and upward movement
of
char-
acters affects all lines following the deleted NL character
through the next
NL
character.
If
the cursor
is
positioned
over an RS character, the Line Delete function has no
effect.
A Single Variable Tab option is available. This option
provides a single tab stop which may be set either by a
message or from the keyboard. This tab stop may be used
for tabulation either by a message or from the keyboard.
The single variable tab stop position may be altered by the
message character sequence:
E p
s 0
c s
where
POS
is
defined
as
a horizontal screen position. Time
fill characters must follow POS for
at
least 17 milliseconds
when contained in data.
The single variable tab stop position may also be
altered by the keyboard to the horizontal position
of
the
cursor using the VAR
TAB
SET key. In order to avoid
superimposition
of
characters, the variable tab stop should
always be set greater than the maximum number
of
char-
acters from the beginning
of
any line to the first variable
tab character. With the SHIFT key depressed, the
TAB
key
causes the cursor
to
move
to
the next single variable tab
stop, either on the same line or at the first character
of
the
next line. There
is
an automatic variable tab stop designated
at the first position
of
each line, in addition
to
the variable
stop, which may be positioned anywhere on the line. The
VT character in a message causes the following character to
be displayed at the next variable tab stop position.
In the time-shared mode
of
operation when data for
one monitor contains an unusually high number
of
variable
tab (VT) and new line (NL) characters, the time required
to
display all
of
the Monitor Data may exceed the time avail-
able for the display.
If
this situation occurs, the display will
be terminated when the monitor display time runs out (all
following characters for this monitor will not be displayed).
The INPUT ERROR indicator
of
the associated keyboard
will be lit, and the System will respond with a NAK.
This option
is
not
to
be used when multiple screens
are addressed by means
of
BSL, GSL
or
SEQ.
A Reposition Cursor option
is
available that
is
used
to
reposition the cursor by means
of
the message character
sequence:
Burroughs -B9351/B9353
Input
and Display Systems Technical Manual Sec. I Page 15
Introduction and Operation
E
PL
S 0 I
C S N
where POS is defined as a horizontal position
on
a line and
LIN
is
defined as a screen line. USASCII characters
2/0
through 6/15 are used
to
define horizontal screen positions
1 through
80
respectively. USASCII characters
2/0
through
3/8
are used
to
define lines 1 through 25 respectively.
If
the cursor
is
repositioned
to
an unassigned (in
memory) screen position the cursor will be moved
to
the
position corresponding
to
the end
of
screen character. Fol-
lowing the reposition sequence, at least 33
.4
milliseconds
of
fill characters (NUL
or
DEL) must be included in a
message.
This
option
is
not
permitted with multiple screen
selection BSL, GSL or SEQ.
A Forms option
is
available which allows a message
to
be displayed
that
inhibits operator access
to
predefined
areas
of
the screen. This
option
operates in either one
of
two
modes: unalterable
or
alterable.
When in the unalterable mode, the RS character (
<J)
is
displayed
in
character position 1
of
line 1. This causes
the
terminal
to
prevent the operator from entering data in any
character position except those between the
US
and
RS
characters. In this mode,
the
INSERT, DELETE and TAB
keys are inhibited
to
prevent
the
operator from expanding
or contracting any preassigned operating area.
If
the
cursor is moved
to
any position between the
RS and
US
characters, the terminal automatica1ly positions
the cursor
to
the
first character position following
the
next
US
character.
For
example,
if
the cursor
is
initially placed
over the character position following a
US
character
and
the
BACKSPACE key
is
depressed,
the
cursor will move
back one position (over the US character) and
then
auto-
matically be repositioned
to
its original position.
The function
of
the TAB key in this mode,
is
to
allow
the operator
to
change from one operating area
to
the
next
by
positioning
the
cursor
to
the
character position follow-
ing the next
US
character. Subsequently,
if
no other
US
characters occur between this cursor position and the end
of
th~
screen,
then
the cursor will be positioned
to
the
character following the first
US
on
the screen (i.e., wrap-
around).
When in the alterable mode, the
US
character (I>)
is
displayed in the first character position
of
line 1. The ter-
minal functions basically
as
in the unalterable mode except
that
the operator
is
allowed
to
expand or contract
the
oper-
ator areas
of
the screen. Each operator area
is
treated as
if
it
were a separate screen and were completely expandable.
If
the cursor
is
positioned
to
the
RS character and data is
entered, the RS character
and
the
data is shifted one char-
acter
to
the right and
the
operator data placed in front
of
the
RS character.
If
the
NEW
LINE key
is
depressed -
Printed in U.S. America 10-12-70
causing the cursor
to
be placed in a non-operator area -
the
terminal will automatically insert a new line character and
assign an additional line
to
the operator area.
The INSERT
and
DELETE keys are enabled with
the
alterable mode. The character delete function
is
modified
to
inhibit
the
deletion
of
RS characters. The line delete
with an alterable form
on
the screen will cause deletion
from the cursor
to
the end
of
the
line or
to
the first RS
character.
The TAB key operates
in
the same manner as in the
unalterable mode;
the
variable tab is still inhibited. Note
that
even though the tab functions are inhibited, the tab
characters may be placed
by
the
processor in either
the
operating
or
non-operating areas for formatting purposes.
In order
to
generate a form
by
means
of
the
key-
board, a Compose Forms mode
is
used. This mode
is
enabled
by
a switch
on
the Control Unit which then allows
the operator access
to
the
entire screen. Forms controls are
disabled
to
permit the operator
to
type RS and
US
char-
acters, thereby generating a form
to
be used for a given
application.
Available for stand alone Terminal Systems only
is
•
the
Paging option. This option provides the terminal oper-
ator with some control over groups
of
messages coming
from the System. Each message from the System should be
no longer than 240 characters or 3 lines when using this
option. With this option, ACK messages are automatically
transmitted
to
the System following each received message.
The ACK will always be sent unless the previous message
included data which fell
in
the last 256 characters
of
avail-
able memory or the
last
3 lines
of
the screen. In this case,
the RECEIVE ALARM indicator will be lit and NAK
is
sent
as
the
response
to
all messages until operator intervention.
The PAGE FULL indicator will be lit, and will remain lit as
long as data remains in the last 256 characters
of
available
memory or the last 3 lines
of
the screen. With the
RECEIVE ALARM indicator lit, the terminal will respond
to
all messages addressed
to
the screen with a NAK. The
operator may take either
of
two actions:
1. Delete characters and/or lines from
the
existing
text
on
the screen until the PAGE FULL indicator is ex-
tinguished. Depressing
the
Receive
key
will allow
the
System
to
send new messages and extinguish the RE-
CENE
ALARM indicator.
2. Depress the
RECENE
key while the PAGE FULL
indicator
is
lit. This will clear the screen, reposition
the cursor
to
the
top
of
the screen, reset
the
RECEIVE ALARM and PAGE FULL indicators, and
allow the System
to
send new messages.
COMMUNICATIONS PROCEDURES
The basic Input Display System
is
compatible with
the proposed Burroughs Standard Data Communications
For
Form
1044187
I
Page 16
(Note
4)
Burroughs -B9351 /B9353 Input and Display System Technical Manual
l
jAD
1 J
~D2
ENO
·~
[sL2]
SOH
.
.
STX
STX
ETX
[ace]
PROCESSOR
(Note
5)
ENO
(Returns
system
to
Contention
Model
Introduction and Operation
~OT
Note
1
TABLE
1-5
TERMINAL
lnvJlid
or
no
reply
Invalid
or
no
reply
I
Invalid
or
no
\'ply
Invalid
or
no
reply
I
'
[
AD
1]
AD2
NAK
[
AD1]
AD2
ACK
'
[
AD1]
AD
2
ACK
•
[
AD
11
AD~
(I
am)
ACK
Note
3
[
AD1J
AD
2
NAK
Note 1 -
If
the terminal
is
not ready to receive,
as
indicated by transmission
of
NAK, the central computer will normally retry
the selection
at
the
terminal's proper sequence; however, for some installations it may be desired
to
repeat a selection
sequence immediately.
Note 2 - Provision
is
made for transmission
of
blocks
of
header and/or text. In this case a block
is
terminated with ETB-BCC.
When one block has been acknowledged,
the
header
or
text
is
resumed after transmission of'BL
#followed
by
SOH
or
STX. Response to blocks is the same
as
response to a message ending in ETX-BCC.
Note 3 -
If
character parity or block check are
not
validated by
the
terminal, it will send NAK. In this case the central computer
will retransmit the message
"p"
times
("p"
may be equal to zero).
If
the terminal still does not acknowledge the
message, the central computer will terminate the sequence with EOT.
Note 4 -
If
the
central computer does not receive a response (ACK
or
NAK)
to
its message, it may time out and retransmit the
block
"n"
times, where
"n"
may equal zero.
If
still
nG>
response is received, the computer will terminate the sequence
with EOT, after recording the error. The central computer will retain the message for transmission on the next selection
sequence
to
this terminal.
Note 5 - In certain systems implementations where downstream communication
is
not
permitted and transmission can only be
to
the central processor, the identification characters in a transmission may represent the terminal address
("you
are") for
selection verification purposes.
Burroughs -B9351/B9353 Input and Display Systems Technical Manual Sec. I
Page
17
Introduction and Operation
Procedures for point-to-point operation. Multi-point opera-
tion
is
capable by the addition
of
options. The basic System
incorporates two modes
of
operation: a Selection Mode and
a Transmission Mode. Refer to Tables 1-5and1-6.
OPERATION
Receipt
of
EOT
will place the terminal in the passive
or idle condition. The terminal
will
examine the input data
and ignore all input characters until such time
as
it receives
an
ENQ
character.
If
the terminal
is
RECEIVE ready, it
transmits the
ACK
character back to the System.
If
the
terminal
is
busy, i.e., in local, transmit or in the process
of
printing, the terminal will respond with a
NAK.
Upon trans-
mission
of
the
ACK
response to ENQ, the terminal
will
assume it has been selected and accept
all
data from STX
to
ETB or ETX. The terminal will also remain selected until it
receives the EOT character.
The terminal
is
designed
so
that
all
header, block
numbers, transmission numbers, addresses and selection
codes are ignored with the exception that they are included
in the error checking network. The terminal will respond
with the
NAK
character unless
all
characters received since
the last terminal response contained no errors. Since
BCC
may or may not be contained in the received message,
re-
sponses will be delayed one character time following ETX
or
ETB
to allow reception
of
the check character. The
terminal will also inhibit the transmission
of
ENQ
once
it
has been selected.
In order to request to transmit data, the operator
presses the SEND key. Upon receipt
of
an
ACK
response,
the terminal will transmit
STX
followed by its data. Trans-
mission
of
ENQ
will initiate a 3 second timer.
If
either a
NAK or no response
is
received when the timer times out, a
retransmit light will be lit
to
alert the operator to retrans-
mit the message. Reception
of
the
ENQ
character
as
a
response to
ENQ
will terminate the request
to
send func-
tion. The terminal will respond with
NAK
and set the
REC
ENE
ALARM
indicator.
TABLE
1-6
TERMINAL
g~J
NO
Contends
for
master status
(I am)
PROCESSOR
-------------------.-------~----------~-----------
(Light
retransmit
indicator;
Manual retransmission)
Proceed
as
in
point
to
point
selection
!Time
out)
[
soJJ
AD
1
AD
2
STX
.
ETX
[ BCC J
I
(Light
retransmit
indicator;
Manual retransmission)
EOT
Invalid
or
[AD
1J
I no
reply
AD
2 (I am)
l
__j
1AK
(Note
2)
_ (Note
1)
I
[:g~
J
NAK
I
Time
Out
I
Invalid
or
no
reply
(Return
system
to
Contention
Mode)
[
AD
1 J
AD2
(You
are)
[AD1
J
AD
2
ENO
ACK
I I
flam)
Note 1 -
If
the central computer receives a message for which character parity, block check,
or
terminal address test fails,
NAK
will be transmitted, calling for a repeat
of
the
transmission. This can be repeated
"n"
times (to be defined for each
particular system and
"n"
may be equal
to
zero), at which time,
if
the test fails, an error will be recorded at the central
computer and EOT will be transmitted, terminating the sequence. The terminal may transmit the same message at the
discretion
of
the operator.
Note 2 -
If
the terminal does not receive ACK, NAK,
or
EOT,
it
will retain its message and remain quiet. The central computer
will time-out and transmit EOT
or
OLE EOT, terminating the sequence. In this
easy
the message may be retransmitted
at the discretion
of
the operator. See section on Error Recovery in Burroughs Standard 1284-9006 for a definition
of
time-out conditions.
Printed in U.S. America 10-12-70 For Form 1044187
I
Page
18
Burroughs -B9351/B9353 Input and Display Systems Technical Manual
Introduction and Operation
COMMUNICATION
OPTIONS
Polling and Select
Polling and Select option
is
available for multi-point
operation. This option permits the terminal to transmit
data only in response to a poll message, unless the terminal
is
in the contention mode. The terminal
is
selected and
will
accept data
if
it
has received a select message. Included in
this option
is
the poll selection decode, the contention
selection decode and the select selection decode. In addi-
tion, an EOT character will be transmitted
as
a no traffic
response
to
a poll message. This option
is
included with the
Fast Select option.
A Selection Addressing option, part
of
Polling and
Select, allows the terminal to respond to
ENQ
only when
ENQ
is
contained in a
message
whose first two characters
are
the correct address for the terminal. This option, used
by itself, will allow a time-shared terminal to operate on a
point-to-point line.
The
terminal
will
interpret the three
least significant bits
of
AD2
as
the terminal or printer
address.
Also
included
as
part
of
the Polling and Select option
is
the Identification Address option which will allow the
terminal to precede all transmitted messages with the
terminal address.
If
the
message
is
a data
message
preceded
by STX, the terminal will precede the
STX
with the
sequence
SOH
ADl AD2.
The basic design
of
the terminal
is
such that the
terminal ignores
all
special selection codes {i.e., FSL, BSL,
GSL and SEQ) even though they are contained in a message
received by the terminal. (Refer to the flow diagram in
Table
1-7.)
With the Fast Select (FSL) option incorporated
in the terminal, receipt
of
an FSL character will cause the
terminal to check for a
STX
and accept the data that
follows. This means that the terminal does not respond
with an
ACK
to indicate it
is
ready for a message, but
accepts it immediately, thus the term Fast Select.
If
the
terminal
is
not RECEIVE ready, no response
will
be gener-
ated, the data following the FSL
will
be ignored, and the
RECEIVE
ALARM
light for the addressed screen will be lit.
TABLE
1-7
EQT
AD
1
AD
2
(you
arel
POL
ENO
PROCESSOR
TERMINAL
··-·-···---------~[
SOH
fl
..------
AD
1
II
aml
I
AD2
EQT
ICan
continue
polling)
Invalid
or
no
response
EQT
I
I
1Nota21
(Can
continue
polling)
r
ACK
I
I
STX
(Light
retransmit
indicator;)
I
ETX
(Manual
retransmission)
I
[ace
J
I I
NAK
(Note
11
'------------------1
EQT
• I
(Can
continue
polling)
Note 1 -
If
the
central computer receives a message for which charncter parity, block check,
or
terminal address test fails, NAK
will be transmitted, calling for a repeat
of
the
transmission. This can
be
repeated
"n"
times
(to
be
defined for each
particular system and
"n"
may be equal to zero), at which time,
if
the test fails, an error will be recorded at
the
central
computer and EOT will be transmitted, terminating the sequence. The terminal may transmit the same message at the
discretion
of
the operator.
Note 2 -
If
the
terminal does
not
receive ACK, NAK,
or
EOT,
it
will retain its message and remain quiet.
The
central computer
will time-out and transmit EOT
or
OLE EOT, terminating the sequence. In this case the message will be retransmitted
when next polled. See section on
Error
Recovery in Burroughs Standard 1284-9006 for a definition
of
time-out
conditions.
Burroughs -B935l/B9353 Input.and Display Systems Technical Manual Sec. I
Page
19
Introduction and Operation
There are three multiple selection decode options:
Broadcast Select (BSL), Group Select (GSL), and
Se-
quential Select (SEQ).
Broadcast Select
When
the Broadcast Select option
is
incorporated
along with the Selection Decode option, the terminal will
respond
to
a received
BSL
code
as
the third character fol-
lowing an
EOT
by putting all incorporated screens into the
RECENE
mode andloading the data following a
STX
onto
all
screens. The starting address for loading
is
derived from
the cursor position
of
screen zero. Those screens with
cursor positions before that ·of screen zero
will
not
be
loaded since an end-of-screen character
will
precede
all
loaded data in their memory blocks. To insure that
all
screens are successfully loaded during a
BSL
operation,it
is
advisable
to
transmit a Form Feed (FF) character following
the STX.
Group Select
The Group Select Option enables the fast selection
of
any pre-selected subset
of
terminal screens. Operation
is
similar
to
that
of
Broadcast Select, except that instead
of
all
screens being sensitive to the message following, only
those screens with their corresponding Select Flip-flop set
will
be
sensitive. The Group Select option requires incor-
poration
of
the Broadcast Select option.
Sequential Select
The Sequential Select option can be added
if
the
Group Select option
is
incorporated. This opt.ion permits
screens to
be
successively selected to receive by receiving a
SEQ
message
containing their address. This option allows
the setting
of
the appropriate Select Flip-flop when a par-
ticular screen's address
is
received followed by an
SEQ
or
SEL. Otherwise, operation
is
identical to Group Select
except that the screen whose address preceded the SEL
will
generate a response after the following ENQ. This screen
will
also generate a response following receipt
of
an
ETB
or
ETX.
Block Check
With the Block Check option installed, all characters
from the
SOH
character
to
ETX or ETB, or from the STX
character
to
ETX or
ETB
will
be
used
to
generate or verify
the Block Check Character. The STX character
is
included
in the block check summation only when it follows
SOH
in
a
message
block.
When
the Block Check option is not installed,
Printed in
U.S.
America 10-12-70
messages received containing a Block Check Character are
accepted; however, the
BCC
is
discarded.
SYSTEM
INTERFACE
The standard interface in the Input Display System
terminal
is
a multi-wire synchronous interface which
is
compatible with RS232 EIA. This interface can be con-
nected
to
the following
Bell
System
DAT
A-phone Data
Sets: 201A and 201B. Data transfer rates up to 2400 baud
can
be
achieved in the synchronous
mode~
Asynchronous
operation
is
optionally available for either dfrect connec-
tion to a system over two wires or with the following
Bell
System DATA-phone Data Sets: 103A/F
an~
202C/D. Data
transfer rates up to
38AK
bits can
be
achieved in the direct
connect operation. Transfer rates for modem operation
is
currently limited
to
1200 baud.
Each character transmitted or received in the asyn-
chronous mode consists
of
ten nominally equal time inter-
vals, representing a start bit, seven data bits (least signifi-
cant bit first), a parity bit and a stop bit. Polarity
of
the
start bit
is
a 'space' or 'O'. Stop bit polarity
is
a 'mark' or
'I'.
Parity
is
even for asynchronous operation.
During synchronous operation, each character trans-
mitted or received consists
of
eight nominally equal time
intervals. The first seven bits represent the 7-bit character
code and are handled least significant bit first. The eighth
bit
is
the parity bit and
is
selected to make the sum
of
the
'marking' bits odd.
In order to obtain synchronism between the System
and the terminal, at least four
SYN
characters are required
preceding all transmissions. The Input Display System
terminal automatically sends four
SYN
characters preceding
all transmissions to the System. Maintaining synchronism,
once a
message
has been started, requires
SYN
characters
as
'time fill' except between ETX or
ETB
and the following
BCC.
SYN
characters are not included in the
BCC
summa-
tion in the Input Display System terminal.
When
using 4-wire, full duplex, the BREAK key may
be
used
to
terminate transmissions by causing circuit
BB
to
be
turned
off
for a period
of
25
ms. This function should
be
disabled when not operating 4-wire.
Operation utilizing switched lines can make
use
of
the
automatic disconnect feature in the control unit. This
feature allows the processor
to
cause the terminal
to
per-
form a local disconnect
of
the switched circuit.
When
the
terminal detects the character sequence DLE, EOT, the ter-
minal will respond by turning the
CD
line to the modem
OFF for a period sufficient to cause the modem to discon-
nect. The
CD
line
is
then returned to the
ON
state.
For Form 1044187
I
This manual suits for next models
1
