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I FMI . - - - - - - - - - - - - - - ,
8U 8T
BW
BV
CS --~(>-~-----------+--------_+------------------------------~~~_,
FROM
A7D.3
FROM CHARACTER
ENTRY REGISTER
H DRIVE
V
DRIVE
----------,
P/O
DISPLAY LOGIC
I
ETX
DECODE
80ARD
I
I
I
I
STARTXMIT
•• -------------------,
%
A·
PAR
R
HI:> PE
ETXDI
STX
ADDR
%3
T
881
882
883
ETXDI
3(CTS+I)
SDl
ENTER HEADER
DIDS 68-523
NOTE: HEAVY LINE DENOTES
DATA FLOW
8
F
LHI
4 _---01
BC
LO
=>
ENTER
HEADER +MR
ENQ F/F
ETXSR
).....,_ .... PF"<' " ' - ,,·OPE ____ ----<DI
LO~
ENQD3 _---01 ..
~/
lO
~
CLEAR IBB1
JAM
H
BJ
RE
L..-....r-..... 8
XMIT
TIME OUT
F/F
>-........
-IJ
Q
1--""
C
K
6
II
ENTER HEADER
T
T+
fiE
ETXD3
8
INITIALIZE TRANSMIT
6
REQUEST TO SEND(RS)
8
h----1 .. R
NOTES:
MR
~
.... -------------------d
XMIT PLSE ....
---------------r---....
XMIT ...
------6:-,
DIDS-402 -2AM13
lEGEND
ADDR
ADDRESS FLIP-FLOP SET
BB1
BUSY BIT 1 'NOT'
BB2
BUSY BIT 2 'NOT'
BB3
BUSY BIT 3 'NOT'
CS
CLEAR TO SEND
MR
MASTER RESET
PAR
PARITY BIT TIME
(be)
PE
PARITY ERROR 'NOT'
RE
RECEIVE ENABLE 'NOT'
RS
REQUEST TO SEND
R
RECEIVE STEERING lEVEL
STX
START OF TEXT FLIP-FLOP RESET
SDl
SHIFT DATA TO/FROM DELAY LINE
T
TRANSMIT STEERING lEVEL
XMT
TRANSMIT KEY DEPRESSED
1.
ENQUIRY-RESPONSE OPTIONS ,--,
2.
POLLING OPTIONS
1\
'
3.
COMMON TO ENQUIRY-RESPONSE
AND POlliNG
4.
HEAVY LINES DENOTE MAJOR FUNCTION
PATHS
5.
BY TOCA IS OPTIONAL CONNECTION
FOR
ONE -STEP TRANSMIT IN
THE POLLING MODE
LO
~
ENQ...........o -
D-"-L-__
O~+--~===3:::l-----I
.. XMIT TO A27. 11
F/F SET
PF
PE
K
FIG (4-25)
START __
------------------------~
XMIT
MR ....
--cr--
CFR ....
----<OI-~
ETXSR __ -------<I
ENTER
HEADER
Io------i ..
CLEAR
8BI
Figure 4-24.
Transmit Enable Circuitry
4-55/4-56
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