Delete Function, Logic Diagram - Raytheon DIDS-400 Series Technical Manual

DIDS-402 -2AM13
The insert-character function is repeated in this manner, until 88
F(~)
pulses have been counted by the 88-count ripple counter.
F(~)
is gated through
NAND-gate A24.6 as 88-Count Complete to reset the function complete flip-flop.
When A40. 9 goes low, A29. 11 is latched high to develop an 88-Count Reset level
for resetting 88-count ripple counter. Simultaneously, Function Complete sets
A38.5 high to return the circuit to its quiescent state. In this manner, an entire
horizontal line (88 characters) is inserted, one character at a time. Each time
the EOL and V DRIVE timing outputs signify the last character of the last line
position, the character is destroyed. After 88 F(.6.) pulses, an entire line of Idle
characters has been inserted and the last line of the screen has been destroyed.
4-23.3.14 Delete-Character Function
The delete-character edit function deletes the character associated with
the cursor and moves all other characters on the line one character position
to the left. In memory, the data character associated with the cursor is
inhibited from entering the delay line (deleted) and the next data character is
advanced by 13
JJ.S
to replace the deleted character in memory. Each successive
character on the line is similarly advanced (stepped left) so that the first charac-
ter of horizontal retrace (an Idle character) is stepped into the last character
of line character slot (see figure 4-52).
DELETE
PB3
FUNCTION COMPLETE
DELETE F/F
(ENABLE 88-COUNT)
SS-COUNT RESET
EOl
V DRIVE
88-COUNT ENABLE
DIDS 68-651
8
D
A38
CURSOR
RQ
9
DELETE CHARACTER
RESET
J
Q
A30
K
Q
R
9
6
8
CE
REGISTER
REFRESH MEMORY
lOOP
DELAY
LINE
Figure 4- 52. Delete Function, Logic Diagram
4-134
8