Programming instructions

KEYBOARD
CONTROL
To
Printer
- Status Bit:
03 Keyboard Flag
Interrupt:
Keyboard Flag
Figure 19 - Keyboard programming logic
The Keyboard flag is connected to the Program Interrupt Control and the
iors instruction, bit 3. A simple sequence which “listens” for keyboard
inputs is:
PROGRAM SEQUENCE
/listen loop for keyboard
400/ ksf
/skip when a character arrives from keyboard
Jmp 400
krb /read in the character
The sequence following the listen sequence beginning.in 403 may operate
for up to 100 + 13.3 milliseconds before returning to listen for the next
character without missing the next character. The average computing time
between any two characters must be less than 100 milliseconds (for an
input rate of 10 characters per second).
TELEPRINTER
The Teleprinter is given 5 bits of information from AC bits 13 to 17, coding
the character to be printed. The teleprinter Buffer (TB) receives this infor-
mation, transmits it to the Teleprinter serially, and when finished turns on
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