AEA PK-232 Technical Reference Manual page 15

PK-232 TECHNICAL MANUAL
PA5
–––––––––––––––
0
1
0
Parallel port A can be controlled by the user directly. Set ADDRESS to $BF0D and then
read or write port A using the IO command.
Parallel port B pins PB4, PB5, PB6 and PB7 drive the Mode LEDs through the 7445 de-
coder at U11:
PB7
–––––––––––––––––––––
0
0
0
0
0
0
0
0
1
1
1
PB3 drives the SEND LED through one of the 7406 drivers at U18. Parallel port B pins
PB0, PB1 and PB2 drive the Status LED through the 7445 decoder at U12:
PB2
–––––––––––––––
0
0
0
0
1
1
1
Parallel Port C drive their functions through parts of the 7406 driver chip at U18:
PC0
PC1
PC2
PC3
When parallel ports B and C are used with the parallel printer, the pins are brought out
from the 8536 unbuffered to the J2 connector:
PK232TM Rev. A 5/87
PA2 PA0
1 0 Narrow shift FSK
1 1 Wide shift FSK
0 1 CW
PB6 PB5 PB4
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
0 0 0
0 0 1
0 1 0
PB1 PB0
0 0
0 1
1 0
1 1
0 0
0 1
1 0
STA LED
CON LED
MULT LED
Bar graph enable
LED
–––
PKT
MORSE
ASCII
BAUDOT
CHECK
FEC
MODE L
ARQ
STBY
(FAX)
(SIGNAL or SIAM)
LED
–––
STBY
PHASE
OVER
IDLE
TFC TRANS
ERROR CONV
RQ CMD
3-5
CHAPTER 3 – THEORY OF OPERATION
Page 15