Connections

There are five connectors on the board, pin 1 of each connector is marked, and they are shown here as they appear on the board (connector viewed end-on).


PL1 STEbus connector


PL2 I/O connector 10-way ribbon-cable

channel A data out 1 o o 2 channel A data in
channel A RTS out 3 o o 4 channelA CTSin
gnd 5 o o 6 n/c
channel B CTS in 7 o o 8 channel B RTS out
channel B data in 9 o o 10 channel B data out

Signals on this connector are at RS232 levels except for SYNCB.


PL3 Parallel I/O connector 16-way ribbon-cable

( bit 3 1 o o 2 bit 4 ) Parallel
keyboard
port
( bit 0 3 o o 4 bit 2 )
( bit 1 5 o o 6 bit 7 )
( bit 6 7 o o 8 bit 5 )
Gnd 9 o o 10 5V
Gnd 11 o o 12 Gnd
DTRB (SCC) 13 o o 14 DCDB (SCC)
DCDA (SCC) 15 o o 16 DTRA (SCC)

PL4 Disk connector 34-way ribbon-cable


PL5 Power connector 5-pin Berg