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).
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.
( 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) |