Apple IIgs Serial Port
Complete documentation here (archive).
The IIgs speaks RS-422, which is differential serial. By tying some lines together, you can talk to a standard PC RS-232 port using a custom-wired null modem cable.
IIgs side (mini DIN8) |
DTE (computer) side (DB9) |
HSKo (1) |
DSR (6) |
HSKi (2) |
DTR (4) |
TxD- (3) |
RxD (2) |
GND (4) and RxD+ (8) |
GND (5) |
RxD- (5) |
TxD (3) |
TxD+ (6) |
N/C |
GPi (7) |
RTS (7) and CTS (8) |