This adapter interfaces between APO-standard 6-wire 6-position RJ11 RS-232 cables and Macintosh Mini DIN-8 Serial Ports.
RJ11 Socket
Mini DIN-8 Male
Signal
1
handshake out
2
3
transmit to transmit-
4
transmit ground to signal ground
4-8
jumper signal ground to receive+
8
receive ground to receive+ (which is jumpered to signal ground)
5
receive to receive+
6
handshake in
Pin assignment for RJ11 socket.
The cable portion of the adapter should ideally be about 3" long, but longer is permissable if it simplifies manufacturing.