craig@x.UUCP (Craig Lund) (05/27/85)
Somebody out there asked for the pinout of the serial port on the back of a Macintosh. The serial port is RS422, NOT RS-232 ! If you wire it right, most RS-232 devices won't care. Pinout: 1 Ground 2 +5 3 Ground 4 Transmit Data + 5 Transmit Data - 6 +12 7 Incoming handshake 8 Receive Data + 9 Receive Data - I connected directly to my UNIX box using the following three-wire connection: MAC Pin UNIX Pin 1 7 5 2 9 3 If this does not work for you, try switching pins 2 and 3 on the UNIX side. Also, some RS-232 ports will require connecting ground and/or +5 to some of the RS-232 control lines. Consult the manual for your RS-232-based computer or modem.