Serial Port (DB25 Male)

Some models of A4000 may have 26-pin header mounted on the motherboard, with a short cable connecting it to the serial connector. Pin 1 of this header is on the side closer to the power supply, and it shares the same pinout as the DB25 listed below (pin 26 is unconnected). Other models of A4000 have a high-rise, right-angle DB25 connector soldered directly to the motherboard.

   Pin 1: Shield Ground
   Pin 2: Transmit Data
   Pin 3: Receive Data
   Pin 4: RTS
   Pin 5: CTS
   Pin 6: DSR
   Pin 7: Data Ground (Do not connect to shield ground.)
   Pin 8: CD
   Pin 9: +12V (20 mA maximum.)
  Pin 10: -12V (20 mA maximum.)
  Pin 11: Amiga Audio Out (Left)
  Pin 12: Unused
  Pin 13: Unused
  Pin 14: Unused
  Pin 15: Unused
  Pin 16: Unused
  Pin 17: Unused
  Pin 18: Amiga Audio In (Right)
  Pin 19: Unused
  Pin 20: DTR
  Pin 21: Unused
  Pin 22: RI
  Pin 23: Unused
  Pin 24: Unused
  Pin 25: Unused