Serial Port Connector - 9-pin

                                 5 4 3 2 1
                             ┌───────────────┐
                              \  ■ ■ ■ ■ ■  /
                                \ ■ ■ ■ ■ /
                                 └───────┘
                                  9 8 7 6

                         Pin In/Out Signal Name
                         ─── ────── ─────────────
                          1    I    Data Carrier Detect
                          2    I    Receive Data
                          3    O    Transmit Data
                          4    O    Data Terminal Ready
                          5    na   Signal Ground
                          6    I    Data Set Ready
                          7    O    Request to Send
                          8    I    Clear to Send
                          9    I    Ring Indicate

   Notes: ■ The signals on pins 1, 6, 8, and 9 are represented at port
            n+6 (where n is the base port; e.g., at port 3feH on COM1).
            See Serial Ports.

          ■ A serial port cable for normal data transfer with the DOS
            InterLink utility uses only three wires.  For remote copy
            operations, you need a 7-wire null-modem cable.  See
            InterLink Cables.

See Also: Cables and Pin Outs
          Serial Port Connector - 25-pin
          Serial Ports
                                    -♦-