ARCHIVED: What are the pinouts for a Macintosh Hardware Handshaking cable?

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A. Most high-speed modems now come with hardware handshaking cables. If yours did not, and you are technically inclined, you can build one using the following pinout diagram.

CABLE DIAGRAM FOR MACINTOSH COMPUTERS

  RS-232         DIN 8 (MAC)          Supra Modem With Hardware Handshake

  ------

  Note: Pins 4 & 8 are hooked together on the MAC side, and also connect to
        pin 7 on the Modem side. Pins 4 & 20 are hooked together on the
        Modem side, and also connect to pin 1 on the MAC side.

  Lines on DB25 port on the Modem
   Pin #      Mnemonic                Description
   1          GND                     Protective frame ground
   2          TxD                     Transmit Data
   3          RxD                     Receive Data
   4          RTS                     Request to Send
   5          CTS                     Clear to Send
   6          DSR                     Data Set Ready
   7          GND                     Reference signal ground
   8          DCD                     Data Carrier Detect
   20         DTR                     Data Terminal Ready
   22         RNG                     Ring Indicator

This information comes from the Supra Technical Support BBS, which can be reached via modem at (503) 967-2444.