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The ///'s plug is female. You will feel dumb trying to plug a female cable connector into a female RS232 port. You will feel dumber trying to plug a DIN-8 connector into a DB-25 socket. You will feel even dumber if you try to force fit the long side of a "D" shaped plug over the short side of a "D" shaped socket. Your spouse will giggle at you. Your dog will shun you.

If you already have an RS232 cable that is mis-plugged, you can buy adapters or "gender menders" at places like Radio Shack. These may be marginally less expensive than buying a new cable.

If you want to communicate directly from your Apple /// to another computer in the same room, you need a special cable called a null modem or a modem eliminator. The RS-232 port on each machine thinks it is talking to a modem. The pins are set up that way. If you don't have a modem between the two computers, you need to re-define the pins. A modem eliminator switches a couple pins so that both computers think they are talking through modems. A ten buck modem eliminator is bunches cheaper than two modems.

Null modems and gender menders and adapters look a whole bunch alike. Some printer cables look just like modem cables, but they -- like null modem adapters -- switch pins around. Do not confuse them or you will have a true failure to communicate. If you have a selection of these cables, label each one.

1.3 Interface Cards

The Apple ///'s built-in serial port is not the only thing available for data communications. The Apple II Super Serial Card (or clone) and the Apple Serial Card /// provide extra serial communications ports. The Apple II SSC is not real good for data communications because of the card's DIP switches. It is a real bore to pop your ///'s lid and flip switches on the card when you want to talk to a different computer. The SC3 does not have that limitation, but it needs a special driver for data communications (check the WAP /// SIG PD). Most Apple /// data communications programs assume you will be talking through the built-in RS-232 port. You are best off using the built-in port for data communications, and using slot cards for other "serial" devices like printers.

2.0 Data Communications Setup

Setting up your Apple /// for data communications involves an Apple /// "driver" file that must be installed in your boot disk's SOS.DRIVER file. In the general case, you need never set or change the data comm driver's parameters (the subject of some truly arcane pages in the Standard Device Drivers manual). Most data comm programs have commands to set and change the driver parms themselves. Use the System Utilities Program's "System Configuration Program" (SCP) to install the driver in your boot disk, and then forget it.

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Revised November 1, 1998 lic
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