Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!tut.cis.ohio-state.edu!sei!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!jh4o+ From: jh4o+@andrew.cmu.edu (Jeffrey T. Hutzelman) Newsgroups: comp.sys.apple2 Subject: Re: RS-232-C Message-ID: Date: 21 Jan 91 23:44:00 GMT References: <7030@crash.cts.com>, <8049@minyos.xx.rmit.oz.au> Organization: Carnegie Mellon, Pittsburgh, PA Lines: 22 In-Reply-To: <8049@minyos.xx.rmit.oz.au> There is one problem with giving the mini-8 pinouts without a diagram - I have seen 2 or three diagrams with totally different numbering schemes, all in official Apple Computer, Inc. Manuals. To be specific about the pinouts given: DTR and DSR are the 2 pins on the bottom. TxD+ and RxD+ are the pins you want to use for normal RS-232 communications; they're the two end pins on the top row. The center pin is ground. TxD- and RxD- are on the ends of the middle row; they're not especially useful, and most cables leave them unconnected. Finally, the top center pin (pin 7) is actually DCD on the IIgs, but some sources claim that it is not connected on Macintoshes. I haven't tried it on Macs, but I know it IS connected on the IIgs. I believe the numbering reads left-to-right as you are facing the back of the computer, but I'm not sure. And don't rely on the numbers on the connector on the IIgs; they probably use aw different numbering scheme than the one in the IIgs owner's manual. Actually, don't trust me on using the positive data lines either; I think that's how I did it last weekend, but I don't remember for sure. Good luck! -------------------- Jeffrey Hutzelman America Online: JeffreyH11 Internet: jh4o+@andrew.cmu.edu BITNET: JHUTZ@DRYCAS >> Apple // Forever!!! <<