Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ncar!ames!dftsrv!mimsy!mojo!russotto
From: russotto@eng.umd.edu (Matthew T. Russotto)
Newsgroups: comp.sys.mac.misc
Subject: Re: Wiring for hayes modem w/handshaking
Message-ID: <1991Mar24.192306.11160@eng.umd.edu>
Date: 24 Mar 91 19:23:06 GMT
References: <27EB1B0B.3468@ics.uci.edu> <1991Mar24.082806.14851@news.arc.nasa.gov>
Sender: news@eng.umd.edu (C-News)
Organization: College of Engineering, Maryversity of Uniland, College Park
Lines: 20

In article <1991Mar24.082806.14851@news.arc.nasa.gov> ogawa@orion.arc.nasa.gov (Arthur Ogawa) writes:

>The pinout given by Cieman has a different klooch, namely the modem
>sees (via its DTR input) that, whenever it asserts its RTS output, the
>Data Terminal (the Mac) is ready.

Unfortunately, Pin 4 is TO the modem-- so what the modem sees is that whenever
the mac is ready to recieve (CTS asserted), the Data Terminal is ready.  This
is bad, as I pointed out in another post.

>Interestingly enough, the NeXT's serial port is RS-423, rather than
>RS-422, as in the Mac. The former supports the four independent handshaking
>signals.

How many pins on the NeXT's port?  In order to support four handshaking
signals, you need at least 9 pins.
(TxD+, TxD-, RxD+, RxD-, CTS, RTS, DSR, DTR, Gnd)
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
     .sig under construction, like the rest of this campus.