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From: russotto@eng.umd.edu (Matthew T. Russotto)
Newsgroups: comp.sys.mac.comm
Subject: Re: hardware handshaking modem cable?
Message-ID: <1990Oct9.022017.16941@eng.umd.edu>
Date: 9 Oct 90 02:20:17 GMT
References: <34644@cup.portal.com>
Sender: news@eng.umd.edu (The News System)
Organization: College of Engineering, Maryversity of Uniland, College Park
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In article <34644@cup.portal.com> drew@cup.portal.com (Andrew E Wade) writes:
>Can anyone tell me if it's possible to get a cable from mac serial port
>to modem that supports hardware handshaking?  If so, where?  Local stores
>I've asked don't understand my question.

Yes, and believe it or not, from Hayes-- I think it's called a Mac-to-V-series
Hardware Handshake cable.  (Hayes puts their name on it, anyway).
You can't use both DTR and hardware handshake.  You can use carrier detect and
hardware handshake, but you need to make your own cable and write your own
program.

If you like hardware hacking, you can convert a standard cable to hardware
handshaking with a DB25-female connector, a DB25 male ribbon connector, and
some ribbon cable.  (this is the no-soldering solution, and can be done with
no tools...) Connect the DB25-F in the standard way.  Now, find out
what pin handshake out is coming from.  It is usually Pin 20 (DTR).  Shift the
wire that would connect to pin 20 on the DB25M so it connects to pin 4 (RTS)--
you do have to pull the ribbon cable apart.  Now find out what pin handshake
in goes into.  It is usually 5,6,8, or (I've seen it once) 19.  Pull this
wire out, and shift it over to pin 5.  (if it was pin 5 already, be happy).
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
      .sig under construction, like the rest of this campus.