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From: steve@wattres.UUCP (Steve Watt)
Newsgroups: comp.unix.ultrix,comp.sys.dec
Subject: Re: adding a modem to a decstation 3100
Message-ID: <448@wattres.UUCP>
Date: 18 Mar 90 08:26:07 GMT
References: <8102@sdcc6.ucsd.edu> <1063@psych.stanford.edu>
Reply-To: steve@wattres.UUCP (Steve Watt)
Followup-To: comp.unix.ultrix
Distribution: usa
Organization: Steven Watt, Consultant
Lines: 27

In article <1063@psych.stanford.edu> connie@psych.UUCP (Constance Stillinger) writes:
>In article <8102@sdcc6.ucsd.edu> ux1925@sdcc12.ucsd.edu (burt bakor) writes:
>> 
>> 
>> Help,
>> 
>> I'm trying to connect a hayes modem to a decstaion 3100 and can't
>I'd like to second this request for info -- I'm supposed to get an

Funny you should mention that...  I was having this EXACT problem less than
two weeks ago...  I discovered that the serial port on the back of the
DECStation is (obviously! :) RS-423 (?!???)

What this means is that the voltage swing does not have to be as great as
RS-232 requires.

Solutions?  Two that I found:
1)  Buy a Telebit.  They don't seem to care
    much if the voltage is low....
2)  Some companies are rumored to sell RS232 boosters which supposedly do
    the trick.  I built one from 1488s and 1489s.  Drop me a line if you
    want a PostScript schematic.

-- 
Steve Watt
...!claris!wattres!steve		wattres!steve@claris.com also works
If you torture your data long enough, it'll eventually confess.