Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!olivea!oliveb!pyramid!lstowell
From: lstowell@pyrnova.pyramid.com (Lon Stowell)
Newsgroups: comp.dcom.modems
Subject: Re: 19200 bidirectional extension to V.32 bis.
Message-ID: <129902@pyramid.pyramid.com>
Date: 10 Oct 90 22:53:32 GMT
Sender: daemon@pyramid.pyramid.com
Reply-To: lstowell@pyrnova.pyramid.com (Lon Stowell)
Organization: Pyramid Technology Corp., Mountain View, CA
Lines: 28

True, most serial chips currently sold only go up to 38.4...for
a few cents more though you can get higher speed versions up to
1.544..

RS-232 works quite well up to around 70 Kilobits as long as you
use twisted pair cabling for data and (sync only) clock leads.
I KNOW what the standard says about 20 Kbps, but have seen
thousands of RS 232 I/F's running at 56 Kbps at AT&T computer
centers....

X.21 is a nice alternative...it is an INTERNATIONAL standard (as
opposed to RS-422) and is becoming quite common on ISDN T/A's...

V.35 is quite tricky to implement--there are a LOT of verrrryyy
noisy examples on the market.  Almost all of the good ones use
discrete transistors and op amps....bleeech!

It will be interesting to see how ISDN BRI affects the
superspeed 2-wire dial modems....I personally wonder if
ubiquitous BRI will happen in my lifetime......


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