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From: fair@dual.UUCP (Erik E. Fair)
Newsgroups: net.med,net.dcom
Subject: Re: Teletypes for the Deaf
Message-ID: <471@dual.UUCP>
Date: Wed, 2-May-84 20:44:48 EDT
Article-I.D.: dual.471
Posted: Wed May  2 20:44:48 1984
Date-Received: Fri, 4-May-84 01:09:07 EDT
References: <1402@dartvax.UUCP>
Organization: Dual Systems, Berkeley, CA
Lines: 21

To the best of my knowledge, TTD devices use Baudot code, which is a 5 bit
(as opposed to 7/8 bit ASCII) code, and it uses an old modem standard
called (I think) Whitehead, which has some interesting characteristics.
Among other things, there is no carrier unless the modem is transmitting
data. It does predate Bell 103.

Most of my information on the subject comes from a Uni-Ops talk given
by Dave Fylstra, formerly of SRI, who was at the time working on a
project called DeafNet, which will eventually look like USENET, in
the sense that there will be regional nodes which communicate with each
other w/ high speed (1200) modems, and have dialins for the local members
which are whitehead modems.

Unfortunately, I don't have a current address for Dave Fylstra, nor do
I know anything more about DeafNet...

	Erik E. Fair	ucbvax!fair	fair@ucb-arpa.ARPA

	dual!fair@Berkeley.ARPA
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	Dual Systems Corporation, Berkeley, California