Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rochester!ciaraldi From: ciaraldi@rochester.ARPA (Mike Ciaraldi) Newsgroups: comp.dcom.modems Subject: Re: Converting a modem+terminal to TTY/TTD Message-ID: <27355@rochester.ARPA> Date: Mon, 27-Apr-87 23:01:57 EDT Article-I.D.: rocheste.27355 Posted: Mon Apr 27 23:01:57 1987 Date-Received: Wed, 29-Apr-87 04:42:59 EDT References: <4262@fritz.UUCP> Reply-To: ciaraldi@rochester.UUCP (Mike Ciaraldi) Distribution: world Organization: U of Rochester, CS Dept, Rochester, NY Lines: 43 In article <4262@fritz.UUCP> dennisg@fritz.UUCP (Dennis Griesser) writes: >In article SASHA@THINK.COM >(Sarah Ferguson) writes: >>Does anyone out there know how to convert a standard modem+terminal >>setup for use as a TTY/TTD machine (phone for the deaf)? >> >>I am told it can be done, but no one I know seems to know how. > >A TTD uses BAUDOT coding, and a strange bit rate. >The simplest other way to do this would involve a cheap computer, say a Radio >Shack Color Computer, bunning a BAUDOT terminal emulator. If you can't find >such a thing in amateur radio periodicals, it would be easy to write. In addition, the modems used by the deaf are not Bell 103 or 212 compatible. As I understand it, when "Deafnet" began in the 1950's, not many people were telecommunicating, and equipment was very expensive, so compatibility with industry standards was not very important. Because WW2-surplus Teletypes (TM) were available fairly cheaply, and they used Baudot, the deaf standardized on Baudot. Someone designed a simple modem that worked at the low baud rate required (45, I think) and was cheap to build. So that's what they used. Nowadays, the mass market has driven down the price of ASCII terminals and 103 and 212 modems, but has not affected TDD quite as much. Still, I have seen people from NTID (National Technical Institute for the Deaf, part of Rochester Institute of Technology) with CRT terminals that are switchable ASCII/Baudot and have switchable modems. I think these go for about $600. For more info, try the newsgroup misc.handicap, or the local or national chapter of ACM SIGCAPH (Association for Computing Machinery, Special Interest Group on Computers and the Physically Handicapped). Good luck. Mike Ciaraldi ARPA: ciaraldi@cs.rochester.edu uucp: seismo!rochester!ciaraldi