Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!think!husc6!panda!genrad!decvax!decwrl!kent From: kent@decwrl.DEC.COM (Christopher A. Kent) Newsgroups: comp.dcom.modems Subject: Re: modem interface to TDD (deaf communications), how? Message-ID: <7415@decwrl.DEC.COM> Date: Thu, 8-Jan-87 13:28:23 EST Article-I.D.: decwrl.7415 Posted: Thu Jan 8 13:28:23 1987 Date-Received: Thu, 8-Jan-87 22:46:17 EST References: <763@sdcc12.ucsd.EDU> Reply-To: kent@decwrl.UUCP (Christopher A. Kent) Distribution: na Organization: DEC Western Research Laboratory Lines: 17 Keywords: TDD deaf Fortunately or unfortunately, TDDs have been around a long time. Longer than ASCII, in fact. Thus, they don't speak ASCII. They use a 5 or 6 bit code called Baudot (it's been too long since I thought about this to recall the details). So while the modems might be compatible, the "terminals" aren't. At one time, I played with the design of a box that would translate. It's really quite straightforward to do; a look-up table and a small finite state machine (implemented in a micro, of course) connected to two UARTs. There might even be a market to do this commercially, though most TDDs have a fairly limited display (typically one line of 30-50 characters) so they aren't much good for general purpose terminals. chris -- Chris Kent Western Research Laboratory Digital Equipment Corporation kent@decwrl.dec.com decwrl!kent (415) 853-6639