lorien@dartvax.UUCP (Lorien Y. Pratt) (05/11/84)
I posted a note recently asking about telecommunications facilities for the deaf to help my grandfather, who has a deaf friend with whom he'd like to communicate. I'd like to thank everybody who contributed to my large number of responses. Here is a summary of the results: It seems that very many people in the deaf community use terminals that communicate in an arcane and outdated 5 bit baudout code. This protocol is completely incompatible with the ASCII that 99% of terminals speak today. I've given the details of this baudout code at the end of the article for you hardware freaks. Seems the reason for this is that the companies that produced machines that ran the soon-to-be outdated protocol found enthusiastic buyers in hams and the deaf and gave them substantial discounts on hardware. California also recently passed some sort of law that forced the phone company go give one free TDD to each deaf person. Small TDD's are available that still speak baudout. They are simple terminals that simply plug into an existing phone system via a modular plug. They have no intelligence. A cheap version is the MINICOM by Ultratech. They run around $240. You can write to: Weitbrecht Communications, Inc. 666 Skyway Suite 230 San Carlos, CA 64070 (415) 592-1622 If you'd like to speak baudout using your home computer, there are several options available. Novations Apple CAT modem (which I seem to recall is very inexpensive, but one of my responders says costs $495) has as one of its options TDD compatibility. Also there's a package called Apple Express. It seems that an Apple IIC with one of these packages would be just *perfect* for someone who wanted communication ability plus some computing power. And at under $1400, it's a pretty cheap. Rumors of something called DeafNet, which was rumored to be a project aimed at a USENET-like network for the deaf. No detailed followup information on that, but I did receive some pointers to groups that help deaf people with telecommunications. They are: Telecommunications for the Deaf, Inc. Barry Strassler, Executive Director 814 Thayer Avanue Silver Springs, MD 20910 (301) 589-3006 Deafnet (provides assistance to local deaf communities) Hal Huntley SRI International Menlo Park, CA HAL@SRI-NIC (415) 859-2236 Hardware info for 5-bit baudout ------------------------------- a) Teletype units use a 5 unit Baudot Code. The character is always preceded by a 1 bit duration start bit (space or 0) and is always followed by a 1.42 to bit stop bit (Mark or 1). [sic: probably meant 1.42 to 2 bit] b) Teletype units transmit data at 45.45 baud +- 0.45 bauds. c) Other information: Transmission Characteristics: Mark (1) 1400Hz +- 1% -9 dB (Level at tip and ring, dBM) Space(0) 1800Hz +- 1% -9 dB Receive Characteristics: Mark (1) 1400Hz +- 1% 72 dB (level, dB SPL) -0dB+43dB tolerance Space(0) 1800Hz +- 1% 72 dB -0dB+44dB