|                 Specifications For TDD Data Transmit/Receive
 
All TDD manufacturers follow these specs but no tolerance level is given:
 
1.  Acoustic coupling (standard G- and K- type handset)
 
    Input level: 65 dB SPL minimum / 110 db SPL maximum
                                   -4        2
                 (0 dB SPL = 2 x 10   dyne/cm )
 
    Output level: 95 dB SPL minimum / 100 dB SPL maximum
                  (acoustic pressure to produce a -9 dBm
                   signal at the telephone set line terminals
                   on an average loop)
 
2.  Direct modular connection
 
    Connector:  standard 6-position modular jack
 
    USOC No.:   RJ11C
 
    Input level: -50 dBm minimum / 0 dBm maximum
 
    Output level: -13 dBm minimum / -9 dBm maximum
 
3.  Modem
 
    Modulation method:  Frequency Shift Keying
 
    Mark frequency:  1400 Hz +-5 Hz
 
    Space frequency:  1800 Hz +-5 Hz
 
    Signal to noise ratio:  13 dB
 
    Carrier to data delay:  180 ms
 
    Carrier to hold time:  156 ms
 
4.  Protocol
 
    Code:  Baudot
 
    Mode:  Half duplex
 
    Transmissions:  Asynchronous
 
    Start bit:  1
 
    Stop bit:   1
 
    Data bits:  5
 
    Parity:  None
 
    Data rate:  45.5 baud (buffered)
 
Note: The above information is from Plantronics, Inc. (manufacturer of
the Vu-Phone) and is assumed to be consistent with other brands as the
Vu-Phone is compatible with all other TDD's.
(1985)
--------------
Curtis E. Reid				
Rochester Institute of Technology
         
 
 Put the world at your finger tips with VuPhone TDD Plantronics developed the VuPhone so you could enjoy easy, reliable
      telephone communications So easy to type VuPhone has a full-size, standard keyboard with excellent touch for
      easy typing. The special control and function keys make everything simple. So easy to read The VuPhone display was carefully designed so you can clearly see what
      you and the other person type. The VuPhone display shows 32 large,
      easy-to-read green numbers or letters at one time. So convenient to use VuPhone offers many features ina light and
      portable package weighing only 6.2 pounds, so you can carry it wherever
      you go, and make your telephone calls wherever there
      is a telephone. VuPhone has rechargeable batteries so
      that if electric power fails or there are no power plugs near the
      telephone, you can still make your call. Saves you money and time VuPhone has a memory that holds up to 700 letters, numbers or
      functions, so you can type your messages before making your call. This
      saves time and money on long distance calls. You can send the same message
      to as many people as you want, so you do not have to type the same
      information again and If you need more than 700 characters. the VuPhone
      allows you to connect any tape recorder and save as much information as
      you need. So reliable 
 From the TDI  International Telephone Directory of
        the Deaf from the  Paul and Sally Taylor Collection at 
        SMECC.  
 
     -- Telephone device for the hearing or speech impaired, TDD or TTY,
      connects to any telephone with built in modem, some models have direct
      hookup. Standard keyboard. 32 character green LED visual display. 700
      character memory can store incoming message. A message can also be typed
      before making call and sent all at once to save phone costs. With the
      memory the same message can be sent to several people. Display will turn
      off after 2 minutes of nonuse. Cassette recorder can be connected.
      Portable, optional carrying case. Rechargeable backup battery for one hour
      of use in power failures. No paper copy.  (From
      ABLE DATA )
   Price: 750.00 to 650.00.   Manufacturer:
 Plantronics, Inc.345 Encinal Street Santa Cruz, California 95060
 United States
 Telephone: 800-544-4660 or 831-426-5858.
 Fax: 831-426-6098.
 
   | 
  
    | EXCERPT FROM
      -    TECHNOLOGY AND HANDICAPPED PEOPLE DECEMBER 1982 BACKGROUND
      PAPER #2: SELECTED TELECOMMUNICATIONS
      DEVICES FOR HEARING-IMPAIRED
      PERSONS Virginia W. Stern,
      M.A. Martha Ross
      Redden, M. S., Ed.D. Project on the
      Handicapped in Science, Office of Opportunities American
      Association for the Advancement of Science, Washington, D.C.   COST OF TDDS TDDs are still very expensive. The reconditioned
 TTYs cost about $300 installed, with additional
 fees for paper supplies and servicing, plus
 the cost of the coupler ($250). For the past several
 years, reconditioned TTYs have been almost impossible
 to obtain and can usually be purchased
 only from someone who is acquiring more modern
 equipment.
 A 1981 catalog of rehabilitative devices describes
 10 portable TDDs made by different companies,
 with prices ranging from $300 to $700, accessories
 not included. One ultraportable model,
 with somewhat limited use, sells for $200 (43). A
 new Baudot model, the Minicom”, introduced by
 Ultratec in 1982, is lightweight and sells for $259.
 All these devices are beyond the budget of many
 deaf families.
 Recognizing that deaf TDD users would have
 to purchase an expensive device before they had
 access to the telephone lines, some States
 (Michigan, Illinois, Florida, Georgia, and a few
 others) lease TDDs for a monthly fee ($15 to $36
 per month). Some States rent with an option to
 buy. Hearing-impaired persons who use an amplifying
 handset on their telephone pay $0.75 per
 month for this service in some communities, and
 $1.50 per month in others; there seems to be no
 standard charge. Some telephone companies will
 sell the amplifier to the customer for a $40 charge,
 but it is difficult for the customers to find out
 about this. As other adaptive devices, it is not
 always easy for TDD users to know what is available
 and what is the most economical way to obtain
 it.
     DISTRIBUTION OF FREE TDDS IN CALIFORNIA An important step in distributing TDD units
 for access to the telephone system was taken in
 California in the fall of 1981. In 1979, owing to
 the work of deaf consumer groups (particularly
 GLAD, the Greater Los Angeles Council on Deafness),
 the California legislature passed a bill requiring
 the telephone companies to distribute free
 TDD equipment to certified hearing-impaired customers
 who could not use a standard telephone
 (California SB 597). Governor Jerry Brown signed
 the bill into law, and the California Public Utilities
 Commission was charged with implementing it.
 In September 1980, the Public Utilities Commission
 began hearings to work out the practical
 aspects of implementing this law that applies to
 California’s 40,000 deaf residents. Almost all
 TDDs owned by deaf Californians employed the
 5-level Baudot code. TDDs were manufactured
 by a number of small companies, many of which
 were located in California and therefore had a
 financial interest in specifications for the devices.
 The issue of the modem code for TDDs was as
 significant in the hearings as was that of the
 system by which TDDs would be distributed.
 Groups participating in the California hearings
 had different goals. The conflict was an example
 of the recurrent conflict between those with investments
 in “old” technology and advocates of
 “new” technology whose stand would inadvertently
 make existing technology obsolescent
 and necessitate the retraining of users. The
 telephone companies wanted to implement the law
 in the most economical and expeditious fashion.
 The manufacturers of TDDs were competing for
 the potentially lucrative equipment contracts from
 the telephone companies. In general, the manufacturers
 wanted to stick with the 5-level Baudot
 code, because changing over to the 8-level
 American Standard Code for Information Interchange
 (ASCII) would be expensive. They also
 feared competition from larger manufacturers
 who had not served the deaf market before. The
 deaf consumer groups were concerned about small
 matters: hard or soft copy, red or green letters
 in the light-emitting-diode readouts.
 Other interested groups were also represented,
 SRI International, a California-based consulting
 firm, had just completed a 3-year grant project
 totaling $375,000, that the National Institute of
 Handicapped Research, Office of Special Education
 and Rehabilitative Services, funded to develop
 an ultraportable hand-held TDD terminal. (A
 prototype was made and tested with representatives
 of the deaf community; although the prototype
 was smaller than any other standard
 typewriter-keyboard TDD, it was expensive and
 never came to production. ) The SRI team, which
 included technology-minded deaf members, was
 very concerned that deaf people, by using the
 Baudot code, would become isolated from the
 rapidly expanding world of computer communications.
 One objective of the SRI project was to
 develop a device that could be used with both
 Baudot and ASCII systems and thus bridge the
 gap between the two. SRI believed firmly that the
 Baudot system was obsolete and that communication
 systems for deaf people should be planned
 with the future in mind.
 After hearing all points of view, the California
 Public Utilities Commission staff recommended
 retaining the Baudot system, and the administrative
 law judge followed their recommendation
 in setting the standard. In an unusual turn
 of events, however, the commissioners reversed
 this decision and recommended that all free TDDs
 had to have dual capacity, that is, to be compatible
 with both Baudot and ASCII systems. Two
 California manufacturers, Krown Research,
 which makes the Portaprinter”, and Plantronics,
 which makes the VU-Phone@, received the first
 contract to produce the devices. * They agreed on
 standardized modems to comply with the ruling
 of the California Public Utilities Commission. A
 trust fund was established to pay for the distribution
 of TDDs. In October 1980, telephone customers
 in California began to pay a 15¢ surcharge
 on their monthly telephone bills. That surcharge
 goes to the trust fund for TDDs.
 Distribution of free TDDs by the telephone
 company also began in October 1980, in Fremont,
 Calif., where there is a substantial deaf community.
 The distribution of free TDDs will continue
 in other areas of the State and should be completed
 by 1984. Customers will receive a free TDD
 regardless of whether they already own one. Consumer
 organizations in different California communities
 are working with the telephone companies
 to arrange to identify eligible consumers.
 There is also the question of possible loss or disappearance
 of equipment to consider. For example,
 when a deaf person moves, does the person take
 the free TDD along?
 Although the California decision may seem like
 the pot of gold at the end of the rainbow, there
 are some members of the deaf community who
 do not support the free distribution of equipment.
 They are willing to make the purchase of a TDD
 a medical deduction on their income tax.** They
 agree that low-income deaf people should be provided
 with TDDs at reduced cost, but they don’t
 want gifts. They worry about other consumers’
 reaction to having to pay for the devices with a
 surcharge on every month’s phone bill, or about
 the stereotyping of all hearing-impaired people as
 “poor.” (The charge on the telephone bills now
 reads “SB 597-TDD, ” which puts the responsibility
 on the State legislature, At one point it was
 suggested that the charge be titled “DEAF,” an
 acronym for Deaf Equipment Acquisition Fund,
 but that idea was rejected. )
 As of July 1982, 4,000 units had been placed
 in California —fewer than expected. Many deaf
 people have no telephone or perhaps do not wish
 to reveal their poor language or typing skills. The
 trust fund has accumulated enough money that
 the surcharge may be reduced.
 
 *VU-Phone is not currently being manufactured. **The Internal Revenue Service began allowing a medical
      deductionfor TDDs in 1971.   |