Collection of telecommunication devices for the deaf (TDD) modems

According to Mary Karol Matchett (on the deed of gift): The Mimicom TTY was purchased from Mr. Paul Peterson, back in mid-1980s while I was a student at NTID/RIT. Mr. Paul Peterson was a math instructor at NTID and was selling a variety of TTY's to the deaf community. The Superprint TTY was purchased from Mr. Paul Peterson or through Harris Communication company back in 1991.

TDD actually stands for a “telecommunication device for the deaf.” A TDD is a teleprinter. It is an electronic device which aids people with hearing or speech difficulties with communication through text and telephone lines. There are several other names that can be used for this device such as a TTY, textphone (commonly used in Europe), teletypewriter and minicom (commonly used in the United Kingdom). The average TDD is similar in size to a small laptop computer and has a QWERTY keyboard. It also has a small display screen that shows the text. TDD's also often have a small paper spool where the text is also printed. Text can be transmitted from one TDD device to another via phone lines or it can still be used when only one person has a TDD. If a deaf person with a TDD calls someone who does not have a TDD, a TDD message relay (answering service) is needed. In this three person arrangement, the dual party operator actually utilizes two telephones where one is used in conjunction with a TDD in order to finish the call. For example, a person with a TDD uses the device to send a message to the relay service who then reads the message. The service uses a second telephone to call the intended party and repeats the message by voice to the recipient. This is truly a great device for use with deaf education.

Source:http://www.deafwebsites.com/technology/telecommunication-devices.html