Teleprinter

Teletype teleprinters in use in England during World War II
Example of teleprinter art: a portrait of Dag Hammarskjöld, 1962

A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations.

Initially, from 1887 at the earliest, teleprinters were used in telegraphy.[1] Electrical telegraphy had been developed decades earlier in the late 1830s and 1840s,[2] then using simpler Morse key equipment and telegraph operators. The introduction of teleprinters automated much of this work and eventually largely replaced skilled operators versed in Morse code with typists and machines communicating faster via Baudot code.

With the development of early computers in the 1950s,[3] teleprinters were adapted to allow typed data to be sent to a computer, and responses printed. Some teleprinter models could also be used to create punched tape for data storage (either from typed input or from data received from a remote source) and to read back such tape for local printing or transmission. A teleprinter attached to a modem could also communicate through telephone lines. This latter configuration was often used to connect teleprinters to remote computers, particularly in time-sharing environments.

Teleprinters have largely been replaced by fully electronic computer terminals which typically have a computer monitor instead of a printer (though the term "TTY" is still occasionally used to refer to them, such as in Unix systems). Teleprinters are still widely used in the aviation industry (see AFTN and airline teletype system),[4] and variants called Telecommunications Devices for the Deaf (TDDs) are used by the hearing impaired for typed communications over ordinary telephone lines.

  1. ^ Nelson, R.A., History Of Teletype Development, archived from the original on November 5, 2020
  2. ^ Roberts, Steven, Distant Writing
  3. ^ [better source needed] "History of the Modern Computer Keyboard". January 4, 2021. Archived from the original on March 2, 2021. Retrieved May 23, 2021. In 1954 at MIT, researchers [began] experimenting with direct keyboard input to computers. Until then, computer users fed their programs into a computer using punched cards or paper tape. Douglas Ross… believed… a Flexowriter [teletypewriter]… could function as a keyboard input device… Thus in 1955 MIT's Whirlwind [became] the first computer in the world to allow its users to enter commands through a keyboard…
  4. ^ Latifiyan, Pouya (Winter 2021). "Aeronautical Fixed Telecommunication network and surrounding technologies". Take off. 2. Civil Aviation Technology College.