Editing Teleprinter (section)

{{Short description|Device for transmitting messages in written form by electrical signals}}
{{Redirect|Teletype}}
{{For|the telecommunications system consisting of teleprinters connected by radio|Radioteletype}}
{{Use mdy dates|date=May 2012}}
[[File:WACsOperateTeletype.jpg|thumb|[[Teletype Corporation|Teletype]] teleprinters in use in England during [[World War II]]|alt=|250x250px]]
[[File:Dag Hammarskjöld - ASCII - teleprinter art -1962.jpg|thumb|Example of [[teleprinter art]]: a portrait of [[Dag Hammarskjöld]], 1962|alt=]]

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 (telecommunications)|point-to-point]] and [[point-to-multipoint communication|point-to-multipoint]] configurations. 

Initially, from 1887 at the earliest, teleprinters were used in [[telegraphy]].<ref>{{Citation |last=Nelson |first=R.A. |title=History Of Teletype Development |url=https://www.thocp.net/hardware/history_of_teletype_development_.htm |archive-url=https://web.archive.org/web/20201105231651/http://www.thocp.net/hardware/history_of_teletype_development_.htm |archive-date=2020-11-05 |url-status=dead}}</ref> [[Electrical telegraphy]] had been developed decades earlier in the late 1830s and 1840s,<ref>{{Citation |last=Roberts |first=Steven |author-link=Stephen Roberts (historian) |title=Distant Writing |url=http://distantwriting.co.uk/index.htm}}</ref> then using simpler [[Morse key]] equipment and [[telegraph operator]]s. The introduction of teleprinters automated much of this work and eventually largely replaced [[skilled labour|skilled]] operators versed in [[Morse code]] with [[Data entry clerk|typist]]s and machines communicating faster via [[Baudot code]].

With the development of early [[computers]] in the 1950s,<ref>{{better source|date=January 2024}} {{cite web |url=https://history-computer.com/keyboard-history-of-the-modern-computer-keyboard/ |title=History of the Modern Computer Keyboard |date=January 4, 2021 |access-date=2021-05-23 |archive-url=https://web.archive.org/web/20210302191307/https://history-computer.com/keyboard-history-of-the-modern-computer-keyboard/ |archive-date=2021-03-02 |quote="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 I|Whirlwind]] [became] the first computer in the world to allow its users to enter commands through a keyboard…"}}</ref> 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 [[Computer data storage|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 line]]s. 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 terminal]]s 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 [[Aeronautical Fixed Telecommunication Network|AFTN]] and [[airline teletype system]]),<ref name=":0">{{Cite journal |last=Latifiyan |first=Pouya |date=Winter 2021 |title=Aeronautical Fixed Telecommunication network and surrounding technologies |journal=Take off |publisher=[[Civil Aviation Technology College]] |volume=2}}</ref> and variants called [[Telecommunications device for the deaf|Telecommunications Devices for the Deaf]] (TDDs) are used by the [[hearing loss|hearing impaired]] for typed communications over ordinary telephone lines.