Editing Electrical telegraph (section)

====Teleprinters====
{{main|Teleprinter|Telex}}
{{more citations needed section|date=January 2020}}
[[File:Phelps' Electro-motor Printing Telegraph.jpg|thumb|Phelps' Electro-motor Printing Telegraph from {{circa|1880}}, the last and most advanced telegraphy mechanism designed by [[George May Phelps]]]]
[[File:Bundesarchiv Bild 183-2008-0516-500, Fernschreibmaschine mit Telefonanschluss.jpg|thumb|right|A Creed Model 7 teleprinter in 1930]]
[[File:Teletype-IMG 7289.jpg|right|thumb|upright=1|[[Teletype Model 33]] ASR (Automatic Send and Receive)]]
An early successful [[teleprinter]] was invented by [[Frederick G. Creed]]. In [[Glasgow]] he created his first keyboard perforator, which used compressed air to punch the holes. He also created a reperforator (receiving perforator) and a printer. The reperforator punched incoming Morse signals onto paper tape and the printer decoded this tape to produce alphanumeric characters on plain paper. This was the origin of the Creed High Speed Automatic Printing System, which could run at an unprecedented 200 words per minute. His system was adopted by the ''[[Daily Mail]]'' for daily transmission of the newspaper contents.

With the invention of the [[teletypewriter]], telegraphic encoding became fully automated. Early teletypewriters used the ITA-1 [[Baudot code]], a five-bit code. This yielded only thirty-two codes, so it was over-defined into two "shifts", "letters" and "figures". An explicit, unshared shift code prefaced each set of letters and figures. In 1901, Baudot's code was modified by [[Donald Murray (inventor)|Donald Murray]].

In the 1930s, teleprinters were produced by [[Teletype Corporation|Teletype]] in the US, [[Creed & Company|Creed]] in Britain and [[Siemens]] in Germany.

By 1935, message routing was the last great barrier to full automation. Large telegraphy providers began to develop systems that used [[telephone exchange|telephone-like rotary dialling]] to connect teletypewriters. These resulting systems were called "Telex" (TELegraph EXchange). Telex machines first performed rotary-telephone-style [[pulse dialling]] for [[circuit switching]], and then sent data by [[ITA2]]. This "type A" Telex routing functionally automated message routing.

The first wide-coverage Telex network was implemented in Germany during the 1930s<ref>{{Cite web |title=Telegraphy and Telex |url=https://new.siemens.com/global/en/company/about/history/technology/information-and-communications-technology/telegraphy-and-telex.html |url-status=live |access-date=25 March 2021 |archive-url=https://web.archive.org/web/20190726052037/https://new.siemens.com/global/en/company/about/history/technology/information-and-communications-technology/telegraphy-and-telex.html |archive-date=26 July 2019}}</ref> as a network used to communicate within the government.

At the rate of 45.45 (±0.5%) [[baud]] – considered speedy at the time – up to 25 telex channels could share a single long-distance telephone channel by using ''[[voice frequency telegraphy]] [[frequency-division multiplexing|multiplexing]]'', making telex the least expensive method of reliable long-distance communication.

Automatic teleprinter exchange service was introduced into Canada by [[CPR Telegraphs]] and [[CN Telegraph]] in July 1957 and in 1958, [[Western Union]] started to build a Telex network in the United States.<ref>Phillip R. Easterlin, "Telex in New York", Western Union Technical Review, April 1959: 45</ref>