Teletype

Teletype
Public domain · source
Name	Teletype
Invented	19th–20th century
Developer	Bell Telephone Laboratories, Western Electric Company, Morkrum Company, AT&T, British Post Office, Royal Navy
Manufacturer	Teletype Corporation, A. B. Dick Company, Siemens, Remington Rand, ITT Corporation, Krieger Company
Type	electromechanical typewriter terminal
Related	Teleprinter, Baudot code, ASCII, RTTY, Facsimile, Morse code

Teletype is an electromechanical device that combined typewriting and telecommunication to send and receive typed messages over wire and radio links. Originating from 19th‑century innovations in Morse code and evolving through 20th‑century developments at Bell Telephone Laboratories and Western Electric Company, it became central to commercial, military, and newswire systems. Teleprinter equipment influenced standards such as Baudot code and ASCII and interfaced with computing systems including machines by IBM, DEC, and UNIVAC.

History

The lineage traces to inventions by Samuel Morse, Alexander Graham Bell, Thomas Edison, and innovators at Western Union and the Post Office network, which led to automated printing telegraphs like the Phelps and Murray systems. Early 20th‑century firms such as the Morkrum Company and Kleinschmidt Electric Company developed practical teleprinters used by AT&T and British Post Office. During World War I and World War II, military services including the Royal Navy, United States Navy, United States Army Signal Corps, and Royal Air Force adopted teleprinter systems for strategic communications alongside technologies from Marconi Company and Siemens-Schuckert. Postwar integration with news agencies like Reuters, Associated Press, Agence France-Presse and commercial services by Dow Jones expanded teletype networks. Standards organizations such as the International Telecommunication Union and American National Standards Institute formalized codes and interfaces that guided later digital terminals.

Design and Operation

Mechanical designs built on concepts from Remington typewriters and synchronous machines developed at Bell Labs, incorporating electromechanical selectors, cams, and gear trains similar to those used in Hollerith tabulating units. Signaling used fixed-length character codes like Baudot code and asynchronous encodings later replaced by ASCII for compatibility with systems from IBM and Digital Equipment Corporation. Interface equipment such as modems and radio teletype (RTTY) hardware linked teleprinters to circuits used by broadcasters like BBC, Voice of America, and Radio Free Europe. Switching and multiplexing technologies derived from work at Western Electric Company and AT&T Long Lines permitted integration into networks administered by entities like Post Office Telephones and Bell System.

Models and Manufacturers

Major manufacturers included the Teletype Corporation (a division of Western Electric Company and later ITT), Remington Rand, Siemens, Morkrum Company (later Morkrum-Kleinschmidt), and Siemens & Halske. Notable models influenced operations in computing centers run by IBM, UNIVAC, Control Data Corporation, Hewlett-Packard, and Honeywell. Equipment variants such as keyboard teletypes, reperforators, and paper tape readers were produced by firms including A. B. Dick Company and Krieger Company. Military procurement programs from agencies like the United States Department of Defense, Ministry of Defence (United Kingdom), and organizations such as NATO specified ruggedized models for use with cryptographic equipment from SIGSALY and keying devices from National Cash Register heritage companies.

Applications and Use

Teleprinters served as terminals in computing installations of MIT, Bell Labs, Stanford Research Institute, and corporate data centers at AT&T, General Electric, Boeing, and Ford Motor Company. Newsrooms at Reuters, Associated Press, The New York Times, and The Washington Post relied on wire services delivered on teleprinters. In transportation, railways like Union Pacific and airlines such as Pan American World Airways used teletype systems for dispatch, reservations, and weather briefings from services like National Weather Service and Met Office. Maritime and aeronautical communications used teletype over circuits provided by International Maritime Organization conventions and aviation authorities including ICAO. Amateur radio operators adapted RTTY modes popularized by groups including the American Radio Relay League.

Legacy and Influence

Teletype technology influenced development of terminal standards used by DEC VT series and inspired human‑computer interaction paradigms in systems from Unix communities at Bell Labs and University of California, Berkeley. The transition from electromechanical teleprinters to electronic terminals and printers paved the way for protocols like RS-232 standardized by Electronic Industries Association and later serial interfaces used in microcomputers such as those by Apple Computer and Commodore. Cultural artifacts reference teleprinter text in works by George Orwell motifs and in journalism histories of E. B. White and Nelly Bly. Preservation efforts by museums such as the Smithsonian Institution, Museum of Communication (Berlin), and Computer History Museum maintain operational units alongside archival material from corporations like Bell Labs and Western Electric Company.

Category:Telecommunications