Teletype teleprinters in use in England during World War II
Example of teleprinter art: a portrait of Dag Hammarskjöld, 1962
Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske. The centrifugal governor to achieve synchronicity with the other end can be seen.
Siemens t37h (1933) without cover
Keyboard of a Baudot teleprinter, with 32 keys, including the space bar
International Telegraph Alphabet 2 development of the Baudot–Murray code
A Creed & Company Teleprinter No. 7 in 1930
Olivetti Teleprinter
Siemens Fernschreiber 100 teleprinter
A Teletype Model 33 ASR teleprinter, with punched tape reader and punch, usable as a computer terminal
A Teletype Model 32 ASR used for Telex service
A Teletype Model 33 ASR with paper tape reader and punch, as used for early modem-based computing

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.

- Teleprinter

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Computer terminal

Electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system.

The DEC VT100, a widely emulated computer terminal
IBM 2741, a widely emulated computer terminal in the 1960s and 1970s (keyboard/printer)
A Teletype Model 33 ASR teleprinter, usable as a terminal
Closeup of an IBM 2741 printing terminal, which used a changeable Selectric "golfball" typing element and was faster than the earlier teletype machines
IBM 2250 Model 4, including light pen and programmed function keyboard
A Televideo ASCII character mode terminal
A typical text terminal produces input and displays output and errors
Nano text editor running in the xterm terminal emulator

The teletype was an example of an early-day hard-copy terminal and predated the use of a computer screen by decades.


Computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio.

Acoustic coupler modems used a telephone handset as the audio medium, with the user dialing the desired number and then pressing the handset into the modem to complete the connection. These systems generally operated at a speed of 300 bits per second.
Collection of modems once used in Australia, including dial-up, DSL, and cable modems.
TeleGuide terminal
The original 300-baud Hayes Smartmodem
USRobotics Sportster 14,400 Fax modem (1994)
V.34 modem implemented as an internal ISA card
V.34 data/fax modem as PC card for notebooks
Dial-up modem bank at an ISP
The Novation CAT acoustically coupled modem
A PCI Winmodem soft modem (on the left) next to a conventional ISA modem (on the right)
DSL modem
Cable modem
A bluetooth radio module with built-in antenna (left)
An ONT providing data, telephone and television service
Null modem adapter

Modems grew out of the need to connect teleprinters over ordinary phone lines instead of the more expensive leased lines which had previously been used for current loop–based teleprinters and automated telegraphs.


Control character or sequence of control characters in a character encoding specification (e.g., ASCII, EBCDIC) that is used to signify the end of a line of text and the start of a new one.

Newline inserted between the words "Hello" and "world"
A text file created with gedit and viewed with a hex editor. Besides the text objects, there are only EOL markers with the hexadecimal value 0A.

In the mid-1800s, long before the advent of teleprinters and teletype machines, Morse code operators or telegraphists invented and used Morse code prosigns to encode white space text formatting in formal written text messages.

Telecommunications device for the deaf

Miniprint 425 TDD. The acoustic coupler on the top is for use with telephone handsets. The printer records the conversation. The specific GA and SK keys allow for speedier use of common abbreviations.
AT&T TDD 2700

A telecommunications device for the deaf (TDD) is a teleprinter, an electronic device for text communication over a telephone line, that is designed for use by persons with hearing or speech difficulties.

User interface

Space where interactions between humans and machines occur.

The Reactable, an example of a tangible user interface
A graphical user interface following the desktop metaphor
A human–machine interface usually involves peripheral hardware for the INPUT and for the OUTPUT. Often, there is an additional component implemented in software, like e.g. a graphical user interface.
IBM 029
Holes are punched in the card according to a prearranged code transferring the facts from the census questionnaire into statistics
Teletype Model 33 ASR
DEC VT100 terminal
AMX Desk made a basic WIMP GUI
Linotype WYSIWYG 2000, 1989
HP Series 100 HP-150 touchscreen
Historic HMI in the driver's cabin of a German steam locomotive
Modern HMI in the driver's cabin of a German Intercity-Express High-Speed Train
The HMI of a toilette (in Japan)
Voice user interface of a wearable computer (here: Google Glass)
HMI for audio mixing
HMI for video production
HMI of a machine for the sugar industry with pushbuttons
HMI for a Computer numerical control (CNC)
slightly newer HMI for a CNC-machine
emergency switch/panic switch
DMD 5620 Terminal

The earliest command-line systems combined teleprinters with computers, adapting a mature technology that had proven effective for mediating the transfer of information over wires between human beings.

Western Union

American multinational financial services company, headquartered in Denver, Colorado.

A Western Union telegram sent on September 7, 1896 to report on the positions of two comets.
A 12-year-old Western Union messenger boy in Tampa, Florida, 1911
Advertisement for Western Union "Tourate" telegram service, 1939
60 Hudson Street, Manhattan, was WU's headquarters in the early and middle 20th century
Western Union Telegraph storefront seen in the Chamber of Commerce Building in Toledo, Ohio, 1895
Logo, 1969 to 1990
Western Union European Regional Operations Center in Vilnius
A Western Union outlet in Angeles City, Philippines
WU phone parlors near Times Square, 2008

In 1958, Western Union began offering telex services to customers in New York City.


Character encoding standard for electronic communication.

ASCII chart from a pre-1972 printer manual
ASCII (1963). Control pictures of equivalent controls are shown where they exist, or a grey dot otherwise.

Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services.


In engineering, electromechanics combines processes and procedures drawn from electrical engineering and mechanical engineering.

A relay is a common electro-mechanical device.

Before the development of modern electronics, electromechanical devices were widely used in complicated subsystems of parts, including electric typewriters, teleprinters, clocks, initial television systems, and the very early electromechanical digital computers.

Punched tape

Form of data storage that consists of a long strip of paper in which holes are punched.

Five- and eight-hole punched paper tape
Creed model 6S/2 5-hole paper tape reader
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
A paper tape, constructed from punched cards, in use in a Jacquard loom. The large holes on each edge are sprocket holes, used to pull the paper tape through the loom.
Wheatstone slip with a dot, space and a dash punched, and perforator punch plate
Diagnostic minicomputer software on fanfold paper tape (1975)
Mylar punched tape was used for durability in industrial applications
Chadless 5-level Baudot paper tape circa ~1975–1980 punched at Teletype Corp
The word "Wikipedia", and a CR/LF as 7-bit ASCII, without a parity bit, least significant bit on the right—e.g. "W" is 1010111
Teletype 33 Automatic Send and Receive teleprinter with paper tape in both the reader and the punch
Paper tape relay operation at US FAA's Honolulu flight service station in 1964
A 24-channel program tape for the Harvard Mark I (c.1944)
Paper tape reader on a computer numerical control (CNC) machine
This secure paper tape canister shows evidence of tampering
The 1943 Colossus code-breaking machine used paper tapes to hold data (replica shown)
This 1959 IBM 1620 relied on paper tape to store data and programs
Tape reader used with a UNIVAC 1105 for the 1960 US Census
A large-capacity industrial tape reader
This early-1960s Monrobot XI computer used two paper tape reader/punches for offline data storage
Fanfold paper tape reader on a PDP-1 minicomputer (1960s)
Paper tape readers for a word-processing system, circa 1970
Large IBM 1130 systems still handled paper tape in the early 1970s (at left of console)
Eight-hole tape from 1974
This 1970s DEC high-speed fanfold reader/punch used optical sensing
Paper tape loop controlling paper positioning in a IBM 1403 line printer (1959-1983)
Late-1970s heavy-duty tape punch used by the US National Security Agency for secret code distribution

Punched tape was used throughout the 19th and for much of the 20th centuries for programmable looms, teleprinter communication, for input to computers of the 1950s and 1960s, and later as a storage medium for minicomputers and CNC machine tools.


A Teletype Model 32 used for Telex service
A late-model British Telecom "Puma" telex machine of the 1980s

The telex network is a station-to-station switched network of teleprinters similar to a telephone network, using telegraph-grade connecting circuits for two-way text-based messages.