Bell Labs and Related Topics

Transistor

9 links

Semiconductor device used to amplify or switch electrical signals and power.

Metal-oxide-semiconductor field-effect transistor (MOSFET), showing gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).

Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1925.

John Bardeen, William Shockley and Walter Brattain at Bell Labs in 1948. Bardeen and Brattain invented the point-contact transistor in 1947 and Shockley the bipolar junction transistor in 1948.

A replica of the first working transistor, a point-contact transistor invented in 1947

Herbert Mataré in 1950. He independently invented a point-contact transistor in June 1948.

Philco surface-barrier transistor developed and produced in 1953

A Darlington transistor opened up so the actual transistor chip (the small square) can be seen inside. A Darlington transistor is effectively two transistors on the same chip. One transistor is much larger than the other, but both are large in comparison to transistors in large-scale integration because this particular example is intended for power applications.

A simple circuit diagram to show the labels of an n–p–n bipolar transistor

BJT used as an electronic switch, in grounded-emitter configuration

Amplifier circuit, common-emitter configuration with a voltage-divider bias circuit

Operation of a FET and its Id-Vg curve. At first, when no gate voltage is applied, there are no inversion electrons in the channel, so the device is turned off. As gate voltage increases, the inversion electron density in the channel increases, current increases, and thus the device turns on.

Transistor symbol created on Portuguese pavement in the University of Aveiro

The first working device to be built was a point-contact transistor invented in 1947 by American physicists John Bardeen and Walter Brattain while working under William Shockley at Bell Labs.

Western Electric

7 links

American electrical engineering and manufacturing company officially founded in 1869.

1969 Western Electric keychain medallion celebrating the 100th anniversary of the company's founding, made from the company's recycled bronze metal of scrapped telephone equipment and issued to employees with an inscribed personal registration number.

222 Broadway, where the company's headquarters were once located

Tower of former Hawthorne Works (as of 2012)

AT&T push-button telephone made by Western Electric, model 2500 DMG black (1980)

Inaugural issue cover of first Western Electric employee magazine in March 1912

Bell Telephone Laboratories, created from the engineering department of Western Electric in 1925, was half-owned by Western Electric, the other half belonging to AT&T.

Unix System III running on a PDP-11 simulator

Unix (trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.

Holmdel Township, New Jersey

7 links

Township in Monmouth County, New Jersey, United States.

The historic Longstreet Farm at Holmdel Park, 2013

The township is notable, among other things, for its historical and present connection to Bell Labs.

C (programming language)

6 links

General-purpose computer programming language.

Dennis Ritchie (right), the inventor of the C programming language, with Ken Thompson

The cover of the book The C Programming Language, first edition, by Brian Kernighan and Dennis Ritchie

"Hello, World!" program by Brian Kernighan (1978)

The TIOBE index graph, showing a comparison of the popularity of various programming languages

A successor to the programming language B, C was originally developed at Bell Labs by Dennis Ritchie between 1972 and 1973 to construct utilities running on Unix.

A picture showing scratches on the readable surface of a CD-R. Music and data CDs are coded using error correcting codes and thus can still be read even if they have minor scratches using error detection and correction.

Information theory

6 links

Scientific study of the quantification, storage, and communication of digital information.

Prior to this paper, limited information-theoretic ideas had been developed at Bell Labs, all implicitly assuming events of equal probability.

Bell System

7 links

System of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company , that dominated the telephone services industry in North America for over one hundred years from its creation in 1877 until its antitrust breakup in 1983.

1912 Bell System advertisement promoting its slogan for universal service

195 Broadway, AT&T headquarters for most of the 20th century

Bell Labs, conducting research and development for AT&T and Western Electric; ownership initially equally split between Western and AT&T

Brian Kernighan

7 links

Canadian computer scientist.

Brian Kernighan speaks at a tribute to Dennis Ritchie in 2012 at Bell Labs.

He worked at Bell Labs and contributed to the development of Unix alongside Unix creators Ken Thompson and Dennis Ritchie.

Vocoder

5 links

Category of speech coding that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption or voice transformation.