Bell Labs is an American industrial research and development (R&D) company credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Ten Nobel Prizes and five Turing Awards have been awarded for work completed at Bell Laboratories.
Linear predictive coding (LPC) is a method used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model.
Harry Nyquist was a Swedish-American physicist and electronic engineer who made important contributions to communication theory.
roff is a typesetting markup language. As the first Unix text-formatting computer program, it is a predecessor of the nroff and troff document processing systems.
Malcolm Douglas McIlroy is an American mathematician, engineer, and programmer. As of 2019 he is an Adjunct Professor of Computer Science at Dartmouth College. McIlroy is best known for having originally proposed Unix pipelines and developed several Unix tools, such as spell, diff, sort, join, graph, speak, and tr. He was also one of the pioneering researchers of macro processors and programming language extensibility. He participated in the design of multiple influential programming languages, particularly PL/I, SNOBOL, ALTRAN, TMG and C++.
The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to minimalist, modular software development. It is based on the experience of leading developers of the Unix operating system. Early Unix developers were important in bringing the concepts of modularity and reusability into software engineering practice, spawning a "software tools" movement. Over time, the leading developers of Unix established a set of cultural norms for developing software; these norms became as important and influential as the technology of Unix itself, and have been termed the "Unix philosophy."
Robert H. Morris Sr. was an American cryptographer and computer scientist.
Version 7 Unix, also called Seventh Edition Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T Corporation in the early 1980s. V7 was originally developed for Digital Equipment Corporation's PDP-11 minicomputers and was later ported to other platforms.
"A Mathematical Theory of Communication" is an article by mathematician Claude E. Shannon published in Bell System Technical Journal in 1948. It was renamed The Mathematical Theory of Communication in the 1949 book of the same name, a small but significant title change after realizing the generality of this work. It has tens of thousands of citations which is rare for a scientific article and gave rise to the field of information theory. Scientific American referred to the paper as the "Magna Carta of the Information Age", while the electrical engineer Robert G. Gallager called the paper a "blueprint for the digital era". Historian James Gleick rated the paper as the most important development of 1948, placing the transistor second in the same time period, with Gleick emphasizing that the paper by Shannon was "even more profound and more fundamental" than the transistor.
Multi-Environment Real-Time (MERT), later renamed UNIX Real-Time (UNIX-RT), is a hybrid time-sharing and real-time operating system developed in the 1970s at Bell Labs for use in embedded minicomputers. A version named Duplex Multi Environment Real Time (DMERT) was the operating system for the AT&T 3B20D telephone switching minicomputer, designed for high availability; DMERT was later renamed Unix RTR.
Frank Gray was a physicist and researcher at Bell Labs who made numerous innovations in television, both mechanical and electronic, and is remembered for the Gray code.
The history of Unix dates back to the mid-1960s, when the Massachusetts Institute of Technology, Bell Labs, and General Electric were jointly developing an experimental time-sharing operating system called Multics for the GE-645 mainframe. Multics introduced many innovations, but also had many problems. Bell Labs, frustrated by the size and complexity of Multics but not its aims, slowly pulled out of the project. Their last researchers to leave Multics – among them Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna – decided to redo the work, but on a much smaller scale.
In computer networking, STREAMS is the native framework in Unix System V for implementing character device drivers, network protocols, and inter-process communication. In this framework, a stream is a chain of coroutines that pass messages between a program and a device driver. STREAMS originated in Version 8 Research Unix, as Streams.
The Service Evaluation System (SES) was an operations support system developed by Bell Laboratories and used by telephone companies beginning in the late 1960s. Many local, long distance, and operator circuit-switching systems provided special dedicated circuits to the SES to monitor the quality of customer connections during the call setup process. Calls were selected at random by switching systems and one-way voice connections were established to the SES monitoring center.
Stewart David Personick is an American researcher in telecommunications and computer networking. He worked at Bell Labs, TRW, and Bellcore, researching optical fiber receiver design, propagation in multi-mode optical fibers, time-domain reflectometry, and the end-to-end modeling of fiber-optic communication systems.
Sergei Alexander Schelkunoff, who published as S. A. Schelkunoff, was a distinguished mathematician, electrical engineer, and electromagnetism theorist who made noted contributions to antenna theory.
Alexander G. Fraser, also known as A. G. Fraser and Sandy Fraser, was a noted British-American computer scientist and the former Chief Scientist of AT&T.
Edward Charles Dixon Molina was an American engineer, known for his contributions to teletraffic engineering.
Robert Pike is a Canadian programmer and author. He is best known for his work on the Go programming language while working at Google and the Plan 9 operating system while working at Bell Labs, where he was a member of the Unix team.
Electrons and Holes in Semiconductors with Applications to Transistor Electronics is a book by Nobel Prize winner William Shockley, first published in 1950. It was a primary source, and was used as the first textbook, for scientists and engineers learning the new field of semiconductors as applied to the development of the transistor. This was the invention that led to electronic computers, ubiquitous communication devices, compact electronics controllers, and a host of other important inventions of the last half of the twentieth century.
