Editing Bell Labs (section)

===1970s===
[[File:The C Programming Language logo.svg|thumb|The C programming language was developed in 1972.]]

The 1970s and 1980s saw more and more computer-related inventions at the Bell Laboratories as part of the [[personal computing]] revolution.

In the 1970s, major central office technology evolved from crossbar electromechanical relay-based technology and discrete transistor logic to Bell Labs-developed thick film hybrid and [[transistor–transistor logic]] (TTL), stored program-controlled switching systems; [[1ESS switch|1A]]/[[4ESS switch|#4 TOLL]] Electronic Switching Systems (ESS) and 2A Local Central Offices produced at the Bell Labs Naperville and Western Electric Lisle, Illinois facilities. This technology evolution dramatically reduced floor space needs. The new ESS also came with its own diagnostic software that needed only a switchman and several frame technicians to maintain.

About 1970, the coax-22 cable was developed by Bell Labs. This coax cable with 22 strands allowed a total capacity of 132,000 telephone calls. Previously, a 12-strand coax cable was used for L-carrier systems. Both of these types of cables were manufactured at Western Electrics' Baltimore Works facility on machines designed by a Western Electric Senior development engineer.<ref>{{cite web |url=https://www.thebmi.org/portfolio/western-electric-baltimore-works/ |title=Baltimore Works |access-date=December 12, 2022 |archive-date=November 27, 2022 |archive-url=https://web.archive.org/web/20221127021240/https://www.thebmi.org/portfolio/western-electric-baltimore-works/ |url-status=live }}</ref>

In 1970, [[A. Michael Noll]] invented a tactile, force-feedback system, coupled with interactive stereoscopic computer display.

In 1971, an improved task priority system for computerized [[telephone exchange]] switching systems for telephone traffic was invented by [[Erna Schneider Hoover]], who received one of the first [[software patent]]s for it.

In 1972, [[Dennis Ritchie]] developed the compiled programming language [[C (programming language)|C]] as a replacement for the interpreted language [[B (programming language)|B]], which was then used in a [[worse is better]] rewrite of UNIX. Also, the language [[AWK]] was designed and implemented by [[Alfred Aho]], [[Peter Weinberger]], and [[Brian Kernighan]] of Bell Laboratories. Also in 1972, [[Marc Rochkind]] invented the [[Source Code Control System]].

In 1976, [[optical fiber]] systems were first tested in [[Georgia (U.S. state)|Georgia]].

Production of their first internally designed [[microprocessor]], the [[BELLMAC-8]], began in 1977. In 1980 they demonstrated the first single-chip [[32-bit]] microprocessor, the [[Bellmac 32]]A, which went into production in 1982.

In 1978, the proprietary operating system [[Oryx/Pecos]] was developed from scratch by Bell Labs in order to run AT&T's large-scale [[PBX/IPBX|PBX]] switching equipment. It was first used with AT&T's flagship System 75, and until very recently was used in all variations up through and including Definity G3 (Generic 3) switches, now manufactured by [[Avaya]].