History of Unix

The history of Unix dates back to the mid-1960s when the Massachusetts Institute of Technology, AT&T 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 had many problems.

Bell Labs, frustrated by the size and complexity of Multics but not the aims, slowly pulled out of the project. Their last researchers to leave Multics, Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna among others. , decided to redo the work on a much smaller scale. In 1979, Dennis Ritchie described their vision for Unix:

1969

In the late 1960s, Bell Labs was involved in a project with MIT and General Electric to develop a time-sharing system, called Multiplexed Information and Computing Service (Multics), allowing multiple users to access a mainframe simultaneously. Dissatisfied with the project's progress, Bell Labs management ultimately withdrew.

Ken Thompson, a programmer in the Labs' computing research department, had worked on Multics. He decided to write his own operating system. While he still had access to the Multics environment, he wrote simulations for the new file and paging system on it. He also programmed a game called Space Travel, but it needed a more efficient and less expensive machine to run on, and eventually he found a little-used PDP-7 at Bell Labs. On the PDP-7, in 1969, a team of Bell Labs researchers led by Thompson and Ritchie, including Rudd Canaday, developed a hierarchical file system, the concepts of computer processes and device files, a command-line interpreter, and some small utility programs. The resulting system, much smaller than the envisioned Multics system, was to become Unix. In about a month's time, Thompson had implemented a self-hosting operating system with an assembler, editor and shell, using a GECOS machine for bootstrapping.

AT&T Unix PC

The 3B1 (also known as the PC7300, or Unix PC) was a Unix workstation computer originally developed by Convergent Technologies (later acquired by Unisys), and marketed by AT&T in the mid- to late-1980s. Despite the name, the 3B1 had little in common with AT&T's other 3B-series computers.

Hardware configuration

PC7300

The initial PC7300 model offered a very limited 512 KB of memory and an extremely slow 5 MB hard drive. This model, although progressive in offering a Unix system for desktop office operation, was painfully slow and had an aggravating 'grinding' noise even when not in active use. The modern-looking "wedge" design was innovative, and in fact the machine gained notoriety appearing in many movies as the token "computer."

AT&T

AT&T Inc. is an American multinational telecommunications corporation, headquartered at Whitacre Tower in downtown Dallas, Texas. AT&T is the second largest provider of mobile telephone and the largest provider of fixed telephone in the United States, and also provides broadband subscription television services. AT&T is the third-largest company in Texas (the largest non-oil company, behind only ExxonMobil and ConocoPhillips, and also the largest Dallas company).As of May 2014, AT&T is the 23rd-largest company in the world as measured by a composite of revenues, profits, assets and market value, and the 16th-largest non-oil company.As of 2016, it is also the 18th-largest mobile telecom operator in the world, with over 128.6 million mobile customers.

AT&T was ranked #6 on the 2015 rankings of the world's most valuable brands published by Millward Brown Optimor.

AT&T Inc. began its existence as Southwestern Bell Corporation, one of seven Regional Bell Operating Companies (RBOC's) created in 1983 in the divestiture of the American Telephone and Telegraph Company (founded 1885, later AT&T Corp.) following the 1982 United States v. AT&T antitrust lawsuit. Southwestern Bell changed its name to SBC Communications Inc. in 1995. In 2005, SBC purchased former parent AT&T Corp. and took on its branding, with the merged entity naming itself AT&T Inc. and using the iconic AT&T Corp. logo and stock-trading symbol.

Dennis Ritchie

Dennis MacAlistair Ritchie (September 9, 1941 – c. October 12, 2011) was an American computer scientist. He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system. Ritchie and Thompson received the Turing Award from the ACM in 1983, the Hamming Medal from the IEEE in 1990 and the National Medal of Technology from President Clinton in 1999. Ritchie was the head of Lucent Technologies System Software Research Department when he retired in 2007. He was the "R" in K&R C, and commonly known by his username dmr.

Personal life

Ritchie was born in Bronxville, New York. His father was Alistair E. Ritchie, a longtime Bell Labs scientist and co-author of The Design of Switching Circuits on switching circuit theory. He moved with his family to Summit, New Jersey, as a child, where he graduated from Summit High School. He graduated from Harvard University with degrees in physics and applied mathematics.

Career

In 1967, Ritchie began working at the Bell Labs Computing Sciences Research Center, and in 1968, he defended his PhD thesis on "Program Structure and Computational Complexity" at Harvard under the supervision of Patrick C. Fischer. However, Ritchie never officially received his PhD degree.

Ken Thompson

Kenneth Lane "Ken" Thompson (born February 4, 1943), commonly referred to as ken in hacker circles, is an American pioneer of computer science. Having worked at Bell Labs for most of his career, Thompson designed and implemented the original Unix operating system. He also invented the B programming language, the direct predecessor to the C programming language, and was one of the creators and early developers of the Plan 9 operating systems. Since 2006, Thompson has worked at Google, where he co-invented the Go programming language.

Other notable contributions included his work on regular expressions and early computer text editors QED and ed, the definition of the UTF-8 encoding, his work on computer chess that included creation of endgame tablebases and the chess machine Belle.

Biography

Early life

Thompson was born in New Orleans. When asked how he learned to program, Thompson stated, "I was always fascinated with logic and even in grade school I'd work on arithmetic problems in binary, stuff like that. Just because I was fascinated."