UNIX System III
AT&T announced System III in late 1981, and it was first released outside of Bell Labs in 1982. UNIX System III was a mix of various AT&T Unixes: Version 7 Unix, PWB/UNIX 2.0, CB UNIX 3.0, UNIX/RT and UNIX/32V. System III supported the DEC PDP-11 and VAX computers.
The system was apparently called System III because it was considered the outside release of UNIX/TS 3.0.1 and CB UNIX 3 which were internally supported Bell Labs Unices; its manual refers to it as UNIX Release 3.0 and there were no Unix versions called System I or System II. There was no official release of UNIX/TS 4.0 (which would have been System IV) either, so System III was succeeded by System V, based on UNIX/TS 5.0.
System III introduced new features such as named pipes, the uname system call and command, and the run queue. It also combined various improvements to Version 7 Unix by outside organizations. However, it did not include notable additions made in BSD such as the C shell (csh) and screen editing.
- Fiedler, Ryan (October 1983). "The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace". BYTE. p. 132. Retrieved 30 January 2015.
- Dale Dejager (1984-01-16). "UNIX History". Newsgroup: net.unix.
- Tanenbaum, Andrew S. (2001). Modern Operating Systems (2nd ed.). Upper Saddle River, NJ: Prentice Hall. p. 675. ISBN 0-13-031358-0.
Whatever happened to System IV is one of the great unsolved mysteries of computer science.