Research Unix

研究 Unix，是一系列的Unix作業系統的通稱，由貝爾實驗室的計算機科學研究中心（Computing Science Research Center，部門編號1127）研發，因此得名，共有11個版本。這些Unix系統運行在DEC PDP-7，PDP-11，VAX，以及Interdata 7/32與8/32電腦上。

歷史

版本

Manual Edition	Release date	Description
1st Edition	Nov. 3, 1971	First edition of the Unix manual, based on the version that ran on the PDP-11 at the time. Includes the Thompson shell, mail, cp, and su. The operating system was two years old,[1] having been ported from the PDP-7 to the PDP-11/20 in 1970.
2nd Edition	Jun. 12, 1972	Total number of installations at the time was 10, "with more expected", according to the preface of the manual.[2]:ii Includes echo and the first C compiler.[1]
3rd Edition	Feb. 1973	Introduced the C programming language, pipes, crypt, and yacc. Commands are split between /bin and /usr/bin, requiring a search path[1] (/usr was the mountpoint for a second hard disk). Total number of installations was 16.
4th Edition	Nov. 1973	First version written in C. Also introduced groups, grep, and printf.[1] Number of installations was listed as "above 20". The manual was formatted with troff for the first time. Version described in Thompson and Ritchie's CACM paper,[3] the first public exposition of the operating system.[1]
5th Edition	Jun. 1974	Widely licensed to educational institutions.[4] Introduced find, dd,[1] and the sticky bit. Targeted the PDP-11/40 and other 11 models with 18 bit addresses. Installations "above 50".
6th Edition	May 1975	Includes ratfor and bc.[1] First version to be also licensed to commercial users,[4] and to be ported to non-PDP hardware. May 1977 saw the release of MINI-UNIX, a "cut down" v6 for the low-end PDP-11/10.
7th Edition	Jan. 1979	Includes the Bourne shell, cpio, sed, ioctl, awk, f77, spell, and stdio.[1] The ancestor of all modern UNIX systems and the last release of Research Unix to see widespread external distributions. Merged most of the utilities of PWB/UNIX with an extensively modified kernel with almost 80% more lines of code than V6. In February, a port called 32V was made to DEC's VAX hardware; 32V was the basis for 4BSD.
8th Edition	Feb. 1985[來源請求]	A modified 4.1cBSD for the VAX, with a System V shell and sockets replaced by Streams. Used internally, and only licensed for educational use.[5] The Blit graphics terminal became the primary user interface.[1] Added a network filesystem that allowed accessing remote computers' files as /n/hostname/path, and a regular expression library that introduced an API later mimicked by Henry Spencer's reimplementation.[6] First version with no assembly in the documentation.[1]
9th Edition	Sep. 1986	Incorporated code from 4.3BSD; used internally. Featured a generalized version of the Streams IPC mechanism introduced in V8. The mount system call was extended to connect a stream to a file, the other end of which could be connected to a (user-level) program. This mechanism was used to implement network connection code in userspace.[7] Other innovations include make and Sam.[1] According to Dennis Ritchie, V9 and V10 were "conceptual": manuals existed, but no OS distributions "in complete and coherent form".[5]
10th Edition	Oct. 1989	Last Research Unix. Although the manual was published outside of AT&T by Saunders College Publishing,[8] there was no full distribution of the system itself.[5] Novelties included graphics typesetting tools designed to work with troff, a C interpreter, animation programs, and several tools later found in Plan 9: the Mk build tool and the rc shell. V10 was also the basis for Doug McIlroy and James A. Reeds' multilevel-secure operating system IX.[9]