Unix is a term used to refer to versions of the Unix
operating system for DEC PDP-7, PDP-11,
VAX and Interdata 7/32 and
8/32 computers, developed in the
Bell Labs Computing Science Research
Center (frequently referred to as Department 1127).
4 See also
6 External links
Unix for the PDP-11, running in SIMH
The term Research
Unix first appeared in the Bell System Technical
Journal (Vol. 57, No. 6, Pt. 2 Jul/Aug 1978) to distinguish it from
other versions internal to
Bell Labs (such as
PWB/UNIX and MERT) whose
code-base had diverged from the primary CSRC version. However, that
term was little-used until Version 8 Unix, but has been retroactively
applied to earlier versions as well. Prior to V8, the operating system
was most commonly called simply UNIX (in caps) or the UNIX
AT&T licensed Version 5 to educational institutions, and Version 6
also to commercial sites. Schools paid $200 and others $20,000,
discouraging most commercial use, but Version 6 was the most widely
used version into the 1980s. Research
Unix versions are often referred
to by the edition of the manual that describes them, because early
versions and the last few were never officially released outside of
Bell Labs, and grew organically. So, the first Research
Unix would be
the First Edition, and the last the Tenth Edition. Another common way
of referring to them is Version x (or Vx) Unix, where x is the manual
edition. All modern editions of Unix—excepting Unix-like
implementations such as Coherent, Minix, and Linux—derive from the
Starting with the 8th Edition, versions of Research
Unix had a close
relationship to BSD. This began by using 4.1c
BSD as the basis for the
8th Edition. In a
Usenet post from 2000,
Dennis Ritchie described
these later versions of Research
Unix as being closer to
BSD than they
were to UNIX System V, which also included some
Unix 8th Edition started from (I think)
BSD 4.1c, but with
enormous amounts scooped out and replaced by our own stuff. This
continued with 9th and 10th. The ordinary user command-set was, I
guess, a bit more BSD-flavored than SysVish, but it was pretty
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, having been ported from the
PDP-7 to the PDP-11/20 in 1970.
Jun. 12, 1972
Total number of installations at the time was 10, "with more
expected", according to the preface of the manual.:ii Includes echo
and the first C compiler.
Introduced the C programming language, pipes, crypt, and yacc.
Commands are split between /bin and /usr/bin, requiring a search
path (/usr was the mount point for a second hard disk). Total
number of installations was 16.
First version written in C. Also introduced groups, grep, and
printf. 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, the first public exposition
of the operating system.
Widely licensed to educational institutions. Introduced find,
dd, and the sticky bit. Targeted the PDP-11/40 and other 11 models
with 18 bit addresses. Installations "above 50".
Includes ratfor and bc. First version to be also licensed to
commercial users, and to be ported to non-PDP hardware. May 1977
saw the release of MINI-UNIX, a "cut down" v6 for the low-end
Includes the Bourne shell, cpio, sed, ioctl, awk, f77, spell, stdio
and pcc augmenting the Dennis Ritchie's C compiler. 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
VAX hardware; 32V was the basis for 4BSD.
Feb. 1985
A modified 4.1c
BSD for the VAX, with a System V shell and sockets
replaced by Streams. Used internally, and only licensed for
educational use. The Blit graphics terminal became the primary user
interface. Added a network file system 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. First version with no assembly in the
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 user space. Other
innovations include make and Sam. According to Dennis Ritchie, V9
and V10 were "conceptual": manuals existed, but no OS distributions
"in complete and coherent form".
Last Research Unix. Although the manual was published outside of
AT&T by Saunders College Publishing, there was no full
distribution of the system itself. 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.
Version 3, Version 4 and Version 5 should not be confused with the
UNIX 3.0, UNIX 4.0 and UNIX 5.0 releases by the AT&T UNIX Support
Group. After Version 10,
Unix development at
Bell Labs was stopped in
favor of a successor system, Plan 9 from Bell Labs, that shared part
of its userland with V10.
Caldera International released
Unix V1-7 and 32V as FOSS
under a permissive BSD-like software license.
Unix Heritage Society and
Alcatel-Lucent USA Inc., on behalf
of itself and
Nokia Bell Laboratories, released v8, v9, v10 under the
condition: "will not assert its copyright rights with respect to
any non-commercial copying, distribution, performance, display or
creation of derivative works of Research Unix®1 Editions 8, 9, and
Ancient UNIX Systems
History of Unix
Lions' Commentary on UNIX 6th Edition, with Source Code
Inferno - Another operating system from the same team
^ a b c d Fiedler, Ryan (October 1983). "The
Unix Tutorial / Part 3:
Unix in the Microcomputer Marketplace". BYTE. p. 132. Retrieved
30 January 2015.
Dennis Ritchie (26 October 2000). "alt.folklore.computers: BSD
(Dennis Ritchie)". Retrieved 3 July 2014.
^ a b c d e f g h i j k McIlroy, M. D. (1987). A Research
annotated excerpts from the Programmer's Manual, 1971–1986 (PDF)
(Technical report). CSTR. Bell Labs. 139.
^ Thompson, Ken; Ritchie, Dennis M. (June 12, 1972). UNIX Programmer's
Manual, Second Edition (PDF). Bell Telephone Laboratories.
^ Ritchie, D. M.; Thompson, K. (1974). "The UNIX Time-Sharing System".
Communications of the ACM. 17 (7): 365–375.
^ a b c
Dennis Ritchie (27 June 2003). "[TUHS] Re: V7 UNIX on VAX
11/750". Retrieved 9 April 2014.
Henry Spencer (1986-01-19). "regexp(3)".
Newsgroup: mod.sources. Usenet: 1316@panda.UUCP. Retrieved 9
^ David L. Presotto;
Dennis M. Ritchie
Dennis M. Ritchie (1990). "Interprocess
Communication in the Ninth Edition
Unix System". Software—Practice
and Experience. 19.
Unix Tenth Edition Manual". Bell Labs. Retrieved 25 December
^ "The IX Multilevel-Secure UNIX System".
^ Caldera releases original unices under
BSD license on slashdot.org
^ "UNIX is free!". lemis.com. 2002-01-24.
^ Broderick, Bill (January 23, 2002). "Dear
Unix enthusiasts," (PDF).
Caldera International. Archived from the original (PDF) on 19 February
^ Darwin, Ian F. (2002-02-03). "Why Caldera Released Unix: A Brief
History". Linuxdevcenter. O'Reilly Media. Retrieved 2016-01-19.
^ Samizdat no more: Old
Unix source code opened for study by Richard
Chirgwin on register.com (30 March 2017)
Wikimedia Commons has media related to Research Unix.
UNIX Evolution (PostScript) by Ian F. Darwin and Geoffrey Collyer
Unix heritage - More links and source code for some Research Unix
The Evolution of the
Unix Time-sharing System by Dennis M. Ritchie
The Restoration of Early UNIX Artifacts by Warren Toomey, School of
IT, Bond University
Full Manual Pages documentation for Research
Unix 8th Edition.
List of new features in Research
Unix 9th Edition.
Unix-like operating systems
Italics indicate discontinued branches. Category