{{Short description|Original Unix operating system from Bell Labs}} '''Research Unix''' refers to the early 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 Sciences Research Center (CSRC). The term ''Research Unix'' first appeared in the Bell System Technical Journal (Vol. 57, No. 6, Part 2 July/August 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 (1985), 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 Time-Sharing System.
'''Ancient UNIX''' is any early release of the Unix code base prior to Unix System III, particularly the Research Unix releases prior to and including Version 7 (the base for UNIX/32V as well as later developments of AT&T Unix).
== History ==
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,{{r|fiedler198310}} 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 as "Version ''x'' Unix" or "V''x'' 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 7th Edition.<ref>{{Cite web |last=Siebenmann |first=Chris |date=Nov 21, 2021 |title=Why V7 Unix Matters So Much |url=https://utcc.utoronto.ca/~cks/space/blog/unix/V7WhyItMattersSoMuch |website=CSpace |access-date=October 18, 2025 |archive-date=July 29, 2025 |archive-url=https://web.archive.org/web/20250729074012/https://utcc.utoronto.ca/~cks/space/blog/unix/V7WhyItMattersSoMuch |url-status=live }}</ref>
Starting with the 8th Edition, versions of Research Unix had a close relationship to BSD. This began by using 4.1cBSD 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,<ref>{{cite web|url=http://yarchive.net/comp/bsd.html|title=alt.folklore.computers: BSD (Dennis Ritchie)|first=Dennis|last=Ritchie|date=26 October 2000|access-date=3 July 2014|archive-date=14 July 2014|archive-url=https://web.archive.org/web/20140714222327/http://yarchive.net/comp/bsd.html|url-status=live}}</ref> which also included some BSD code:{{r|fiedler198310}}
{{blockquote|Research 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 eclectic.}}
== Versions == {| class="wikitable" ! 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. The operating system was two years old,<ref name="reader">{{cite tech report |first1=M. D. |last1=McIlroy |author-link1=Doug McIlroy |year=1987 |url=http://www.cs.dartmouth.edu/~doug/reader.pdf |title=A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 |series=CSTR |number=139 |institution=Bell Labs}}</ref> having been ported from the PDP-7 to the PDP-11/20 in 1970. Includes ar, as, bcd, cal, cat, chdir, chmod, chown, cmp, cp, date, dc, df, du, ed, glob, init, ld, ln, ls, mail, mesg, mkdir, mkfs, mount, mv, nm, od, pr, rm, rmdir, roff, sh, sort, stat, strip, su, sum, tty, umount, wc, who, write; also precursors of fsck, reboot, and adb. The system also had a B and Fortran compiler, a BASIC interpreter, device files and functions for managing punched tape, DECtape, and RK05 disks. |- | 2nd Edition | Jun 12, 1972 | Total number of installations at the time was 10, "with more expected", according to the preface of the manual.<ref name="V2">{{cite book |first1=Ken |last1=Thompson |first2=Dennis M. |last2=Ritchie |title=UNIX Programmer's Manual, Second Edition |date=June 12, 1972 |publisher=Bell Telephone Laboratories |url=http://sunsite.icm.edu.pl/pub/unix/UnixArchive/PDP-11/Distributions/research/1972_stuff/unix_2nd_edition_manual.pdf |archive-url=https://web.archive.org/web/20161006034736/http://sunsite.icm.edu.pl/pub/unix/UnixArchive/PDP-11/Distributions/research/1972_stuff/unix_2nd_edition_manual.pdf |url-status=dead |archive-date=2016-10-06 }}</ref>{{rp|ii}} Adds echo, exit, login, m6 macro processor, man, nroff, strip, stty, tmg compiler-compiler and the first C compiler.{{r|reader}}<ref name="V2"/> |- | 3rd Edition | Feb 1973 | Introduced a C debugger, pipes, crypt, kill, passwd, size, speak, split, uniq, and yacc. Commands are split between /bin and /usr/bin, requiring a search path<ref name="reader"/> (/usr was the mount point for a second hard disk). Total number of installations was 16. |- valign=top | colspan="3" | |- valign=top | 4th Edition | Nov 1973 | First version written in C. Also introduced comm, dump, file, grep, nice, nohup, ps, sleep, sync, tr, wait, and printf(3).<ref name="reader"/> Included a SNOBOL interpreter. 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,<ref>{{cite journal |first1=D. M. |last1=Ritchie |first2=K. |last2=Thompson |year=1974 |url=https://www.bell-labs.com/usr/dmr/www/cacm.html |title=The UNIX Time-Sharing System |journal=Communications of the ACM |volume=17 |issue=7 |pages=365–375 |doi=10.1145/361011.361061 |s2cid=53235982 |doi-access=free |archive-date=2017-02-18 |access-date=2017-03-04 |archive-url=https://web.archive.org/web/20170218050938/http://www.bell-labs.com/usr/dmr/www/cacm.html |url-status=live }}</ref> the first public exposition of the operating system.<ref name="reader"/> |- | 5th Edition | Jun 1974 | [[File:Version 5 Unix SIMH PDP11 Emulation.png|thumb|Version 5 Unix for the PDP-11, running on SIMH]] Licensed to selected educational institutions.{{r|fiedler198310}} Introduced col, dd, diff, eqn, find, lpr, pwd, spell, tee, {{r|reader}} and the sticky bit. Targeted the PDP-11/40 and other 11 models with 18 bit addresses. Installations "above 50". |- | 6th Edition | May 1975 | [[File:Version 6 Unix SIMH PDP11 Emulation KEN.png|thumb|Version 6 Unix for the PDP-11, running in SIMH]] Includes bc, chgrp, cron, newgrp, ptrace(2), ratfor, tbl, units, and wall.{{r|reader}} First version widely available outside of Bell Laboratories, licensed to commercial users,<ref name="fiedler198310">{{cite news | url=https://archive.org/stream/byte-magazine-1983-10/1983_10_BYTE_08-10_UNIX#page/n133/mode/2up | title=The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace | work=BYTE | date=October 1983 | access-date=30 January 2015 | author=Fiedler, Ryan | pages=132}}</ref> and to be ported to non-PDP hardware (Interdata 7/32). May 1977 saw the release of MINI-UNIX, a "cut down" v6 for the low-end PDP-11/10. |- | 7th Edition | Jan 1979 | [[File:Version 7 Unix SIMH PDP11 Emulation DMR.png|thumb|Version 7 Unix for the PDP-11, running in SIMH]] Includes the Bourne shell, ioctl(2), stdio(3), and pcc augmenting Dennis Ritchie's C compiler.{{r|reader}} Adds adb, at, awk, banner, basename, cu, diff3, expr, f77, factor, fortune, iostat, join, lex, lint, look, m4, make, rev, sed, tabs, tail, tar, test, touch, true, false, tsort, uucp, uux. The ancestor of UNIX System III 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. Ported to PDP-11, Interdata 8/32 and VAX (UNIX/32V). 32V was the basis for 3BSD. |- valign=top | colspan="3" | |- valign=top | 8th Edition | Feb 1985<br/>{{citation needed|date=March 2015|reason=See talk page}} | A modified 4.1cBSD{{Citation needed|date=December 2022|reason=See talk page}} for the VAX, with a System V shell and sockets replaced{{Citation needed|date=December 2022|reason=Either "replaced" is ambiguous or it is incorrect. See talk page}} by Streams. Used internally, and only licensed for educational use.<ref name="dmrV8910">{{cite web |title=[TUHS] Re: V7 UNIX on VAX 11/750 |first=Dennis |last=Ritchie |author-link=Dennis Ritchie |website=minnie.tuhs.org |date=27 June 2003 |access-date=9 April 2014 |url=http://minnie.tuhs.org/pipermail/tuhs/2003-June/002195.html|archive-url=https://web.archive.org/web/20170305042336/http://minnie.tuhs.org/pipermail/tuhs/2003-June/002195.html|archive-date=2017-03-05}}</ref> Adds Berkeley DB, curses(3), cflow, clear, compress, cpio, csh,<ref>{{cite web |url=https://minnie.tuhs.org/cgi-bin/utree.pl?file=V8/usr/src/cmd/csh |title=csh |author=<!--Not stated--> |date=n.d. |website=The Unix Heritage Society |access-date=December 19, 2022 |archive-date=December 20, 2022 |archive-url=https://web.archive.org/web/20221220030733/https://minnie.tuhs.org/cgi-bin/utree.pl?file=V8/usr/src/cmd/csh |url-status=live }}</ref> cut, ksh{{Citation needed|date=December 2022|reason=ksh is not in the v8 archive from the Mountain Avenue plan 9 file server and ksh is not from 4.1cBSD}}, last, netstat, netnews, seq, telnet, tset, ul, vi, vmstat. The Blit graphics terminal became the primary user interface.<ref name="reader"/> Includes Lisp, Pascal and Altran. 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.<ref>{{cite newsgroup |title=regexp(3) |first=Henry |last=Spencer |date=1986-01-19 |newsgroup=mod.sources |message-id=1316@panda.UUCP |url=https://groups.google.com/forum/#!original/mod.sources/OqVZYQNSmDs/G_T2jHu5QI8J |access-date=9 January 2013 |archive-date=2025-09-15 |archive-url=https://web.archive.org/web/20250915161221/https://groups.google.com/forum/#!original/mod.sources/OqVZYQNSmDs/G_T2jHu5QI8J |url-status=live }}</ref> First version with no assembly in the documentation.{{r|reader}} |- | 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 user space.<ref>{{cite journal |first1=David L. |last1=Presotto |first2=Dennis M. |last2=Ritchie |year=1990 |journal=Software: Practice and Experience |volume=19 |title=Interprocess Communication in the Ninth Edition Unix System |url=https://www.bell-labs.com/usr/dmr/www/ipcpaper.html |archive-date=2017-04-03 |access-date=2017-03-04 |archive-url=https://web.archive.org/web/20170403063718/https://www.bell-labs.com/usr/dmr/www/ipcpaper.html |url-status=live }}</ref> Other innovations include Sam.<ref name="reader" /> According to Dennis Ritchie, V9 and V10 were "conceptual": manuals existed, but no OS distributions "in complete and coherent form".<ref name="dmrV8910"/> |- | 10th Edition | Oct 1989 | Last Research Unix. Although the manual was published outside of AT&T by Saunders College Publishing,<ref>{{cite web |url=http://www.cs.bell-labs.com/10thEdMan |title=Unix Tenth Edition Manual |publisher=Bell Labs |access-date=25 December 2013 |url-status=dead |archive-url=https://web.archive.org/web/20150203070035/http://www.cs.bell-labs.com/10thEdMan/ |archive-date=3 February 2015 }}</ref> there was no full distribution of the system itself.<ref name="dmrV8910"/> 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.<ref>{{cite web |title=The IX Multilevel-Secure UNIX System |url=http://www.cs.dartmouth.edu/~doug/IX/ |access-date=2013-12-25 |archive-date=2015-09-23 |archive-url=https://web.archive.org/web/20150923211409/http://www.cs.dartmouth.edu/~doug/IX/ |url-status=live }}</ref> |- valign=top | colspan="3" | |- valign=top | Plan 9 | 1992 | Plan 9 was a successor operating system to Research Unix developed by Bell Laboratories Computing Science Research Center (CSRC). |- valign=top | colspan="3" | |- valign=top | Inferno | 1997 | Inferno is a descendant of Plan 9, and shares many design concepts and even source code in the kernel, particularly around devices and the Styx/9P2000 protocol. It shares with Plan 9 the Unix heritage from Bell Labs and the Unix philosophy. |}
==Licensing== After the publication of the Lions' book, work was undertaken to release earlier versions of the codebase. SCO first released the code under a limited educational license.{{Citation needed|date=October 2009}}
Later, in January 2002, Caldera International (later to become SCO Group and made defunct) relicensed (but has not made available) several versions under the four-clause BSD license, up to and including Version 7 Unix (UNIX/32V).<ref>{{cite web|url=http://www.lemis.com/grog/UNIX/|title=Liberal license for ancient UNIX sources|last=Johnson II|first=Dion L.|date=2002-01-24|access-date=2017-03-30|archive-date=2022-03-05|archive-url=https://web.archive.org/web/20220305150312/http://www.lemis.com/grog/UNIX/|url-status=live}}</ref><ref name="Caldera-license.pdf"/> {{As of|2022}}, there has been no widespread use of the code, but it can be used on emulator systems, and ''Version 5 Unix'' runs on the Nintendo Game Boy Advance using the SIMH PDP-11 emulator.<ref name="gbaunix">{{cite web |url=http://www.kernelthread.com/publications/gbaunix/ |title=UNIX® on the Game Boy Advance |last=Singh |first=Amit |date=August 2004 |access-date=2009-10-22 |archive-date=2006-08-31 |archive-url=https://web.archive.org/web/20060831141959/http://www.kernelthread.com/publications/gbaunix/ |url-status=dead }}</ref> ''Version 6 Unix'' provides the basis for the MIT xv6 teaching system, which is an update of that version to ANSI C and the x86 or RISC-V platform.
The BSD vi text editor is based on code from the ed line editor in those early Unixes. Therefore, "traditional" vi could not be distributed freely, and various work-alikes (such as nvi) were created. Now that the original code is no longer encumbered, the "traditional" vi has been adapted for modern Unix-like operating systems.<ref>{{cite web |url=https://ex-vi.sourceforge.net/ |title=The Traditional Vi |access-date=2025-08-11 |archive-date=2025-08-13 |archive-url=https://web.archive.org/web/20250813052344/https://ex-vi.sourceforge.net/ |url-status=live }}</ref>
SCO Group, Inc. was previously called Caldera International. As a result of the ''SCO Group, Inc. v. Novell, Inc.'' case, Novell, Inc. was found not to have transferred the copyrights of UNIX to SCO Group, Inc.<ref>{{cite web|url=http://www.groklaw.net/pdf3/SCOvNovell10-4122.pdf|archive-url=https://web.archive.org/web/20110926220558/http://www.groklaw.net/pdf3/SCOvNovell10-4122.pdf|url-status=usurped|archive-date=September 26, 2011|title=10th Circuit Court of Appeals Decision}}</ref> Concerns have been raised regarding the validity of the Caldera license.<ref>{{cite web|url=https://wiki.tuhs.org//doku.php?id=events:free_licenses|title=The Push to Get Free Unix Licenses|author=Warren Toomey|access-date=2025-06-15|archive-date=2025-05-20|archive-url=https://web.archive.org/web/20250520232649/https://wiki.tuhs.org/doku.php?id=events:free_licenses|url-status=live}}</ref><ref>{{cite web |url=https://virtuallyfun.com/wordpress/2018/11/26/why-bsd-os-is-the-best-candidate-for-being-the-only-tested-legally-open-unix/ |title=Why BSD/OS is the best candidate for being the only tested legally open UNIX. |date=26 November 2018 |access-date=15 June 2025 |archive-date=15 June 2025 |archive-url=https://web.archive.org/web/20250615084518/https://virtuallyfun.com/wordpress/2018/11/26/why-bsd-os-is-the-best-candidate-for-being-the-only-tested-legally-open-unix/ |url-status=live }}</ref>
==The Unix Heritage Society== ''The Unix Heritage Society'' was founded by Warren Toomey.<ref name="lwn.net/725297">{{cite news |last1=Davis |first1=A. Jesse Jiryu |title=Assembling the history of Unix |url=https://lwn.net/Articles/725297/ |access-date=15 June 2023 |work=LWN.net |date=June 14, 2017 |archive-date=15 June 2023 |archive-url=https://web.archive.org/web/20230615220253/https://lwn.net/Articles/725297/ |url-status=live }}</ref><ref name="bsdnow.tv/476">{{cite web |last1=Jude |first1=Allan |title=Warren Toomey interview |url=https://www.bsdnow.tv/476 |website=BSD Now |access-date=15 June 2023 |date=October 13, 2022 |archive-date=15 June 2023 |archive-url=https://web.archive.org/web/20230615220257/https://www.bsdnow.tv/476 |url-status=live }} [https://aphid.fireside.fm/d/1437767933/c91b88f1-e824-4815-bcb8-5227818d6010/64bc3a0c-43cf-4e97-af97-b31d799c1154.mp3 MP3 44:34]</ref> First edition Unix was restored to a usable state by a restoration team from the Unix Heritage Society in 2008. The restoration process started with paper listings of the source code which were in PDP-11 assembly language.<ref>{{cite journal |last=Toomey |first=Warren |date=July 2010 |title=First Edition Unix: Its Creation and Restoration |journal=IEEE Annals of the History of Computing |volume=32 |issue=3 |pages=74–82 |doi=10.1109/MAHC.2009.55|bibcode=2010IAHC...32c..74T |s2cid=18586380 }}</ref><ref>{{Cite web |url=https://www.usenix.org/legacy/events/usenix09/tech/full_papers/toomey/toomey.pdf |title=The Restoration of Early UNIX Artifacts |access-date=2025-06-15 |archive-date=2025-06-27 |archive-url=https://web.archive.org/web/20250627095821/https://www.usenix.org/legacy/events/usenix09/tech/full_papers/toomey/toomey.pdf |url-status=live }}</ref>
== Legacy == In 2002, Caldera International released<ref>[http://slashdot.org/articles/02/01/24/0146248.shtml Caldera releases original unices under BSD license] {{Webarchive|url=https://web.archive.org/web/20081012193225/http://slashdot.org/articles/02/01/24/0146248.shtml |date=2008-10-12 }} on slashdot.org (2002)</ref> Unix V1, V2, V3, V4, V5, V6, V7 on PDP-11 and Unix 32V on VAX as FOSS under a permissive BSD-like software license.<ref>{{cite web|url=http://www.lemis.com/grog/UNIX/|publisher=lemis.com|title=UNIX is free!|date=2002-01-24|access-date=2017-03-30|archive-date=2022-03-05|archive-url=https://web.archive.org/web/20220305150312/http://www.lemis.com/grog/UNIX/|url-status=live}}</ref><ref name="Caldera-license.pdf">{{cite web|url=http://www.tuhs.org/Archive/Caldera-license.pdf |archive-url=https://web.archive.org/web/20090219220353/http://www.tuhs.org/Archive/Caldera-license.pdf|archive-date=19 February 2009 |title=Dear Unix enthusiasts |last=Broderick |first=Bill |date=January 23, 2002 |publisher=Caldera International}}</ref><ref>{{cite web|url=http://www.linuxdevcenter.com/pub/a/linux/2002/02/28/caldera.html|archive-url=https://web.archive.org/web/20040601025000/http://www.linuxdevcenter.com/pub/a/linux/2002/02/28/caldera.html |publisher=O'Reilly Media |work=Linuxdevcenter |title=Why Caldera Released Unix: A Brief History |first=Ian F. |last=Darwin |date=2002-02-03|archive-date=2004-06-01 |access-date=2022-01-18}}</ref>
In 2017, The Unix Heritage Society and Alcatel-Lucent USA Inc., on behalf of itself and Nokia Bell Laboratories, released V8, V9, and V10 under the condition that only non-commercial use was allowed, and that they would not assert copyright claims against such use.<ref>{{Cite news |last=Chirgwin |first=Richard |date=30 March 2017 |title=Samizdat no more: Old Unix source code opened for study |url=https://www.theregister.co.uk/2017/03/30/old_unix_source_code_opened_for_study/ |work=The Register |archive-date=30 March 2017 |access-date=30 March 2017 |archive-url=https://web.archive.org/web/20170330134247/https://www.theregister.co.uk/2017/03/30/old_unix_source_code_opened_for_study/ |url-status=live }}</ref>
== See also == * History of Unix * List of Unix systems
== References == {{Reflist|30em}}
== External links == {{Commons category|Research Unix}} *[http://www.collyer.net/who/geoff/history.html UNIX Evolution] ([http://www.collyer.net/who/geoff/history.ps PostScript]) by Ian F. Darwin and Geoffrey Collyer *[http://www.tuhs.org/ Unix heritage] - More links and source code for some Research Unix versions *[https://www.bell-labs.com/usr/dmr/www/hist.html The Evolution of the Unix Time-sharing System] by Dennis M. Ritchie *[http://www.usenix.org/events/usenix09/tech/full_papers/toomey/toomey.pdf The Restoration of Early UNIX Artifacts] by Warren Toomey, School of IT, Bond University *[http://man.cat-v.org/unix_8th/ Full Manual Pages documentation for Research Unix 8th Edition]. *[https://groups.google.com/forum/#!original/comp.unix.wizards/9iC6Z3LboDA/AVjXvtLxpcMJ List of new features in Research Unix 9th Edition]. *[https://github.com/ambiamber/Run-UNIX-v9 Emulator for running UNIX v9]. * Pamela Jones (August 23, 2003) [https://www.tech-insider.org/internet/research/2003/0823.html Ancient UNIX Released Under What Terms?], Groklaw *[https://www.tuhs.org/ The Unix Heritage Society (TUHS)], for the preservation and maintenance of historical UNIX systems **[https://minnie.tuhs.org/UnixTree/ code, disk images, and related] at TUHS *[http://man.cat-v.org/unix-1st/ Unix First Edition Manual Pages] *[https://github.com/jserv/unix-v1 Restoration of 1st Edition UNIX kernel sources from Bell Laboratories]
{{Bell Unix}} {{unix-like}}
Category:Bell Labs Unices Category:Computing platforms Category:Discontinued operating systems Category:Unix variants