Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1a 12/4/83; site rlgvax.UUCP Path: utzoo!linus!security!genrad!decvax!harpo!seismo!rlgvax!guy From: guy@rlgvax.UUCP (Guy Harris) Newsgroups: net.unix Subject: Re: UNIX Family Tree? - (nf) Message-ID: <1522@rlgvax.UUCP> Date: Thu, 5-Jan-84 17:05:05 EST Article-I.D.: rlgvax.1522 Posted: Thu Jan 5 17:05:05 1984 Date-Received: Sat, 7-Jan-84 02:35:17 EST References: <2171@fortune.UUCP> Organization: CCI Office Systems Group, Reston, VA Lines: 68 Bell Labs released the early versions of UNIX (System I and II internally)... Actually, those weren't System I and System II. There were several UNIX development streams in Bell; "version 6" and "version 7" came from the "Research" group, so they are referred to as "Research UNIX". There was also a UNIX supported by a group within Bell Labs, used for various Bell System projects, which was called USG UNIX (for Unix Support Group), and there was a UNIX done for the PWB (Programmer's WorkBench) project called PWB/UNIX. PWB/UNIX was based on a version later than version 6 (it had a C compiler, linker, archiver, Standard I/O library, etc. similar to the one released with the "Phototypesetter, Version 7" tape, and a kernel similar to the one made by adding the list of "50 changes" to UNIX that Ken Thomson sent out to V6). Later, the PWB/UNIX stuff was added to a version earlier (I believe) than the released Version 7 (but with the V7 file system, etc.) which made a system called UNIX/TS 1.0, which was more-or-less System I. This became one of the two official UNIXes (the other was a descendant of MERT called UNIX/RT), and the descendants of UNIX/TS 1.0 have been collectively referred to as USG UNIX. with the sixth edition of the manual (So, people named it version 6). Berkeley hacked up version 6 and shared it with other institutions. Bell labs incorporated some Berkeley features and released the version 7 ( this is where the compatibility ended). Well, most of the changes between V6 and V7 were from Bell, not from Berkeley. Neither "Version" 6 nor "Version" 7 were really "versions" in any formal sense; I believe "Version 6" literally was "what happened to be on the Research machine when the 'Version 6' tape was spun." V7 was just a snapshot of what the Research people had done to UNIX since V6. Bell labs went on with system III internally and Berkeley developed BSD4.1. Eventually, Bell labs decided to support UNIX officially and released system III while developing system IV. Berkeley turned to virtual memory with BSD4.2. Actually, BSD 3.0 was the first release with virtual memory. I'm not sure whether the "First Berkeley Software Distribution" was their hacked V6 or their hacked V7 (for the PDP-11), but the "Second Berkeley Software Distribution" was a hacked V7 for the PDP-11. The "Third Berkeley Software Distribution" was based on UNIX/32V, which was UNIX V7 ported to the VAX-11. The "Third Berkeley Software Distribution" had virtual memory. The "Fourth Berkeley Software Distribution" (frequently called, for obvious reasons, 4BSD) had a lot of new stuff, like job control, etc.. There have actually been several "Second BSD" and "Fourth BSD" releases; the current "Second BSD" release is 2.9BSD, and the current "Fourth BSD" release is 4.2BSD. 4.2BSD is the one with the totally new file system, the totally new IPC/networking system, the new signal mechanism, etc., etc.. Bell labs decided to support the same version they sell and use (Finally!), but didn't want to use the number 4 or IV. No, the reason that the version they sold which was supported and up-to-date with the one they used internally was called System V was that it was Bell release 5.0; "System V" would have been Bell release 4.0, 4.1, or 4.2. Why they went with the Roman numerals, I dunno... Any corrections, Dennis? (DMR is the closest thing to an official UNIX historian around; if he says it, you can believe it (but if you tell us that UNIX was originally written in JOVIAL for the PDP-14, *that* will change quickly! :-)).) (Also, the internal history of UNIX within Bell is even more ramified that my discussion implied; that wouldn't be directly relevant to versions of UNIX released to the outside world, but would be a *very* interesting discussion. Any takers from AT&T Bell Laboratories?) Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy Brought to you by Super Global Mega Corp .com