====== Some MERT History ====== //This comes from a thread in the [[https://groups.google.com/d/msg/net.unix/-H9x36DMOBQ/tHDE2z7Z4qEJ|net.unix Usenet newsgroup]]// Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ih1ap.UUCP Path: utzoo!linus!decvax!harpo!ihnp4!ih1ap!pat From: pat@ih1ap.UUCP (Patrick A. Fargo) Newsgroups: net.unix Subject: UNIX History Message-ID: <270@ih1ap.UUCP> Date: Wed, 11-Jan-84 15:18:47 EST Article-I.D.: ih1ap.270 Posted: Wed Jan 11 15:18:47 1984 Date-Received: Fri, 13-Jan-84 04:01:20 EST Organization: AT&T Bell Labs, Naperville, IL Lines: 42 After reading the various responses to the history of UNIX within and outside AT&T Bell Laboratories, I decided to provide some other details of the development inside the labs. I ordered the 2nd PDP 11/70 at Indian Hill in 1976. I will try to give a list of important changes in perspective. After development of the first UNIX systems in research, Joe Maranzano of Murray Hill created a UNIX support group. This group would package, fix bugs, and enhance the research version periodically. A year after this new group was formed, Heiz Lacklama and Doug Bayer of Holmdel modified UNIX for a PDP 11/70 using the 3 memory management registers so that UNIX ran as a supervisor. This product, called MERT for Mult Environment Real-Time operating system, was eventually support by the same UNIX support group. The third major entry was UNIX/PWD. The programmers workbench contained programs which controlled remote job entry, and source control. These were developed at Piscataway N. J. In this time period, new PDP processors such as the PDP 11/34, and PDP 11/23 and even a PDP 11/55 were released and off- springs to UNIX developed for them. The PCC (Portable C Compiler) and satellite library for UNIX was generated and new MINI UNIX products arose. On the other hand, UNIX for a HONEYWELL and UNIVAC 1100 series was also started. Around 1978, the UNIX support group in conjunction with a computer task force decided to support two major releases. UNIX/TS and UNIX/RT. UNIX/TS was USG UNIX and PWD UNIX combined. The UNIX/RT was basically supported MERT. Columbus had modifyed a version of MERT extensively, and called their product CB UNIX. Another version of MERT formed the basis for DMERT, a Duplex operating system. The thrust of only two supported versions was that UNIX/RT showed very good promise as being the more used version and anything that could be done in UNIX/TS would work in UNIX/RT. The advent of the PDP VAX computer now created four products. UNIX/RT and UNIX/TS for both PDP 111/70 and VAX 780 computers. In 1979 UNIX/RT was announced as 1 year to freeze, with UNIX/RT VAX officially dead. The remaining UNIX/TS VAX was again modified by the Indian Hill computer center into another product called UNIX/TS Augmented. Finally, the product internal to AT&T Bell Labs call UNIX/TS was the only major product supported. I hope this little history was interesting. If you have further questions I will try and answer them within company constraints. Patrick A. Fargo 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!decvax!harpo!seismo!rlgvax!guy From: guy@rlgvax.UUCP (Guy Harris) Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <1541@rlgvax.UUCP> Date: Wed, 11-Jan-84 17:27:53 EST Article-I.D.: rlgvax.1541 Posted: Wed Jan 11 17:27:53 1984 Date-Received: Fri, 13-Jan-84 04:22:37 EST References: <270@ih1ap.UUCP> Organization: CCI Office Systems Group, Reston, VA Lines: 60 Correcting a few typos: "Heiz Lacklama" is actually Heinz Lycklama, now of Interactive Systems; "UNIX/PWD" is actually PWB/UNIX. MERT was actually a separate OS from UNIX, which had a UNIX overlay on top of it (so the first case of putting a UNIX-compatible interface on top of a different OS was Bell's own MERT!). In this time period, new PDP processors such as the PDP 11/34, and PDP 11/23 and even a PDP 11/55 were released and offsprings to UNIX developed for them. The 11/55 was just an 11/45 with faster memory and a faster floating point unit, so the standard UNIX that ran on an 11/45 would run on the 11/55. The 11/34 and 11/23 would, by and large, run versions of UNIX that ran on the 11/40, except that they could support the floating point instructions. (They also had other features, like the 11/34's cache and the 11/23+'s 22-bit UNIBUS, but standard UNIX know about them.) UNIX/TS was USG UNIX and PWD UNIX combined. And was derived from a version of UNIX that was mostly Research V7, although it was, I believe, slightly earlier than the released V7 (it had a V6-ish) terminal driver, for instance) - the original USG UNIX and PWB/UNIX were derived from V6 or from V6es later than the released V6 - a set of "50 changes" that would turn V6 into what was running at Research at the time when the changes were sent out was done by Ken Thompson, and there was a "Phototypesetter, Version 7" distribution that contained the "modern" nroff/troff/eqn/tbl, the "modern" C compiler with "long", "typedef", etc., the "modern" linker and archiver, and the Standard I/O library. Most of the "50 changes" and "Phototypesetter, Version 7" stuff was in PWB/UNIX 1.0. Another version of MERT formed the basis for DMERT, a Duplex operating system. For the 3B20-D; the D stood for Duplex and meant there were two CPUs in a redundant configuration. In 1979 UNIX/RT was announced as 1 year to freeze, with UNIX/RT VAX officially dead. Just out of curiosity, why was UNIX/RT canned if, as stated earlier, it was felt that UNIX/RT could do everything UNIX/TS could and more? The remaining UNIX/TS VAX was again modified by the Indian Hill computer center into another product called UNIX/TS Augmented. Was there also *another* UNIX/TS variant called UNIX/TS+ (plus)? Finally, the product internal to AT&T Bell Labs call UNIX/TS was the only major product supported. And was named just UNIX as of release 3.0 (release 3.0.1 was publicly released as System III); it incorporated stuff from TS Augmented and TS+. Was CB-UNIX based on UNIX or MERT, and how much stuff going into the mainstream UNIX (S3, S5) came from CB-UNIX? Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ih1ap.UUCP Path: utzoo!linus!decvax!harpo!ihnp4!ih1ap!pat From: pat@ih1ap.UUCP (Patrick A. Fargo) Newsgroups: net.unix Subject: UNIX History Message-ID: <271@ih1ap.UUCP> Date: Thu, 12-Jan-84 08:06:26 EST Article-I.D.: ih1ap.271 Posted: Thu Jan 12 08:06:26 1984 Date-Received: Fri, 13-Jan-84 06:33:56 EST Organization: AT&T Bell Labs, Naperville, IL Lines: 23 Thanks to Guy Harris for the corrections. In response to his other questions: 1). Why was UNIX/RT canned instead of TS? Good question! I believe because of staffing a choice had to be made. Since DMERT was RT based and would be supported, USG felt UNIX/TS had more potential from a computer center standpoint. 2). Was UNIX/TS+ another modified UNIX/TS? Yes, the UNIX/TS Augmented that I spoke of was actually called UNIX/TS++. Modifications were made that were mostly hidden from the user interface. 3). What was CB-UNIX based on? CB-UNIX was a modified MERT. The SCCS project modified extensively, the version of MERT they had. Later, they incorporated the MERT changes in UNIX/RT releases. Eventually, an agreement to take the requested CB modifications into the standard UNIX/RT product was reached and that line of modified O.S. ceased. Thanks again for the corrections, P. A. Fargo AT&T Bell Laboratories IH Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ihuxf.UUCP Path: utzoo!linus!decvax!harpo!ihnp4!ihuxf!larry From: larry@ihuxf.UUCP (Larry Marek) Newsgroups: net.unix Subject: Re: UNIX History (UNIX/RT) Message-ID: <1701@ihuxf.UUCP> Date: Thu, 12-Jan-84 10:53:11 EST Article-I.D.: ihuxf.1701 Posted: Thu Jan 12 10:53:11 1984 Date-Received: Fri, 13-Jan-84 06:39:07 EST References: <271@ih1ap.UUCP> Organization: AT&T Bell Labs, Naperville, IL Lines: 15 This is about as UNofficial as it can be, but from the point of a computer system ``user'' UNIX/RT was a **PIG**. It may have been great for certain applications, but it certainly did NOT make a good general time-sharing system! Another point is that the whole system was riddled with bugs. I had the opportunity to work with some of the RT folks (on a few of the bugs) and my impression was that they were a small group of people that were just overloaded. Apparently the "management" decision was that RT wasn't worth the effort to "rescue" it. -- Larry Marek ihnp4!ihuxf!larry Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site abnjh.UUCP Path: utzoo!linus!decvax!harpo!eagle!mhuxl!abnjh!usenet From: usenet@abnjh.UUCP (usenet) Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <399@abnjh.UUCP> Date: Thu, 12-Jan-84 12:34:24 EST Article-I.D.: abnjh.399 Posted: Thu Jan 12 12:34:24 1984 Date-Received: Fri, 13-Jan-84 07:00:22 EST References: <270@ih1ap.UUCP>, <1541@rlgvax.UUCP> Organization: ATTIS, NJ Lines: 13 The story goes that the stuff new to 5.0 (called System V when it was released to the outside world) was put there to satisfy the needs of the people at Columbus, who were using UNIX as a base for writing 'Operations Support Systems', ie. programs to be used by operating companys in non-programmer environments. They needed things like shared memory and inter-process communication. Those features had already been done for CB-UNIX (Whether as part of DMERT or UNIX, I dont know.) but were re-done but the UNIX Support Group people. The hope was that the Columbus people would all convert over to 5.0 and efforts could be consolidated. I dont know whether this hope was realized, I left the Labs about the time this was happening. Rick Thomas Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ih1ap.UUCP Path: utzoo!linus!decvax!harpo!ihnp4!ih1ap!pat From: pat@ih1ap.UUCP (Patrick A. Fargo) Newsgroups: net.unix Subject: UNIX History (UNIX/RT) Message-ID: <272@ih1ap.UUCP> Date: Thu, 12-Jan-84 12:52:55 EST Article-I.D.: ih1ap.272 Posted: Thu Jan 12 12:52:55 1984 Date-Received: Fri, 13-Jan-84 07:02:46 EST Organization: AT&T Bell Labs, Naperville, IL Lines: 5 The point about the performance and reliability of UNIX/RT is well taken, and I agree. But remember, UNIX/RT (MERT) was in existence about 1 and a half years less than UNIX/TS. The bug rate was higher, and UNIX/RT performance was increased dramatically for a few projects at the labs. Overall apprasail of UNIX/RT by the developers themselves were RT before TS. Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ih1ap.UUCP Path: utzoo!linus!decvax!harpo!ihnp4!ih1ap!pat From: pat@ih1ap.UUCP (Patrick A. Fargo) Newsgroups: net.unix Subject: UNIX History Message-ID: <273@ih1ap.UUCP> Date: Fri, 13-Jan-84 08:11:58 EST Article-I.D.: ih1ap.273 Posted: Fri Jan 13 08:11:58 1984 Date-Received: Sat, 14-Jan-84 03:17:35 EST Organization: AT&T Bell Labs, Naperville, IL Lines: 7 A clarification about a statement I made concerning CB-UNIX. The SCCS project at Columbus was NOT Source Control. It was short for Switching Control Center System or something like that. Thanks to Andy for the help. P. A. Fargo BTL -IH Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site mhtsa.UUCP Path: utzoo!linus!philabs!seismo!harpo!eagle!mh3bs!mhtsa!jimjwf From: jimjwf@mhtsa.UUCP Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <414@mhtsa.UUCP> Date: Fri, 13-Jan-84 20:53:49 EST Article-I.D.: mhtsa.414 Posted: Fri Jan 13 20:53:49 1984 Date-Received: Sun, 15-Jan-84 00:06:04 EST References: <273@ih1ap.UUCP> Organization: AT&T Bell Laboratories, Murray Hill, NJ Lines: 19 CB UNIX was not derived from MERT but grew out of the internal distributions from the USG (generic 1,2 and 3) (yes thats a new set of numbers, not to be confused with any of the other UNIX numbering conventions). The USG 3 system had some of the real time things that CB wanted and they were incorporated into CB-UNIX. One of the reasons that UNIX developed quickly and MERT did not was the support/feedback from the CB Labs. They had some sharp people and a good exchange with the USG when UNIX was an infant, but grew to love their version of UNIX and did not swing their applications to MERT/UNIX-RT. I suspect that if they had, RT might have been a good product but with only a few customers and an over-burdened support staff RT was put on the shelf. Any old USGer's care to add to this. I hope some one is collecting all of this UNIX folklore and plans to print it paperback. Jim Farrell AT&T Bell Labs Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!seismo!...@BRL-VLD.ARPA From: gwyn%b...@BRL-VLD.ARPA Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <15460@sri-arpa.UUCP> Date: Fri, 13-Jan-84 21:39:34 EST Article-I.D.: sri-arpa.15460 Posted: Fri Jan 13 21:39:34 1984 Date-Received: Mon, 16-Jan-84 01:25:49 EST Lines: 5 From: Doug Gwyn (VLD/VMB) The UNIX System V IPC was already present in USG UNIX 4.1. (Not related to 4.1BSD.) It appears to me that these features must have been in UNIX/RT. Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!seismo!...@BRL-VLD.ARPA From: gwyn%b...@BRL-VLD.ARPA Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <15461@sri-arpa.UUCP> Date: Fri, 13-Jan-84 22:01:43 EST Article-I.D.: sri-arpa.15461 Posted: Fri Jan 13 22:01:43 1984 Date-Received: Mon, 16-Jan-84 01:26:04 EST Lines: 33 From: Doug Gwyn (VLD/VMB) Guy Harris has given much more accurate UNIX history notes than most of what has filtered into the ARPAnet on this topic. I would like to add a couple of comments: It was fairly easy to take the 6th Edition UNIX 11/45 floating-point processor (FP11) support and add it into the 11/40 version for a PDP-11/34. One subtle problem with using the 11/40 kernel on an 11/34 is that the faulted-instruction restart code was not entirely correct for the 11/34, although later the 11/23 was again 11/40-compatible in this regard. The 6th Edition UNIX floating-point support also had some bugs that needed to be fixed if one was going to make heavy use of floating-point on an 11/34 or 11/23, as we did at Geotronics Corp. The most important Columbus product to appear in USG UNIX would probably be the augmented "make", which is much nicer than the 7th Edition UNIX version, although still not perfect. All it takes to make UNIX quite usable for real-time data acquisition is: (1) plock(2) or equivalent to ensure that user-mode code is memory-resident when needed. (2) strict priority scheduling, which can be as simple as adding a privileged "real-time process queue" to the existing scheduler. (3) data acquisition device driver and user-mode dual-buffered program that cooperate nicely. One of the past USENIX tapes contained Geotronics contributions for items (1) and (2) for 6th Edition UNIX. John Quarterman, now with the University of Texas Dept. of CS, did a really nice job of making (3) work for the proprietary 11/23-based system used in the field by Geotronics Corp. 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!decvax!harpo!seismo!rlgvax!guy From: guy@rlgvax.UUCP (Guy Harris) Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <1551@rlgvax.UUCP> Date: Sun, 15-Jan-84 13:57:00 EST Article-I.D.: rlgvax.1551 Posted: Sun Jan 15 13:57:00 1984 Date-Received: Mon, 16-Jan-84 01:35:03 EST References: <15460@sri-arpa.UUCP> Organization: CCI Office Systems Group, Reston, VA Lines: 76 The UNIX System V IPC was already present in USG UNIX 4.1. (Not related to 4.1BSD.) For you real UNIX trivia freaks, the USG 4.0 IPC was different from the USG 4.1 IPC. The original message send/receive system calls sent to a process ID; they were changed to send to message queues, which had a 32-bit unique ID, instead (which makes more sense, as it permits you to transparently replace servers). (It might be interesting to see how many changes to the Berkeley IPC mechanism would be needed to provide yet another domain which provides compatibility with the S5 IPC mechanism; obviously, the socket addresses would be the unique IDs. The trick is that the S5 messages have a "long" which is a "message type", and the S5 "msgrcv" call can ask to be delivered only messages of a certain type, or messages with a certain type number or lower number. Also, message queues (and other "IPC objects") have an owner UID, owner GID, and permission bit set associated with them.) The semaphore code was also very different (it may have been descended from semaphore code done for the pre-UNIX/TS USG systems), and the shared memory code was the MAUS code which used a dedicated part of physical memory for the shared space. The history of Bell UNIX IPC mechanisms looks rather multi-branched; anybody out there with the full story? It's also interesting to see mention of various such branches in the BSTJ issue on UNIX (the July-August 1978 issue, Vol. 57, No. 6, Part 2). They make casual reference to "the UNIX interprocess message facility", "the semaphore capability of the UNIX system", and to "run levels" in "the standard UNIX 'init' program" in the article on the Network Operations Control System, and also describe the MAUS shared-memory facility which was originally done for that system. (Another aside: the MAUS was credited to Dale DeJager and R. J. Perdue; I remember seeing some code from Gould which was part of their driver and support code for their 5000 series electrostatic printer- plotter for DEC systems which was also credited to R. J. Perdue - was this the same guy?) A lot of those features probably came out of Columbus but never made it into the UNIXes released to the outside world until System III (the 'init') or System V (the messages and semaphores). Andy Tannenbaum sent me a "man" page for an "init" from a pre-UNIX/TS USG system which also had the run levels, and Hal Pierson (ex-Labs, now working here) mentioned that they had done both a semaphore system and the run-level based 'init' for a system they did which collected output from the console terminal ports of Electronic Switching Systems processors and allowed "craftsmen" (which I think is AT&Tese for "field engineer") to peruse that output for maintenance purposes. They also realized that these craftsmen wouldn't know an inode if it came up and bit them in the *ss, so they had to replace "icheck" and "dcheck" with a new program which would do most of the dirty work of file system repair for them - Hal wrote one called "fcheck", which cleaned V6 file systems, and which appeared in source-code form on the PWB/UNIX 1.0 distribution tape. Unfortunately, PWB/UNIX 1.0 modified the V6 file system so that it didn't support "huge" files, and the eighth indirect pointer pointed directly to a block as the other seven did, so the "fcheck" there wouldn't fix a vanilla PWB/UNIX file system, but it worked just fine on a vanilla V6 FS. When I discovered it, quite by accident, I looked at it and it sure looked like a super-duper file system fixer; once we got it up, we never went back to "icheck" and "dcheck" again. Later on, of course, Ted Kowalski rewrote it to work on a V7 filesystem, added some extra checks, gave it the ability to reconnect files with no directory entries, put comments into the code (something Hal still has trouble doing :-)), cleaned it up some, and renamed it "fsck". It appears to me that these features must have been in UNIX/RT. MERT had its own set of new features, including yet *another* message facility which didn't look like any of the "Ken&Dennis-derived" UNIX systems' facilities, but I don't know what they did in UNIX/RT. A lot of source material is in the BSTJ UNIX article, and may appear in some issues of Bell Labs' "UNIX Systems Newsletter" which was distributed to UNIX sites within AT&T & operating companies. Anybody for a "net.unix.history" newsgroup - at the end of the year, maybe we gather up all the articles, give them to some editor (maybe Dennis, who certainly doesn't have anything more important to do :-)) who can cull out the chaff, and publish it somewhere? Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site lzmi.UUCP Path: utzoo!linus!security!genrad!grkermit!masscomp!clyde!floyd!harpo!eagle!mhuxl!houxm!hogpc!pegasus!lzmi!dale From: dale@lzmi.UUCP Newsgroups: net.unix Subject: Re: UNIX History Message-ID: <166@lzmi.UUCP> Date: Mon, 16-Jan-84 20:20:17 EST Article-I.D.: lzmi.166 Posted: Mon Jan 16 20:20:17 1984 Date-Received: Fri, 27-Jan-84 06:24:39 EST References: <270@ih1ap.UUCP> Organization: AT&T Information Systems, Lincroft, NJ Lines: 42 A correction to the comment on the source of CB-UNIX. I was the supervisor of the group in Columbus for a number of years that was responsible for the development of CB-UNIX. The system was derived from the UNIX operating system that was used in the SCCS (Switching Control Center System), which incidentally was the first application of UNIX outside of research. (UNIX was running on an 11/20, at the time, without memory management and we deployed the first version of SCCS in New Jersey Bell in New Brunswick, NJ.) The SCCS version of UNIX had a number of unique features for the times: semaphores and line disciplines (in 1974!) for example. Hal Pearson was responsible for semaphores, and Bill Snider for line disciplines. Messages and shared memory were first added to CB-UNIX in about 1975 or 1976. Shared memory was called MAUS (pronounced moss, standing for Multiple Access User Space) and was derived from an earlier version done by R. J. Purdue. CB-UNIX became rather widely accepted within BTL as a base for turnkey Operations Systems--many of which have been described in the BSTJ. Note that CB-UNIX was not a derivative of UNIX/RT, but of Version 6 and Version 7. PWB UNIX was also a derivative of Version 7. USG UNIX was originally a derivative of Version 6 and 7 with some CB-UNIX facilities added. Eventaully a decision was made to consoldate to two versions of UNIX: UNIX/TS and UNIX/RT. RT was a derivative of MERT, and TS a derivative of PWB UNIX. RT was to be used by Operations Systems, but was never too widely accepted. Eventually, UNIX/TS was augmented to have many of the features present in CB-UNIX (this was done by Roger Faulkner at Indian Hill, BTL. This, in turn, became the base for UNIX 4.0, which was never released externally. While this augmentation was going on, UNIX/TS was being changed into UNIX 3.0 which was release externally as SYSTEM III. In more recent history, CB-UNIX has been eliminated entirely in favor of UNIX 5.0. (one reason is because it never ran on anything other than the 11/70) I once had a viewgraph with all this on it which I had great fun trying to explain. Now for trivia: How many know where in UNIX lore you would find the following quote: "Values of beta will result in dom!" Dale DeJager AT&T Information Systems Lincroft, N.J.