The VAX is one of the most successful computer-families of Digital Equipment Corporation (and perhaps
the whole industry). The name VAX, which stands for "Virtual Address
eXtension" refers to the large virtual address space, which was meant to be an
extension to the PDP-11
architecture. In the first months of the project, the machine was called
PDP-11/780. The hardware and the main operating system for it, VMS (Virtual
Memory System) were developed parallelly.
The beginning...
Many thanks
to Steve Rothman!
Digital started to think about a possible wide-word machine in 1973, but the early decision was to build a new 36-bit machine based on the successfull PDP-10. This new machine was to superceed the high-end of the PDP-11 line, so the strongest PDP-11, the 11/70 was developed as an interim machine until the new 36-bitter would be ready. One year later however a few people (Bill Demmer was among them) questioned whether this was the right way to go. They felt that Digital needed a machine that would made migration from the PDP-11 easy. Following that, the decision was made to consider an "extended PDP-11" alternative to the 36 bit machine. The 36-bit project, led by Len Hughes (engineering and Dave Rodgers (lead architect/project engineer/engineering supervisor) got the nickname "Unicorn", while the 32-bit machine was later called "Star". The latter took off on April 1st, 1975 (this is just an anecdote, it was a few days earlier).
The "extended PDP-11" project was led by Gordon C. Bell, and one of the main goals was PDP-11 compatibilty. The team consisting of five people (Gordon Bell, Bill Demmer, Richie Lary, Steve Rothman and Bill Strecker) created a proposed architecture, which was to be reviewed in June, 1975. The team (called VAX-A team) worked through April and May on the third floor of building 12 in the Maynard mill; the result was the so-called "VAX Blue Book" - the specification of a 32-bit machine, distributed in loose blue binders. The architecture we now know as VAX is a subset of what was originally planned: many features were dropped because they weren't economically realisable. There were two other commitees too besides team A: VAX-B and VAX-C; the first consisted of technology reviewers, the second worked on business issues. The name "VAX" was coined probably by Gordon Bell.
After the meeting in June, the "Unicorn" project got
cancelled (that's one of the reasons why 36-bit fans hate VAXen; and it only
got worse later in the mid-eighties, when the whole
PDP-10/DECsystem-10/DECSYSTEM-20 line was "killed" in favor of the VAX), and
the "32-bit engineers" went on implementing their architecture, with some of
the engineers of "Unicorn". When the architecture work on paper seemed to be
near its end, a few members of the team went on to build the VAXHS, the VAX
Hardware Simulator: a modified PDP-11 for developing VMS and the FORTRAN
compiler (four of these machines were made). After this was finished, the
development group took off to design the second VAX computer ("Comet").
The VAX Timeline
Disclaimer: the pages don't focus on figures, numbers, and such. This is a history page, not the summarized edition of all technical manuals ;-)
1977. Introduction of the VAX-11/780 "supermini" computer
1978. VMS1.0 shipped
1980. The second generation: 11/750, the first LSI VAX
1981. VAX Information Architecture
1982.VAX-11/730, the "mini-VAX", ALL-IN-1 (integrated office softwaresystem); RA60 and RA81 hard disk drives
1983. Computer Interconnect (CI) "clustering" technique for interconnecting VAX processors giving greater computing power; the 11/725; ULTRIX, VAXELN
1984. VAX-11/785, 8600, MicroVAX I, VAXstation I: the first microprocessor VAX-implementation; ULTRIX-32; Rdb/VMS and Rdb/ELN
1985. MicroVAX II, MicroVAX II/GPX; VMS 4.2; VAX11 ACMS (transaction-processing)
1986. VAX 8800; 8200, 8300; VMS 4.5; LAVC (local area VAX-cluster)
1987. MicroVAX/VAXstation 2000: low-cost micro-workstation, MicroVAX 3500, 3600; VAX 8874, 8878: pre-packaged high-end clusters
1988. VAX 6200: the dawn of a new era; VMS 5.0; DSSI, Dual-Hosting; Network Application Support
1989. MicroVAX 3100; 3800, 3900;VAX 6000-300; 6000-400; 9000 (the last non-microprocessor based Digital machine), DECwindows
1990. MicroVAX 3300, 3400; VAX4000; VAX 6000-500; VAXft (Fault Tolerancy), OpenVMS
1992. VAX 7000, 10000, the last of the "big" VAXen
About these pages, links, etc...
All comments are welcomed, but please don't ask me for part numbers, spare parts, and don't expect answers to questions like "how do I boot up a 11/725 I found in the dust bin" and "how do I format a harddisk" in e-mail! I don't have the knowledge, nor the time to answer all the questions I get every day. Please try the newsgroups comp.sys.dec and alt.sys.pdp11, chances are that the people there know much more about PDP-11 systems, than I do, and they might help you if you ask politely! Good luck, I hope you all get your answers, and I'm sorry I'm not the one to tell them...