Talk:VAX

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PRIME Computer reference[edit]

From the article:

'"VAX" is originally an acronym for virtual address extension, both because the VAX was seen as a 32-bit extension of the older 16-bit PDP-11 and because it was (after Prime Computer) an early adopter of virtual memory to manage this larger address space.'

Why do we call out Prime here? There's nothing special about Prime. Lots of computers had virtual memory, and using it to manage an increase of address space is nothing new. The PDP-6/10 family went from 18 to 22 bit physical addresses and 23 bit virtual addresses as well and used several different forms of virtual memory to manage it. All existed before Prime. IBM had similar developments before Prime.

The reference to Prime should be removed. — Preceding unsigned comment added by 168.159.213.206 (talk) 19:02, 11 August 2014 (UTC)

My guess is that they were talking specifically about machines considered "minicomputers" or "superminicomputers"; there were definitely machines and OSes that did paged or segmented virtual memory before the VAX, such as the GE 645 under Multics, the IBM System/360 Model 67 under TSS/360/CP/CMS/etc., the Burroughs B5000 under MCP, etc.
But Prime wasn't the first minicomputer company to offer virtual memory; apparently Norsk Data's Nord-1 had it in 1969. Guy Harris (talk) 20:52, 11 August 2014 (UTC)
I vaguely remember that PRIME was considered special because it had the first 32-bit minicomputer. John Sauter (talk) 21:11, 11 August 2014 (UTC)
The Nord-5 article claims, albeit without a reference, that it "is believed to be the first 32-bit minicomputer". Guy Harris (talk) 21:27, 11 August 2014 (UTC)

Plural[edit]

I think we really should say something about the widespread use of the plural form 'vaxen', as it was (and to an extent still is) quite widespread, and has also been quite infuential on computer/geek culture (e.g. talking about 'UNIX boxen' as plural for 'UNIX box').

You only have to read this talk page to see the plural used twice. Unfortunately I'm not sure quite what we can say about it. I'm sure getting references to its use will be easy. But anyone know where and how this form came to be? Roybadami (talk) 22:00, 8 January 2015 (UTC)

I'm not sure it's up to Wikipedia to document slang. The official word from DEC - and I can probably find references for this; there was an official announcement about it - was that "VAX" is a name of a type of computer; hence it is not a noun, more like an adjective. Hence "VAX computer" is the singular, and "VAX computers" is the plural form. Jeh (talk) 23:55, 8 January 2015 (UTC)
Yeah, that's largely down to the trademark lawyers. It's the same reason that, at least back when MIT cared about the trademark, we weren't supposed to talk about X (or X Windows), but instead were supposed to talk about the X Window System. Doesn't have much bearing on how people talk about this stuff in the real world. I think the word "VAXen" is widespread enough -- and was influential enough both on the cuture of the time and on the culture that followed (e.g. "UNIX boxen") that it deserves a mention. [Sorry for slow motion reply] Roybadami (talk) 23:03, 21 August 2015 (UTC)
As I've said in a few other discussions, Wikipedia is not the Urban Dictionary. And as many, many editors will tell you, we need more than a personal impression of widespread usage. I have no objection to the term's inclusion as long as good reliable sources are cited to support the claim. (RSs might include, for example, use of the term "VAXen" in the bodies of articles at recognized news sites or magazine articles; it would not include readers' comments to same, as those are "user-contributed content", not normally subject to editorial review.) In that case though the fact that this was an unofficial term, never used by DEC, needs to be added. Jeh (talk) 23:21, 21 August 2015 (UTC)

Read My MIPS, No More VAXS[edit]

The VAX was the first really good virtual machine, being designed from the ground up. TOPS-10 did a kind of VA but it was next to useless, being an after thought. The IBM-370 was the end of the line for the RTS and RA. The VAX killer 390 kept it in business more by customer loyalty and killer contracts. 220.244.239.97 (talk) 00:48, 18 June 2015 (UTC)

In the hope of making sense of this, I must ask what you mean by VA, RTS and RA. John Sauter (talk) 03:29, 18 June 2015 (UTC)

citation needed?[edit]

When it was introduced, many programs were written in assembly language, so having a "programmer-friendly" instruction set was important.[citation needed] I believe, which of course needs a citation, that this is just barely not true. That VAX came at the time of the transition, such that it was designed for the past, and not the future. Also the VAX page size of 512 bytes, again based on the past, was too small almost immediately. (and again, citation needed.) Gah4 (talk) 05:36, 30 September 2016 (UTC)

I was there, and I can assure you that from the year of its introduction (1978) and for many years after, a great many programs for the VAX were written in its assembly language (VAX MACRO, aka MACRO-32). As was much of VMS itself and many of its utilities. This was particularly true in DEC's traditional market of scientific computing as well as in utility programs. None of the HLLs available from DEC in the early days of VMS were particularly suitable for OS or utility programming, other than the very expensive Bliss-32, for which very few customers spent the money, so few people outside DEC were comfortable coding. Even after DEC shipped a C compiler (1983 iirc; certainly no earlier than 1982) many of the OS's internal interfaces could only be accessed from MACRO or Bliss. Some relied on uses of specific registers for e.g. argument passing and this was not (and remains not) possible with any HLL available from DEC other than Bliss. A glance through the contributed programs catalog in the DECUS library of the day will confirm the heavy use of MACRO-32. This was even true after the Alpha was introduced; DEC wrote a compiler that would turn VAX MACRO into machine code for the Alpha, preserving the register usage, etc., from the VAX MACRO code. I am happy to look for references for the existing text but you're not going to find any correct ones that support your view. Jeh (talk) 06:01, 30 September 2016 (UTC)
I was doing scientific programming on VAX from about 1978 through much of the 1980s, and pretty much all in Fortran. I do remember system programming calls done from Fortran, such as QIO calls. The only one I remember running into in Macro-32, which I believe was output form the Bliss-32 compiler, such that those without the compiler could use it, is Kermit. That is, until C-Kermit was ported to VAX/VMS. Now, consider from the Forward to "VAX Architecture Reference Manual"": "Computer design continues to be a dynamic field; I expect we will see more rather than less change on innovation in the decades ahead. No matter how computers evolve, however, it is clear that the VAX architecture is a major contribution to progress in the field. It will be as important to study and understand a generation from now as it is today." That was written in 1986. I did have a reference for the page size being too small, but I don't remember now where. Gah4 (talk) 07:12, 30 September 2016 (UTC)
Oh heck, the VAX didn't originally even have a native Fortran compiler at first release, only the compiler from RSX running in compatibility mode, as did the resulting code! And the optimization, even after F77 for VMS appeared, was not great. A good MACRO programmer could often do better.
Yes, you have the "system service" calls. Ever try building a $GETJPI itemlist in Fortran? Pain in the behind, while in Macro it is trivial. On the other hand... File access from VAX Fortran (even after the "native" compiler shipped) was primitive. For simple stuff, sure, it's fine. But if you look at the $FAB and $RAB macros you'll find a wealth of options that the VMS HLLs never provided. For example, the default file name and related file name specs.
Opinion such as that from the VAX ARM cannot be considered anything but a primary, first-party source. Nor does it say anything about why a "programmer-friendly" ISA was considered important, either. Jeh (talk) 07:25, 30 September 2016 (UTC)
Yes. What I was saying is that VAX was near the beginning of the transition away from mostly assembly code for systems programming. At about the time that Unix showed that operating systems could be writing in high-level languages like C. Yes, it took some years for the transition, but not near as long as VAX was expected to last. We are about now one generation from 1986. On the other hand, IBM direct descendants of S/360 are still commercially viable in z/ systems. Gah4 (talk) 08:25, 30 September 2016 (UTC)