Re: [TUHS] 32V memory management: not quite V7 style swapping -- source code update

[Paul Ruizendaal via TUHS <tuhs@minnie.tuhs.org>]

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Clem,

> You got me thinking and I'm curious if anyone really knows historically how many sites ran a 32V system?

I don’t know the answer to that, but my outsider impression is that 32V and 32-bit Sys III had a very small installed base, and hence that the innovations in it are not all that well known or understood.

However, in searching the web for things related to “scatter loading” I find some references to Xenix. It may be that some of the 32V/SysIII stuff lived in high volume during the mid-80’s through that code base.

——

Going on a tangent, I am wondering about “mmap”. John Reiser wrote that he based the idea on PMAP from Tenex/TOPS-20, and fretted over a system call with 6 parameters. This would be 1980 at the latest.

In their 1981 discussion paper “Proposals for the enhancement of Unix on the VAX” Joy and Fabry propose some mmap like ideas, but without this API specifically. In the 1983 “4.2BSD system manual” they propose the mmap call in more or less its current form, but it is not implemented. It remained unimplemented until SunOS 4 in 1988 and 4.3BSD Reno in 1990.

It makes me wonder how close to the current “mmap" the code in the demand paging version of 32V was; it might have been quite close.

By the way, from that discussion paper it seems that CSRG had access to the demand paging version of the 32V code in 1981 but unfortunately it does not seem to have survived there (I've checked the DVD that Kirk McKusick provides, but the 32V code on there seems the same as what Keith Bostic provided to TUHS).

Paul

> On Jun 6, 2021, at 8:23 PM, Clem Cole <clemc@ccc.com> wrote:
> 
> Paul,
> 
> You got me thinking and I'm curious if anyone really knows historically how many sites ran a 32V system?   In those days (late 70s/early 80s) the universities that knew and and even many sites inside the Bell System, the Vaxen I ran 4.1BSD (say the Marx's brothers at Whippany along with the Vax in the underseas research lab were we put the AP I did for my thesis).  There were a couple in Summit I know, and probably Homdel and I'm guessing in some of the operating companies, but I never got the feeling 32V was popular.  The folks with Vaxen that I knew, if you were able to run BSD (4.1 and eventually 4.2), did.  Later on the only non-'pure-joy' systems I knew were a couple of Ultrix systems because they wanted the support from DEC and IIRC were using FORTRAN and wanted the DEC compiler which only ran on Ultrix or VMS.  Inside of AT&T, I personally think I knew more folks with VMS (Fortran being the key anchor)  than those that ran 32V.
> ᐧ


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