I distinctly remember I renamed to boot image on our research VAX (alice!)
from "vmunix" to "unix". It had been long enough by that point that the
lingering prefix was starting to sound like a brag.

-rob


On Sun, Jan 1, 2023 at 4:53 PM G. Branden Robinson <
g.branden.robinson@gmail.com> wrote:

> At 2023-01-01T00:35:12-0500, Dan Cross wrote:
> > On Sun, Jan 1, 2023 at 12:27 AM Warner Losh <imp@bsdimp.com> wrote:
> > > On Sat, Dec 31, 2022, 9:38 PM Jonathan Gray <jsg@jsg.id.au> wrote:
> > >> [snip]
> > >> Bourne's AsiaBSDCon 2016 talk also lists 1976
> > >> and goes on to discuss sbrk() use causing problems with ports
> > >> https://youtu.be/7tQ2ftt3LO8?t=715
> > >
> > > And at 5:18 he says he had a vax lab with three vaxen and the Lab's
> > > vax port didn't have virtual memory. Bill Joy with 3BSD which had
> > > virtual memory. They installed it on the vaxen because they were
> > > hitting physical memory limits for some of their programs....
> >
> > One wonders what is meant by "virtual memory" in this context. I
> > contend that Unix has had "virtual memory" since moving off of the
> > PDP-11/20, in the sense of having a virtual address space that was
> > mapped onto a (possibly contiguous) physical address space. I think
> > all of these references mean demand paging, possibly with page
> > reclamation or whole-process swapping under memory pressure.
>
> I apologize if this point is too elementary, but I speculate that one
> possible source of confusion comes from a file naming convention: which
> of these (multiple) virtual memory or demand-paged VM systems installed
> the kernel under the name "vmunix" vs. "unix".
>
> Which ones did and did not?
>
> When I was first learning Unix I asked a local expert why the kernel was
> named "vmunix".  They told me that it was because it supported virtual
> memory (and explained what that was, because I was even more callow then
> than now).
>
> Then I asked where the non-VM kernel was.  I was informed that there
> wasn't one--it didn't even exist for modern architectures.  I wondered
> then why, if virtual memory was a given, you wouldn't just go back to
> using the filename "unix".
>
> I wondered similar things when encountering the "vmlinux" file a couple
> of years later.
>
> Reflexive obeisance to traditions has a cost.
>
> Regards,
> Branden
>