[Info-vax] Prices of Microvax 3100's

[John Wallace]

On May 3, 10:34 pm, David Froble <da... at tsoft-inc.com> wrote:
> John Wallace wrote:
> > On May 3, 2:59 pm, koeh... at eisner.nospam.encompasserve.org (Bob
> > Koehler) wrote:
> >> In article <0c85168b-2bb2-413c-b27a-214935e8d... at w7g2000vbg.googlegroups.com>, AEF <spamsink2... at yahoo.com> writes:
>
> >>> So why not run Charon or SIMH? Speaking of which -- and please pardon
> >>> me if this is a stupid question -- do these things run as a separate
> >>> process or do they take over the entire machine? I don't see why it
> >>> can't be the former. Just making sure.
> >>    SIMH is just an ordinary application as far as I've seen.  It can
> >>    be a significant CPU load, but I've been able to timeshare with it
> >>    on all the desktop OS I've tried it with.
>
> > SIMH can be greedy, as can others, but the main issue with coexistence
> > is likely not the behaviours of the VMS-hosting emulator application,
> > but the behaviour of Windows and Windows-based applications on Windows
> > systems, and in in particular the impact of any undesirable behaviour
> > on VMS and the applications in the VMS environment. (I hope that
> > sentence made sense).
>
> > That's why from time to time you see people round here asking about
> > Linux versions of the emulators and why at least one of the emulators
> > has a version that runs on QNX, the realtime OS. If the host OS has to
> > be Windows then it's presumably safest to treat the Window box as a
> > single purpose box but that isn't really much of a guarantee of good
> > behaviour, especially in the presence of the stuff usually associated
> > with a Window box of any kind.
>
> Stan Quayle was re-selling Charon, and according to what he wrote in the past, windoz
> wasn't a problem.  What he indicated happened was shutting down many of the services that
> normally come enabled in a windoz distribution.  He also indicated that they ran windoz on
> one CPU, and dedicated another to the emulator.  So, you had a decent CPU dedicated to
> nothing but the emulator, which I guess gave some decent performance.
>
> What I haven't seen is a chart of what windoz services were needed, and what ones could be
> disabled.  Sure would be better than everyone having to re-discover that information by
> trial and error.
>
> If you shut off enough of the bloated services on windoz, I've got to wonder how close one
> can come to a real real-time OS?

"If you shut off enough of the bloated services on windoz, I've got to
wonder how close one
can come to a real real-time OS?"

You can try it but what chances are there that it will work, or if it
does, that the next Windows Update or AV Update or whatever will break
something? Realistically it can't be meaningfully done with a Window
box, with or without CHARON. Stan sells QNX as a CHARON host for when
realtime matters.

My experience says you can come pretty close to what a lot of people
(but not everyone) would class as realtime with a suitably configured
Linux. There's lots of stuff you can readily configure, and if it's
not configurable enough or doesn't do what you want, you get the
source and can have someone change it.