Digital Standard Mumps

Warner Losh imp at
Thu Apr 18 18:41:49 CDT 2019

On Thu, Apr 18, 2019 at 5:11 PM Paul Koning <paulkoning at> wrote:

> > On Apr 18, 2019, at 3:06 PM, Warner Losh <imp at> wrote:
> >
> > On Thu, Apr 18, 2019 at 12:41 PM Dan Veeneman via cctalk <
> cctalk at> wrote:
> > On 4/18/2019 2:27 PM, Paul Koning via cctalk wrote:
> > > my memory is that DSM-11 is an operating system all its own, not just
> a language processor running on top of a standard OS like RSTS.
> >
> > In the late 1980s and early 1990s, we used DSM running on VMS 4.7 for a
> > nationwide (United States) mortgage credit reporting system.
> >
> > The big claim to fame for RSTS/e  was I thought that it let you load
> 'foreign' executives so you could run RT-11 or RSX-11 or whatever binaries
> all on one system. I'd imagine DSM-11 images would be easy if it were a
> real OS. I'd always thought of RSTS/e as a poor-man's hypervisor. But maybe
> I'm misremembering how much it could do...
> Poor man's hypervisor, I like that.
> That's reasonably accurate.  RSTS/E had "run-time systems", originally the
> interpreter, support library, and user interface of the BASIC-PLUS language
> machinery.  Starting in, I think, RSTS/E V5B, it was generalized step by
> step to become a collection of such things: a user interface, execution
> environment, and other stuff.  It might be very narrowly tailored, like the
> TECO run-time system, it might be the interpreter library for a language,
> like the FORTH and ALGOL run-time systems, or it might be a fairly complete
> emulation of a different OS, like the RT11 and RSX run-time systems.

I know I ran BASIC-Plus, TECO and RT-11 binaries (FORTRAN code) on the
RSTS/E system I started out on (6C or 7.0, iirc). We also had some RSX-11
binaries too for something I've long-ago forgotten.

> I first used a very primitive version of this feature in V5B around 1975,
> to run an assembly language program before there was any general RSTS
> support for doing that.

Yea, I couldn't recall if it was tailored or generic. I think it was, as
you say, tailored from  massaged versions of the original executives, iirc,
but maybe they were reimplementations like the crazy glue code that we had
at university that was an RT-11 .SAV file with some weird glue to make it
run in 7th Edition Unix that we ran on a VAX 11/750 using the pdp-11
emulator hardware it had...


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