[TUHS] Re: On the uniqueness of DMR's C compiler

[Tom Perrine <tom.perrine+tuhs@gmail.com>]

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Hi Jon (and others),

I was part of the KSOS (later KSOS-11 and KSOS-32) team at LOGICON, which
picked up a follow-on contract to use KSOS-11 in a true multi-level-secure
production environment. Our target was SYSTEM_LOW as TOP SECRET.

Yes, we used that compiler for all the KSOS kernel and all the trusted
user-space code.

KSOS-11 only ran on PDP-11/70, and it did use split I&D.

I have access to the KSOS-11 source code, and have been trying to rebuild
that OS, BUT I haven't been able to find that Modula compiler.

KSOS-11 was a very small kernel, but there was a set of libraries that
presented a UNIX system call interface, so it could run some PWB userspace
tools, if they were re-compiled.

I'm using the term KSOS-11, as there was a follow-on project (KSOS-32) that
ported the original PDP KSOS to 11/780. I wrote a completely new (simpler)
scheduler, the bootstrap and memory management layer for that one.

And, for "reasons", the entire KSOS project at Logicon was shut down just a
week or so after the first user login to KSOS-32.

KSOS-11 itself and some multi-level applications did ship to DoD customers,
and it ran MLS applications for the Navy and USAFE.

--tep

ps. Jon was kind enough to remind me that we had corresponded about this in
the past -and- to remind me to send to the list, and not just him :-)


On Wed, May 8, 2024 at 9:08 AM Jon Forrest <nobozo@gmail.com> wrote:

> There was also a Modula2 compiler for the PDP-11 from a university in the
> UK,
> propably York. It was used to some degree at Ford Aerospace for the
> KSOS secure Unix project. I think it required separate I&D.
>
> Jon
>

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