rewriting legacy OS for new iron

From: Ron Hudson <>
Date: Tue Sep 14 11:46:07 2004

On Sep 14, 2004, at 9:04 AM, Lyle Bickley wrote:

> In a past life ;-) I used and worked with RSTS/E running on an 11/70 -
> including creating a lot of software, adding libraries, etc. - while
> running
> the Quant. Analysis Group at Fidelity.
> I now have RSTS/E running on my 11/83 - including the same account
> (and my
> personal software) that I worked with over twenty five years ago.
> To port RSTS/E to Intel would be a major chore. RSTS/E supports the
> BASIC-PLUS, BASIC-PLUS2, TECO, etc. run-time systems. It
> "automagically" can
> run programs from any of those "OS"es!

Yes, it would be. With all of us who program working together perhaps
we can do
it. We would be able to say how it would work.

> So porting RSTS/E would mean porting all of those runtimes and their
> associated libraries (RT, RSX, etc.) as well. Whew!!!

> I thinks its a LOT easier (and more fun) to simply run it on real DEC
> hardware
> - or if you can't create that environment - run it on Intel via the
> SIMH or
> ERSATZ emulators.

I wish I had some DEC hardware, what's the physically smallest PDP11
one could
find? I am running RSTS/E on simh.

> Cheers,
> Lyle
> On Tuesday 14 September 2004 07:17, Paul Koning wrote:
>>>>>>> "Ron" == Ron Hudson <> writes:
>> Ron> Would there be any interest in re-writing somthing like RSTS/E,
>> Ron> ITS, TWENEX or one of the other legacy OS to work on x86
>> Ron> machines? The idea would be to do something like Linux has done
>> Ron> for unix but for one of the other OSs, I think all the ones I
>> Ron> mentioned ran on pdp machines, whatever we choose to write could
>> Ron> have once run on anything.
>> What would it mean to "run" such an OS on an x86? Consider RSTS,
>> which is the only one of those three I know well. The OS itself is
>> 100% assembly language. The system services are defined in terms of
>> request blocks in low user memory along with system call instructions
>> (EMT opcode of the PDP-11). Applications were generally written in
>> Basic-Plus (or -2), or in PDP11 assembler; rarely in some other
>> language such as TECO, or FORTH, or others.
>> I could imagine creating a Basic-Plus environment that emulates that
>> aspect of RSTS. I could also imagine a BP2 compiler that generates
>> X86 code. The surrounding machinery -- "run time systems", the system
>> service semantics, etc. -- that would be tricky. Assuming you get
>> that far, you have a user mode analog of the original, so old
>> applications (if written in Basic-Plus or BP2) would run. The same
>> would go for TECO. Assembly language applications have no chance
>> short of running an emulator at least for user mode. The same goes
>> for FORTH, since it tends to hook right into the assembly style system
>> service API, though obviously you could replace just that small part
>> and keep the rest.
>> paul
> --
> Lyle Bickley
> Bickley Consulting West Inc.
> "Black holes are where God is dividing by zero"
Received on Tue Sep 14 2004 - 11:46:07 BST

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