[Simh] Musings on potential SIMH candidate systems

[Christian Brunschen]

You're aware there's an emulator of sorts already in progress?

  http://rottedbits.blogspot.co.uk/2013/05/imlac-emulator-progress.html

// Christian

On 11 April 2015 at 23:20, Alan Frisbie <frisbie at flying-disk.com> wrote:

> I am only just getting started with SIMH, so perhaps I'm getting
> a bit ahead of myself, but here goes...
>
> A classic graphics system of the early 1970s was the Imlac PDS-1.
> The display was a vector-stroke type, driven by a display list in
> memory and continuously refreshed.   It had a CPU for
> communicating with a host (typically a PDP-10) and local
> calculations, and a GPU (Graphics Processing Unit) for executing
> the elements of the graphics display list, both running out of
> the same memory.   Peripherals were generally limited to a serial
> line, the light pen, and a single switch (often a foot switch).
>
> The CPU looked very much like a 16-bit PDP-8, which should be
> almost trivial to simulate.   The GPU would be a bit trickier,
> as it would have to draw lines on the host's display.   The real
> problem, as I see it, would be how to have *two* simulated
> computers operating simultaneously from the same memory.   I seem
> to recall a discussion on this list about how that would be
> difficult, but can't recall the details.
>
> Does anyone have any ideas on how this might be done?
>
> I would be interested in doing it, as I just happen to have an
> Imlac PDS-1D here, and would like have a simulator before I sell
> the actual unit.   I also have a complete set of documentation
> with all schematics, plus some software.
>
>
> A second system of interest is the CDC 6600.   Again, the problem
> as I see it is combination of a CPU and multiple PPUs (Peripheral
> Processing Units).   It also used ones-complement arithmetic,
> which might cause difficulties.   Does anyone have any thoughts
> on these matters?
>
> Alan Frisbie
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20150411/619d68f6/attachment.html>