Concurrent Controls Multiuser DOS

Bill Degnan billdegnan at
Sat Oct 3 22:25:24 CDT 2020

I have Concurrent Link XM and Softlink and stuff like that here but I never
used it much.

On Sat, Oct 3, 2020 at 8:03 PM Liam Proven via cctalk <cctalk at>

> On Sat, 3 Oct 2020 at 18:14, Jonathan Haddox via cctalk
> <cctalk at> wrote:
> >
> > I'm researching Multiuser DOS out of my own interest.  A version made by
> Concurrent Controls specifically.  However, I have been unable to find
> documentation on it to satisfy my curiosity on how it works and how it is
> configured.  They must have somehow broken the 640K barrier or virtualized
> each user session, I'd like to understand it better.  What were it's
> limitations, I'm guessing that each user didn't get direct access to
> hardware.  Anyone out there have a document or experience with it?
> It's just one fork of the old DR Concurrent DOS/386, descended from
> Concurrent CP/M. The Wikipedia article is a good start:
> I say this with slight bias as I wrote a chunk of it. Yes, I had some
> experience with it, installing and supporting it on customers' systems
> in the late 1980s.
> --
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