Maybe - re- DMX11

Nigel Johnson Ham g4ajq1 at gmail.com
Tue Oct 26 19:14:00 CDT 2021


I have to wonder if DMX was to satisfy the requirements of Bell Canada. 
I worked as an FE on a Univac system with, suspiciously, 64 serial lines
going out on private lines and TWX all over Canada.

Now if you think back to the late seventies, an operator using a system
designed in the late sixties and which was generating a lot of revenue
would want to carry it on with something more modern, and there were
already a lot of PDP11s on the floor.  Incidentally, that is where
Datapac and Sympatico started.

Perhaps nobody could see the consumer internet coming, so this may have
been what Bell were demanding of CSS in Ottawa?

Of course, there was always Telidon!  I worked on one such system as a
private contractor that was built at Bell labs in Ottawa and went on
line at the Simcoe Street Offcie in Toronto.  It had two DEC DH11s and
two Able Computer DMAX/16s, a total of 64 lines.

Just my.01 worth !

cheers,

Nigel



On 2021-10-26 7:37 p.m., Bob Smith via cctalk wrote:
> I left in 79, I designed the AUtodin II  mode 1A//Mode VI line usints.
> Those were synchronous comms interfaces for Bisync.ADCCP/ etc
> connections while CSS did the Mode 1 I think it was Asynch interface
> line unit.
> I suspect DMX is the commercial version of that Autodin II Asynch
> design, using the KMX/COMMIOP cpu and a dedicated unibus system unit
> set to support the lineunits
> BUT I could be wrong maybe DMX was something completely different but
> it seems to tickle my memory.
> bb


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