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: