On Tue, Jan 31, 2017 at 4:33 PM, Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:

> From: Nigel Williams
> Is it a reasonable claim that the PDP-10 made time-sharing "common"

... I'm presuming that "common" should be read as ubiquitous and accessible
> I'm wondering if it was really the combination of the PDP-11

Good question; I think a case can be made both ways.

I agree.

> (lower-cost more models)

One observation I will make: the two don't have identical time-lines; the

earliest PDP-10 models predate the PDP-11 by a good chunk, and the PDP-11

out-lasted the PDP-10. So that has a big influence, I think, on the
q
uestion

above.

Certainly if you include the virtual address extension - aka VAX to the PDP-11 family - which was birthed in '76. Then I would agree the PDP11/VAX/UNIX combo had case for a larger footprint for making timesharing "common" from 70-79 -- which is the time period mentioned in the Wikipedia article.

But I do think to fair to the Wikipedia authors, the 10 and 20 families during the 1970s were the pretty much the machines that defined the idea of timesharing to most small colleges and smaller universities until UNIX takes its stride.

CDC and IBM had a footprint in large and well funded places. But even in those schools, the 10/20 was still king in the CS Dept, until UNIX displaced it.