18 Jun
2018
18 Jun
'18
6:39 p.m.
On Jun 18, 2018, at 1:58 AM, Johnny Billquist
<bqt(a)update.uu.se> wrote:
On 2018-06-18 04:00, Ronald Natalie <ron(a)ronnatalie.com> wrote:
Eh... Yes... But...
The "separate" bus for the semiconductor memory is just a second Unibus, so the
statement is still true. All (earlier) PDP-11 models had their memory on the Unibus.
Including the 11/45,50,55.
It's just that those models have two Unibuses.
No, you are confusing different things I think. The fastbus (where the memory was) is a
distinct bus. The fastbus was dual ported with the CPU in one port and a second UNIBUS
could be connected to the other port.
Well, it
is an easy observable fact that before the PDP-11/70, all PDP-11 models had their memory
on the Unibus. So it was not only "an ability at the lower end", b
That’s
not quite true. While the 18 bit addressed machines all had their memory directly
accessible from the Unibus, the 45/50/55 had a separate bus for the (then new)
semiconductor (bipolar or MOS) memory.