30 Jul
2016
30 Jul
'16
3:51 p.m.
> I guess it will require getting ahold of a
backplane, and seeing what
> I can find out with an ohm-meter.
It looks like I'll still have to do this at some
point, to confirm my
theories about how the two busses are wired on the backplane
(separation of UB and EUB address lines, and cross-connection of the
data lines, for the EUB/SPC slots)
I have checked an -11/24 backplane, and the wiring is indeed as I
hypothesized (above).
Another mystery: The "PDP-11 UNIBUS Processor
Handbook" (1985) says
(pg. 4-10) that in the 5.25" box, "only one MS11-P memory module can be
configured". Anyone know the cause/source of that restriction?
...
I can't come up with any technical rationale for that limit? Am I
missing something? Or is it just DEC marketing, trying to limit how
powerful the machine can be?
I would still be grateful for any insight from anyone about this.
Noel