7 Feb
2015
7 Feb
'15
4:04 p.m.
OK, thanks. It seemed like too wild an idea but I thought I'd at least
ask. Would've been cool if it was engineered to allow one to simply change
power harnesses and regulators and have a normal backplane, but I get that
that's not the case. Not I understand why every 11/45 picture I've seen
includes a second chassis!
This MOS / Bipolar section of the backplane is definitely not compatible
with M7891, correct?
thx
jake
On Sat, Feb 7, 2015 at 4:12 PM, Paul Anderson <useddec at gmail.com> wrote:
Again, I agree with Tony. I would not hack up the cpu
backplane,and put in
a BA11-KE above the 45. Assuming you have it in a H960, 6 feet tall
cabinet, I would mount it 10 1/2 above the 45 for convenience and air
flow.
That should give you all the room you'll ever need.
On Sat, Feb 7, 2015 at 12:53 PM, tony duell <ard at p850ug1.demon.co.uk>
wrote:
and
are
to
wire-
The first 25 slots are for an initial "unibus a" terminator, cpu,
floating point and memory, which, since I only have one bipolar matrix,
is
> an enormous waste of like ten slots (they're wired for weird voltage would
presumably explode other boards installed there, right?).
Yes, AFAIK those memory slots are custom-wired so don't use them for
anything else.
> So then there are three slots available at the end, 26, 27, 28 that also
marked "non-standard voltage." I guess that means that putting
normal
boards in there is right out, too. Anyway, the
unibus out and bridge
9200
jumper that connects unibus a and unibus b are
supposed to go there.
That's it for the main backplane.
You can put 3 quad-height SPC boards in there, if you don't then you have
to fit grant continuity cards. It's traditional to put the console DL11
there.
> I'm going to duck after asking this, but would it be at all feasible > rewire the main 11/45 backplane to get rid
of the weird voltages in
those
bipolar
slots so they'd accommodate normal boards like these?
I am sure it's _possible_ but I wouldn't do it. The 11/45 is rare enough
as it is, I wouldn't make a permanent change to the CPU backplane. And
be warned it may not be an easy change, there's a PCB under all that wrap that carried power and ground at least. If
you have to change any of
that it is a _very_ big job.
> Short of that, what can I do? I definitely don't want another
chassis.
Any reason not to have a 5.25" or 10.5" expansion box. From what I recall
it is
possible to drop the CPU and PSUs by 5.25" fairly easily so you should be
able
to make room for the former.
-tony