11/45 hack?

[Paul Anderson]

I wouldn't worry about memory yet. Shorten the bus( move the terminator) to
just one memory backplane, and take out anything you don't have to have to
run xxdp. once it's running, add one option at a time and retest the system.

It takes longer, but can be better in the end.

Paul

On Sat, Feb 7, 2015 at 11:46 PM, Paul Anderson <useddec at gmail.com> wrote:

> I'm pretty sure it's not.
>
> Do you only have one G401?  strange...
>
> On Sat, Feb 7, 2015 at 6:04 PM, Jacob Ritorto <jacob.ritorto at gmail.com>
> wrote:
>
>> 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:
>> >
>> > > >
>> > > >   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
>> > and
>> > > > 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
>> > are
>> > > > 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
>> > to
>> > > > 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
>> > wire-
>> > > 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
>> > >
>> > >
>> >
>>
>
>