Small DEC cardcage with backplane

Jerome H. Fine jhfinedp3k at
Sat Mar 7 15:37:10 CST 2015

 >Jon Elson wrote:

> >On 03/06/2015 11:30 AM, Pontus Pihlgren wrote:
>> >On Fri, Mar 06, 2015 at 10:28:57AM -0600, Jon Elson wrote:
>>> >On 03/05/2015 05:00 PM, Sander Reiche wrote:
>>>> Hi all,
>>>> I'm currently searching around for a small cardcage+backplane, if 
>>>> I'm not
>>>> mistaken DEC part numbers H9281-BA or H9281-BB for a bigger one. 
>>>> The -BA
>>>> (4x dual heights) has my preference as I'm looking to build a very 
>>>> nice,
>>>> cute and not that power hungry PDP-11. 
>>> Unibus or Q-bus?  I have some Q-bus backplanes that came from the
>>> WELL.
>>> Picked them up at some surplus place in the bay area, I think
>>> probably Mike
>>> Quinn's.
>>> The backplanes don't have a manufacturer's label.  They may have
>>> been custom
>>> made by the WELL, I don't know.  I also don't know if they are Q-18
>>> or Q-22.
>>> They have a card cage, cooling fan and Todd power supply.  I have
>>> two of them.
>>> Jon
>> What size? 
> 9 slots x 4 connectors wide.  Standard Q-bus.

If I remember correctly, a 9 slot x 4 connectors wide are ABCD and
available with support for either 18-bit or 22-bit addresses.  The
last slot usually expects a terminator board.  I can't remember the
actual part numbers.

There are also more recent backplanes in a BA23 box which are
8 slots by 4 connectors wide.  The BA23 box also contains bays
for 2 * 5 1/4" drives, one of which is usually an MSCP drive for
which there is a distribution panel at the rear of the drive bay
that is connected to an RQDX1, RQDX2 or an RQDX3 via a
50 pin cable.  The first 3 slots and ABCD and the remaining
5 slots are ABAB.  There were many, many BA23 boxes sold
and they may be easier to find.

Jerome Fine

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