KD-11F (11/03) in a BA11-N??

[Bob Armstrong]

  I have a BA11-N chassis that says "11/03-L" on the front, and the
backplane in it is an H9273-A.   I want to get this to work with a 11/03 CPU
(a real KD11-F M7264) but there's something strange about this backplane
that I can't figure out.

  The boards I'm using are the M7264, an M8044 (MSV11-D), M8017 (DLV11-E)
and a BDV11.  In a small, 4 slot 11/03 chassis (a BA11-S, I think) all these
boards work fine together, however in the BA-11N there's no joy.  It powers
up, but the processor appears to halt immediately - it never executes the
BDV11 bootstrap.

  But, if I replace the 11/03 CPU in the BA11-N with a 11/23 CPU card, then
everything is fine.  So the 11/03 works fine in the BA11-S but not in the
BA11-N, and the 11/23 works fine in the BA11-N.

  It seems fairly likely that there's some kind 16/18/22 bit addressing
issue here, but what's the fix?  It must have been possible to use the
KD11-F in the BA11-N, given the 11/03-L designation.  

  FWIW, the backplane has not been field upgraded with wire wrap to add the
extra address bits.  In fact, the H9273-A doesn't even have wire wrap pins
at all - the pins are all cut off right at PCB level.  Is this the standard
backplane for a 11/03-L system?   I'm wondering if at some time maybe the
whole backplane was replaced with a newer one.

Thanks,
Bob

P.S.  Yes, I do know that BA11-S backplane is QQ/QQ where as the H9273 is
QQ/CD.  I don't think that's the problem - there's nothing in the CD slots
below the 11/03 card.