11 Apr
2015
11 Apr
'15
8:25 a.m.
From: Johnny Billquist
> Remember the jumpers I found on the 11/84
backplane? They can turn the
> PMI section (AFAICT) into a real QBUS.
I don't remember any jumpers.
http://www.classiccmp.org/pipermail/cctalk/2015-February/003756.html
> For QBUS _memory_, it should 'just work',
in the same way that you can
> plug an M8190 into a Q/CD backplane with some QBUS memory, and it will 'just
> work'. (I.e. the M8190 will automatically do QBUS memory cycles if
> that's the kind of memory that's out there.)
I'll believe that when you plug the Qbus memory
*before* the CPU in a
Q/CD backplane.
But the QBUS part of _any_ QBUS backplane is not 'directional' in the same
way the CD part of the backplane in an ordinary Q/CD backplane is. (Note that
the 11/84 backplane's CD section is _not_ 'directional' the way a normal Q/CD
backplane's CD section is. See:
http://www.classiccmp.org/pipermail/cctalk/2015-February/003757.html
for more.) So for plain QBUS memory, it doesn't matter where it is in the
QBUS backplane, in relation to the CPU.
Noel