PMI memory on an -11/93 (Was: Installing an operating system on an 11/83)

Noel Chiappa jnc at mercury.lcs.mit.edu
Tue Feb 22 17:17:27 CST 2022


    > From: Christian Gauger-Cosgrove

    > From the KDJ11-E module user's guide ... the solder-side of the CD
    > fingers is left unpopulated, but for the +5 and ground pins.
    > The only PMI compatible option then would be the KTJ11-B UNIBUS adapter.

I forget how the -11/84-94 backplane is wired (it's wierd - the QBUS CD slots
are bussed together in a group, they're not in pairs like an ordinary Q/CD
backplane - but I forget the fine details), but how does the PMI get from the
CPU to the KTJ11, then? I know on the same backplane, it supports PMI memory
cards with the KDJ11-B.

And speaking of the KDJ11-B, I just looked at one, and _it_ doesn't have any
lands on the C/D connectors, side 2, either! Probably because the PMI only uses
side 1 lands:

  https://gunkies.org/wiki/Private_Memory_Interconnect#Pinout

Given that the KDJ11-E can do master-slave cycles through the KTJ11-B (to
read UNIBUS device registers), it has to be able to do master-slave cycles on
the PMI. What I don't know is whether, on a 2MB KDJ11-E, it will try and send
memory reads for locations > 2MB out the PMI, or whether all reads below the
UNIBUS address space (in 22-bit address terms) are sent to the local memory
_only_.

Someone with a 2MB KDJ11-E should try it...

	Noel


More information about the cctech mailing list