PDP-11 Memory

Allison Parent allisonportable at gmail.com
Fri Jan 11 13:25:20 CST 2019


Most Probable cause is interrupt grant is broken.  For most microspheres backplanes the first three slots are different than remaining.


Phoned this in!


On Jan 11, 2019, at 12:28 PM, Bill Gunshannon via cctalk <cctalk at classiccmp.org> wrote:


Well, it has been so long since I had to put together an
entire system I forgot what fun it can be.

With almost documentation I was able to configure 4 1meg
memory modules and I tested them all in my 11/23+ box.


KDJ11-B with 4 different (but similar) memory cards.
"MAP" option of the KDJ11 shows 4 meg (minus the I/O
Page) and all the right CSR's for the first four blocks.

Really wanted to make this a deskside so I moved the
cards to a MicroPDP box (Yes, I have a coule of the
deskside pedestals).  Power on, Memory CSR error.
Move then back to the 11/23+ works fine.  If I only
put the first three in the MicroPDP box it works.
But as soon as I try to put in a fourth module I
get the memory CSR error.  Tried different cards
(although working in the 11/23+ box would make me
think it is not a problem with the card) no help.

Anybody care to take a stab at what might be causing
this problem?

bill


More information about the cctalk mailing list