PDP emulation

From: CLASSICCMP_at_trailing-edge.com <(CLASSICCMP_at_trailing-edge.com)>
Date: Mon Mar 6 08:01:26 2000

>> I tried swapping my M8186 (11/23) for M8192 (11/73) but it doesn't run.
>> Maybe I need to rebuild the kernel (I've got an original distribution, not
>> one of the images from PUPS), but perhaps it would work with more memory or
>> by swapping RLV11 for RLV12.

>Cpu doesn't run or doesn't run V7? The image I have only wants some 256k
>of ram out of all teh installed ram. I get the impression it was
>configured for an 11/34 or similar and that is mostly a 11/23 save for the
>11/23 mmu can go to 22 bits.

The V6 and V7 images currently available have device drivers that
were built for Unibus systems. They expect a Unibus Map to be present
for accessing memory above 256Kbytes (many of the drivers were built to
always expect a Unibus map). The "safe" thing to do on a Q-bus system
(or an emulated Q-bus system, like Supnik's emulator) is to run with 256Kbytes
or less.

(Even that isn't perfectly safe, some of the tape drivers simply refuse to
work with a Unibus map no matter how much/little memory is there.)

(And yes, I know there are Q-bus systems with Unibus maps, but I'm ignoring
those right now.)

Tim.
Received on Mon Mar 06 2000 - 08:01:26 GMT