2 Nov
2005
2 Nov
'05
5:45 p.m.
Alas DEC
didn't publish a source listing (or even a binary
dump) of the console firmware in the printset. This is going
to make troubleshooting a little harder, since you probably
don't know what it should be doing. It is clearly running a
program, and that program is reading the keyboard and
scanning the display. So it is somewhat correct.
Well, in the Maintenance Manual of the KY11-LB that I have
*is* the 8008 software, there is even a chapter that describes
the 8008 instruction set (IIRC, I skipped that chapter). Ok. I am working on a theory.
My first step (already done) is to minimalize the system. It is
now just the PSU (...) and the DD11-PK backplane. I removed the
cache and FP11 option. The backplane now only holds the 2 CPU
boards, and the M9312, M9302, the SLU and the KY11-LB.
All other slots have in position C-D a G7273 grant-cont card.
The symptoms are still the same, btw.
The theory is as follows. If the KY11-LB does not do UNIBUS
accesses when just the keypad is used, you could have the
I am pretty sure it doesn't do UNIBUS accesses when you type in a number.
Firstly, it doesn't know when you've finished the number (until you press
onoe of the other keys), and secondly, the number you type in may well
not be data for the current addresss -- it might be a new address, or a
value to put into the Switch Register.
I wonder, though, if the thiog needs signals from the arbiter to work
properly. I can't see why it would, but maybe if one of the bus lines is
in the 'wrong' state it gets very confused.
-tony