21 Dec
2015
21 Dec
'15
8:48 a.m.
From: Eric Smith
So far I have dumped the following LSI-11 Microms:
3010D, DEC P/N 23-001B5 (also designated CP1631-10) - addr 0x000-0x1ff
3007D, DEC P/N 23-002B5 (also designated CP1631-07) - addr 0x200-0x3ff
Excellent work!
I was going to point out that there is another uROM (KEV11) for the LSI-11,
for the EIS/FIS, and also that there is some variation in the numbers of
the uROM chips, but along the way, I ran into a puzzle.
DEC documentation differs on the location of the two uROM's in the LSI-11/2
(KD11-HA, M7270): the 'Microcomputer Products Handbook' gives the order (from
the handle end) as KEV11, uROM 1, uROM 0, Control, Data Path; the print set
for the KD11-HA gives KEV11, Control, uROM 1, uROM 0, Data Path!
From which I conclude that either: i) one of the
documents, perhaps the
Handbook, is wrong, or ii) the 'Control' chip must
also be a uROM, and that
there is some variation in how the 3 chips can be plugged in?
Here is more data from a couple of boards I have access to (from the handle
end):
- 2007C 23-002C4, 3010A 23-001B5, 3007D 23-002B5
- 2007C 23-002C4, 3010D 23-001B5, 3007D 23-007B5
- 2007C 23-003C4, 3010D 23-008B5, 3007D 23-007B5
Anyone know what's up here?
Getting back to the KEV11, the one I have seen is a 3015 23-003B5.
the control chip also contains PLAs that can force
microcode jumps under
various conditions despite there being no corresponding jump instruction in
the Microms.
Hmm. Any idea/way to read them out?
Noel