dumping Western Digital Microms (PDP-11, WD16, Pascal Microengine)
jnc at mercury.lcs.mit.edu
Mon Dec 21 11:00:59 CST 2015
> 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 ...
> 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?
> Anyone know what's up here?
To answer my own post, I looked at the prints (should have done this before I
posted, sigh), and there is no way it can be ii). The Control chip has a
bunch of discrete signals on pins where the uROM's have micro-instruction bus
pins. So there's no way you can swap them around.
So the 'Microcomputer Products Handbook' diagram (pg. C-18) has to be wrong.
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