dumping Western Digital Microms (PDP-11, WD16, Pascal Microengine)

Noel Chiappa 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.


More information about the cctalk mailing list