PDP-11/05 microcode dump?

steven at malikoff.com steven at malikoff.com
Sat May 7 19:40:56 CDT 2016

Noel reckoned
> BTW, when you say that the microcode listings in your 1973 print set are
> "Revision B", are you referring to the "Microprogram Flow", "Microprogram
> Symbolic Listing", or "Microprogram Binary Listing", because they can be at
> different revision levels (given in the box in the extreme lower right
> corner)?

That's a good question, my conclusion about being the same was from a cursory
glance only, going on the first few page and making a mistaken assumption the
rest were the same. Now you mention it, I've spent a little bit more time looking
at the print set and I now understand the revision differences as detailed.

Microprogram Flow-
Mine is Rev B. Pages 6,7,9,10,12,13 are still 27-JUL-72, 5-SEP-72 27-JUL-72,
27-JUL-72, 27-JUL-72,27-JUL-72 respectively. Not sure why they used a DD-MMM-YY date
format when the rest of the dates are US format, probably for improved legibility.

But, I can see these are noted on the update grid on the first page, anyway, I added
the dates for a bit of extra info.

Microprogram Symbolic Listing-
Mine is Rev D. Pages dated 27-JUL-72, 5-SEP-72, 22-AUG-73, 22--AUG-73, 27-JUL-72.

Microprogram Binary Listing-
Mine is Rev D. Pages 27-JUL-72, 5-SEP-72, 18-OCT-72, 22-AUG-73, 22-AUG-73, 27-JUL-72.

Microprogram Cross Reference Listing-
Same lineprinter listing as the pdf, but the odd thing here is that mine has the
listing pages numbered properly yet the later pdf listing has them struck out and
annotated underneath.

> ....so I'd be fairly surprised if the microcode was
> actually identical. I think you'd have to look at every bit to be sure; the
> data on which chips changed

You are right. I made the assumption thet were identical from the first four or
so pages being the same lineprinter listing, just re-copied, but did not expect
to find the pdf having later dated pages inserted into the listing - who would
do that these days (or even back the?) that they would not just run off a whole
new listing. I appreciate your detailed comment as I've learned something I didn't
know yesterday! Probably no point scanning mine in as it's superseded by the
later listings in the pdf. Mine is more legible however.

Sometime I'll get my 11/05's running, still working on converting modern rack
slides into serviceable ones to fit the H960s. It's coming along but quite slowly,
it's a suprising amount of work. Until then my gear is likely to stay piled up on
a trolley.


More information about the cctalk mailing list