early PDP-11/45 info sought

[Fritz Mueller]

Hi Jay,

> On Jan 27, 2019, at 7:07 PM, Jay Jaeger <cube1 at charter.net> wrote:
> 
> I think I can help some... I DO have earlier PDP-11/45 CPU drawings...

Man, this list is the absolute best!

The '72 KB11-A drawings would be most immediately useful.  If you only have time for a subset of pages, I would find the schematics for M8100, M8103, M8105, and M8106 particularly interesting.  

It would also be interesting to compare the M8103 ROM listings between the '72 and '74 drawing sets and see whether they snuck in any microcode changes/fixes.

I do have KT11-C and FP11-B in my system, but haven't checked their provenance yet.  To the extent that I've had to repair these, anyway, they've matched the drawings that I do have.

> I have a PDP-11/45 From U. Wisc. ECE that claims to be S/N 1525

Wow, another <2000 11/45!  Do you have yours up and running?  Do have its ECO history?  I found one other oddity during my restore that seems related to early 11/45's -- no +15V to pin CU1 in SPC slots 26-28, which keeps any EIA DL11 from working correctly in those slots (though the contemporary 20ma DL11-A would work).  I have a feeling this might have been addressed in a later ECO.  It would be interesting to check this on your backplane?

Thanks for taking a look through your library, and for the generous offer to take the time to do some scans.

   cheers,
     --FritzM.