early PDP-11/45 info sought
Jay Jaeger
cube1 at charter.net
Tue Jan 29 13:08:32 CST 2019
On 1/27/2019 11:01 PM, Fritz Mueller via cctalk wrote:
> 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.
Will start scanning today.
>
> 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?
>
My 11/45 has not been on for a lonnnng time. Some time ago I had it on,
it could sometimes boot RT-11, but failed MUL diagnostics - but I was
not confident that the diagnostic itself was correct.
I will see if I can check on the +15V issue (hopefully without having to
turn the thing on) - I don't have a real TTY for it to talk to, so it
isn't something I would have noticed.
> Thanks for taking a look through your library, and for the generous offer to take the time to do some scans.
>
> cheers,
> --FritzM.
>
>
>
Not a problem. Fortunately, when I migrated to my new PC this winter, I
had the foresight to test my scanner - which did NOT work because the
TWAIN drivers for it (a Ricoh IS300e) would no longer install, and
installed a virtualbox VM running Windows 7 to talk with it.
JRJ
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