PDP-11/05 microcode dump?

Mattis Lind mattislind at gmail.com
Fri May 6 12:16:24 CDT 2016


fredag 6 maj 2016 skrev Josh Dersch <derschjo at gmail.com>:

> On 5/6/16 6:26 AM, Noel Chiappa wrote:
>
>>      > From: Mattis Lind
>>
>>      > Has anyone dumped the microcode of the PDP-11/05?
>>      > ...
>>      > When tracing the microprogram flow it looks very suspicious.
>> Comparing
>>      > the same sequence with a better working pair reveal a few
>> differences.
>>      > All these can be narrowed down to one single PROM chip.
>>
>> Josh had an 11/05 that had a uROM fail, and he had to blow a new one
>> (IIRC he
>> sent in a report, it's in the list archive). I'm not sure if it's the
>> same one
>> as the one you need, but if his post doesn't give the chip ID, no doubt
>> he can
>> let us know.
>>
> I had two uCode ROMs fail, it was just that fun.  Unfortunately they were
> at E114 and E102 (A11A2 and A20A2), not E103 so my transcriptions aren't
> going to help.


Now this is confusing. Maybe this related to why Bill thought I made a
typo. In the schematic I have which is the same as the one at bitsavers:
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1105/1105_RevAH_Engineering_Drawings_Jul76.pdf

E102 / A04A2, E112 / A10A2, E103 / A20A2 and E114 / A11A2.

Are there plenty of different versions of PCB and microcode??

>
>
/Mattis


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