On 04.08.2017 09:24, Rod Smallwood via cctalk wrote:
Hi List
Hi Rod!
I looks like I have at last got a KK8-E CPU set to continue
getting my 8/e back running again.
It looks that you have one more set stored in my facility in Hannover!!!
I became feeling more and more bad about that. Then I forgot it again.
Then I felt even more bad by not remembering WHOSE boards those are
(because there is no "Rod Smallwood" written nowhere on the packet).
Now I have connected that again....!
The system has a working rebuilt PSU with all of the caps reformed or
replaced. Voltages are good.
Wow, I never did that. I always made a smoke test.
There's 16k of core at the back with a terminator at the end.
Not bad.
Power up and all the lamps come on either bright or dim (off) except the
RUN light.
Sounds not so wrong.
2. Are there any tests like resistance I can do on the CPU board set
before inserting them in the correct front slots?
There are no "correct" slots. Not for *any* of the boards. You can mix
it up completely. Even the front panel could be omitted, doubled, or put
into an expansion box.
BUT.. There actually IS a DEC recommended order, yes... And having the
terminator board somehow at the end of the Omnibus seems to be a good idea.
3. In the event the CPU set does not even do a simple write to and read
from memory. Where do I start to look?
At the schematics? Front panel (!), timing generator, major state registers.
The DEC stuff was designed quite wrong-insertion resistant. But:
There is just one MAJOR fault you HAVE TO AVOID: NEVER NEVER NEVER plug
in the middle board of an RK8E controller upside down!!
I did it. Once. It leads to impressive fireworks on many boards.
Regards
Philipp
