PDP-11/45 RSTS/E boot problem

Ethan Dicks ethan.dicks at gmail.com
Wed Feb 13 14:54:24 CST 2019

On Wed, Feb 13, 2019 at 2:43 AM Fritz Mueller via cctalk
<cctalk at classiccmp.org> wrote:


> Put the M795 out on an extender, loaded 167777 in RKBAR, and had a look around with a logic probe.  Narrowed it down to E34 (a 7430 8-input NAND).  Pulled, socketed, replaced, and off she goes!
> I can now successfully boot and run both V6 Unix and RSTS/E V06C from disk.


I have had an RK11-C for a long time that I've never tried to power up
(I got an RKV11-D and used that on Qbus machines instead).  The saga
has been interesting for me as I contemplate getting mine working in
the next couple of years.  I had to look up the M795.  I had forgotten
there was one dual-height module in the entire controller.

It's interesting that it was a bad 7430 in yours.  I find that for
equipment of that vintage, my usual suspects are failed 7474s and
failed 7440s, probably 80% of the total.  Behind that, it goes 7420s
and then maybe 7430s.


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