PDP-11/45 RSTS/E boot problem

Paul Koning paulkoning at comcast.net
Wed Feb 13 07:34:37 CST 2019

> On 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.

Congratulations.  You have successfully performed a repair of the type done at customer sites by highly trained DEC field service personnel.  They were the ones who traveled with an oscilloscope, a tool case including soldering iron, and a case full of replacement chips.

One difference is that the diagnostics didn't point to the problem, which in my experience is rather an unusual situation.  Nicely done.


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