PDP-11/45 RSTS/E boot problem

[Ethan Dicks]

On Mon, Feb 4, 2019 at 3:15 PM Paul Koning via cctalk
<cctalk at classiccmp.org> wrote:
> > On Feb 4, 2019, at 3:43 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
> That translates into "the problem depends on the physical address of the code being executed".
>
> The obvious answer is bad memory.

At the board level, yes.  Deeper, it could be bad memory bits or bad
memory decode.

A simple ones-and-zeros test can identify bad DRAMs.  It's not as
likely to find bad decoding, which could result in the same chips
tested more than once and other chips not tested at all.  I've found
both problems in real MS11-L boards I have for my stack of 11/04 and
11/34s I'm testing.

ISTR in the DEC world, they were good about that.  I have multiple
papertapes for the PDP-8, that I think were literally called "ones and
zeros" and "memory address" tests.  I would think XXDP has something
similar in terms of progressive tests that expect the previous stage
passed.

-ethan