strange number corruption on pdp11/34

Noel Chiappa jnc at
Tue Jan 27 17:05:08 CST 2015

    > From: Johnny Billquist

    > If it comes as far as booting RSX as well as XXDP, there can't be
    > anything seriously wrong with the CPU...

Yeah, I see your point, but why all the zeros, then? That's what I could't
work out.

Anyway, it should be really easy to make sure e.g. ASH, MUL and DIV are
working; it's vaguely plausible that one of them is broken. (Unix V6, I think,
might even boot even if MUL was broken. I know the bootstrap uses DIV, to
calculate the cylinder in the disk driver.) If not, cross that off the list,
and try the next thing... Which is?


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