PDP-11/45 RSTS/E boot problem

Paul Koning paulkoning at comcast.net
Thu Feb 7 12:42:23 CST 2019

> On Feb 7, 2019, at 1:37 PM, Fritz Mueller via cctalk <cctalk at classiccmp.org> wrote:
>> On Feb 7, 2019, at 9:47 AM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
>> So, with UISA0 containing 01614, that gives us PA:161400 + 04200 = PA:165600,
>> I think. And it wound up at PA:171600 - off by 04000 (higher) - which is
>> obviously an interesting number.
> Thanks, Noel.
>> ...it might be interesting to look at PA:165600 and see what's actually _there_
> A sea of zeros, as it turns out.
> I'm thinking it might be worth obtaining a full memory dump of the text segment at the point of fault (I can do this with a small toggle-in program to dump it over the serial console), , and then compare that to the complete text section in the ls binary. That would give us more of a clue about whether blocks of memory are duplicated or swapped, what the size, alignment, and stride of the corrupted blocks is, how many there are, etc.
> I'll get an IR trace out this weekend.  Another thing I _could_ do with the LA is an IO command trace on the RK11 (though that's a lot of probes to hook up to get disk address, count, and memory address).

How about a Unibus trace?  That would give you the RK11 commands as well as the data it sends in response.


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