PDP-11/45 RSTS/E boot problem

[Fritz Mueller]

> On Feb 4, 2019, at 2:28 AM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
> 
> I'm pretty sure the command only gets a few instructions in before it blows
> up.  Here are the process' registers, and the _entire_ contents of the user
> mode stack:
> 
> R0 177770
> R1 0
> R2 0
> R3 0
> R4 34
> R5 444
> SP 177760
> PC 010210
> 
> 060: 000000 000020 000001 177770 177774 177777 071554 000000

Okay, I've had a bit of time in front of the machine to repro this and take a look.  What I actually see is:

R0 177770
R1 0
R2 0
R3 0
R4 0
R5 34
R6 141774
PC 000254

(remember, for the last, this will have been after taking a trap to 250, where I have the usual "BR .+2; HALT" catcher installed)

Also, memory at 060 (PA:164060) is all zeros as far as the eye can see...

I have a bit of water on the basement floor right now after the recent rains here, which is complicating setup of the LA.  There's a big puddle where I normally place it...