PDP-11/45 RSTS/E boot problem

[Mattis Lind]

Den tis 5 feb. 2019 kl 00:23 skrev Fritz Mueller via cctalk <
cctalk at classiccmp.org>:

>
> > 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...
>

Would it be any difference if you run the machine at full speed or lower
speed or even single step past this instruction? With the KM11 installed
you could even single step the 5 minor states in each micro instruction.
Would it be possible to insert a breakpoint or halt and run the program,
insert original instruction and single step?

The TIG module has a separate non crystal controlled oscillator which one
could tune for marginal checking.

Would it be possible to isolate the test case outside the UNIX environment?

/Mattis



>
> 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...
>
>
>