[Simh] VAX 780 & 3BSD

[Kevin Handy]

Jason wrote:

>3bsd crashes on me too, but it doesn't kill simh...
>
>Here is what I get:
>
>Boot
>: ra(0,0)vmunix
>61856+61008+70120 start 0x4b4
>
>Invalid SCB vector, PC: 80000676
>
>  
>
FWIW: It's a simh error message, defined in VAX/vax_sys.c,
not a 3bsd error. Error code is apparently STOP_ILLVEC

Signaled from this line in VAX/vax_cpu1.c

    if (newpc & 2) ABORT (STOP_ILLVEC);                     /* bad flags? */

Looks like it's getting an odd-address error of some kind.

Could the 780 have ignored/masked the low bit? More likely
data corruption is occurring somewhere. Can you find the
3bsd source code being executed and trace back from there?