Jeff writes:
>
> > **** INTERNAL TRAP
> > Instruction Memory Protection Trap

Generally an indication you're trying to call a routine
that requires PM, and you don't have PM.

> > [VSM] Undecoded status.info = -60
> > ABORT: CARS.PUB.DB
> >        PC=a.fff7f000 $RECOVER_END
> >           CALLX stub: 534.000096d0 semester+$234
> > NM* 0) SP=41846a30 RP=534.00009448 ?semester+$8
> >          export stub: 5e8.00038ac0 cars0000+$1810
> > NM  1) SP=41846970 RP=5e8.00017ad0 carslinkage+$d14
> > NM  2) SP=418466f0 RP=5e8.00035dcc _start+$14c
> > NM  3) SP=418463f0 RP=5e8.00000000
> >      (end of NM stack)

Your main program (Space ID $5e8) called semester (which is in an
XL (Space ID $534)).

semester tried to call something external to its XL, and that routine
(whatever it is) is "protected" to require the caller be more privileged
than you are now.  The CALLX stub is used to jump from a procedure running
at one ring level to a procedure running at a more privileged (lower numbered)
ring level.  The register dump shows you're currently at ring 3 (PRIV=3),
which is "user mode".

What routine is CALLX trying to get into?

You can find out by doing either of:

   1) With AVATAR (plug :), look at semester;

or

   2) :setdump
      :run cars.pub.db

      when you hit the abort, you'll be thrown into debug.

      enter: dv r1, 8

      Assuming the first output word is $0000000a, then try:

          dcs [r1 + 4]

      If the first output word was something else, then try:

          dc [lptr r1]

      ... this should tell you the name of the privileged routine you're
      apparently trying to call.

--
Stan Sieler                                          [log in to unmask]
                                     http://www.allegro.com/sieler.html