[comp.sys.apple2] Visit Monitor CDA

THROOP@GRIN1.BITNET ("Throop,Henry B") (04/19/91)

Could someone tell me where the program counter and text screen are saved
with the Visit Monitor CDA?

Henry

parkern@jacobs.CS.ORST.EDU (Neil Parker) (04/19/91)

In article <9104190320.AA17312@apple.com> THROOP@GRIN1.BITNET ("Throop,Henry B") writes:
>Could someone tell me where the program counter and text screen are saved
>with the Visit Monitor CDA?
>
>Henry

I presume you mean "Where does the CDA menu save the current program's PC
and text screen?"

The program counter is on the stack, buried underneath several JSL's.
(Unless the interrupted program was a emulation-mode program using the
alternate stack in bank 1, in which case you have to get the address out of
the alternate stack.)

The Toolbox Reference Manuals would seem to suggest that you can get the PC
out of the interrupt state record using GetAddr($0009) or
GetInterruptState(intStateRcdPtr,$14), but as far as I can tell, that only
works after a BRK, not an IRQ.

On ROM 01, the text screens are copied to the following locations:

     $00/0400-07FF --> $E0/0C00
     $01/0400-07FF --> $E0/1000
     $E0/0400-07FF --> $E0/1400
     $E1/0400-07FF --> $E0/1800

	       - Neil Parker
--
Neil Parker                 No cute ASCII art...no cute quote...no cute
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