[A83] Re: TI-OS resumes
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[A83] Re: TI-OS resumes
> Van: Peter-Martijn Kuipers <hyper@hysoft-automation.com>
>
> > > Van: Peter-Martijn Kuipers <hyper@hysoft-automation.com>
> > >
> > > Wait, wait, what are you referrring to?
> >
> > Some mails ago somebody thought of a program like:
> >
> > pop hl
> > push hl
> > jp _disphl
> >
> > to display where the TIOS calls your program... But it -indeed- it
> > should be "to display where the returns to the TIOS" (I don't know
> > what was exactly written down there, so don't pin me on this...)
>
> I checked it out, and the return address is indeed a different address
> than the address from which the prog ist started.
> However, if you follow the call right before the address you return to,
> you can find the calling address
Oh yes, normaly 3 bytes before the adress you 'return to' the actual call
is located.
And that might also be so on the Ti-83(+) when running a program from TIOS,
but in general you can not count on it that the caller did things like
this:
--------------------
[..code..]
call _your_routine_
return_point:
[..more code..]
--------------------
Since there could also be done this:
--------------------
[..code..]
call blah
return_point:
[..more code..]
blah:
[..possibly some code here..]
jp _your_routine_
--------------------
or:
--------------------
[..code..]
ld {16bit reg},return_point
push {16bit reg}
jp _your_routine_
--------------------
And there are probably some more possibilities (a 'calculated call' in HL
for example), but I hope *you* get the point.
Henk Poley <><
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