Re: A89: Re: Re: Re: ASM without libraries


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Re: A89: Re: Re: Re: ASM without libraries




> >
> > > ok.. the thing was just that old plusshell attached a 900bytes or so
> loader.
> >
> > OK, now I get what you meant.
> >
> > > the kernel handles romcalls? why should it interfere with that?
> >
> > Not the romcalls themselves, but the relocation of them (keeps them in a
> list
> > similar to the library calls and replaces them with the appropriate
> address when
> > relocated).
> >
>
> Could you please explain this to me -- it's one of those things that I don't
> understand that just keeps haunting me.  The ROM is never relocated, right?
> So all addresses ROM functions could be inserted at compile time, right?
> How is relocation involved then?  Why does the program's location in memory
> affect how ROM functions are called?  Do JSR's/BSR's use relative addresses
> or something?

They could be inserted at compile time... but then the program would only work
on one ROM version, and, in the case of the 89 and 92+ (which have the same ROM
functions), only one calculator model. The whole point with the ROM call table
is to provide compability between different versions.


 / Niklas Brunlid
Check out Prosit for the TI-89 / TI-92 Plus at http://c625.sparta.lu.se
Random PQF Quote follows:

"I daresay," said Granny, pushing the Fool aside and stepping over a
writhing taproot. "If anyone locked *me* in a dungeon, there'd be screams."
        -- (Terry Pratchett, Wyrd Sisters)




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