Re: TI-86 shell for running ZShell programs
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Re: TI-86 shell for running ZShell programs
>It is highly unlikely that a
>converter will ever be made, and if so, it will only convert the simplest of
>85 ASM programs.
A converter, as I have said, is realtively simple. And most of the
programs that exist for the 85 ARE the simplest of programs. Those that
are not, like XC-1701, Mc Miks, and Mega Racers, would not only be nearly
impossible to translate, but they would also need reprogramming to take
advantages of new system routines that simply weren't available on the
85, such as _PDspGrph, _ILine, and _getkey (Not _GetKy). Consider this:
Most 85 games did a few things:
1) Use Text_MEM and TEXT_Mem2 for variables, and possibly GRAPH_MEM as a
display buffer
2) Call GetKey a lot and page port 1 for keys
3) Output Graphics by writing to $FC00 for the Video Memory
4) Use CALL_() or variant for subroutines.
1 can be changed for most apps, 2 can be changed for all programs, 3
doesn't need to be changed, and 4 is also relatively easy to change. As
soon as I finish Asteroids, I'll start work on this. Probably, it will be
a desktop program. I'll just convert all the 85 games I can find and see
if they work. What works, I'll repost with the author's permission and
the shell. It will require some memory paging, though. My only concern
is that the text mem may overlap the paged area of RAM.
James Yopp
jyopp@pobox.com
"Time is the fire in which we burn."
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