Re: LZ: Making fixed int progs
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> > >The easiest way is to increase the ZShell string about 500-600 byte and
> > >then put the interrupt handler there. If the interrupt handler will be a
> > >big program, make two program: one in the ZShell string that will search
> > >and execute the "real" program which is the bigger one.
> >
> > This is the way your Game Wizard does it. Does it really have to be an
> > extra 600 bytes?
>
> Well, first 257 bytes for the table at $9100-$9200 and then the interrupt
> routine starts at $9292, and you can't change that. Then I've used
> the "holes" ($90A?-$90FF and $9201-$9291) for variable storage. Some
> variables are after the interrupt handler at $9292. The handler isn't
> so big, it mostly checks if on+enter is pressed and then it uses rst10h
> and rst20h to find Game Wizard and execute it. You can't make it so much
> smaller, BUT you could make the GWiz program about 1k smaller, because
> 1k is just empty space where the screen is temporary stored. I've tried
> to use the same routine to allocate 1k as in Robs grayscale, but for
> some reason it didn't work! I don't have a clue why, and if someone can
> tell me why it didn't, I will be happy :-) Maybe it has something to do
> with that it's in an interrupt, or should that matter?
>
yes, that matters.. think:what if memory was being moved when the
interrupt was called: the adresses for the end of used mem could eb
invalid, so you could corrupt data..
Rob Taylor MAIL - mailto:rtaylor@ticalc.org
WEB - http://www.u-net.com/~rtaylor/
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