Re: LZ-Adv: Interrupt-without graph mem???
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Thayne Miller wrote:
>
> I downloaded GameWizard 0.9 by Jimmy Mardell (mja@algonet.se) off
> ticalc.org a few days ago. It uses an interrupt system to activate a
> menu when you hold <on> and press <enter>. This can be activated in a
> ZShell program or even outside of ZShell. When it is activated you can
> pull up the menu even when you are on the graph screen. I thought that
> interrupts used addr. 8888h (which is in the graph mem) to store the
> interrupt routine that they want to use (as in greyscale). How is it
> possible to change the graph mem, but not mess up the interrupt??? Does
> it have something to do with a VBL interrupt? Is that why you have to
> hold <on> for it to work? How does this work and how could I use it to
> say...activate a small asm program?
The interrupt array (the one with 257 identical bytes) is stored right
AFTER zshell. The trick is that you make the zshell string longer (by
just adding spaces after it in basic mode). If you make it about 600 bytes
longer, you can store then interrupt table at $9100-$9200 and the interrupt
routine at $9292. Then there are some holes where you can store variables
that the interrupt program uses.
Of course you can't run two programs with the this method at the same time...
The idea with patching ZShell is Mike Bakers. The problem is that those
programs won't work when the next ZShell version comes out, since that
zshell is probably a bit bigger.
<pre>
--
Jimmy Mårdell I just don't care about the whales,
mailto:mja@algonet.se who cares if the ecosystem fails?
http://www.algonet.se/~mja We are the crowns of creation,
IRC: Yarin we may do whatever we please - Fuck nature /CRD
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