RE: LZ: Startup and ZS4.5

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RE: LZ: Startup and ZS4.5

On  2 Sep 96 at 18:53, Micah/Richard Brodsky wrote:


> Didn't someone write a reset-trapping interrupt handler to make it look like 
> the calc was reset, but it could be restored? I believe it was called XMEM or 
> something like that.
> --MZB


Yeah, I wrote that program a long time ago. It actually doesn't trap
the resetting, but simply works on the fact that when you do a
reset/mem, the memory isn't cleared. What happens is that a few
pointers and the like are deleted. When you run the program it
places an interrupt handler that will check for the key F5 (I think
it was) to be pressed, and if it's pressed it restores the pointers.
This can be done since the interrupt mode is not changed by a
reset/mem. So it actually lets the calc do the reset, but "unresets"
it afterwards when you press F5. The drawbacks are that it doesn't
work with reset/all and that it (at least in my implementation) is
not very crash-safe.


I also want to point out that I didn't make this program in order to
cheat, but because I found it very interesting that it worked. :-)




Mattias Lindqvist
CS student at LTH, Sweden
E-mail: d96mli@efd.lth.se