RE: LZ: Shareware Games
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RE: LZ: Shareware Games
On Tue, 3 Dec 1996 16:43:06 -0500 (EST),
Tony Lieuanllen wrote...
>I have friends with TI-82's, and I would like to have the real graphlink,
>so I thought of charging for the games, but that copying thing got in my
>way too. The only thing I could think of would be to set some variable
>that they would never change (say the window stuff for parametric mode or
>something, they aren't that advanced with their calculators :) With asm,
>it's possible (though I doubt it) to be able to read some sort of a
>serial number, so if you could hard code that in ( a lot of work, I know)
>then it would only run on the calc with that number. The only real
>things I can think of.
>
>Tony Lieuallen = lieuallen@iop.com
I suppose the ROM version number could be read off the rom version byte in
ZShell, but of course, that would only work to keep some calculators from
running games transfered from other calcs. Maybe have a checksum type of
thing as well where you've added a few bytes to the end of ZShell (for a
fixed position) where you store this number. Transfering the program from
another calculator would require a backup, and might not work anyway if the
rom version is different. Incentive might be added not to try transfering
the program to another calc by making the program do something nasty if it
caught the transfer (by the checksum or rom version thing), say, like
erasing the memory...
Just a thought.
Thanks,
Michael Wyman
wyma0012@gold.tc.umn.edu