Re: [stella] Re: Help with efficient code

Subject: Re: [stella] Re: Help with efficient code
From: Greg Miller <gmiller@xxxxxxxx>
Date: Tue, 30 Sep 1997 05:58:41 -0500
Jim Nitchals wrote:
> Finding bugs in the 6502 and exploiting them was a favorite technique
> in disguising copy protection code in Apple II and Atari 400/800 disk
> based games.

Yep... My personal favorite, tho, were the copy protection routines that used
off-by-one instructions... jsr $xxxx and jsr $xxxx+1, both of which called
valid code. Made it difficult to change one routine without screwing up the
other... disguising sector numbers and addresses to be loaded was, of course,
also a popular tactic... ever take a look at the Temple of Apshai Trilogy
code? Yipes.
Video games and CCGS:
TW (online game):
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