>> And why would these have back doors if they're Atari games?
>
>For various reasons.... :-)
>
>The main one being that the 2 main vectors (reset & NMI) jump
>to code outside the keyed area (intentionally or unintentionally,
>they didn't care). As mentioned, various games do this. Harry's
>Monitor cart does this too.
Minor mistake here. The reset vector has to point into the keyed area
or it wouldn't pass the encryption check. A game would have to jump
out of the keyed area after the encryption check started the code in
there. Some games with bankwitching did that because they couldn't
include the BS area in the keycheck, but still wanted to put some code
there. Most games mentioned in the other post did the jump fully on
purpose as the very first instruction.
>Maybe a programmer got tired of waiting on the key process,
>so they froze the keyed area. Of course this probably wasn't
>the case since the devkit didn't require a keyed cart.
Or maybe it was too much trouble to have the game keyed again and
again during beta testing. They probably didn't have a dev system
or a modified 7800 for all of their testers.
The three games that the original question was about seem to be
programmed by GCC for Atari, BTW.
Thanks, Eckhard Stolberg
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