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Old 01 October 2012, 10:23   #24
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Originally Posted by dlfrsilver View Post
Hello Laurent

Can you talk about the copy protection used on the amiga release (internal and external ?)



That's a very good topic. As an cracker myself at that time (the lapsing period is over now), I took the copy protection very seriously.
The physical protection was provided by an external company. I don't remember much more.
But the important thing was to hide the protection code in the rest of the game code. For that, I used many tricks (e.g. processor prefetch, self-modifying code to fool debuggers; encryption using the video memory at some key point during the game,...). The principle was to hide many protection checks during the execution; not a stupid single call to a protection code.
However, on Amiga, it was cracked very quickly because hardware debuggers were available. On Atari ST, it was one of the most difficult game to crack. It eventually collapsed but it took a very long time.
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