Thank you for sharing that. Did Dungeon Master use your copy protection? My understanding is that its protection was so tough that people gave up and actually bought the game.
My copy protection was made for a niche high quality Atari ST graphics program that only got sold in very small numbers. The developer (my customer) want to get sure he really get money for every copy.
And I put a lot of effort into randomization of my copy protection detection software. I want get sure nobody developed an automatic cracking program for my copy protection. But I left a easy to find exit point where cracker could easy remove my copy protection detection software. Manually. That worked. Everything can be cracked. But my copy protection got never in deep analysed because I made it really really hard to do it.
The developer (my customer) of the Atari ST graphics program was wicked :)
When he detected (in runtime at random places) that the program was cracked, he added a invisible watermark to the output of the graphics program.
When someone produced public, commercial work with a cracked version of his software, he could prove it was done with a non-paid cracked version of his software. He could "convince" several user to pay him retrospective.
