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dweitkunat's picture
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Joined: 2018 Jul 1
Alternate Reality: The City - Multiple layers of copy protection

Has anyone successfully played this on a real machine? I was able to use yoyomacs hack to get into the city, but once inside, I am attacked continuously until dead. I have tried this with some 10 or so characters and it seems to me that this is just more copy protection. I thought maybe looking at the character disk would shed some light but I think the data is encrypted because it's unintelligible in Fedit. Surely SOMEONE has figured this out? Otherwise this game is just never going to be playable?

Philip Price mentioned over at the Atari forums he's on that there are supposed to be 'weak bits' written to the disk during manufacturing that are checked for at runtime. He says this is the basis for the ingame protection like scurvy afflicting your character after some time. Could possibly be the same detection for what I mentioned above but I'm no good with understanding hex dumps so I'm just lost.

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SkyCapt's picture
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Joined: 2017 Jan 11

Your "weak bits" might be like the "double sector" floppy trick, in which you can repeatedly read a certain sector and not get an actual error, but instead get two intermittently differing 'versions' of the sector data. In some cases the entire block of sector data can differ while in some circumstances maybe only a few of the bits can differ. The sector had to be read a lot more than twice to ensure finding the differing data, and often involved moving the drive head to help find the differing data, such as reading the double sector as the head approached from one direction and then reading the double sector again as the head approached from the opposite direction.

Letting copies be made that appear to run, but then some detail within the game changes usually meant to stop the fun, we called "code-worms" and despised whoever did this. Code-worms have two parts, a trigger, and a response. In this case, failing the copy protection check is the trigger, and unplayability is its response. Can look like an innocent 'bug' but they'd do it purposely.