more Apple ][ musings
My latest distraction is the Apple ][ disk. I'm sure some of you, like me, remember the golden age of copy protection & cracking which happened around the Apple ][. Much of that was because the A2 was largely software driven. (Another Woz brilliant lunancy cost-cutting effort like A2 graphics.)
Unfortunately, because the A2 was pre-Internet, there isn't a lot of surviving detailed documentation on the web. The one piece I'm missing is a detailed description of how the bits get written onto the disc. I'm just interested in how fiendish copy protection could have been, since it was certainly possible for someone to basically create their own disk format. Sync bytes? We don't need any stinkin' sync bytes? No sectors either, just read in all 50K bits per track straight into RAM. Have your own 6 data bit to 8 disk byte translation process. Use those half and quarter tracks.
Of course the problem with any of these complex non-standard disk format schemes is the game still ends up executing in RAM. So many crackers simply worked out ways to save RAM to disk and then patch the code to skip over any disk accesses. Another method was to rip the boot loader code off the disk and reverse engineer the routines.
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