When I got a copy of Fahrenheit I wanted to get rid of the annoying key disc security. Well after doing a disassembly of the code, I was able to figure out a one bit modification to disable the key disc feature.
- Get an ISO or a BIN/CUE file of either Fahrenheit disc
- Modify byte 0x786 from 0x01 to 0x00 (it is the same location for both ISO and BIN/CUE)
This modification for disc 2 allows the disc to played without requiring disc 1 (so you can play the 32x version with just one disc). This modification for disc 1 allows the disc to be played without requiring a switch to disc 2 (so you can play the plain version even with a 32x installed).
Here is the partial disassembly of the code (IP, SP, and MAINCODE all assemble byte perfect with asmx):
I even made DVD cases by adding the words "NO KEY" to the DVD cover art availble from thecoverproject.net: