If I try to start the first version of the game Karateka for Apple IIe on an Apple IIc, the Apple IIc will restart after reading the game from disk after a few seconds. Later versions of Karateka for Apple IIc will work. What is the bug in the first version that caused it not to work with Apple IIc?
For the cracked version the problem was identified long ago:
I have heard that it is only the cracked version of Karateka which has a problem.
The problem is that on every disk access, Karateka takes a copy of the ROM from the Disk II controller card and patches it. It then uses the patched copy to do the disk I/O. The resulting code crashes on the IIc and IIgs because the routines in the firmware are in a slightly different location. -- David Empson
The IIgs problem is with the slot 6 "Disk Port" firmware. The problem will not occur if the slot configuration is set to "Your Card" and a Disk II Interface Card is present.