Could Apple have used some kind of hardware decryption algorithm between the contents of the chips and the actual ROM data being put on the bus?
The reason I'm wondering this is:
In my IIci hack thread, I was working with olePigeon to get his Turbo 040 card to work with my custom ROM. He dumped the Turbo 040 ROM contents for me (version 4.01) using a program I wrote to grab them in-system (similar to CopyROM), and I compared his in-system dump against your raw chip dump of version 4.01. His ROM contents were completely different and had many human-readable strings relating to the Turbo 040 card and valid 68k machine code. The raw chip dump looked like gobbledygook. So assuming your chip dump worked correctly on the Turbo 040, Daystar was known to use a hardware ROM encryption scheme. Maybe it's possible Apple did the same thing on these x500/x600/PEx machines?
The reason I'm wondering this is:
In my IIci hack thread, I was working with olePigeon to get his Turbo 040 card to work with my custom ROM. He dumped the Turbo 040 ROM contents for me (version 4.01) using a program I wrote to grab them in-system (similar to CopyROM), and I compared his in-system dump against your raw chip dump of version 4.01. His ROM contents were completely different and had many human-readable strings relating to the Turbo 040 card and valid 68k machine code. The raw chip dump looked like gobbledygook. So assuming your chip dump worked correctly on the Turbo 040, Daystar was known to use a hardware ROM encryption scheme. Maybe it's possible Apple did the same thing on these x500/x600/PEx machines?