Well, in the end I wasn't much help. I'm surprised the misplaced ROMs didn't give you the red screen though
Swapping the ROMs completely messes up the word order - even the init vector is nonsense. You can't expect the ROM checksum routine (which turns on the red background) to work under these circumstances...
Doesn't damage anything though (in contrast to reversing the ROMs) but makes the CPU fail to run
any code very reliably.
