The 68HC11G5 has 16K of ROM. Presumably, the ROM was hard coded at the factory. I say that because it isn't EPROM or EEPROM, the package is windowless, and I can find no information about programming it.
I'm also assuming that the suffix, FN1, would tell me what the ROM contents are but I can find no information about that either. The chip is obsolete, I guess.
The only thing I can think of that may be in the ROM is Motorola's BUFFALO monitor. Can someone confirm or deny my suspicion?
Jim