From what I've found in my stuff, it contains one of the following types of data:
ROM MSX/MSX2 ROM Image
ROM Read Only Memory Image
ROM MZ700 Emulator
ROM Nintendo 64 Emulation ROM Image
Or it could be something else entirely that I don't know about. A good first move would be to get something like Hexplorer and open it into that. Where did you get this file and what was it for? If you answer those questions, you should have an idea what type of data it contains and how to open it for editing. Good luck and I hope this will help you out.
