romcmp man page
romcmp — MAME rom and romsets check and comparison tool
romcmp [-option] [dir1|zip1] [dir2|zip2]
romcmp is a tool developed to detect the most common errors that can occur when dumping ROMS, for example stuck bits and address line errors.
It can check the ROMs in ZIP files or subdirectories; it can also be used to compare two ROM sets, by giving it two files or subdirectories as parameters. It will determine which ROMS are identical and which are the closest matches. This is useful when figuring out if a newly dumped ROM set is a clone of another ROM set.
Enables a slower, more comprehensive comparison.
romcmp jumpkids.zip will output the following:
23.3c FIXED BITS (xxxxxx1x)
23.3c FIRST AND SECOND HALF IDENTICAL
This tells us that the 23.3C ROM in Jump Kids is bad, and incidentally, it causes the missing sound in that game.