The NES Pac-Man is a port of the revolutionary arcade game about eating.
Namco games often contain some generic copyright and/or credits text at the very beginning of their ROMs. This one contains the following text:
|Japan / Tengen Versions||COPY RIGHT 1984 1980 NAMCO LTD. ALL RIGHTS RESERVED|
|US / European Versions||COPY RIGHT 1984 1993 NAMCO LTD. ALL RIGHTS RESERVED|
Additionally, the name "HIROKI AOYAGI" is loaded into RAM at address $52, in order to distinguish between soft and hard resets (the high score is retained after a soft reset).
The Japanese release has two revisions.
The "CHRACTER" spelling was fixed.
The only other change in the ROM is one byte to move a block of data from RAM $0625 to $0620 for some reason. Not certain what it actually does, but it seems to be sound-related.