HAL21 (Japan) ARCADE ROM
Below is a table representhing the roms for HAL21 (Japan) and its clones (if any). Red roms are similar between all versions but green roms differ, which means that if you wish to change the game's region or language, it may be possible make the change simply by reprogramming fresh roms with other version's contents.
Note that the rom information displayed here is automatically parsed from Multiple Arcade Machine Emulator (MAME) C source code, so some of it can be incorrect. However, if you notice that some parts of the data are constantly incorrectly displayed in more than one game, please contact me so that I can fix the problem.