The original roms for The Simpsons Arcade game did not include an option for free play. This rom by DogP (unofficial) replaces the chip at location 15C (J12) to offer Free Play Only. You will have to keep/reinstall your old chip to take coins again. This version requires you must change the setting "7. START BUTTON" to "WITH START BUTTONS to enable shared credits.
****This is only compatible with 4P rom version and not the 2 player eproms/version.****
This is a working rom pull from a board that was returned to stock.