go for it, master system controllers dont have the same issues as genesys ones... they can be used safely in c64 and amiga... just to remind i used genesys controllers on the amiga , not in the 64, some games in the amiga make use of two buttons and these controllers are useful... not in the 64 , and the amiga joystick ports dont seem to have the same issues ( FRYING THE CIA CHIPS, FOR INSTANCE)