@alvin im not sure if this plays a big role or if my attempt was correct, i am doing all this to try to boot to a working killer instinct rom. from recalbox the rom only works on mame2015. recalbox will not save the core i change to, but in my .sh file with the controller values and everything, i changed the -core default to -core mame2015, this still has not worked but figured that would be worth mentioning.