Okay I'm doing some experimentation with the starfox 1.0 american rom. I want to add this line of hex code to the rom:
"A9 A0 8D 37 30"
This should tell the gsu series superfx chips to enable a mode that'll make it run smoother. Obviously you need a gsu 1 / 2 instead of the mario chip to make use of it. Anyway I need help getting the game rom to run this line of code once (during initialization) so it sets the gsu chip to high speed multiplier mode. Any help is greatly appreciated.
Got it done, thanks to help from people on nesdev and tiido.