So guys, I don't normally post here, but it's worth a shot because maybe someone knows something I don't. I recently tried Pole Position in MAME with my USB racing wheel. Most arcade games are fine with it since it's essentially like an analogue stick without up and down, and most arcade games use this approach. Pole Position, however, doesn't: it uses a spinner, like the racing controller on the Atari 2600. In the service menu it's clear: each position of the spinner is between $00 and $FF, and as you move it around it changes to whatever position it's on at that moment (and doesn't recentre when you let go, naturally). This basically means that unless you can a) get a real spinner controller or b) hack up a mouse to do something similar, your only acceptable option is to use a regular digital joypad/stick, since at least that way you can smoothly go left and right, whereas a typical analogue stick causes chaos.
But I'm a ROM hacker, so immediately I wondered if I could hack the ROM to use typical analogue controls instead of the spinner. I can understand the principle, but one problem is that all arcade games are a different system. All I know for sure is that the main CPU is a Z80, which is good since I can understand that. What I don't know is how the input is registered. I found a reference in the RAM to the same value I saw onscreen in the service menu, but I don't know if that was just for displaying the number on the screen. Anyone got any thoughts/knowledge to share? The best alternative seems to be the Dreamcast port, though maybe there's something else I haven't seen before.