ok, I checked out analog mame, and I've got a question. If I make an analog pedal, will it only work with the list of games on analog mame? or can I use an analog pedal to control others as well?
That list is only of games in mame that use mame's IPT_PEDAL input type. Other games in mame use mame's IPT_AD_STICK (ie analog joystick) input type for the gas and brake. For the ad_stick and pedal games, analog pedals work the best.
At some point, mame:analog+ will change some of the games that mame has with ad_stick input to two pedal inputs; if the original game had dual/split pedals, ipt_ad_stick prevents accurate inputs like the original while two ipt_pedal's are like the original.
BTW, if you are designing your own pedals, you might want to have a hardware switch to change between single/composite pedals and dual/split pedals. Most of the higher end PC pedals have a driver switch that does this, while the lower end PC pedal are composite. This is mostly for the future, though, as currently only a couple games in mame are set up for dual pedals.