I have recently been trying to make inroads into development for arcade systems. I have noted that some people like taito and siebu kaihatsu are using pc based hardware now for their arcade platforms, even sega are looking at using linux based systems for their aurora hardware - a low end replacement for the naomi.
This has got me thinking, are there any game engines that do not require an os, free or not? i.e are there game engines that will boot the pc system directly into your game? I know that such a system would be dependant on finite hardware combinations etc etc etc, but im interested to see whats out there.