I've obtained a version of xmame that's been modified to work on the PSP. Well, that was the idea... the author used PSPE to do the dev work, and in fact it doesn't work on the PSP at all! It does work on PSPE though. It runs only one game, Omega Fighter (omegaf.zip). Since this is version 0.0, I'm sure the author will get it working on a real PSP (with bios 1.0) soon. I worked out what keys are used and here is the list: F2 - Insert coin F1 - Start game left arrow then right arrow - answers the OK request D - fire arrows to move. Original article I added the 19th comment (the one explaining the keys).