I haven't added many new games, rather been improving ones that are already there.
The biggest improvements are to sound which will now support:
16-bit sound
16 channels
GP2X style mixer (it's fast!)
Updates from GP2X MAME such as improved sound chips for Konami games like Yie Ar Kung Fu.
Updated DRZ80; many games using Z80 will now work. ie. 1943 (US), Black Tiger, Gunsmoke, etc.
There's a few improved drivers in there as well such as qiz, zookeeper and warp warp now fully work have sound.
The problem with the poor old GP32 is that it can literally only go so fast; the limited total bandwidth of the system seems to be the biggest bottleneck. The GP32 sound bug and the inaccurate GP SDK sound handling is rearing it's ugly head here. I've tried many new ideas for mixers and sound algorithms. Funny thing is I implemented a pre-calculated divide lookup table and was really surprised to see a similar idea now being use in the GP2X version.
Adding new, big games with big resource requirements are not really going to be the worth the while. They just aren't going to run at an acceptable rate with sound. Yes, perhaps without sound, but I'm not a fan of playing in silence.
1943 is one game which is a good benchmark. It uses two CPUs and FM sound with moderately sophisticated graphics. Even at 166Mhz, autoframeskip <=2 and 80% underclock on CPUs the GP32 is pushing only 16-19FPS. Mind you, without sound it's full 60FPS.
Basically anything that uses the more advanced FM sound hardware is slow. That's YM2203, YM2151, YM2610, etc. The simple AY8910 fair much better as do many other sound systems.
The low sound problem is still sort of there, though the better mixer does help a little. I explained what the issue is in the MAME GP2X 4.6 thread. The solution would be some sort of normalization of volume; boosting quiet games and reducing "noisy" ones (these may suffer from excess clipping). I may have some ideas, though any input from devs who are familiar with this kind of problem would be appreciated.
