it keeps telling me that BIOS is not found. i dont understand where i have to put it at
Did you just put the bios in and try to start a game? Look in the menus, there should be an option like "set bios" (I don't have my dingoo handy, so I can't tell you exactly what it says). Because you can have multiple bios images, you have to tell picodrive which one you want to use.
But if you're in the "set bios" menu and it's telling you bios not found, IDK what the problem is. Either you didn't put them in the right place (look at DiegoSLTS's post), or they're not the right files.
so do i only put the US one, or do i put all three
I think you need the corresponding region's bios to play games from that region. If you're only playing US games, you should only need the US bios.
I play games on: Game Boy Color, Game Boy Advance, GBA SP, NDS Phat, NeoGeo Pocket Color, Panasonic FZ-10 3DO, Nintendo Entertainment System, Sega Nomad, Sega CDX w/Power Base Converter, PlayStation, Sega Saturn, PC, EGP1000, Dingoo A330, LetCool N350JP, PAP-GAMETA, and (FINALLY!) GCW-Zero SE.
Currently playing: Guardian War (3DO), Final Fantasy II USA Proto (NES on Letcool), EVERYTHING!!! (GCW).