...You need to look into this sorta thing. The psp is far to weak to emulate a system that is stronger, though they did a EXTREMLY rough beta for the dreamcast...it wasnt released (and with .02fps, I dont think it's worth it.) It can do nearly all the consoles below it if you have the right emulators (ps1 is built in, just needs converting, though yabuse the saturn emulator needed alot of work...) Go to quickjump .net (google it) and have a look, daedalus, the n64 emulator is looking preety good Nes, megadrive, master system, gameboy, gbc...god it goes on.
well i had the gba emulator but when i clicked the home button(in daedulusx64 it takes you to a sort of menu)it had the game paused but when i tried going back to the game it freezed
Depends on the firmware you are on/version of the emulator. It's homebrew, it wont always be perfect.