New Features
Version 0.71.1 (September 10, 2007)

    * Initial release

Installation

Unzip neopop.zip into /PSP/GAME/ folder on the memory stick. This should create the following directory tree:
PSP/
GAME/
NEOPOPPSP/
GAMES/ (game roms)
SCREENS/ (screenshots)
SAVEDATA/ (save states and flash data)
BUTTONS.CNF (Button configuration file)
[any other files]
NEOPOPPSP%/
EBOOT.PBP

Game ROM's may reside anywhere (the GAMES subdirectory is recommended, but not necessary). NeoPop PSP supports ROM loading from ZIP files.
Controls

The emulator currently "ships" with the following default key mappings:
During emulation:

    * Analog stick - Directional pad up/down/left/right
    * Directional pad - Directional pad up/down/left/right
    * 仩 (square) - Button A
    * ✕ (cross) - Button B
    * SELECT - Option
    * L + R - Return to the emulator menu

By default, button configuration changes are not retained after button mapping is modified. To save changes, press 仜 (circle) after desired mapping is configured. To load the default mapping press 仮 (+++++).
Known Issues

    * There are a number of bugs that are emulation-related and will not be fixed unless someone else fixes them. See the official homepage for a list of bugs (including missing audio in Sonic Pocket Adventure).
    * DAC audio playback is currently not implemented. This is most noticeable in the absence of the usual 'Se-ga!' voice at the beginning of the Sonic Pocket Adventure. If enough people are interested, support may be added in the future (it's mostly missing because the emulator is already slow).
    * Enabling the frame limiter seems to slow down the emulation unnecessarily. For now, keep it turned off.
    * Music playback seems to be lagging in comparison to video—this is hard to confirm, since the emulator never reaches 60fps with sound, making it is impossible to test it at full framerate.
    * If you have any comments, please contact me.

http://psp.akop.org/neopop/