An anonymous Japanese homebrew coder has released a new update for PCE for PSP, a TurboGrafx-16/PC Engine emulator for the PSP. The latest update has added a downgrade version of the emulator.
That's all we can gather for now since the ReadMe included in the release is also in Japanese. So give it a try guys and tell us if you find any significant changes from the previous release.
Download: PCE for PSP v0.81a3