Homebrew developer notaz just issued an update for the PSP Genesis and Sega CD Emulator, PicoDrive. This version includes the addition of a few new features, such as the disable sprite limit option, and black level adjustment.

This release is mostly about bigfixes, however, so check out the changelog below to see if the problem you've been experiencing while using the emulator is finally addressed:

//Fixed sprite masking code. Thanks to Lordus for explaining how it works.
Added "disable sprite limit" option.
Added black level adjustment to display options.
Changed reset to act as 'soft' reset.
Added detection for Puggsy (it doesn't really have sram).
Some small timing adjustments.
Added support for SVP (Sega Virtua Processor) to emulate Virtua Racing. No recompiler for PSP version though.
Changed config file format, files are now human-readable. Game specific configs are now held in single file (but old game config files are still read when new one is missing).
Fixed a bug where some key combos didn't work as expected.
Adjusted fast renderer to work with more games, including VR.
Fixed a problem where SegaCD RAM cart data was getting lost on reset.
PicoDrive now comes with a game config file for some games which need special settings, so they should now work out-of-the-box. More games will be added with later updates.//

For those who are interested in using this homebrewed emulator but don't know how to start using it, just go over the in-depth readme file included with the download. Just make sure to grab the version most compatible to your PSP's set-up, and refer to the installation and troubleshooting guide in the readme.