Christopher has updated PSP CHess to v0.28. Changes:
castling support in wild5 and fischer random – redid all castling code mp3 background music (slows down computer a little more than mod file) –>switching back and forth and back between mp3 and mod is not working. mp3->mod->mp3 and mod->mp3->mod may cause crash. mod->mp3->mp3 is fine. Bottom line: if you want mp3 music, switch from mod->mp3 and do not switch back without restarting pspChess. selectable background music new variants: wild 5, wild 8, and wild 8a. See http://freechess.org/Help/HelpFiles/wild.html for description
http://bace.bowron.us/
http://forums.ps2dev.org/viewtopic.php?t=1760