Originally Posted by VulcanDragon
You can't play any and all PS1 games on the PSP, but the new version of the firmware does support the new downloadable PS1 game service that Sony is operating. The trouble is that I believe you need a PS3 to do it. I.e., you download the game to the PS3, then transfer it to the PSP; downloading to a PC or directly to the PSP is not an option, I think.
Also, of course, updating to the brand spanking newest firmware version probably means you can't run most homebrew, unless someone has already figured out how to get kernel access.
PSP ver. 3.02 O-E custom firmware FTW
It's 1.5 + 3.02 combined. You can homebrew on it. For PSP updates, I go to Qj.net