x-fire: you should've started your own thread but to answer your question you need to update your cfw to 3.52 M33, then 3.52 M33-4, then 3.90 M33. To update to 3.52 M33 you need to download the
3.52 M33 official release. In that file you'll find a folder titled M33CREATOR. You need to put two files into that folder. You have to find, download, and put the OFFICIAL SONY 3.52 and 1.50 update eboots into that folder. After that's done then you need to drag the M33CREATOR folder to the GAME150 folder under PSP. If you don't have the folder already there, create it.
Thread starter: There is a guide for getting to custom firmware (cfw) in my signature down below. You don't need to go to cfw to play PS1 games if they are bought from the PlayStation Network. But for all the other thousand PS1 games that aren't on there that you want to play you will need cfw.