Before we discuss building a CSO PSP archive full of games, you must understand the file format itself.

A "full" CSO archive is useless if games stutter. Here is how to optimize:

If you are attempting to curate a full library of PSP games, relying solely on pre-compressed CSO archives can be a mixed bag.

Your CSO PSP archive full is useless if you cannot play it.

A: You likely used Level 9 compression on a game with LBA (Logical Block Addressing) protection. Re-rip the game as ISO or use Level 1 compression.