Maximum compression, smallest file sizes, but requires significant CPU power to decompress in real-time. Pros and Cons of Using CSO Archives
Original tool by Booster. Basic usage:
For batch processing: Drop an entire folder of ISOs onto the executable to convert your whole library simultaneously. Method 2: Using UMDGen (Graphical Interface) cso psp archive
PSP_Archive/ ├── ISOs/ # Original .iso files (backup) ├── CSOs/ # Compressed .cso files for play ├── Saves/ # .sav or PPSSPP save states ├── Firmware/ # Official updates (e.g., 6.61.PBP) ├── DLC/ # Game DLC folders (NPJHxxxxx) ├── Tools/ # maxcso.exe, UMDGen, etc. └── README.txt # Info on which game has issues with CSO smallest file sizes
: If you have Custom Firmware (CFW) installed, your PSP can read these files directly from the ISO folder. cso psp archive