| Problem | Likely Cause | Solution | |---------|--------------|----------| | "Corrupted data" on PSP | CSO compressed at level 9 | Re-compress at level 1 or 2 using CISO | | Emulator crashes on launch | CSO header corruption | Verify with csoverify tool | | Audio stuttering in cutscenes | Too high compression for original CPU | Switch to ISO or level 1 CSO | | Can't find CSO in PPSSPP | File extension not recognized | Ensure .cso – PPSSPP doesn't auto-open .zip or .7z | | CSO larger than original ISO | Zero compression + padding | Extract to ISO and recompress properly |
These files work on original PSP models (1000, 2000, 3000), the PSP Go, and the PlayStation Vita (via the Adrenaline ePSP environment). cso psp archive
PPSSPP can create CSO files from ISOs: