A CSO file is a of a PSP game. While a standard ISO file is an exact, uncompressed copy of a UMD (Universal Media Disc), a CSO uses compression algorithms to shrink the file size—sometimes by up to 50%—without losing any actual game data. Key Benefits and Trade-offs
: It applies DEFLATE compression to standard ISO files, typically reducing file size by 40–60% . cso psp archive
Connect your PSP to your PC. Look for a folder named ISO in the root of your memory stick. If it’s not there, create it. A CSO file is a of a PSP game
Dump your UMD using Custom Firmware on a PSP. Hold the R-trigger on boot to enter the Recovery Menu, enable "USB device: UMD," then plug into your PC. Copy the UMD.ISO file. Connect your PSP to your PC