.CSO File

File extension cso is used for compressed ISO images. They are often used as a medium to play PSP games. The standard medium used by Sony PlayStation Portable is Universal Media Disc (UMD).

CSO format has nine levels of compression. Higher levels mean better compression, but slower loading times of compressed ISOs.

These cso files are created by PSP ISO Compressor.

CSO CISO compressed ISO file allows playing PSP games from memory card, but PSP must have installed user customized firmware, that includes support to reading of cso files.

Files with cso extension are in most cases disk images saved in a common disk format for Sony Playstation. Very often used for backups of game disks. CSO format needs a special customized firmware so PSP can read them.

How to open:

The *.cso file is compressed ISO image file and can be opened in SONY PlayStation Portable, that has installed user customised firmware with support to open the CSO CISO compressed ISO file.

How to convert:

PSP ISO Compressor supports conversion of *.cso files in to other disk file formats.