If you have a Dreamcast game in .ISO format and need it in .CDI format, you have likely hit a compatibility wall. While later consoles like the PlayStation 2 or Xbox heavily utilized the ISO format, the Dreamcast ecosystem relies heavily on the CDI format due to its ability to store complex disc layouts and audio tracks.

: Standard ISOs often require a "Utopia Boot Disc" to start. CDI images are usually "self-boot," meaning the console loads the game directly.

A standard .iso file is a single track. BootDreams needs the filesystem inside. So, first, mount your ISO as a virtual drive (Windows 10/11 can double-click an ISO to mount it) or extract it using 7-Zip.

Open Command Prompt in the folder containing cdi4dc.exe . Use the following structure:

Click