Sega Dreamcast


  • Cores:
    • RetroArch
      • flycast (default)
    • RetroRun
      • flycast
  • Path: dreamcast
  • Supported Extensions: .cdi .gdi .chd .m3u
  • Bios: Required
  • Libretro Documentation:

File Extensions

Dreamcast games are generally stored as either .gdi or .cdi files. Currently .gdi is the preferred format because .cdi uses some lossy compression. Historically, .cdi was the traditional format, and some romhack patches may only function on .cdi files.

Like many CD-based systems, Dreamcast supports .chd format. .gdi files can be easily converted into .chd format by using the .gdi file as an input, but .cdi files are more complicated. It’s probably easiest just to use .cdi files as they are. For more information on converting .gdi files, please see the documentation on Converting to CHD.


The Dreamcast bios is required. It should be put in /roms/bios/dc/dc_boot.bin.

BIOS md5
dc_boot.bin e10c53c2f8b90bab96ead2d368858623