GD-ROM

The GD-ROM format is Sega's proprietary disc format used for the Sega Dreamcast home console, as well as for the arcade systems NAOMI, NAOMI 2, Triforce, and Chihiro.

Holds a 0GDTEX.PVR image that can be shown on the Bios CD player screen.

GD-R discs

GD-R discs stored at Sega of America

GD-R discs are the recordable version of Sega's proprietary disc format. GD-Rs lack the security ring between the standard density and high density sections, and thus only boot on a retail Dreamcast system using a System Disc 2. The Katana Dev.box will also play these discs.