List of Dreamcast widescreen codes
From Sega Retro
The following is a list of codes for the Sega Dreamcast cheat devices, allowing games to run in 16:9 anamorphic widescreen.
The Dreamcast cannot render natively in a 16:9 resolution - the output of the console will remain 4:3, however the codes below will alter geometry to avoid a "stretched" look when appearing on a widescreen television (or emulator). This concept is far more common on the PlayStation 2, GameCube, Xbox and Wii - while the result can lead to blurrier visuals with "rectangular" pixels, the benefits of widescreen, i.e. a wider field of view, will be carried forward.