Sega Dreamcast

Glossary

Dreamcast modding comes with its own vocabulary. Here are the terms you will encounter most often throughout this guide.

MIL-CD — a Sega music-disc format whose loose authentication allows most retail Dreamcasts to boot software burned to ordinary CD-Rs.
GD-ROM — the Dreamcast's original high-density optical disc and the mechanical drive that reads it. This drive is the part that most commonly fails with age.
ODE — optical drive emulator. A solid-state board that replaces the GD-ROM drive and loads disc images from SD or USB storage.
GDEMU — a popular solderless SD-card ODE designed around the VA1 board.
USB-GDROM — an ODE supporting USB and SD storage with built-in automatic region patching.
MODE — Terraonion's premium ODE supporting both board revisions.
VA0 / VA1 — the two main Dreamcast mainboard revisions. Your revision affects which mods fit and work best.
GDI — a disc-image format that preserves the GD-ROM track layout faithfully.
CDI — a single-file disc image, convenient but sometimes a lossy conversion.
VGA — a progressive-scan video output mode for sharp picture on compatible displays.
DreamShell — a homebrew operating environment with a file browser and disc loader.
VMU — the Visual Memory Unit, the Dreamcast's memory card with its own small screen.