A GDI file is a plain text file (usually 1–3 KB) that acts as a table of contents. It points to several (usually .bin files). A complete GDI set includes:

GDI files are "archival masters" because they are uncompressed and unmodified. This contrasts with

A modern alternative found on Archive.org. It compresses a GDI file without losing any data, making it the preferred format for modern emulators and ODEs (Optical Drive Emulators) like the GDEMU. Why Archive.org is the Go-To Resource

One of the most impressive aspects of the archive is its scope. The collection includes not only commercial games but also beta versions, prototypes, and even unreleased titles. For example, fans of the Shenmue series can find the original GDI files for the game, including the infamous "Shenmue: The Town of Heaven" prototype.

In 2023, Nintendo forced Archive.org to remove thousands of Switch ROMs. However, Dreamcast GDI files remain largely untouched because: