The Model 3 hardware was released in several revisions, known as "Steppings" (Stepping 1.0, 1.5, 2.0, 2.1). A ROM image for a game like Virtua Fighter 3 might require the specific BIOS of a Stepping 1.0 board, while Daytona USA 2 required Stepping 2.1. Archivists in 2021 had to ensure that archives contained not just the game data, but also the specific BIOS revisions required to run them, leading to complex file structures often denoted by parent/clone relationships in MAME dat files.
Supermodel/ |-- Config/ |-- NVRAM/ |-- ROMs/ |-- vf3.zip |-- scud.zip |-- dayto2pe.zip sega model 3 rom archive 2021