The Amiga ROM contains the initial bootstrap code and the core of the AmigaOS. When you power on an Amiga, the CPU reads the ROM immediately. It initializes the custom chips (Agnus, Denise, Paula) and loads the Workbench.
The Amiga ROM was not static. As Commodore released new models—Amiga 500, 600, 1200, 4000—the ROM evolved from to 3.1 (and later, the community-driven 3.2 and 3.X). This created a unique ecosystem tension. amiga rom