The Neo Geo BIOS is more than just a startup screen; it is the hardware abstraction layer that made the Neo Geo versatile enough to dominate arcades for 15 years while simultaneously serving the home market. For enthusiasts today, understanding BIOS versions is critical for maintenance, region modification, and ensuring games run uncensored on original hardware.
When a Neo Geo is turned on, the BIOS performs a specific routine:
Typically, the BIOS is mapped to the lower address range of the CPU. When the system is powered on, the 68000 jumps to the reset vector located in the BIOS ROM, beginning the boot sequence.