Geo Bios Rom: Neo

This brings us to the fan-made revolution:

The Neo Geo has a checksum routine. When you boot a game, the BIOS reads the program ROMs, calculates a value, and compares it to a known hash. If you have a bad dump, a broken trace, or—most famously—a bootleg cartridge with hacked header data, the BIOS throws up a solid green background, black text, and a blinking cursor. neo geo bios rom