CGB Bootstrap ROM

The Game Boy Color bootstrap ROM (often mistakenly called a BIOS although it does not handle basic in- or output) is the ROM that is executed after the Game Boy Color is turned on. Just like the DMG bootstrap ROM, it checks the inserted game cartridge for integrity by calculating the complement checksum, locking out cartridges that may be corrupted or don't have the copyrighted Nintendo logo within.

The ROM assigns color palettes to certain Game Boy Mono games and even lets the user choose one of twelve pre-programmed palettes, six of which are unique to the manual selection.

It does so by computing a hash for every Nintendo Licensee game and checking it against an internal database of hashes. However, a big chunk of color table actually went unused: only 94 hashes are on record, which only use 45 different palette configurations out of 174 possible configurations of which 146 are unique! Minus the six unique colors from manual select and the 45 associated with games, this makes for a whopping 95 palette configurations that are unused!

To access the unused palettes using an emulator that allows the bootstrap ROM to load, use the Gameshark code with the ID of the desired entry. The selected palette will load regardless of whether or not buttons have been pressed.

Plain-Text Format Download
The same information that is provided in the tables below in handy plain-text format:

Manual Select Palette Configurations
A total of twelve palette configurations are in here. Six of these are unique to the manual selection mode and are underlined in the table. The button combinations trigger the respective configuration and are previewed in the respective shades while the Nintendo Game Boy Color logo is still being displayed on the screen.

Assigned Palette Configurations
There are a total of 45 unique palette configurations in here, six of which are shared with the Manual Select Palette Configurations. The hash column contains all hashes (and disambiguation values in parentheses) that result in the respective entry being chosen, the games for which are listed as well.

Notice that entry 0x03/0x1C with hash 0x00 is actually a dummy entry. This entry is used for all games that are not found in the hash table or don't have a Nintendo Licensee code.

Unused Palette Configurations
There are a total of 123 palette configurations in here, 15 of which are duplicates of Assigned Palette Configurations and 13 of which are duplicates within this table. These duplicate are marked with their respective original entry in small script.