Game Boy core

This page is the home of the newly-ported Game Boy core for Turbo Chameleon 64.

This is an experimental core, and while I do my utmost to make sure it works for everyone and will try to help solve any problems that arise, you run this core entirely at your own risk.

If you’d like to show your appreciation for this core, or motivate me to work on this and other cores in future, donations are welcome at or Anyone donating £20 or more via PayPal or sponsoring on Patreon at the second tier will be thanked by name in a “Core Supporters” shout-out page in subsequent releases.

Please note: it’s vitally important that you download the correct version of the core for your Chameleon.

Game Boy for Chameleon V1 hardware: If you have a single mini-DIN socket on the left hand side of your Chameleon, to which a breakout cable attaches for the keyboard and mouse, then you have V1 hardware and need this version:

Game Boy for Chameleon V2 hardware:  If you have three mini-DIN sockets on the left-hand side, with the keyboard and mouse plugging in directly, you have V2 hardware, and need this version:

Using the core

Flash the .rbf file into your Turbo Chameleon 64 using the chaco utility, and optionally copy the file to the root directory of your SD card.

To play Game Boy Color games you will need to download a copy of the Game Boy Color BIOS – named gbc_bios.bin – and copy it to the root directory of your SD card.

Since the Turbo Chameleon 64 can’t support more than three gamepad buttons via the DB9 ports, the extra buttons are mapped as follows

Gamepad buttonPS/2 keyboardC64 keyboardCDTV controller
SelectRight shiftRight shiftVolume up*
Button ARight AltButton B
Button BRight CtrlButton A

Other keys

FunctionPS/2 keyboardC64 keyboardCDTV controller
MenuF12<- (top left)Power

The scandoubler can be toggled on or off by holding down the menu button for a period of 1 second or more.

You can return to the Chameleon C64 core by pressing the middle and rightmost buttons on the Chameleon cartridge simultaneously.

Source code can be found at github, as usual – see

Huge thanks to everyone who’s supported my projects in recent months – it’s very much appreciated.

The Game Boy core was originaly written by Till Harbaum with further development and fixes by Gyorgy Szombathelyi, Bruno Duarte Gouveia and paulb-nl. The audio implementation is from the PACE project, and the T80 CPU core is by Daniel Wallner and Mike Johnson.