Atari ST (MiSTery)

This page is the home of the newly-ported Atari ST core for Turbo Chameleon 64.

This is a port of the “MiSTery” core from the MiST platform, now supporting hard drive images, configuration files and the C64 keyboard!

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.

MiSTery 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:

MiSTery 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.

You will need a TOS ROM image in the root directory of your SD card, named TOS.IMG

The core supports 2 floppy drive images and 2 hard drive images, which can be set on the “Storage” page of the menus.

The core can load and save configuration files, but can’t currently create new ones. For this reason, a “blank.cfg” file is provided, for your convenience, along with an “STEColor.cfg” example configuration file


FunctionPS/2 keyboardC64 keyboardCDTV controller
MenuF12run/stop + <- (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 MiSTery core was written by Gyorgy Szombathelyi, building upon previous work by Till Harbaum, and incorporating components written by Jorge Kwik, with reference to schematics of original chips recovered by Christian Zietz.