Upgrade THEC64 and THEVIC20

Firmware upgrades for THEC64 provide new features and/or correct any technical issues. We always recommend that you upgrade to the latest version of the firmware.

Ensure that your USB memory stick is formatted using FAT32 (with MBR), else your upgrade file will not be detected. When updating, ensure that THEC64 or THEVIC20 only has one joystick plugged in to it. We recommend that you use the rear USB port for your memory stick to upgrade. We do not recommend that you upgrade with a USB hub or from any of the side USB ports. See the FAQ for further details.

Visit here for the firmware upgrade details page for THEC64 Mini.

Version 1.5.2 – Changes and additions


To enable REU support you can use either a filename flag or a CJM file parameter. Note that REU support does not work with VIC20 software.

To select using a filename flag, use one of the following:

R5 = 512K REU enabled
R2 = 2MB REU enabled
RM = 16MB REU enabled
For example:


See the user manual for further details on the use of filename flags.

To select with a CJM file, use one of the following parameters:
reu512 = 512K REU enabled
reu2048 = 2MB REU enabled
reu16384 = 16MB REU enabled
For example:


See the user manual for further details on creating CJM files.

To switch the joystick in use between joystick port 1 or port 2 when running a C64 program, press and hold the joystick ☰ button, and then pressing joystick Ⓐ for port 1 or joystick Ⓑ for port 2. This will override the J1 filename flag or CJM primary port setting, if either are supplied.

Changes from previous versions

How to Upgrade THEC64

    1. In Classic mode, press MENU, select Options > Device settings > System information
    2. In Carousel mode, select Device settings (spanner icon) > System information
    3. Look for the Build version (e.g. theC64-1.3.2-amora)
    4. Check that the latest version linked to above is greater than the version installed on your device
    5. Download and save the file (e.g. theC64-1_4_2.bin) to your USB memory stick. Don’t place the file inside a folder on the stick or rename the file. If you do, THEC64 won’t find the upgrade
    6. Insert the USB memory stick into an unoccupied USB port on THEC64
    7. Press MENU and choose Device settings> System information from the menu
    8. The upgrade file is detected and you are asked to Close or Apply
    9. If you choose not to upgrade at this time, select Close and press FIRE, or just press the MENU button on the joystick If you Apply the upgrade, the following screen will appear showing the upgrade process:

After a successful upgrade, THEC64 will restart automatically.

You can check the firmware version afterwards by following point (1) above.

Note that you cannot install a firmware earlier than the build version currently installed.