The C64FC is a real-time reprogrammable cartridge for the Commodore 64, allowing you to upload programs to the C64. Software can be uploaded as a complete image, or gradually patched on demand, all while the C64 is running and executing the code.
The file transfer is done via USB 1.0 to an ATmega16 micro controller, which does USB communication using V-USB.
The uploaded program is stored on an IDT7006 16K dual-port RAM, which the C64 will see as read-only memory. 8K and 16K carts are supported, as well as PRG loading.
The current version is C64FC 1.0 RC3, and a few of these boards will be shipped out to a selected handful of beta testers.