Using the tool EasyTransfer, you can flash the EeasyFlash cartridge banks of the EF3 cartridge over USB - without the need of a disk drive. To be able to flash the cartridge over USB, it is required that:
First activate the EF3 menu. Then, using EasyTransfer GUI, please select the Write CRT -tab. Browse and select the .crt file you want to flash. When you click “Go!”, EasyProg is started. After confirming the splash screen (on the C64), you are prompted to select the EF slot to be written. The rest of the flashing process is similar as when using EasyProg with a disk drive.