...
C3= C403 100uF/16V electrolyte polar
CPU update/firmware/bootloader
in case you want upgrade the firmware, you have to update the bootloader.
I´dont give support about the update processes since I bricked my CPU while updating it and ended in a installation of an original CPU
https://github.com/sunflowr/recpu/releases
1.4.3 Version:
bootloader: bootloader.1.4.3.syx
REEMU reemu.1.4.3.syx
1.30: don't use it (buggy)
1.20 Version
bootloader: bootloader.syx
REEMU: reemu.syx