B-21 C-boards are the only ones that can be reporgrammed...
they can be made to work like any other C-Board.
you either need to program a battery backed board (you can use a CPS1 infinitiy key to do this, or the ArcadeHacker Arduino Revive method) or there are some custom made C-board that allow you to set via Jumper.
Alternatively you can use a non-battery B-21 and patch the game ROMs.
If you want an original B-04 C board it will not need to be reprogrammed... it's already configured for the specific games that use that chip.