$C000 - This is the address NESmaker writes to when switching banks. The value to write to this address has the following format:

m cc ppppp
| || +++++- PRG-ROM bank to swap in ($00-1E)
| ++------- CHR-RAM bank to swap in ($00-03)
+---------- One screen mirroring select (unused because NESmaker only uses V-mirroring by default)