I guess I'm just not familiar with the Everdrive. Does it provide extra memory the CPU can use similar to the FDS?
From my understanding Everdrive works as a disk emulator for whatever system it's designed for and since this one supports famicom disk system roms I'm assuming krikzz probably designed the fpga on the Everdrive to cover the extra ram and what not. I am no expert in this stuff though so I could very well be wrong.