====== EverDrive GB original (GB/GBC) programming ======

===== Registers =====

==== 0xBE00 (SPI_DATA) ====

SPI data port used for communication with the SD card. Write to send and receive a byte; read to get the last received byte.

==== 0xBE80 (?) ====

==== 0xBF00 (REG_INDEX) ====

The index of the register to be accessed.

==== 0xBF80 (REG_DATA) ====

TODO: Can this be read?