auto System::portRead(uint16 addr) -> uint8 {
  //IEEP_DATA
  if(addr == 0x00ba) return eeprom.read(EEPROM::DataLo);
  if(addr == 0x00bb) return eeprom.read(EEPROM::DataHi);

  //IEEP_ADDR
  if(addr == 0x00bc) return eeprom.read(EEPROM::AddressLo);
  if(addr == 0x00bd) return eeprom.read(EEPROM::AddressHi);

  //IEEP_CMD
  if(addr == 0x00be) return eeprom.read(EEPROM::Status);
}

auto System::portWrite(uint16 addr, uint8 data) -> void {
  //IEEP_DATA
  if(addr == 0x00ba) return eeprom.write(EEPROM::DataLo, data);
  if(addr == 0x00bb) return eeprom.write(EEPROM::DataHi, data);

  //IEEP_ADDR
  if(addr == 0x00bc) return eeprom.write(EEPROM::AddressLo, data);
  if(addr == 0x00bd) return eeprom.write(EEPROM::AddressHi, data);

  //IEEP_CMD
  if(addr == 0x00be) return eeprom.write(EEPROM::Command, data);
}