With the Nand Write Protect (NWP) chip installed you can easily use the DVD eject button to toggle Read-Write or Read-Only mode for the Xbox 360 NAND flash indicated by a bi-color LED (which actually gives three different colors by mixing two). The chosen protection state is saved in the EEPROM of the PIC12F629 microcontroller, this effectively keeps the data stored during console power off. Avoid any attempts from M$ messing with your flash content or just prevent any official updates from being installed by mistake.
Design and PIC coding by GodzIvan! For those who wish to use their own PIC flasher and components to build this mod, get his release in the download section here.