HI
In short
jus put and press small needle in here .. the CD driver will open even there is no electric.
I guess thats quite nice...
Could become use full hell I never knew that.
But I don't think my PC has that...
All roms have this actually and if you screw around with pcs enough you will have to use it at some point.
Might add thats its not a good idea to try this while the rom is spooling up