power off preserving {HEAD ~ means} for powering off {TAIL ~ the system} after transferring the data held in the first storing means to the hard disk 
for powering off
power off preserving { HEAD ~ means } for powering off { TAIL ~ the system } after transferring the data held in the first storing means to the hard disk
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH