When the sensor senses a change in {HEAD ~ gravitational or inertial acceleration} of {TAIL ~ said data processing system}, it alerts system electronics to temporarily park a read/write head in a safe position 
of
When the sensor senses a change in { HEAD ~ gravitational or inertial acceleration } of { TAIL ~ said data processing system } , it alerts system electronics to temporarily park a read / write head in a safe position
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH