In one embodiment, the scan logic 20 deduces this distance yet to be covered from the comparison of {HEAD ~ the output} of {TAIL ~ the analog} to digital converter 44 with the map of plot A, and outputs a media position error signal 
of
In one embodiment , the scan logic 20 deduces this distance yet to be covered from the comparison of { HEAD ~ the output } of { TAIL ~ the analog } to digital converter 44 with the map of plot A , and outputs a media position error signal
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH