For example, the UP 503 may interrupt the current data stream and move backwards or forwards in {HEAD ~ the TM} 507 by accessing {TAIL ~ previous or subsequent data} in response to a RW command or a FF command, respectively 
by accessing
For example , the UP 503 may interrupt the current data stream and move backwards or forwards in { HEAD ~ the TM } 507 by accessing { TAIL ~ previous or subsequent data } in response to a RW command or a FF command , respectively
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH