{HEAD ~ The disks} are divided into {TAIL ~ sectors} and each sector as a symbol marking printed thereon 
are divided into
{ HEAD ~ The disks } are divided into { TAIL ~ sectors } and each sector as a symbol marking printed thereon
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH