Once the low order bit has been set, a check for an interrupt is made to determine if {HEAD ~ the predetermined period} of {TAIL ~ monitoring}, e.g., 1000 cycles, has been exhausted via step 66 
of
Once the low order bit has been set , a check for an interrupt is made to determine if { HEAD ~ the predetermined period } of { TAIL ~ monitoring } , e.g. , 1000 cycles , has been exhausted via step 66
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 HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH