Each FIFO buffer 710 {HEAD ~ a 710 d} accepts every fourth or Mth count for a total of {TAIL ~ N counts} 
Each FIFO buffer 710 { HEAD ~ a 710 d } accepts every fourth or Mth count for a total of { TAIL ~ N counts }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL