{TAIL ~ Fault tolerant memory system} which utilizes data from a shadow memory device upon the detection of erroneous data in {HEAD ~ a main memory device} 
{ TAIL ~ Fault tolerant memory system } which utilizes data from a shadow memory device upon the detection of erroneous data in { HEAD ~ a main memory device }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD