queueing means for storing {TAIL ~ data requests} to said {HEAD ~ main memory} means by a requesting processor and for storing data to be returned to a requesting processor 
queueing means for storing { TAIL ~ data requests } to said { HEAD ~ main memory } means by a requesting processor and for storing data to be returned to a requesting processor
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH