When one or more of the plural portals is selected, data can be input or output in a manner which is predictable, straight forward, free of scheduling constraints, and very efficient, without {HEAD ~ contention} between {TAIL ~ the separate portals} 
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When one or more of the plural portals is selected , data can be input or output in a manner which is predictable , straight forward , free of scheduling constraints , and very efficient , without { HEAD ~ contention } between { TAIL ~ the separate portals }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL