interface means, connected to said cache means, for enabling said cache means to transmit or receive {TAIL ~ data} to/from {HEAD ~ said system bus} and including a second directory means reflective of the most current validity status of any data moved on said system bus, said interface means further including: 
interface means , connected to said cache means , for enabling said cache means to transmit or receive { TAIL ~ data } to / from { HEAD ~ said system bus } and including a second directory means reflective of the most current validity status of any data moved on said system bus , said interface means further including :
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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