interface means, connected to {HEAD ~ said cache means}, for enabling said {TAIL ~ cache} means to transmit or receive data to/from 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 { HEAD ~ said cache means } , for enabling said { TAIL ~ cache } means to transmit or receive data to / from 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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH