Unit unavailability detector for a data processing system

Claim 1

IN A DATA PROCESSING SYSTEM HAVING STORAGE MEANS CONTAINING A PLURALITY OF ADDRESSABLE STORAGE LOCATIONS, SAID STORAGE MEANS BEING COMPRISED OF PORTIONS, SAID PORTIONS BEING DISTINGUISHABLE BY ADDRESS MANIFESTATIONS, SAID DATA PROCESSING SYSTEM INCLUDING ADDRESSING MEANS CAPABLE OF SPECIFYING ADDRESSES FOR PORTIONS OF A STORAGE MEANS TO INCLUDED WITHIN THE PARTICULAR CONFIGURATION OF SAID SYSTEM, SAID SYSTEM ALSO INCLUDING MEANS TO GENERATE A MANIFESTATION FOR APPLICATION TO INDIVIDUAL STORAGE PORTIONS TO INDICATE THE SELECTION OF THAT STORAGE PORTION FOR OPERATION, SAID DATA PROCESSING SYSTEM FURTHER INCLUDING ADDRESS MONITORING MEANS TO SENSE THE PRESENTATION OF ADDRESS MANIFESTATIONS WHICH SPECIFY STORAGE PORTIONS NOT INCLUDED WITHIN SAID SYSTEM AND INVALID ADDRESS MANIFESTATION GENERATING MEANS RESPONSIVE THERETO GENERATE AN INVALID ADDRESS MANIFESTATION, A STORAGE MONITORING DEVICE, COMPRISING: A PLURALITY OF CIRCUIT MEANS, ONE OF EACH OF SAID STORAGE PORTIONS, EACH OF SAID CIRCUIT MEANS NORMALLY AT A POTENTIAL OF A FIRST KIND, SAID CIRCUIT MEANS ASSUMING A POTENTIAL OF A SECOND KIND IN DEPENDENCE UPON THE UNAVAILABILITY OF THAT PORTION DUE TO A POWER FAILURE OR MAINTENANCE ACTION; AND MEANS RESPONSIVE TO SAID CIRCUIT MEANS AND TO SAID SELECTION MANIFESTATIONS TO GENERATE AN UNAVAILABLE STORAGE MANIFESTATION IN DEPENDENCE UPON THE CONCURRENT PRESENCE OF A SIGNAL OF SAID SECOND KIND AND A SELECTION MANIFESTATION CORRESPONDING TO THE RELATED STORAGE PORTION, SAID MEANS CAUSING SAID INVALID ADDRESS MANIFESTATION GENERATING MEANS TO GENERATE AN INVALID ADDRESS SIGNAL IN RESPONSE TO SAID UNAVAILABLE STORAGE MANIFESTATION.