Stored data protection system

Claim 1

IN COMBINATION, A MAGNETIC STORAGE MEDIUM HAVING AT LEAST ONE RECORDING SURFACE, A RECORDING HEAD MOUNTED ADJACENT SAID RECORDING SURFACE FOR MOVEMENT OVER A PREDETERMINED RANGE, MEANS FOR MOVING SAID STORAGE MEDIUM AT CONSTANT SPEED RELATIVE TO SAID HEAD TO CAUSE SAID HEAD TO TRANVERSE A PATH ON SAID SURFACE DETERMINED BY THE POSITION OF SAID HEAD WITHIN SAID RANGE, A SOURCE OF INFORMATION SIGNALS, SWITCHING MEANS ACTUABLE TO FIRST AND SECOND STATES AND OPERABLE IN ITS FIRST STATE TO SUPPLY SIGNALS FROM SAID SOURCE TO SAID HEAD, FIELD REGISTER MEANS FOR STORING A CODE DEFINING A FIELD OF ADDRESSES, ADDRESS REGISTER MEANS FOR STORING AN ADDRESS CODE, POSITIONING MEANS CONTROLLED BY SAID ADDRESS REGISTER MEANS FOR MOVING SAID HEAD TO A POSITION WITHIN SAID RANGE DETERMINED BY THE ADDRESS CODE, AND COMPARATOR MEANS CONTROLLED BY SAID FIELD REGISTER MEANS AND SAID ADDRESS REGISTER MEANS FOR ACTUATING SAID SWITCHING MEANS TO ITS FIRST OR ITS SECOND STATE ACCORDING AS THE ADDRESS CODE STORED IN SAID ADDRESS REGISTER MEANS IS OUT OF OR IN THE FIELD DEFINED BY THE CODE STORED IN SAID FIELD REGISTER MEANS, RESPECTIVELY.