Memory protection system

Claim 1

AN ELECTRONIC DATA HANDLING APPARATUS COMPRISING A MAIN MEMORY FOR STORING BLOCKS OF WORDS THEREIN AND INCLUDING A PLURALITY OF X AND A PLURALITY OF Y DRIVE LINES, ONE OF SAID PLURALITY OF DRIVE LINES FOR ACCESSING BLOCKS OF WORDS AND THE OTHER FOR ACCESSING WORDS WITHIN SAID BLOCKS, EACH BLOCK BEING ASSOCIATED WITH A PARTICULAR PROGRAM TO BE EXECUTED BY SAID APPARATUS, AN AUXILIARY MEMORY INCLUDING A PLURALITY OF GROUPS OF CORES, EACH GROUP BEING TRAVERSED BY ONE OF SAID ONE PLURALITY OF DRIVE LINES AND EACH OF SAID GROUP STORING INDIVIDUAL FIRST CODES EACH IDEN TIFYING A BLOCK OF WORDS WHEREBY ACCESSING WORD IN SAID MAIN MEMORY ACCESSES A GROUP OF CORES ASSOCIATED THEREWITH TO READ OUT SAID ACCESSED WORD AND SAID FIRST CODE, MEANS TO STORE A SECOND CODE IDENTIFYING THE PROGRAM BEING EXECUTED BY SAID APPARATUS, MEANS TO ACCESS A WORD IN SAID MAIN MEMORY, SAID ACCESS MEANS ENERGIZING ONE OF SAID DRIVE LINES SLIGHTLY AHEAD OF THE OTHER WHEREBY SAID FIRST CODE IS READ OUT AHEAD OF A WORD IN SAID MAIN MEMORY MEANS TO COMPARE SAID FIRST AND SECOND CODES AND MEANS RESPONSIVE TO SAID COMPARISON TO CONTROL THE ALTERNATION OF SAID ACCESSED WORD.