Memory system including means for selectively altering or not altering restored data

Claim 1

IN A DATA PROCESSING SYSTEM, THE COMBINATION COMPRISING: A MAIN MEMORY, FOR THE STORAGE OF A PLURALITY OF DATA UNITS, COMPRISED OF A PLURALITY OF SELECTIVELY ADDRESSABLE CELLS EACH OF WHICH IS CAPABLE OF STORING ONE OF SAID DATA UNITS; A TEMPORARY MEMORY; MEANS COUPLED BETWEEN SAID MAIN MEMORY AND SAID TEMPORARY FOR TRANSFERRING SAID DATA UNITS FROM SAID MAIN MEMORY TO SAID TEMPORARY MEMORY; A FIRST CONTROLLABLE DATA RETURN PATH FOR PROVIDING COMMUNICATION DIRECTLY FROM SAID TEMPORARY MEMORY TO SAID MAIN MEMORY; A SECOND CONTROLLABLE DATA RETURN PATH, INCLUDING A DATA MODIFYING MEANS, FOR PROVIDING COMMUNICATION FROM A TEMPORARY MEMORY OF SAID MAIN MEMORY; AND MEANS FOR SELECTIVELY RENDERING ONE OF SAID DATA RETURN PATH OPERATIVE.