Future Developments in Large Magnetic Film Memories

Abstract

Some judgments are formulated about memory organization, fabrication techniques and cell structures which are generally applicable to improving the speed-cost ratio of static magnetic storage devices. More specifically, for magnetic films, techniques for realizing simultaneously high bit density and simple fabrication are discussed. Based on very rough estimates, it is proposed that for a million-word memory, a cost reduction of almost two orders of magnitude over present day stores with speeds of approximately one microsecond or less should be feasible with films. Alternative cell configurations and areas of engineering compromise are discussed. Experimental results with etched cells having dimensions as small as 2 mils (0.05 mm) for both quasiclosed and open structures have been obtained. Both multiword readout and a method for sharing sense amplifiers by ``band switching'' are considered.