Logic Circuits Using Square-Loop Magnetic Devices: A Survey

The past decade has been a productive period for development in the field of large-scale digital computers. Magnetics has played an increasingly important part in these developments [1]-[8]. Magnetic cores, tapes, and drums have found almost universal acceptance for memory functions. Some future computers will undoubtedly use magnetic logic and control circuits. This survey is a capsule view of twenty-four square-loop magnetic logic circuits which have been proposed or developed so far, with a brief description of the way each circuit or circuit family meets the requirements of logic circuitry. All circuits are treated with a consistent terminology, and the generic relationships among circuits are stressed. Included in this survey are parallel and series transfer core-diode schemes, core-transistor schemes, and all-magnetic schemes of various topologies.