Magnetic Domain Wall Memory

摘要

The goal of this program was to perform the necessary research and development to demostrate the feasibility of a programmable 64-bit memory utilizing Bubble Domains as the storage element. Since the target of this type of development is a low cost, high density (1,000,000 bits/sq in.), physically small replacement for drum type memories, the model must also demonstrate that it is capable of extension to meet these requirements. It was the specific objective of this program to develop and refine the techniques for the generation, propagation and detection of these small bubble domains. It was not the objective of this program to pursue the refinement of bubble domain material. Various types of replication generators employing current loop splitters are discussed and experimental data on both continuous and controlled generation is presented. Results indicate that through an optimization of design, replication generators of the type presented here will be operational at high data rates. Bubble domain switching remains a problem and for a time will be the limiting function of a bubble domain device. This function is necessary when continuous generation, passive annihilation, or memory organizations such as the major-minor loop are used. The switches presented here are limited to the conductor loop type which effects bubble switching when activated by a current pulse. Both passive and active annihilators are discussed.