Apertured sheet read-only memory

The technical feasibility of a simple, high-performance, read-only memory (ROM) has been demonstrated. This memory uses apertured sheets of doctor-bladed linear ferrites with printed information patterns. It offers favorable sense-signal/drive-current ratios, low current-level electronics, one diode/word decoding matrix, straightforward fabrication, and compact construction. A prototype memory of 32 words, each of 36 bits, has been successfully demonstrated with a 50-ns cycle time (20-Mc repetition rate). A large ROM of 128 words, 50 bits each, was also operated satisfactorily.