On the design and performance of a small 60-nsec destructive readout magnetic film memory

The design of a small very-high-speed magnetic film memory using existing components is summarized. The memory has a capacity of 32 words and 36 bits per word, operates in a destructive-readout mode, and has a cycle time of 60 nsec and an access time of 32 nsec. The storage medium is a continuous sheet of NiFe film. The operational characteristics of the film and the properties of the strip line array are given, with worst case pulse conditions applying to both. The design and operation of the electronic circuitry are also described. A model of the memory, populated with three word-driver circuits and three regeneration-loop circuits for reading, rewriting, and writing, has been built and operated successfully. The paper concludes with oscillograms of waveforms which were obtained in closed regeneration-loop operation with that model.