The Anticipatory Control of a Cyclically Permutable Memory

A control method based on anticipatory shift with lookahead is proposed for accessing files stored in a cyclically permutable memory as characterized by, for example, bubble-domain devices. The performance of this method is analyzed and is shown to yield significant reduction of access time. By using a basic simple model, an explicit formula is obtained for relating performance to the size of requests, the shift register length, and the number of control sections allowed. Several generalizations are also discussed.