A 300 nanosecond search memory

This paper describes a 24 digit, 128 word, transistorized magnetic thin film search memory with a 300 nanosecond read cycle time. With further improvement such a memory could work with a 100 nanosecond cycle time. A search or associative memory is one in which an input word is compared simultaneously with all stored words; an output is produced on all words that differ from the input word. Variations of this memory permit search between limits by setting up a "don't care" condition for some of the stored bits; however, the emphasis in this paper is on the equality search. The writing system described is capable of doing a complete rewrite of all 128 words in 13 milliseconds; much faster writing systems are possible. Applications are in sorting, cataloging, information retrieval, translation, and searching.