THEMIS, three-hole element memory with integrated selection

In data processing systems there is a growing demand for cheap and large random access stores with high transfer rates. An extended store having a minimum module capacity of 10 Mbit with an access time of about 1 μs and a cycle time of 6 μs is presented. The store is equipped with a magnetic word selection system which is manufactured in the same steps as the storage matrix. This reduces the number of interconnections and drive circuits to such an extent that this number is even lower than in 2½D core stores. Also, on the digit and sense line the number of interconnections and the number of circuits is low because of the high tolerable number of bits per line. Due to these features and the simple production process, a low cost and high reliability are anticipated. The stack of 10⁷bits inclusive of the magnetic selection has a content as low as 6 dm³and can be operated with currents of about 250 mA.