An experimental 65-nanosecond thin film scratchpad memory system

As computers become larger and more complex, the need for a high-speed scratchpad type memory becomes greater. Furthermore, the size and speed requirements increase. An early memory, suitable for use as a scratchpad, was described by H. Amemiya, R. L. Pryor, and T. R. Mayhew. This memory used two ferrite cores per bit and had a read/regenerate cycle time of 200 nanoseconds. More recently, a 64-word by 20-bit thin magnetic film memory was described by G. J. Ammon and C. Neitzert. This memory had a read/regenerate cycle time of 125 nanoseconds and its speed was limited primarily by the electronic circuitry. A number of other memories and memory designs, suitable for use as scratchpads, have been reported in the literature. Future need for a 256 to 1,024 word memory having a cycle time of 50 nanoseconds has been indicated. A project was therefore initiated to study the feasibility of such a system.