OKITAC-5090A

The OKITAC5090 was the first machine in Japan to use magnetic core memory for all internal memory. It was completed in 1961, but the OKITAC5080 was developed as a prototype in the previous year. The OKITAC5080 used magnetic core memory for the main memory unit, where almost all Japanese models of the time used magnetic drums, and it was a transistor-based computer which employed a static circuit system. Oki electric industry stopped multiplexing input/output devices and switched to a series system, simplified circuits using the high speed performance of magnetic cores, and there by achieved higher speed and reliability. The results of development of the OKITAC5080 were reflected in the OKITAC5090.