Japanese Computer Pioneers

Kiyasu Zen-itiKiyasu Zen-iti
1915〜2006

Kiyasu Zen-iti was born on December 11, 1915, and graduated from Electrical Engineering Department, Engineering Faculty of Tohoku Imperial University in 1939. Immediately after the graduation, Kiyasu joined the Electrotechnical Laboratory of the Ministry of Communications, where he was assigned to do research, at its Second Research Division, on transmission technologies, particularly carrier filters. While doing this research, Kiyasu was confronted with vast amount of numerical calculations, and became keenly aware of the need of automatic digital computer. Kiyasu was interested also in analogue computers while he participated, as a wartime researcher, in research on wireless piloting of airplanes. The ETL's Second Division became a part of Electrical Communication Laboratories (ECL) of NTT in 1950 after going through several reorganizations of governmental offices.

In preparation for the advent of electronic automatic telephone switching systems and electronic computers, Kiyasu did reseach on information theory and logic circuits. In 1952, Kiyasu, in consultation with Sakamoto Chikafusa, established the Electronic Computer Reseach Committee (Chairman: Maeda Ken-ichi , Secretary: Kiyasu) in the Institute of Electrical Communication Engineers of Japan, to promote research on electronic computers by providing a place for presentation of and discussion on such research work.

In 1954 at this Committee Takahasi Hidetosi and Goto Eiichi of the University of Tokyo published 'Parametron' as a novel logic element. As Kiyasu had been an advocate of eliminating the use of vacuum tubes, he decided to employ parametron as logic elements in a computer under consideration at the ECL. He expanded and strengthened the research activities on parametron computers, and organized a joint research group consisting of NTT, KDD and the University of Tokyo. In 1957, a parametron computer, MUSASINO-1 (M-1 for short) was completed at the ECL of NTT. M-1 attained 50-hour continuous unattended run, and provided computation services for the needs within the ECL. M-1 was opened to researchers of various organizations including universities, and executives and engineers of communication equipment manufacturers, and its technologies were transferred to many organizations. The M-1 technologies together with the research at the ETL, seminars at the Institute of Electrical Communication Engineers of Japan, and promotion by the Ministry of International Trade and Industry made academia and industry interested in computers, and supported Japanese computer industry to stand on its own feet. As Kiyasu believed that storage unit was crucial in the progress of computers, he proposed to enhance the research activities in the ECL on magnetic core memory, magnetic drum, and magnetic tape, and to commence a new research project on ferro electrics memory.

Kiyasu introduced the concept of digital automatic computers to telephone switching, and proposed the concept of communication network between computers and between human and computer. He also proposed to demonstrate the mathematical proposition with the use of computers.

He died on December 7, 2006.


(Takahashi Shigeru)
(As of Aug. 29, 2003)