DATE2025.12.08 #News
Plaque dedication ceremony for IEEE Milestone "Parametron, 1954" at Hongo Campus, The University of Tokyo
On November 27, 2025, the plaque dedication ceremony for the IEEE Milestone "Parametron, 1954" was held in Room 1220, Faculty of Science Bldg. 4, Hongo Campus, The University of Tokyo.
The IEEE (Institute of Electrical and Electronics Engineers) is one of the world's largest professional organizations with over 400,000 members in more than 160 countries. In 1983, a year before its 100th anniversary, IEEE established the Milestone Program to honor the achievements that have contributed to society and industry in the 25 years since their development.
The certification plaque “Parametron, 1954” presented by IEEE
The Parametron honored here is an electronic logic element invented in 1954 by Eiichi Goto (later Professor Emeritus at the University of Tokyo), then a graduate student in the laboratory of Professor Emeritus Hidetosi Takahasi of the Department of Physics, Faculty of Science. It operated on the principle of majority logic. An externally forced oscillation is applied to a resonant circuit composed of a pair of magnetic ferrite cores and a capacitor to start an oscillation. The phase difference of the rising oscillation to the external oscillation was mapped to logical 0 or 1. It formed the basis for the PC-1 (Parametron Computer 1) developed in Takahasi's laboratory and for computers of the time. By 1961, it was used in half of all commercially used computers in Japan.
The ceremony was hosted by the IEEE Tokyo Chapter and attended by Toshio Fukuda, 2020 IEEE President (Emeritus Professor, Nagoya University); Toshiro Hiramoto, IEEE Tokyo Section Chair (Professor, The University of Tokyo); Haruko Kawahigashi, IEEE Tokyo Section board member and History Committee Chair (Mitsubishi Electric); and Makiko Kato, Secretariat of the IEEE Japan Council. The venue was a Department of Physics lecture room closely associated with Emeritus Professor Eiichi Goto, where President Fukuda handed the commemorative plaque first to President Teruo Fujii of the University of Tokyo, and subsequently to Shin-ichi Ohkoshi, the site owner and Dean of the Graduate School of Science, The University of Tokyo. The ceremony proceeded with the greetings from President Fujii, Section Chair Hiramoto, Yasushi Matsuo, Department Chair, Department of Physics (representing the department where Professor Goto spent his student years), and Dean Ohkoshi of the Graduate School of Science. Chiaki Ishikawa, IEEE member and graduate of the Department of Physics, Faculty of Science, The University of Tokyo—who authored the IEEE Milestone nomination document—delivered an overview of the Parametron and explained its historical and technical significance to the audience.
Toshio Fukuda, 2020 IEEE President, and President Teruo Fujii
Toshio Fukuda, 2020 IEEE President, and Dean Shin-ichi Ohkoshi
Following this, Eiiti Wada, a professor emeritus of the University of Tokyo, who was a graduate student at Takahasi laboratory, delivered a commemorative lecture titled “The Parametron Era at the Takahasi Laboratory.” He shared personal episodes including the immense difficulties of rebuilding scientific research in the post-war period, the excitement and deep emotion he felt when his own program successfully ran for the first time on the PC‑1, and memorable anecdotes about Goto’s hand-built television set and others.
In addition, Department of Information Science —which Goto co-served while holding a professorship in physics—was represented by Issei Sato, who delivered congratulatory remarks. Hiroaki Aihara, Executive Vice President of the University of Tokyo, who attended Goto’s lectures as a graduate student, also offered a congratulatory address honoring Goto’s legacy and achievements.
Lecture by Professor Emeritus Eiiti Wada of The University of Tokyo
The plaque will be installed on the wall of the entrance corridor of Koshiba Hall at the site of the former Faculty of Science Building No. 1, where Takahasi laboratory was. PC-1 was installed and operated there. Participants visited the Science Gallery before the luncheon (Faculty of Science Bldg. 1, Room 205), and then disbanded in groups afterward. Incidentally, the Quantum Flux Parametron (QFP), which is an evolutionary development of the original Parametron principle, is still a hot research topic to reduce power consumption of computing element by superconductivity at ultra-low temperature.
Group photo at the certification plaque dedication ceremony
Acknowledgments: I would like to express my sincere appreciation to the Graduate School of Science, Department of Physics, Department of Informatics and Electronics, and Central Administration Bureau of The University of Tokyo for their cooperation in preparation and operation, as well as to the administrative, public relations, and secretarial staff.
Written by: Chiaki Ishikawa (Milestone applicant, graduate of Department of Physics)