Yamamoto Takuma was born in Kumamoto City on September 11, 1925. After graduation from the Japan Army Academy, he attended and graduated from the Japan Army aviation military school in 1945. He joined Fujitsu Ltd. after graduating from the Faculty of Electrical Engineering at the University of Tokyo in 1949. Since then, he has served as director of data transmission technology Division, General Manager of Software technology Division, Information Processing Group and as the Group President of Electronic Business Group, successively. He became the Board Director in 1975, the Managing Director in 1976, the Executive Director in 1979, the President and Representative Director in 1981, the Chairman of the Board and Representative Director in 1990, and Chairman Emeritus in 1997. During his career, he engaged in the development of the H type switchboard from its early stages, the development of the crossbar switchboard, and also worked in the research and development of the electronic automatic exchange.

Yamamoto also worked on in the field of computer developments in cooperation with Ikeda Toshio, who was called a genius computer architect, in 1952. And, he also took an active part as a pioneer in this field in Japan. That is, after completing the first relay formula automatic calculation tabulation machine in Japan, via the development of FACOM222, a large-sized transistor general-purpose electronic computer, he played a pioneering role in the realization of large-sized and medium sized general-purpose computers that used integrated circuitry and large-scale integrated circuits. The prize of "Excellent Work" and the "National Commendation for Invention" were awarded by the Japan Institute of Invention and Innovation for those results in 1958, 1965 and 1968. Especially, the creation of computer systems that were highly-reliable, fast, and economically efficient through use of large-scale integrated circuitry contributed greatly to the development of the society, economy, as well as science and technology.

He worked diligently to accomplish these developments with in-house technology. Under his leadership, the development of the first general-purpose operating system in Japan (FACOM230-60), the development of online systems in early stage, the development of large-scale integrated circuits, and the development of high density multilayer printed-circuit boards and large-scale circuit design technology and the processing technology all became possible. At the same time, he established the basic principles for adding new features, improving performance and developing excellence in cost performance while satisfying social and market requirements while maintaining the compatible with IBM machines in the 1970s. These efforts came into fruition with the FACOM M series. As a result, Fujitsu's revenue surpassed IBM Japan in fiscal year 1979.

In the area of international business development, he took a leadership role in the management of Amdahl Co. in the United States after equity investment in the company in 1972. Fujitsu also took a stake in ICL, the largest computer company in the U.K., after nine years of technical cooperation. Under his leadership, both companies' businesses expanded substantially. One of the most significant events during Yamamoto's tenure as President was a legal dispute with IBM. Since Fujitsu's strategy had been to maintain compatibility with IBM machines, the dispute with IBM was inevitable. This legal dispute was settled as a result of arbitration with settlement package paid to IBM, which allowed Fujitsu to continue to maintain compatibility with IBM machines. The problem ended when it became unnecessary to retain access to IBM information with the arrival of downsizing.

Yamamoto held a number of other important positions, such as deputy Chairman of National Land Council of the National Land Agency of the Japanese government, Special member of the University Deliberation Council of the Ministry of Education, Culture, Sports, Science and Technology of the Japanese government, chairman of the board of the High-performance Computer Development Technological Union, chairman of the Communication Industries Association of Japan, chairman of the Japan Electronic Industry Development Association and vice chairman of the board of councilors of KEIDANREN.

• 1970 Awarded the Science Technology Service Prize of the Minister of Science and Technology.
• 1984 Awarded the Blue Ribbon with Medal of Honor
• 1993 Received the IPSJ Contribution Award
• 1995 Received the IEICE (Institute of Electronics, Information and Communication Engineers) Contribution Award
• 1996 Designated IEICE creditable member
• 1997 Designated as Honorary Knight Commander of the Most Excellent Order of the British Empire
• 1997 Received the Grand Cordon of the Order of the Sacred Treasure

Yamamoto died on January 17, 2012.