Japanese Computer Pioneers

Toda IwaoToda Iwao
1934〜

Toda Iwao was born on February 1st, 1934. and received BS.,MS. and Ph.D from University of Tokyo. In 1958 he joined the research laboratory of Nippon Telegraph and Telephone Public Corporation(NTT). He was engaged in the research of MUSASINO-1, the first parametron computer in the world, with Kiyasu Zen-iti, Muroga Saburo and Takashima Kensuke and later developed a theory of majority decision elements with Muroga Saburo, which is a mathematical model of parametron. In 1961 he designed a computer dedicated for toll charge calculation, where he developed a logic simulator and actually applied it to the design of the above computer. This was the first practical application of logic simulators in the world.

From 1964 to 1965. he visited University of California, Berkeley and University of Illinois, Urbana and was shocked by the big technical and educational gap between US and Japan.

Coming back to Japan he initiated the development of a complier for EPL(precursor of PL/1).

In 1965 NTT decided to launch data communication services to the public and at the same time the research for the data communications was moved to high gear. He implemented a project called DIPS, which aimed at developing a series of on-line computers to be used for NTT’s data communication services. The first computer of the series was named DIPS-1 targeting at the world fastest on line computer at that time, whose development was started in 1968. As a chief architect he designed its architecture incorporating (1) a large scale main memory, (2) multi-processors, (3) a paging mechanism and (4) a cache memory. To foster the domestic computer industry, DIPS-1 was developed jointly with NEC, Hitachi and Fujitsu. The architecture was common for the three vendors, the hardware was manufactured separately and the software was jointly developed by the vendors.

He adopted aggressively such new hardware technologies to DIPS-1 as IC memory and new I/O interfaces. To the software development he not only introduced the concepts of quality control but also applied many software engineering technologies. These experiences of DIP-1 development formed the scaffold for the software engineering technologies of the participating vendors.

DIPS-1 was put into commercial use in 1973 at Shiba exchange office of NTT to offer a time sharing service called Demos-E.

After it a series of DIPS computers were developed incorporating the remarkable progress of LSI technologies under his leadership and they were used for NTT’s in-house use as well as to provide outsourcing services by NTT. Its development was terminated in 1992.

The total number of engineers involved in the DIPS project is estimated to exceed 50,000. Many of them became the leaders of computer business at the participating vendors.

Toda Iwao was promoted to a senior executive vice president of NTT in 1988 and led the whole R&D of NTT. In 1992 he moved to Fujitsu and ran the networking business.


(As of Apr. 1, 2004)