Masatoshi Shima was born in Shizuoka, Japan, in 1943. He holds a BS in chemistry from Tohoku University (1967) and a Dr. Eng. from Tsukuba University (1991).
In 1969, Shima worked at Japanese calculator manufacturer Busicom when it accepted a proposal by Intel to implement the logic for their new calculator in large-scale integration (LSI) logic. Following Marcian "Ted" Hoff's initial concept, Shima, Hoff, and Mazor jointly defined the functional specifications of the new chip, called the Intel 4004, and now known as a microprocessor.
Shima worked on the 4004's logic design, logic simulation, and test program generation. In 1971, the completed Busicom calculator was shipped and Intel began developing microprocessors on its own as a viable business, one with world-changing consequences.
Shima was recruited by Intel to design the 8-bit 8080 microprocessor, and later moved to Zilog with Federico Faggin and Ralph Ungermann to develop the highly successful z80.
In 1980, he returned to Japan as a director of the Intel Japan Design Center. In 2000, he became professor at Aizu University in Japan, and retired in 2004.
Shima shares the Kyoto Prize (1997) with Hoff, Faggin, and Mazor.