Masatoshi Shima was the
engineer responsible for the Busicom calculator design. He came
from Japan a few days after Faggin joined Intel, to check the logic design of
the chip set. He was dismayed and very angry to see that Hoff's proposal had not
progressed from his last visit, six months before, against Intel's promises. He
stayed on and helped Faggin with the detailed logic design to partially recover the
delay in the schedule agreed upon six months before. Besides Shima, the other
members of the 4000 family design team were one electronic technician, and three
draftsmen, of which only one knew how to layout silicon gate devices.
Masatoshi Shima was a software and logic engineer with practically no knowledge of MOS process technology
and MOS circuit and chip design. During the first six months of the MCS-4 development, he stayed at Intel
to check on the project development and was the only engineer helping Faggin
during the design phase of the chips.
Shima took directions and learned from Faggin, while completing various tasks being assigned to him.
Shima's contributions were fairly routine tasks that any good engineer could have accomplished.
On page 74 of his book "The Birth of the Microcomputer: My Recollections,"
Published in August 1987 by Iwanami Shoten, Tokyo, Shima says: "Mr. Faggin
taught me the semiconductor process, circuitry design, layout designů.
Since April I worked with Mr. Faggin in the same room and I learned a lot from him,
then because of that, I could build up the basis as LSI engineer for later use.
In this over 6 months period I learned circuitry techniques based on the
layout which is most important basis of LSI design and I also learned how
to use the mask design and I learned the methodology of LSI development and also how
challenging and creative job excites the engineer and also that success bring big joy
and also big money. So I learned all of this through the job of 6 months.
For me developing 4004 with Mr. Faggin, for better or worse, was more than doing
drugs and even now I feel my blood run backwards. Even now when I look at LSI
development for new application field all my blood feels like going backward."
In 1970, the architecture and logic design of a simple CPU had been done many times before,
becoming fairly routine tasks. What had not been done before was to creatively do the circuit
design and the layout of such a complex chip as the 4004 to fit into a small enough chip to
be commercially viable. That was Federico Faggin's key contribution, made possible by his
intimate knowledge of the MOS silicon gate technology he developed at Fairchild Semiconductor
two years before. Faggin was also very familiar with computer architecture and with logic design
since he had co-developed and built an early experimental electronic computer at Olivetti R&D Labs in
Italy before coming to the US.