Project Leader
The Intel 4004 Microprocessor and the Silicon Gate Technology
A testimonial from Federico Faggin, designer of the 4004 and developer of its enabling technology
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The 4000 Family
Silicon Gate Technology
The 8008
The Busicom Chip Set
Project Leader
There was a considerable time gap between the architectural proposal made by Ted Hoff and Stan Mazor to Busicom, the Japanese calculator manufacturer who owned exclusive rights to the 4000 family chip-set, and the beginning of the implementation of the microprocessor. The proposal was idling for six months without any progress, until Faggin was hired from Fairchild to lead the project in April 1970. This gap defines two phases of separate activities: the first phase of architectural definition, the second phase of design and development. There was no interaction between Hoff, who by then was working on other projects, and Faggin during the development phase. Soon after joining Intel, Faggin completed some architectural issues left unresolved and designed the microprocessor without any participation or help from Ted Hoff or Stan Mazor.

Faggin was expert in Silicon Gate Technology, the technology that he had created at Fairchild Semiconductor. He also knew computer architecture intimately having co-designed and built one of the early small computers at Olivetti, in Italy, before attending University, when he was 19 years old. This combined knowledge provided a unique background for a most challenging job. In 1968, the basic problem of the industry was not so much the identification of a viable computer architecture, but being able to implement a high-performance chip with about 2500 transistors, within the capabilities of a very limited technology. Small computers had been designed and built for years using small-scale and medium-scale integration TTL circuits (for example, see 8008).

Faggin worked furiously for 11 months to implement the Busicom chip set. He made all the decisions that can make or break a project and took the risk of a possible failure. The rapid and successful implementation of the 4004 was also one of the key factors that gave Intel the lead over other competing microprocessor architectures being considered by other companies at that time. Contrary to many reports in the press, Faggin and not Hoff was the leader of the project.

Gordon Moore Interview on the First Microprocessor
"…and then we hired Dr. Faggin who we had known back at Fairchild to come in and actually lead the project to realize the processor that Dr. Hoff had conceived."
Gordon Moore talks about the first microprocessor in his office at Intel’s Headquarters in a clip from the documentary “Silicon Valley Story,” (1996), by journalist and film director Chiara Sottocorona.