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Invention

The Microprocessor

Computer Engineering

The microprocessor is a complete central processing unit fabricated on a single integrated circuit, combining the arithmetic, logic and control functions that earlier computers spread across many chips or discrete components onto one chip small and cheap enough to embed in an ordinary product. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/

Facts
Disputed
Year
1971 1
Intel's 4004, released commercially in November 1971, is the usual popular reference point, but Texas Instruments engineers Gary Boone and Michael Cochran filed a single-chip CPU patent the same year, and Garrett AiResearch's Central Air Data Computer, designed by Ray Holt and Steve Geller for the US Navy's F-14 Tomcat, ran as a complete CPU built from a chip set as early as 1968-1970; the Garrett design stayed classified for military use and was not published for years, which is why it rarely appears in the popular history even though it predates the commercial chips.
Patent or First-Use Date
1971-11-15 1
Date of the first known advertisement for the Intel 4004, the first commercially available microprocessor.
Significance
The microprocessor is what let computing power leave the machine room: it is the component that made the personal computer possible, and later the embedded controller found in nearly every electronic device. 1
Connections

Associated With

Electrical Engineering, Fields
Photolithography, Methods
Silicon, Materials

In Field

Computer Engineering, Fields

Held Differently

Federico Faggin, Engineers

Led the Intel 4004 design team; the 4004 is the commercially released side of the same priority dispute the live open question on this entity already names (Garrett AiResearch CADC vs. Texas Instruments' 1971 patent vs. Intel's 4004).

Source Federico Faggin (Wikipedia)
Ray Holt, Engineers

Why this is disputed. Holt led the design of Garrett AiResearch's classified Central Air Data Computer chip set, built 1968 to 1970 for the F-14 Tomcat, which computed flight parameters on a multi-chip processor architecture roughly a year before Intel released the 4004. The CADC's military classification kept it secret until 1998, so Intel's commercially available 4004 became the design most popular histories of computing credit as the first microprocessor.

Source The World's First Microprocessor: F-14 Central Air Data Computer (Hackaday)Hackaday staff

Open Questions

Was Garrett AiResearch's classified Central Air Data Computer chip set (1968-1970), Texas Instruments' 1971 single-chip CPU patent, or Intel's commercially released 4004 (1971) the first true microprocessor?, Open Questions
Source Microprocessor (Wikipedia)Wikipedia contributors

Preceded By

The Integrated Circuit, Inventions
Sources
1. Microprocessor (Wikipedia)
Wikipedia contributors, Wikimedia Foundation
  • Intel 4004 (1971) subsection, First projects section
    The first known advertisement for the 4004 is dated November 15, 1971, and appeared in Electronic News.
  • Lead section
    A microprocessor is a computer processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs.
View the Source
The World's First Microprocessor: F-14 Central Air Data Computer (Hackaday)
Hackaday staff, HackadayInvented By: Ray Holt, CADC vs 4004 section
Quote, Invented By: Ray Holt, CADC vs 4004 section
The Tomcat was the first aircraft to use a microprocessor-driven flight system, as well as the first microprocessor unit (MPU) ever demonstrated, beating the Intel 4004 by a year.
View the Source
Federico Faggin (Wikipedia)
Wikimedia FoundationInvented By: Federico Faggin, lead section
Quote, Invented By: Federico Faggin, lead section
He is best known for designing the first commercial microprocessor, the Intel 4004.
View the Source
Open Questions (1 open question)
Was Garrett AiResearch's classified Central Air Data Computer chip set (1968-1970), Texas Instruments' 1971 single-chip CPU patent, or Intel's commercially released 4004 (1971) the first true microprocessor?

The three claims answer different questions, first working design, first patent, first commercial product, and the classified CADC design was not publicly documented until years after it was built, so the historical record itself was incomplete for years, not merely uncollected.

What would resolve this A settled convention for whether "first microprocessor" means first working design, first patent or first commercial release would resolve which claim wins under that definition; no new archival evidence is expected to change the underlying facts.
History of technologyWikipedia contributors, Microprocessor (Wikipedia)
Dissenting Readings (1 dissenting reading)
Year

Intel's 4004, sold commercially from November 1971, is the version of "first microprocessor" that reached the public and shaped the popular history of computing. Engineers Ray Holt and Steve Geller argue for an earlier claim: their Central Air Data Computer chip set, designed at Garrett AiResearch for the US Navy's F-14 Tomcat fighter, ran as a complete CPU built from six MOS chips as early as 1968 to 1970, before the 4004 existed, but stayed classified for military use and was not publicly documented until years later, so it earned no contemporary recognition. Texas Instruments engineers Gary Boone and Michael Cochran filed a patent on a single-chip CPU architecture in 1971 as well, contesting Intel's claim from a different direction, over a design that was patented but never shipped as a commercial product the way the 4004 was. Whether "first microprocessor" should credit the first working design, the first patent, or the first commercially available product is the underlying disagreement, not merely a factual gap.

A dissenting reading, from an independent laneWikipedia contributors, Microprocessor (Wikipedia), Wikimedia Foundation

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