Milestone-Proposal:Intel 4004 Microprocessor

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Docket #:2020-04

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To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Intel 4004 Microprocessor, 1971

Plaque citation summarizing the achievement and its significance:

Utilizing new silicon-gate MOS technology, the Intel 4004 microprocessor incorporated the electronic functionality of a 4-bit computer's Central Processing Unit (CPU) onto a single chip, with cost and performance improvements over existing multi-chip designs. Although initially designed for a family of desktop calculators, software customization enabled by its general-purpose instruction set made the single-chip microprocessor a key component of the digital information age.

In what IEEE section(s) does it reside?

Santa Clara Valley

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: Santa Clara Valley
Senior Officer Name: Taylor Winship

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: Santa Clara Valley
Senior Officer Name: Taylor Winship

IEEE section(s) monitoring the plaque(s):

IEEE Section: Santa Clara Valley
IEEE Section Chair name: Tayor Winship

Milestone proposer(s):

Proposer name: David Laws
Proposer email: Proposer's email masked to public

Proposer name: Brian Berg
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

Robert N. Noyce Building (Intel Headquarters), 2200 Mission College Blvd, Santa Clara, CA 95054 USA 37.3882663, -121.9637798

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. At the entrance to the Intel Museum, which is in the lobby of the Robert N. Noyce Building

Are the original buildings extant?

The 4004 was primarily developed in what is now called SC1 (for "Santa Clara 1"), at 3065 Bowers Ave., Santa Clara, CA, which is extant but which is not accessible to the public. The museum is less than 2 miles from SC1. (The 4004 project began in 1969 while Intel was still in its original headquarters at 365 Middlefield Rd., Mountain View, CA.)

Details of the plaque mounting:

By the entrance to the Intel Museum, on the ground floor of the Robert N. Noyce Building.

How is the site protected/secured, and in what ways is it accessible to the public?

The Intel Museum is open to the public during normal business hours. There is no charge for entry.

Who is the present owner of the site(s)?

Intel Corporation

What is the historical significance of the work (its technological, scientific, or social importance)?

The Intel 4004 was a complete 4-bit parallel central processing unit (CPU) on a single silicon chip. Introduced in 1971 as a member of the MCS-4 Micro Computer Chip Set, it was the first commercial microprocessor integrated circuit offered to the general public. The success of the product established the commercial viability of the microprocessor concept, led to the development of 8-bit chips from Intel and other vendors, and also led to the use of microprocessors first in embedded products, personal computers, and then throughout the industry. Single-chip microprocessors are now ubiquitous throughout the world.

What obstacles (technical, political, geographic) needed to be overcome?

The key technical obstacle was adapting Intel's P-channel silicon-gate MOS process to accommodate 2300 transistors in a chip size that was economical and practical to manufacture in volume. This required innovation in process technology (buried contact and bootstrap load), circuit design (dynamic RAM registers and stack pointer, a new static MOS shift register, counter, etc.), and mask layout techniques. Political/commercial obstacles included initial reluctance by management to promote a chip that could compete with the company’s existing customers, and lack of knowledge on the part of users on how to use the device. The latter was overcome with extensive customer education programs, and specific hardware and software development tools.

What features set this work apart from similar achievements?

By the late 1960s, designers were striving to integrate the CPU functions of a computer onto a handful of MOS LSI chips. Some notable examples include: (1) in 1969, Lee Boysel created the Four-Phase Systems Inc. AL-1, an 8-bit CPU slice that was expandable to 32 bits, and (2) in 1970, Steve Geller and Ray Holt of Garrett AiResearch designed the MP944 20-bit chip set to implement the F-14A Central Air Data Computer on six chips. Both were multi-chip custom designs for specific applications. The Intel 4004 was a general-purpose device that integrated more of the essential logical elements of a processor onto a single chip than prior solutions. These functions included a program counter, instruction decode/control logic, the ALU, data registers, and the data path between these elements. Although originally designed to implement a family of programmable calculators by way of a contract that Intel had with the Japanese company Busicom, the 4004's programmable features enabled applications in peripherals, terminals, process controllers, and test and measurement systems.

As discussed with reference to Federico Faggin in the 29 Sept 1969 issue of Electronics, the new direction in MOS technology at that time was the development of a self-aligned gate MOS process (to reduce parasitic capacitances) combined with a lower power supply voltage (from -24 volts to -15 volts) by reducing the maximum threshold voltage from -9 volts to -3.5 volts. This was accomplished for the first time in 1968 by using polysilicon instead of aluminum in the gate electrode. The result was a technology that, for the same power dissipation, resulted in (1) a 5x speed improvement, (2) reduced leakage current (by more than 100 times), (3) higher circuit density (especially for random logic designs) using the buried contact, which allowed fabricating an insulated contact between junctions and polysilicon, thereby resulting in half the chip area for the same function, and (4) higher reliability by using phosphorus gettering to reduce metal impurities, which was impossible with an aluminum gate. This increase in speed and functionality within a single chip allowed the 4004 to be a single-chip CPU, with a resultant improved cost and greatly improved performance, as compared with a multi-chip implementation.

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

The Marconi Society's 1988 Marconi Prize to Federico Faggin "for his pioneering contributions to the implementation of the microprocessor, a principal building block of modern telecommunications" [1].
The 1988 Gold Medal for Science and Technology to Federico Faggin from the Italian Prime Minister.
The 1994 IEEE Computer Society's W. Wallace McDowell Award to Federico Faggin “for the development of the Silicon Gate Process, and the first commercial microprocessor” [2].
The 1996 National Inventors Hall of Fame inductees included Federico Faggin [3], Marcian E. (Ted) Hoff [4] and Stanley Mazor, for the microprocessor [5].
The 1997 Kyoto Prize recipients included Federico Faggin [6], Marcian Edward Hoff, Jr. [7], Stanley Mazor [8] and Masatoshi Shima [9] in Advanced Technology: Electronics.
The 2000 Robert N. Noyce Award presented by the Semiconductor Industry Association to Federico Faggin, Stanley Mazor and Ted Hoff, "Inventors of the Microprocessor" [10].
The 2009 Computer History Museum Fellows included Federico Faggin, Marcian Edward "Ted" Hoff, Stan Mazor and Masatoshi Shima "for their work on the Intel 4004, the world’s first commercial microprocessor" [11].
The 2009 National Medal of Technology and Innovation recipients included Federico Faggin, Marcian E. Hoff, Jr. and Stanley Mazor, as presented by President Obama "for the conception, design and application of the first microprocessor, which was commercially adopted and became the universal building block of digital electronic systems, significantly impacting the global economy and people's day-to-day lives" [12].

Faggin, F. “Power supply settable bi-stable circuit” U.S. Patent 3753011 [13]
Hoff, Jr., M. E.; Mazor, Stanley; Faggin, Federico. "Memory System for a Multi-Chip Digital Computer" U.S. Patent 3821715 [14]

"A faster generation of MOS devices with low thresholds is riding the crest of the new wave, silicon-gate IC's," Electronics (29 Sept 1969) pp. 88-89.
Faggin, F. and Hoff, M.E. "Standard parts and custom design merge in four-chip processor kit," Electronics (24 April 1972) pp. 112-116.
Altman, Laurence "Single Chip Microprocessors open up a New World of Applications," Electronics (18 April 1974) pp. 81-87.
Noyce, R., and Hoff, M. "A History of Microprocessor Development at Intel," IEEE Micro, Vol. 1, No. 1 (1981) pp. 8-21.
Faggin, F.; Hoff, M.E., Jr.; Mazor, S.; Shima, M. "The history of the 4004," IEEE Micro, Vol. 16, Issue 6 (December 1996) pp. 10-20.
Faggin, F., Shima, M., Hoff, M.E., Feeny, H., Mazor S. "The MCS4 - An LSI micro-computer system," IEEE 1972 Region Six Conference, IEEE Press (1972) pp. 8-11.
Intel MCS-4 Micro Computer Set Data Sheet, 1971 (12 pages).
Augarten, Stan. "The First Microprocessor - 4004," State Of The Art: A Photographic History of the Integrated Circuit, New Haven & New York: Ticknor and Fields, 1983, pp. 30-31.
Malone, Michael S. "The Microprocessor: A Biography," New York: Springer-Verlag TELOS, 1995, pp. 3-20.

Federico Faggin: An Interview Conducted by John Vardalas, IEEE History Center Interview #442, 27 May 2004 [15].
Federico Faggin Oral History, interviewed by Gardner Hendrie (22 Sept 2004, 13 Dec 2004 and 3 March 2005), Computer History Museum Catalog # 102658025 [16].
Ted Hoff and Stan Mazor on their contributions to the Intel 4004, Ted Hoff and Stan Mazor interviewed by David Laws (20 Sept 2006), Computer History Museum Catalog #102657974 [17]
Oral History Panel on the Development and Promotion of the Intel 4004 Microprocessor, Federico Faggin, Hal Feeney, Ted Hoff, Stan Mazor and Masatoshi Shima, interviewed by Dave House, and edited by David Laws (25 April 2007), Computer History Museum Catalog #102658187 [18]

The Designer Behind the First Microprocessor: Federico Faggin [19] (length: 4:19)
Ted Hoff, Inventor of the Microprocessor, Richard Newton Distinguished Innovator Lecture Series, U.C. Berkeley (8 Sept 2009) [20] (length: 48:08)
Intel 4004 Microprocessor 35th Anniversary, Computer History Museum (13 Nov 2006) [21] (length: 1:37:59)

Who Invented the Microprocessor?, David Laws (20 Sept 2018) [22]

The Microprocessor Chronicles: The History of the Microprocessor "The history of the invention of the microprocessors through three and half decades of technological change as told by those that made it happen. Interviews with Dennis Carter, Federico Faggin, John Hennessy, Ted Hoff, Dave House, Stan Mazor, Regis McKenna, Gordon Moore, Jerrt Sanders, Albert Yu," Stanford University Library; Palo Alto, CA, 2005 [23]

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).