Editing Microprocessor (section)

====Intel 4004 (1971) ====
{{Main|Intel 4004}}
[[File:C4004 (Intel).jpg|thumb|Intel's first microprocessor, the [[4004]], with cover removed (left) and as actually used (right)]]
[[File:Intel_4004_ad.jpg|thumb|Intel advertisement in [[Electronic News]] magazine from 1971 emphasizing the 4004's affordability, compactness, ease of programming, and flexibility.]]
The [[Intel 4004]] is often (falsely) regarded as the first true microprocessor built on a single chip,<ref>{{cite web | title=The Microcomputer Revolution | first=Pamela E. | last=Mack | date=30 November 2005 | url=http://www.clemson.edu/caah/history/FacultyPages/PamMack/lec122/micro.htm | access-date=2009-12-23 | url-status=live | archive-url=https://web.archive.org/web/20100114160413/http://www.clemson.edu/caah/history/FacultyPages/PamMack/lec122/micro.htm | archive-date=14 January 2010 }}</ref><ref>{{cite web | title=History in the Computing Curriculum | url=http://www.hofstra.edu/pdf/CompHist_9812tla6.PDF | access-date=2009-12-23 | url-status=dead | archive-url=https://web.archive.org/web/20110719211222/http://www.hofstra.edu/pdf/CompHist_9812tla6.PDF | archive-date=2011-07-19 }}</ref> priced at {{US$|60|1971|round=-1}}.<ref>{{cite web |first=Peter |last=Bright |title=The 40th birthday of—maybe—the first microprocessor, the Intel 4004 |publisher=arstechnica.com |date=November 15, 2011 |url=https://arstechnica.com/business/2011/11/the-40th-birthday-ofmaybethe-first-microprocessor/ |url-status=live |archive-url=https://web.archive.org/web/20170106233202/http://arstechnica.com/business/2011/11/the-40th-birthday-ofmaybethe-first-microprocessor/ |archive-date=January 6, 2017 }}</ref> The first known advertisement for the 4004 is dated November 15, 1971, and appeared in ''[[Electronic News]]''.<ref>{{Cite web|url=https://www.intel.la/content/www/xl/es/history/museum-story-of-intel-4004.html#:~:text=1971:%20Era%20of%20integrated%20electronics,wide%20variety%20of%20electronic%20devices.|title=intel's first microprocessor|access-date=2025-02-05}}</ref> The microprocessor was designed by a team consisting of Italian engineer [[Federico Faggin]], American engineers [[Marcian Hoff]] and [[Stanley Mazor]], and Japanese engineer [[Masatoshi Shima]].<ref>{{cite journal | title=The History of the 4004 | last1=Faggin | first1=Federico | last2=Hoff | first2=Marcian E. Jr. | last3=Mazor | first3=Stanley | last4=Shima | first4=Masatoshi | journal=IEEE Micro | date=December 1996 | volume=16 | issue=6 | pages=10–20 | doi=10.1109/40.546561 }}</ref>

The project that produced the 4004 originated in 1969, when [[Busicom]], a Japanese calculator manufacturer, asked Intel to build a chipset for high-performance [[desktop calculator]]s. Busicom's original design called for a programmable chip set consisting of seven different chips. Three of the chips were to make a special-purpose CPU with its program stored in ROM and its data stored in shift register read-write memory. [[Ted Hoff]], the Intel engineer assigned to evaluate the project, believed the Busicom design could be simplified by using dynamic RAM storage for data, rather than shift register memory, and a more traditional general-purpose CPU architecture. Hoff came up with a four-chip architectural proposal: a ROM chip for storing the programs, a dynamic RAM chip for storing data, a simple [[I/O]] device, and a 4-bit central processing unit (CPU). Although not a chip designer, he felt the CPU could be integrated into a single chip, but as he lacked the technical know-how the idea remained just a wish for the time being.

While the architecture and specifications of the MCS-4 came from the interaction of Hoff with [[Stanley Mazor]], a software engineer reporting to him, and with Busicom engineer [[Masatoshi Shima]], during 1969, Mazor and Hoff moved on to other projects. In April 1970, Intel hired Italian engineer [[Federico Faggin]] as project leader, a move that ultimately made the single-chip CPU final design a reality (Shima meanwhile designed the Busicom calculator firmware and assisted Faggin during the first six months of the implementation). Faggin, who originally developed the [[silicon gate]] technology (SGT) in 1968 at [[Fairchild Semiconductor]]<ref>{{cite conference | title=Insulated Gate Field Effect Transistor Integrated Circuits with Silicon Gates | last1=Faggin | first1=F. | last2=Klein | first2=T. | last3=Vadasz | first3=L. | conference=International Electronic Devices Meeting | publisher=IEEE Electron Devices Group | date=23 October 1968 | url=http://www.intel4004.com/images/iedm_covart.jpg | format=JPEG image | access-date=2009-12-23 | url-status=live | archive-url=https://web.archive.org/web/20100219143313/http://www.intel4004.com/images/iedm_covart.jpg | archive-date=19 February 2010 }}</ref> and designed the world's first commercial integrated circuit using SGT, the Fairchild 3708, had the correct background to lead the project into what would become the first commercial general purpose microprocessor. Since SGT was his very own invention, Faggin also used it to create his new methodology for [[random logic]] design that made it possible to implement a single-chip CPU with the proper speed, power dissipation and cost. The manager of Intel's MOS Design Department was [[Leslie L. Vadász]] at the time of the MCS-4 development but Vadász's attention was completely focused on the mainstream business of semiconductor memories so he left the leadership and the management of the MCS-4 project to Faggin, who was ultimately responsible for leading the 4004 project to its realization. Production units of the 4004 were first delivered to Busicom in March 1971 and shipped to other customers in late 1971.{{citation needed|date=March 2014}}