Editing Intel 4004 (section)

==Distinction as first commercially-available microprocessor chip==
{{See also|Microprocessor#History|Microprocessor chronology}}

Multi-chip CPU designs were produced before the 4004. The [[Four-Phase Systems]] AL1 chip in 1969 combined registers and an ALU, but required an external control unit.<ref name=":0">{{Cite web |last=Shirriff |first=Ken |date=2016-08-30 |title=The Surprising Story of the First Microprocessors - IEEE Spectrum |url=https://spectrum.ieee.org/the-surprising-story-of-the-first-microprocessors |url-status=live |archive-url=https://web.archive.org/web/20241216162417/https://spectrum.ieee.org/the-surprising-story-of-the-first-microprocessors |archive-date=2024-12-16 |access-date=2024-12-29 |website=[[IEEE Spectrum]] |language=en}}</ref><ref>{{Cite web |last=Shirriff |first=Ken |date=2015 |title=The Texas Instruments TMX 1795: the (almost) first, forgotten microprocessor |url=https://www.righto.com/2015/05/the-texas-instruments-tmx-1795-first.html |url-status=live |archive-url=https://web.archive.org/web/20241228143736/http://www.righto.com/2015/05/the-texas-instruments-tmx-1795-first.html |archive-date=2024-12-28 |access-date=2024-12-29}}</ref> The [[MP944]] multi-chip processor based on a chipset of six unique chips (which separated steering logic, computation, and intermediate data storage into separate chips) was completed in 1970 for the [[Grumman F-14 Tomcat|F-14]] fighter jet as part of its [[F-14 CADC|Central Air Data Computer]] (F-14 CADC) and was [[Classified information|classified]] until 1998. The 4004 instead combined instruction decoding, computation, result routing, and register storage all on the same single chip.

On September 17, 1971 (two months before the 4004), the [[Texas Instruments]] TMS0100 (originally designated TMS1802NC) was announced as a "calculator on a chip" that integrated a CPU with ram and a program read-only memory. But while it was marketed as "totally programmable", this programming had to be done by changing a [[photomask]] in the manufacturing process.<ref>{{cite web |last=Woerner |first=Joerg |date=November 16, 2001 |title=The "Calculator-on-a-chip" |url=http://www.datamath.org/Story/Datamath.htm#The%20%22Calculator-on-a-chip%22 |access-date=March 22, 2016 |website=Datamath Calculator Museum}}</ref> It along with its 1974 successor the [[TMS1000]] (which used a [[Mask rom|factory-programmed mask ROM]]) have been considered the first microcontrollers — a computer on a chip containing not only the CPU, but also ROM, RAM, and I/O functions and which typically contains a permanent on-chip program that directs the chip to perform a dedicated function.<ref>{{cite web |last=Woerner |first=Joerg |date=February 26, 2001 |title=Texas Instruments: They invented the Microcontroller |url=http://www.datamath.org/Story/Intel.htm#Texas%20Instruments:%20They%20invented%20the%20Microcontroller |access-date=March 22, 2016 |website=Datamath Calculator Museum}}</ref><ref>{{Cite web |last=Leibson |first=Steven |date=2022-11-21 |title=A History of Early Microcontrollers, Part 2: The Texas instruments TMS1000 |url=https://www.eejournal.com/article/a-history-of-early-microcontrollers-part-2-the-texas-instruments-tms1000/ |url-status=live |archive-url=https://web.archive.org/web/20241225143756/https://www.eejournal.com/article/a-history-of-early-microcontrollers-part-2-the-texas-instruments-tms1000/ |archive-date=2024-12-25 |access-date=2024-12-29 |website=[[EEJournal]] |language=en-US}}</ref> While its designer was recognized by the US Patent Office in 1996 as the inventor of the microcontroller, microcontrollers generally run a fixed internal program and aren't easily reprogrammable and so are distinguished from microprocessors.<ref>{{cite news |author=Markoff |first=John |date=1996-06-20 |title=For Texas Instruments, Some Bragging Rights |url=https://www.nytimes.com/1996/06/20/business/for-texas-instruments-some-bragging-rights.html |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20241209100402/https://www.nytimes.com/1996/06/20/business/for-texas-instruments-some-bragging-rights.html |archive-date=2024-12-09 |access-date=2024-12-29 |newspaper=[[New York Times]]}}</ref> But because the 4004 executed instructions from ''external'' memory, it can serve in a general-purpose computer that is easily programmed and so is distinguished as a microprocessor.<ref name=":0" />

According to [[Nick Tredennick]], a microprocessor designer and expert witness to that 1996 patent case:

{{blockquote
| Here are my opinions from [the] study [I conducted for the patent case]. The first microprocessor in a commercial product was the [[Four Phase Systems#System|Four Phase Systems AL1]]. The first commercially available (sold as a component) microprocessor was the 4004 from Intel.<ref>{{cite web |url=http://corphist.computerhistory.org/corphist/documents/doc-487ecec0af0da.pdf |archive-url=https://web.archive.org/web/20110814002348/http://corphist.computerhistory.org/corphist/documents/doc-487ecec0af0da.pdf |archive-date=2011-08-14 |url-status=live |title=Dissertation 2004 |access-date=2017-11-14 }}</ref>
}}