Editing Microprocessor (section)

====Garrett AiResearch CADC (1970)====
{{Primary sources|section|date=March 2010}}
{{Further|F-14 CADC}}

In 1968, [[Garrett AiResearch]] (who employed designers [[Ray Holt (computer scientist)|Ray Holt]] and Steve Geller) was invited to produce a digital computer to compete with [[electromechanical]] systems then under development for the main flight control computer in the [[US Navy]]'s new [[F-14 Tomcat]] fighter. The design was complete by 1970, and used a [[MOSFET|MOS]]-based chipset as the core CPU. The design was significantly (approximately 20 times) smaller and much more reliable than the mechanical systems it competed against and was used in all of the early Tomcat models. This system contained "a 20-bit, [[Pipeline (computing)|pipelined]], [[Parallel computing|parallel]] [[multiprocessor|multi-microprocessor]]". The Navy refused to allow publication of the design until 1997. Released in 1998, the documentation on the [[Central Air Data Computer|CADC]], and the [[MP944]] chipset, are well known. Ray Holt's autobiographical story of this design and development is presented in the book: The Accidental Engineer.<ref>{{Cite web|url=https://firstmicroprocessor.com/|archiveurl=https://web.archive.org/web/20140106143912/http://www.firstmicroprocessor.com/|url-status=dead|title=First Microprocessor|archivedate=January 6, 2014|website=First Microprocessor &#124; 50th Anniversary of the Microprocessor 2020}}</ref><ref>{{cite web | title=World's First Microprocessor Chip Set | last=Holt | first=Ray M. | url=http://www.firstmicroprocessor.com | publisher=Ray M. Holt website | archive-date=January 6, 2014 | access-date=2010-07-25 | url-status=live | archive-url=https://web.archive.org/web/20140106143912/http://www.firstmicroprocessor.com/ }}</ref>
Ray Holt graduated from [[California State Polytechnic University, Pomona]] in 1968, and began his computer design career with the CADC.<ref>{{Cite magazine |last=Fallon |first=Sarah |title=The Secret History of the First Microprocessor, the F-14, and Me |url=https://www.wired.com/story/secret-history-of-the-first-microprocessor-f-14/ |access-date=2024-01-21 |magazine=Wired |language=en-US |issn=1059-1028 |archive-date=18 January 2024 |archive-url=https://web.archive.org/web/20240118132936/https://www.wired.com/story/secret-history-of-the-first-microprocessor-f-14/ |url-status=live }}</ref> From its inception, it was shrouded in secrecy until 1998 when at Holt's request, the US Navy allowed the documents into the public domain. Holt has claimed that no one has compared this microprocessor with those that came later.<ref>{{cite speech | title=Lecture: Microprocessor Design and Development for the US Navy F14 FighterJet | last=Holt | first=Ray | date=27 September 2001 | location=Room 8220, Wean Hall, Carnegie Mellon University, Pittsburgh, PA, US | url=http://www.pdl.cmu.edu/SDI/2001/092701.html | access-date=2010-07-25 | url-status=live | archive-url=https://web.archive.org/web/20111001020654/http://www.pdl.cmu.edu/SDI/2001/092701.html | archive-date=1 October 2011 }}</ref> According to Parab et al. (2007), {{Blockquote|text=The scientific papers and literature published around 1971 reveal that the MP944 digital processor used for the F-14 Tomcat aircraft of the US Navy qualifies as the first microprocessor. Although interesting, it was not a single-chip processor, as was not the Intel 4004{{snd}}they both were more like a set of parallel building blocks you could use to make a general-purpose form. It contains a CPU, [[RAM]], [[ROM]], and two other support chips like the Intel 4004. It was made from the same [[PMOS logic|P-channel]] technology, operated at [[military specifications]] and had larger chips{{snd}}an excellent computer engineering design by any standards. Its design indicates a major advance over Intel, and two year earlier. It actually worked and was flying in the F-14 when the Intel 4004 was announced. It indicates that today's industry theme of converging [[Digital signal processor|DSP]]-[[microcontroller]] architectures was started in 1971.<ref>{{cite book | title=Exploring C for Microcontrollers: A Hands on Approach | last1=Parab | first1=Jivan S. | last2=Shelake | first2=Vinod G. | last3=Kamat | first3=Rajanish K. | last4=Naik | first4=Gourish M. | publisher=Springer | page=4 | year=2007 | isbn=978-1-4020-6067-0 | url=http://ee.sharif.edu/~sakhtar3/books/Exploring%20C%20for%20Microcontrollers.pdf | access-date=2010-07-25 | url-status=live | archive-url=https://web.archive.org/web/20110720043756/http://ee.sharif.edu/~sakhtar3/books/Exploring%20C%20for%20Microcontrollers.pdf | archive-date=2011-07-20 }}</ref>}} This convergence of DSP and microcontroller architectures is known as a [[digital signal controller]].<ref>{{cite book|editor=Yovits, M. C.|author1=Dyer, S. A.|author2=Harms, B. K.|chapter=Digital Signal Processing|title=Advances in Computers|year=1993|volume=37|pages=104–107|publisher=Academic Press|doi=10.1016/S0065-2458(08)60403-9|isbn=9780120121373|chapter-url=https://books.google.com/books?id=vL-bB7GALAwC&pg=PA104|url-status=live|archive-url=https://web.archive.org/web/20161229031814/https://books.google.com/books?id=vL-bB7GALAwC&pg=PA104|archive-date=2016-12-29}}</ref>