Editing DEC Alpha (section)

===Alpha===
The new design uses most of the basic PRISM concepts, but was re-tuned to allow VMS and VMS programs to run at reasonable speed with no conversion at all. The primary Alpha instruction set architects were Richard L. Sites and Richard T. Witek.<ref>{{cite book |url=https://www.elsevier.com/books/alpha-axp-architecture-reference-manual/sites/978-1-4831-8403-6 |isbn=978-1-4831-8403-6 |title=Alpha AXP Architecture Reference Manual – 2nd Edition |author1=Richard L. Sites |author2=Richard T. Witek |date=2014-05-16 |publisher=Digital Press |access-date=2018-09-20 |archive-date=2018-09-20 |archive-url=https://web.archive.org/web/20180920122621/https://www.elsevier.com/books/alpha-axp-architecture-reference-manual/sites/978-1-4831-8403-6 |url-status=live}}</ref> The PRISM's Epicode was developed into the Alpha's [[PALcode]], providing an abstracted interface to platform- and processor implementation-specific features.

The main contribution of Alpha to the microprocessor industry, and the main reason for its performance, is not so much the architecture but rather its implementation.<ref>{{Cite web|url=https://www.ibm.com/developerworks/library/pa-microhist/|title=Great moments in microprocessor history|last=Warner|first=W.|date=December 22, 2004|website=IBM|access-date=January 18, 2018|archive-date=January 19, 2018|archive-url=https://web.archive.org/web/20180119120058/https://www.ibm.com/developerworks/library/pa-microhist/|url-status=live}}</ref> At that time (as it is now), the microchip industry was dominated by automated design and layout tools. The chip designers at Digital continued pursuing sophisticated manual circuit design in order to deal with the complex VAX architecture. The Alpha chips show that manual circuit design applied to a simpler, cleaner architecture allows for much higher operating frequencies than those that are possible with the more automated design systems. These chips caused a renaissance of custom circuit design within the microprocessor design community.

Originally, the Alpha processors were designated the ''DECchip 21x64'' series,<ref name=X21>{{cite web
|title=cpu-collection.de – DEC Alpha AXP
|url=http://www.cpu-collection.de/?l0=co&l1=DEC&l2=Alpha+AXP
|quote=The first processors of the Alpha family were designated the DECchip 21064 series (the "21" signifying 21st century)
|access-date=2018-09-20
|archive-date=2018-09-20
|archive-url=https://web.archive.org/web/20180920160836/http://www.cpu-collection.de/?l0=co&l1=DEC&l2=Alpha+AXP
|url-status=live
}}</ref> with "DECchip" replaced in the mid-1990s with "Alpha". The first two digits, "21" signifies the 21st century, and the last two digits, "64" signifies 64 bits.<ref name=X21/> The Alpha was designed as 64-bit from the start and there is no 32-bit version. The middle digit corresponds to the generation of the Alpha architecture. Internally, Alpha processors were also identified by ''EV'' numbers, EV officially standing for "Extended VAX" but having an alternative humorous meaning of "Electric [[Vlasic Pickles|Vlasic]]", giving homage to the [[Glowing pickle demonstration|Electric Pickle]] experiment at Western Research Lab.<ref name=pickle>{{cite journal
  | title = WRL Technical Note TN-13: Characterization of Organic Illumination Systems
  | publisher = Digital Equipment Corporation
  | year = 1989
  | url = https://www.hpl.hp.com/techreports/Compaq-DEC/WRL-TN-13.html
  | format = [[PDF]]
  | access-date = 2007-10-04
  | author1 = Bill Hamburgen
  | author2 = Jeff Mogul
  | author3 = Brian Reid
  | author-link3 = Brian Reid (computer scientist)
  | author4 = Alan Eustace
  | author-link4 = Alan Eustace
  | author5 = Richard Swan
  | author6 = Mary Jo Doherty
  | author7 = Joel Bartlett
  | journal = 
  | archive-date = 2008-05-12
  | archive-url = https://web.archive.org/web/20080512033558/http://www.hpl.hp.com/techreports/Compaq-DEC/WRL-TN-13.html
  | url-status = dead
  }}</ref> The number in the EV designations indicated the semiconductor process which the chip was designed for. For example, the EV4 processor used DEC's CMOS-4 process.<ref name="comerford" />

In May 1997, DEC sued [[Intel]] for allegedly infringing on its Alpha patents in designing the [[Original Intel Pentium (P5 microarchitecture)|original Pentium]], [[Pentium Pro]], and [[Pentium II]] chips.<ref>{{cite magazine|title=DEC, Cyrix sue Intel|first1=Gale|last1=Bradley|first2=Jim|last2=DeTar|magazine=Electronic News|volume=43|issue=2168|pages=1, 60|date=May 19, 1997|issn=1061-6624|url=https://archive.org/details/sim_electronic-news_1997-05-19_43_2168/mode/1up}}</ref> As part of a settlement, much of DEC's chip design and fabrication business was sold to Intel. This included DEC's [[StrongARM]] implementation of the [[ARM architecture family|ARM computer architecture]], which Intel marketed as the [[Intel XScale|XScale]] processors commonly used in [[Pocket PC]]s. The core of Digital Semiconductor, the Alpha microprocessor group, remained with DEC, while the associated office buildings went to Intel as part of the Hudson fab.<ref>{{cite interview |first=Allan |last=Baum |interviewer= David Brock |title=Oral History of Allen Baum |date=July 18, 2018 |url=https://archive.computerhistory.org/resources/access/text/2018/06/102717165-05-01-acc.pdf |archive-url=https://web.archive.org/web/20210207063355/https://archive.computerhistory.org/resources/access/text/2018/06/102717165-05-01-acc.pdf |archive-date=2021-02-07 |url-status=live |page=60}}</ref>