Editing Semi-Automatic Ground Environment (section)

==Development==
Systems scientist [[Jay Forrester]] was instrumental in directing the development of the key concept of an interception system during his work at Servomechanisms Laboratory of MIT. The concept of the system, according to the [[Lincoln Laboratory]] site was to 
"develop a digital computer that could receive vast quantities of data from multiple radars and perform real-time processing to produce targeting information for intercepting aircraft and missiles."<ref name="Lincoln Laboratory"/>

[[File:SAGE console.jpeg|right|thumb| The AN/FSQ-7 had 100 system consoles, including the OA-1008 Situation Display (SD) with a [[light gun]] (at end of cable under plastic museum cover), cigarette lighter, and ash tray (left of the light gun).]]

The [[AN/FSQ-7 Combat Direction Central|AN/FSQ-7]] was developed by the Lincoln Laboratory's Digital Computer Laboratory and Division 6, working closely with IBM as the manufacturer. Each FSQ-7 actually consisted of two nearly identical computers operating in "duplex"<ref>{{Cite web|title = MIT Lincoln Laboratory: History:Early Digital Computing (continued)|url = https://www.ll.mit.edu/about/History/digitalcomputing_2.html|website = www.ll.mit.edu|access-date = 2016-01-12|quote = To ensure continuous operation each computer was duplexed; it actually consisted of two machines.|url-status = live|archive-url = https://web.archive.org/web/20151117020231/http://www.ll.mit.edu/about/History/digitalcomputing_2.html|archive-date = 2015-11-17}}</ref> for redundancy. The design used an improved version of the Whirlwind I magnetic core memory and was an extension of the Whirlwind II computer program, renamed AN/FSQ-7 in 1953 to comply with Air Force nomenclature. It has been suggested the FSQ-7 was based on the [[IBM 701]] but, while the 701 was investigated by MIT engineers, its design was ultimately rejected due to high error rates and generally being "inadequate to the task."<ref>{{Cite book|title = From Whirlwind to Mitre: The R&D Story of The SAGE Air Defense Computer|last1 = Redmond|first1 = Kent|publisher = MIT Press|year = 2000|isbn = 978-0262182010|pages = 187–188|last2 = Smith|first2 = Thomas}}</ref> IBM's contributions were essential to the success of the FSQ-7, and IBM benefited immensely from its association with the SAGE project, most evidently during development of the [[IBM 704]].<ref>{{Cite book|title = From Whirlwind to Mitre: The R&D Story of The SAGE Air Defense Computer|last1 = Redmond|first1 = Kent|publisher = MIT Press|year = 2000|isbn = 978-0262182010|pages = 437–438|last2 = Smith|first2 = Thomas}}</ref><ref>{{Cite book|title = AN/FSQ-7: The Computer That Shaped The Cold War|last = Ulmann|first = Bernd|publisher = De Gruyter Oldenbourg|year = 2014|isbn = 9783486727661|pages = 70}}</ref>

On October 28, 1953, the [[Air Force Council]] recommended 1955 funding for "ADC to convert to the Lincoln automated system"{{r|Schaffel}}{{rp|193}}  ("redesignated the '''SAGE System''' in 1954").{{r|Schaffel}}{{rp|201}}  The "''experimental SAGE subsector, located in [[Lexington, Massachusetts|Lexington, Mass.]], was completed in 1955…with a prototype AN/FSQ-7…known as XD-1''"<ref name="Intro" /> (single computer system{{r|SageTalk}} in Building F).{{r|RedmondSmith}}  In 1955, Air Force personnel began IBM training at the [[Kingston, New York]], prototype facility,{{r|EdwardsBenj}} and the "[[4620th Air Defense Wing]] (experimental SAGE) was established at Lincoln Laboratory"

On May 3, 1956, [[Earle E. Partridge|General Partridge]] presented ''[[CINCNORAD]]'s Operational Concept for Control of Air Defense Weapons'' to the [[Armed Forces Policy Council]],{{r|VolumeI}} and a June <!--29, -->1956 symposium presentation identified [[Waterfall model|advanced programming methods]] of SAGE code.<ref>{{Cite journal |author=United States Navy Mathematical Computing Advisory Panel  |date= 29 June 1956 |title=Symposium on advanced programming methods for digital computers |location=Washington, D.C. |publisher =Office of Naval Research, Dept. of the Navy |oclc=10794738 }}</ref>  <!--[[MITRE]] was formed in 1958 to provide oversight and management during deployment, phone lines were by the [[Bell System]], and 500,000 lines of [[assembly language]] were by [[System Development Corporation]].{{Citation needed|date=July 2011}}-->  For SAGE consulting [[Western Electric]] and [[Bell Telephone Laboratories]] formed the [[Air Defense Engineering Service]] (ADES),<ref>{{Cite report |last=McMullen |first=Richard F. |year=1965 |title=The Birth of SAGE, 1951–1958 |volume=ADC Hist Study 33}}  (cited by <!--Volume I p. 271 and--> Schaffel p. 207/312)</ref> which was contracted in January 1954.{{r|RedmondSmith}}  IBM delivered the FSQ-7 computer's prototype in June 1956,<ref name=IBM>{{cite web |work=SAGE: The First [computerized<nowiki>]</nowiki> National Air Defense Network |url=http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/sage/ |title=Overview &#124; |date=7 March 2012 |publisher=IBM.com |access-date=2013-05-08 |quote=the AN/FSQ-7…was developed, built and maintained by IBM. … In June 1956, IBM delivered the prototype of the computer to be used in SAGE. |url-status=dead |archive-url=https://web.archive.org/web/20130512051530/http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/sage/ |archive-date=2013-05-12 }}</ref> and Kingston's XD-2 with dual computers{{r|SageTalk}} guided a [[Cape Canaveral]] BOMARC to a successful aircraft intercept on August 7, 1958.{{r|Schaffel}}{{rp|197}}  Initially contracted to [[RCA]], the AN/FSQ-7 production units were started by IBM in 1958{{Citation needed|date=July 2011}} (32 DCs were planned{{r|Schaffel}}{{rp|207}} for networking NORAD regions.)<ref>{{Cite journal |date=Mar–Apr 1956 |title=SAGE: The New Aerial Defense System of the United States |journal=The Military Engineer}} (cited by Schaffel pp. 311, 332)</ref>  IBM's production contract developed 56 SAGE computers for $.5 billion (~$18 million per computer pair in each FSQ-7){{r|SageTalk}}—[[cf.]] the $2 billion WWII [[Manhattan Project]].

[[General Operational Requirement]]s (GOR) 79 and 97 were "the basic USAF documents guiding development and improvement of [the semi-automatic] ground environment.{{r|NORAD1958A}}{{rp|97}}  Prior to fielding the AN/FSQ-7 centrals, the USAF initially deployed "pre-SAGE semiautomatic intercept systems" ([[General Electric AN/GPA-37 Course Directing Group|AN/GPA-37]]) to [[Air Defense Direction Center]]s, ADDCs{{r|NORAD1958A}}{{rp|11}} (e.g., at "[[NORAD Control Center]]s").{{r|NORAD1958B}}  On April 22, 1958, NORAD approved [[Project Nike|Nike]] [[Army Air Defense Command Post|AADCPs]] to be collocated with the USAF manual ADDCs at [[Duncanville Air Force Station]] TX, [[Olathe Air Force Station]] KS, [[Belleville Air Force Station]] IL, and [[Osceola Air Force Station]] KS.{{r|NORAD1958B}}