Editing Texas Instruments (section)

===Geophysical Service Incorporated===
In 1930, [[J. Clarence Karcher]] and [[Eugene McDermott]] founded Geophysical Service, an early provider of [[reflection seismology|seismic exploration]] services to the petroleum industry. In 1939, the company reorganized as Coronado Corp,<ref>{{cite web| url = http://www.ti.com/corp/docs/company/history/lowbandwidthtimeline.shtml| title = Coronado Corp.}}</ref> an oil company with Geophysical Service Inc (GSI), now as a subsidiary. On December 6, 1941, McDermott along with three other GSI employees, J. Erik Jonsson, Cecil H. Green, and H. B. Peacock purchased GSI. During World War II, GSI expanded its services to include [[electronics]] for the [[United States Army|U.S. Army]], [[United States Army Signal Corps|Army Signal Corps]], and [[United States Navy|U.S. Navy]]. In 1951, the company changed its name to Texas Instruments, spun off to build seismographs for oil explorations<ref name="TIcalcsMedium">{{cite web |url=https://gen.medium.com/big-calculator-how-texas-instruments-monopolized-math-class-67ee165045dc |title=Big Calculator: How Texas Instruments Monopolized Math Class |access-date=September 26, 2019 }}</ref> and with GSI becoming a wholly owned subsidiary of the new company.

An early success came for TI-GSI in 1965, when GSI was able (under a [[security clearance|Top Secret]] government contract) to monitor the [[Soviet Union]]'s underground [[nuclear weapon]]s [[nuclear testing|testing]] under the ocean in [[Vela Uniform]], a subset of [[Project Vela]], to verify compliance of the [[Partial Nuclear Test Ban Treaty]].<ref>{{cite web |url=http://www.ti.com/corp/docs/company/history/timeline/gps/1960/docs/65-gsi-ti.htm |title=GSI/TI part of Vela Uniform project to detect underground nuclear explosions |publisher=Texas Instruments |access-date=September 23, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160303214827/http://www.ti.com/corp/docs/company/history/timeline/gps/1960/docs/65-gsi-ti.htm |archive-date=March 3, 2016|df=mdy-all}}</ref>

Texas Instruments also continued to manufacture equipment for use in the seismic industry, and GSI continued to provide seismic services.  After selling (and repurchasing) GSI, TI finally sold the company to Halliburton in 1988, after which sale GSI ceased to exist as a separate entity.