[3] He was hired by Geophysical Service Incorporated in 1948, a company which then focused on the oil and gas drilling industry; GSI subsequently evolved into Texas Instruments.
In 1958, he was the head of the semiconductor team as Jack Kilby invented the integrated circuit, which Texas Instruments used in the development of the company's hand-held calculators, printers and personal computers, as well as toys.
With increasing competition later in his career from Asian suppliers, Shepherd shifted Texas Instruments away from consumer products and focused on semiconductor technology.
into world leadership not only in semiconductors, but took the chip industry into consumer electronics with calculators, digital watches and toys where Texas Instruments dominated even companies like Hewlett-Packard and Intel".
As described in his obituary in The New York Times, Shepherd was "an engineer to the core" even in retirement, taking responsibility for construction of buildings, dams and fire protection equipment on the ranch.