John Diebold, a business visionary who preached computerization during the era of Elvis and Eisenhower as the future of worldwide industry, has died at the age of 79. Diebold died of esophageal cancer Monday at his home in suburban Bedford Hills, said a nephew. Although Diebold is now hailed as a prophet of the computerized future, his zeal for computers was not widely shared in the 1950s. Diebold laid out his vision of a computerized future with his 1952 book, “Automation,” which presented the then-radical notion of using programmable devices in daily business.