Researched from the 1940s, infrared touchpanels first gained traction in the University of Illinois's PLATO educational computers during the 1970s. But not until the 1982 World's Fair in Knoxville, Tennessee, did the wider public get a chance to try touch input. The U.S. Pavilion showcased 33 televisions covered with Elographics' new transparent touch-sensitive panels. The next year (and completely separately), Hewlett-Packard introduced its HP-150, the first commercial touchscreen computer, which used an 8-inch Sony CRT surrounded by infrared receivers. Two decades later, Apple, Google, HTC, Nokia, and others are engaged in a multitouch catfight. Lame.
Image credit: Vintage Computing