The Intel 4004, the world's first microprocessor, debuted in 1971. The rights to the chip, however, initially belonged to a Japanese calculator maker called Busicom, which commissioned Intel to build it in 1969.
By the time the chip came out, calculator prices had dropped, and Busicom wanted a discount. Intel agreed on the condition that it could sell the 4004 (technically a bundle of three chips) outside the calculator market. Busicom agreed.
Still, it took a while for the invention to catch on.
"I think it gave Intel its future, and for the first 15 years, we didn't realize it," Intel Chairman Andy Grove said in a 2001 interview. "It has become Intel's defining business area. But for...maybe the first 10 years, we looked at it as a sideshow. It kind of makes you wonder how many sideshows there are that never become anything more."