Our modern world would not exist without the personal computer, full stop. (For one thing, you wouldn't be reading this.) It's hard to settle on a firm date for its invention. The first commercial unit that didn't require assembly from a kit made its appearance in France in 1972. That Micral N would be followed by the Commodore PET and the Apple II in 1977 and in 1981 by the machine that lent its name to the whole category: the IBM PC.