The personal computer's appeal to business users came about when two critical components came together: a professionally designed PC for the retail market and the killer application. After the release of the Apple I - in the form of what we would today call a motherboard - Steve Jobs realised that not all potential customers wanted to build their own PCs.

Owen Linzmayer writes in Apple Confidential 2.0 that Jobs hated the crude metal cases of hobbyist computers of the time and insisted that the Apple II have a professionally designed plastic enclosure that would appeal to consumers. He got his way and the Apple II went on sale (for $1 298) on 17 April 1977 in the now familiar package with a built-in power supply and keyboard. The monitor was extra, as were the disk drives, modem and all the other peripherals that came later. But that was only the first piece of the puzzle and it took more than two years before the other pieces fell into place.