There have been exactly three seminal events in the history of the personal computer, events which shaped the entire industry in one moment. In reverse chronological order:
3. January 1984, the introduction of The Macintosh
2. August 1981, the introduction of the IBM PC
1. January 1975, the introduction of the Altair 8800.
Arthur P. Salsberg was the Editor of Popular Electronics in the mid 70's. He chose the lead article and cover photo for the January 1975 issue. He was a bit late into the game, as his chief rival had featured a similar construction project the year before. But Art had over 400,000 subscribers (about one-in-500 for the US population back than), and all of them saw, and WANTED, the Altair 8800 at the same time. This made Art a god in technical publishing, and makes him one of the guys who "started" or "founded" the PC revolution. One of his subscribers, Paul Allen, showed his copy to his friend, Bill Gates. They wrote a BASIC interpreter for the computer, and started Microsoft to sell it.