In the winter of 1974, Paul Allen showed up at Bill Gates' dorm at Harvard with the new issue of Popular Electronics in his hand. MITS, a company in Albuquerque, had made a home, or "personal," computer and was calling it the Altair.
“Hey, this thing is happening without us,” Allen said to Gates, referring to the home-computing revolution they always jabbered on about. So, as Walter Isaacson records in the Harvard Gazette, the two went into a eight-week fugue state of writing code. Which is how, in the mid-70s, computational legends were born.