I've heard a number of claims about how Microsoft came into existence with IBM's help. I don't know the truth, but there is enough evidence to make it clear that Bill Gates didn't deserve either the credit or the fortune that Microsoft got.
There's actually much more to the story than meets the history buff (as there often is). Mr. Gates had dropped out of Harvard, because his buddy, Paul Allen, coaxed him into it. Originally, the company sold copies of BASIC on cassette tape and a digital road sign that displayed the speed of cars approaching the sign to its driver.
Bill's parents, William and Mary Gates, were disappointed to learn that their son had dropped out of Harvard, and when Mary Gates subsequently found herself at a fund raiser, hobnobbing with top executives at IBM, naturally the subject turned to her son. Ostensibly, her motivation was to get him motivated to finish college, so she pitched for them to give him a job. What the executives heard, however, was that here was a link to someone who might be able to supply the suits from Boca Raton with a BASIC interpreter.
Soon, Bill was being visited by two astute gentlemen from IBM, and a deal was sealed for [what came to be known as] Microsoft BASIC. The two IBM guys were also out west to visit Dr. Gary Kildall, founder of Digital Research, to broker a deal for his version of the CP/M operating system. Their attempt to meet with him failed. They had neglected to make an appointment and, learning that he was on the golf course on their arrival, followed him out there to get the negotiations started. Dr. Kildall, not liking the aggressive tactics of the gentlemen from Boca Raton, rebuffed their deal. They had already done this before visiting with Mr. Gates, so after the deal for BASIC was settled, when Bill asked if there was anything else he could do for them, they mentioned that they needed a CP/M disk operating system. Bill didn't have one, but he knew someone who did, so he promised he'd get back with them. He bought Tim Patterson's clone of CP/M called 86/DOS. After the deal between Bill and IBM, it became known as IBM PC DOS. But, it was really just another of the many versions of CP/M.
It's funny to me how people who write history seem willing to bend the truth and leave out the slightly embarrassing parts about the worlds richest men. In the deepest of details, the origins of the rich and famous titans of industry are mere day to day copings with the mundane punctuated by intense conflicts and struggles. It is often the unforeseen turn of events that defines the opportunities. The character of the men is often obscured in our tendency to obsess on the outcome of defining moments, rather than how those moments came into fruition.
I can't be certain of exactly how much of this version is "the truth." I wasn't there. But it does have the ring of truth, and I didn't make any of it up. I read about this back then, before Gates became the World's richest man, and before History became tarnished by the weather of time.
Best,
Herb