Sams says he did get together with Kildall in Pacific Grove a short time later, but they couldn't reach an agreement. At around the same time, he saw Gates again. He and Gates both knew of the operating system Paterson had built at Seattle Computer Co. As Sams recounts, "Gates said: 'Do you want to get [QDOS], or do you want me to?' I said: 'By all means, you get it."' Gates bought Paterson's program, called QDOS, for $50,000, renamed it DOS, improved it, and licensed it to IBM for a low per-copy royalty fee.
It wasn't until nearly a year later that Kildall discovered that Gates, a longtime friend, had plucked the plum software deal out of his grasp. IBM sent test versions of its PC out shortly before it was announced in August, 1981, and a consultant working for DRI noticed the operating system was remarkably similar to CP/M. The consultant, Andy Johnson-Laird, remembers that Kildall looked at the screen and was stunned. "There were some shallow changes, but it was essentially the same program," says Johnson-Laird in an interview with BusinessWeek.