That was the year after MS initially licensed it.
MS did buy it eventually, but not immediately.
MS bought SCP's QDOS less than one year after IBM came to them to discuss software for the IBM PC. source - Paul Allen's autobio, Tim Paterson's blog entry.
alt Hacker News
MS bought SCP's QDOS less than one year after IBM came to them to discuss software for the IBM PC. source - Paul Allen's autobio, Tim Paterson's blog entry.