In late 1980, someone at IBM had a pretty neat idea. Responding to the popularity of “personal computers” like the Apple II and the TRS-80, IBM decided to get into the game. After a fast-paced development, IBM announced the first IBM Personal Computer 5150 in August 1981. To hit the market quickly, IBM mostly used off-the-shelf parts and licensed or purchased other components from third parties. One of those was the operating system.