The History of the Disk Operating System (DOS) In the beginning, before the advent of user-friendly operating systems, computers ran using the CP/M operating system (Control Program for microcomputers). The program itself seemed simple, but the complexity of using it meant that not many fully understood how to use it. Since the program was also limited in use, as it was designed for 8-bit systems, a new operating system was needed when the 16-bit IBM systems came out. IBM attempted to purchase CP/M from its inventor Gary Kildall, but he proved to be elusive and refused to sell. IBM through Microsoft and owner Bill Gates, acquired and licensed a similar program, the Q-DOS program. The first commercially available operating system, PC-DOS, was based on this purchase. To maintain the rights to PC-DOS, Bill Gates convinced IBM to allow him to separate sales of the operating system from that of the computer. This separation between software and hardware allowed him to create MS-DOS and the global dynasty it holds today (Bellis). Types of DOS and When They Were in Use In the early days of DOS programming, there were many variations, but MS- DOS did not begin as a Microsoft product. CP/M was designed by Gary Kildall, called the man who could have been Bill Gates. As Business Week's Steve Hamm puts it: "There's no question that Kildall was one of the industry's pioneers. He invented the first microcomputer operating system in the early 1970s, making it possible for hobbyists and companies to build microcomputers. early personal computers. Legal aspects aside, Microsoft's original DOS was based in part on Kildall's CP/M. His intuition was that by creating an operating system separate from the hardware, applications... were at the heart of the paper ... operating systems (pp. 14-17). Ann Arbor, MI: Nimble Books.ReferencesBellis, M. (n.d., 2012, from http://inventors.about.com/od/computersoftware/a/Putting). -Microsoft-On-The-Map.htmCeruzzi, P.E. (1998 A history of modern computing (pp. 270-272). London, England: The MIT Press.DOS (Disk Operating System) (n.d.). S. and Greene , J. (2004, October 25). The Man Who Could Have Been Bill Gates. In Business Week. Retrieved January 14, 2012, from http://www.businessweek.com/magazine/content/04_43/b3905109_mz063.htmWatson, J. (2008). A history of computer operating systems (pp. 14-17). Ann Arbor, MI: Agile Books.