 The GM-NAA I/O, created by Owen Mock and Bob Patrick of General Motors Research Laboratories in early 1956 (or late 1955) for their IBM 701 mainframe computer is generally considered to be the first "batch processing" operating system and possibly the first "real" operating system.Rudimentary forms of operating systems existed before batch processing, the Input/Output Control System (IOCS) being one example.However, what specifically differentiated and made the GM-NAA I/O as the first of its kind was that instead of having a human operator manually load each program as what previous systems were only capable of doing, computerized software as used on GM-NAA I/O, thereafter handled the scheduling, management, and multi-tasking of all computer applications.