OS/360

text from wikipedia. OS/360 OS/360, officially known as IBM System/360 Operating System,[1][2] was a batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was heavily influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages. It was among the earliest operating systems to make direct access [...]