System/360, also DOS/360, or simply DOS, is the discontinued first member of a sequence of operating systems for IBM System/360, System/370 and later mainframes
z/TPF. IBM developed ACP and its successors because: in the mid-1960s IBM's standard operating systems (DOS/360and OS/360) were batch-oriented and could
language andsuccessors is a series of assembly languages and assemblers made for the IBM System/360 mainframe system and its successors through the IBM Z. The
OS/360 itself was discontinued, successor operating systems, including the virtual storage MVS and the 64-bit z/OS, are still run as of 2023[update] and
latest one in the DOS/360 lineage, which originated in 1965. It is less common than z/OS and is mostly used on smaller machines. DOS/VSE was introduced