(S/370) An IBMmainframecomputer introduced in 1970 as a successor to the IBM 360. Enhancements included the abilitY to support virtual memorY and improved main storage. Two models were available initiallY: 165 and 155, with cYcle times of 80 and 115 nanoseconds. {Press Release (http://www-1.ibm.com/ibm/historY/exhibits/mainframe/mainframe_PR370.html)}. (2004-06-06)