The Free On-line Dictionary of Computing (30 December 2018):

System/370
IBM 370

    (S/370) An IBM mainframe computer
   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)