The IBM 701 Electronic Data Processing Machine, known as the Defense Calculator while in development, was IBM’s first commercial scientific computer and its first series production mainframe computer, which was announced to the public on April 29, 1952. It was invented and developed by Jerrier Haddad and Nathaniel Rochester based on the IAS machine at Princeton. The business-oriented sibling of the 701 was the IBM 702 and a lower-cost general-purpose sibling was the famous IBM 650, which became the first mass produced computer in the world.