The model for a class of computing machines designed by John von Neumann. The IAS (Institute for Advanced Study) machine was started at Princeton in 1946 and was completed in 1951. This machine used electrostatic storage devices—cathode-ray tubes—as the main memory. Such tubes, called Williams tubes, could each store 1024 bits. Other computers modelled after the IAS computer included ORACLE, JOHNNIAC, ILLIAC I, MANIAC, and IBM 701.