From ACE to the G-15

The 1946 Turing proposal for a stored-program computer at Britain´s National Physical Laboratory is briefly described. The author´s participation in the Test Assembly design, NPL´s design of the ACE Pilot Model, and the subsequent design of the ACE are presented. The author´s return to the United States and his efforts to build a similar computer at the National Bureau of Standards are described. Finally, the design of the Bendix G-15 and how it is related to the other computers is discussed. These computers were characterized by having re-circulating memories and logical designs that permitted the execution of several instructions per memory cycle.