This is the first draft of a report on the EDVAC, written by John von Neumann. It was prepared under Contract No. W-670-ORD-4926 between the United States Army Ordnance Department and the University of Pennsylvania Moore School of Electrical Engineering. The report was completed on June 30, 1945. It is an exact copy of the original typescript draft, with typographical errors corrected and forward references filled in where possible. Missing references are indicated by empty braces. Added material is enclosed in braces. The text and figures have been reset using TeX for improved readability, but the original manuscript layout has been preserved. A more modern interpretation of the von Neumann design is provided by M. D. Godfrey and D. F. Hendry in a 1993 IEEE paper. The report outlines the structure of a high-speed automatic digital computing system, focusing on its logical control. It discusses the main subdivisions of the system, including the central arithmetic part (CA), the central control part (CC), and the memory (M). It also describes the input (I) and output (O) parts, as well as the outside recording medium (R). The report details the principles governing arithmetic operations, the use of vacuum tubes, and the design of circuits for arithmetic operations such as addition, subtraction, multiplication, and division. It also covers the binary point, the square root operation, and the organization of the CA and memory. The report discusses the capacity of the memory, the organization of the memory, and the logical control of the device. It also addresses the use of E-elements, which are hypothetical elements that function like vacuum tubes. The report concludes with a discussion of the principles governing the arithmetic operations and the use of E-elements.This is the first draft of a report on the EDVAC, written by John von Neumann. It was prepared under Contract No. W-670-ORD-4926 between the United States Army Ordnance Department and the University of Pennsylvania Moore School of Electrical Engineering. The report was completed on June 30, 1945. It is an exact copy of the original typescript draft, with typographical errors corrected and forward references filled in where possible. Missing references are indicated by empty braces. Added material is enclosed in braces. The text and figures have been reset using TeX for improved readability, but the original manuscript layout has been preserved. A more modern interpretation of the von Neumann design is provided by M. D. Godfrey and D. F. Hendry in a 1993 IEEE paper. The report outlines the structure of a high-speed automatic digital computing system, focusing on its logical control. It discusses the main subdivisions of the system, including the central arithmetic part (CA), the central control part (CC), and the memory (M). It also describes the input (I) and output (O) parts, as well as the outside recording medium (R). The report details the principles governing arithmetic operations, the use of vacuum tubes, and the design of circuits for arithmetic operations such as addition, subtraction, multiplication, and division. It also covers the binary point, the square root operation, and the organization of the CA and memory. The report discusses the capacity of the memory, the organization of the memory, and the logical control of the device. It also addresses the use of E-elements, which are hypothetical elements that function like vacuum tubes. The report concludes with a discussion of the principles governing the arithmetic operations and the use of E-elements.