First Draft of a Report on the EDVAC

The First Draft of a Report on the EDVAC (commonly shortened to First Draft) is an incomplete 101-page document written by John von Neumann and distributed on June 30, 1945 by Herman Goldstine, security officer on the classified ENIAC project. It contains the first published description of the logical design of a computer using the stored-program concept, which has come to be known as the von Neumann architecture; the name has become controversial due to von Neumann's failure to name other contributors. Von Neumann wrote the report by hand while commuting by train to Los Alamos, New Mexico and mailed the handwritten notes back to Philadelphia. Goldstine had the report typed and duplicated. While the date on the typed report is June 30, 24 copies of the First Draft were distributed to persons closely connected with the EDVAC project five days earlier on June 25. Interest in the report caused it to be sent all over the world; Maurice Wilkes of Cambridge University cited his excitement over the report's content as the impetus for his decision to travel to the United States for the Moore School Lectures in Summer 1946. Von Neumann describes a detailed design of a "very high speed automatic digital computing system." He divides it into six major subdivisions: a central arithmetic part, CA; a central control part, CC; memory, M; input, I; output, O; and (slow) external memory, R, such as punched cards, Teletype tape, or magnetic wire or steel tape. The CA will perform addition, subtraction, multiplication, division and square root. Other mathematical operations, such as logarithms and trigonometric functions are to be done with table look up and interpolation, possibly biquadratic. He notes that multiplication and division could be done with logarithm tables, but to keep the tables small enough, interpolation would be needed and this in turn requires multiplication, though perhaps with less precision. Numbers are to be represented in binary notation.