The “First Draft of a Report on the EDVAC” is a 101-page document written by John von Neumann and distributed on June 30, 1945. It provided the first theoretical description of what would become known as the von Neumann architecture—the fundamental design paradigm for virtually all modern computers.
Background
Von Neumann joined the ENIAC project at the University of Pennsylvania’s Moore School of Electrical Engineering in 1944, brought in as a consultant due to his work on the Manhattan Project, which required massive computations. At the Moore School, he participated in discussions with J. Presper Eckert and John Mauchly about the design of ENIAC’s successor, the Electronic Discrete Variable Automatic Computer (EDVAC).
The Stored-Program Concept
The document’s most revolutionary idea was the stored-program concept: storing both program instructions and data in the same memory. Prior computers like ENIAC required physical rewiring to change programs. The stored-program architecture meant computers could be reprogrammed simply by loading new instructions into memory.
The report describes a computer with five main components:
- Central arithmetic unit - performs mathematical operations
- Central control unit - coordinates all operations
- Memory - stores both numbers (data) and orders (instructions)
- Input mechanism - receives data from outside
- Output mechanism - delivers results
Controversy
The report was circulated by Herman Goldstine bearing only von Neumann’s name, despite being based on collaborative discussions with Eckert, Mauchly, and others[1]. This led to lasting controversy over credit for the stored-program concept.
Impact
Despite its “draft” status, the report was widely circulated and profoundly influenced computer design worldwide. Maurice Wilkes read it and designed EDSAC at Cambridge, which became the first practical stored-program computer. The architecture it described—now called the von Neumann architecture—remains the foundation of virtually all computers today[2].
Sources
- Haverford College. “John von Neumann and the Report on the EDVAC.” Documents the controversy over authorship credit.
- Wikipedia. “Von Neumann architecture.” Describes the lasting influence of this design.