01Overview
In 1945 the EDVAC report described the stored-program computer: five parts — arithmetic unit, control unit, memory, input and output — with instructions and data sharing memory, fetched and executed in address order. Before it, ENIAC was programmed by hand-patching cables; the stored program made software a thing independent of hardware.
The price is the “von Neumann bottleneck”: bandwidth between CPU and memory caps throughput. Hence caches, pipelines, multicore and prefetching. High-performance processors still bargain with that 1945 structure, while GPUs and neuromorphic chips try to route around it.
02History
- 1945
The EDVAC report
The classic description of the stored-program architecture.
- 1948
The Manchester Baby
The first machine to run a stored program.
- 1949
EDSAC goes into service
The first practical stored-program computer.
- 1951
UNIVAC I
The first commercial computer.
03Core concepts
Stored program
Instructions and data live in one addressable memory.
The five parts
Arithmetic unit, control unit, memory, input and output.
Von Neumann bottleneck
Bandwidth between CPU and memory becomes the performance ceiling.
04Hands-on
Do it once — it beats reading it ten times
Write a 30-line interpreter for a tiny stored-program machine: memory holds both instructions and data
05Self-check
Say it in your own words first, then open the answer. Whatever you cannot explain is what to review next.
Can you explain "Stored program"?
Instructions and data live in one addressable memory.
Can you explain "The five parts"?
Arithmetic unit, control unit, memory, input and output.
Can you explain "Von Neumann bottleneck"?
Bandwidth between CPU and memory becomes the performance ceiling.
What problem did it solve, and why was there nothing better at the time?
Go back to the history section: how was this done before, and what did it cost?
If you had to build it today, how would you break it down?
Use the hands-on task above: write a plan of at most three steps before you start.
06Key people
John von Neumann
1903 – 1957
Proposed the stored-program architecture and game theory.
Maurice Wilkes
1913 – 2010
Led EDSAC and pioneered microprogramming.
07Further reading
- First Draft of a Report on the EDVAC
- Computer Organization and Design