From Relays to Electronic Computers
Colossus and ENIAC: Why “First Computer” Needs Context
Compare special-purpose and general-purpose machines and distinguish programming from stored programs.
In this lesson
Lesson goals
Compare special-purpose and general-purpose machines and distinguish programming from stored programs.
The idea explained
Colossus was operating at Bletchley Park by early February 1944 for specialized cryptanalytic work. It was electronic but not a general-purpose stored-program machine. ENIAC’s public unveiling in February 1946 marked a major step in general-purpose electronic computation; its original programming involved wiring and switch settings. Compare capabilities rather than awarding an unqualified title: electronic speed, breadth of tasks and stored-program flexibility are different advances.
Dates and milestones
- Early February 1944: Colossus is operational at Bletchley Park.
- February 1946: ENIAC is publicly demonstrated at the University of Pennsylvania.
Why was this a turning point?
Electronic switching removed mechanical movement from each logic step, but changing tasks remained a separate challenge.
Activity: try before reading the answer
Is “ENIAC was the first computer ever” precise? Rewrite it with a capability qualifier.
Answer and explanation
Describe it as a landmark early general-purpose electronic digital computer, explaining its original programming method and contrasting specialized machines.