Computing · 1944

Colossus

Bletchley Park's tube machine that broke Hitler's high-command cipher.

Tommy Flowers built Colossus with about 1,600 tubes (2,400 in the Mark 2) to attack the Lorenz cipher, reading tape at 5,000 characters per second. Ten were operating by war's end, kept secret until the 1970s.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 3

Flip-flop circuit 1918
Vacuum tube 1904
Telephone exchange 1878

Related measurements

The dashed line marks when it first worked.

Fastest computer in the world Latest: 2.2×10¹⁸ operations per second (2026) Source: Wikipedia: List of fastest computers; Wikipedia: History of supercomputing

Computation per constant dollar, 1850-2006 Latest: 7.3B million units of computer power per 2006 $ (2003) Source: Nordhaus 2007, Two Centuries of Productivity Growth in Computing, J. Econ. Hist. 67(1), Table 6