The correspondence to the right appeared in Nature 441, 25, (4 May 2006); doi:10.1038/441025d; copyright © Macmillan Publishers Ltd.
Colossus was the first electronic digital computer

Your timeline (Milestones in scientific computing, Nature 440, 401-405; 2006) starts in 1946 with ENIAC, "widely thought of as the first electronic digital computer". But that title should arguably be held by the British special-purpose computer Colossus (1943), used during the Second World War in the secret code-breaking centre at Bletchley Park.

Modern computing history starts even earlier, in 1941, with the completion of the first working program-controlled computer Z3 by Konrad Zuse in Berlin. Zuse used electrical relays to implement switches, whereas Colossus and ENIAC used tubes. But the nature of the switches is not essential - today's machines use transistors, and the future may belong to optical or other types of switches.

Jürgen Schmidhuber
IDSIA, Galleria 2, 6928 Manno-Lugano, Switzerland & Robotics and Embedded Systems, Tech. Univ. München, Computer Science, Boltzmannstr. 3, 85748 Garching, Germany

Related links:
1. Zuse
2. Turing
3. Goedel
4. Schickard
5. Leibniz
Schickard Leibniz Kurt Goedel Turing Konrad Zuse

Check out the Computer history speedup page: Omega point by 2040?
Schmidhuber's law: computer history speed-up