The Harvard Mark I

Harvard Mark I, IBM, Automatic Sequence Controlled Calculator, Harvard University, computer, atomic bomb, Nagasaki, Hiroshima, calculations, Howard AikenHaving first been suggested in November 1937 by Howard Aiken, the Automatic Sequence Controlled Calculator was a massive computer, capable of performing hugely long calculations.

Its most notable contribution to the war effort was working out the best method for the atomic bombs that were dropped on Hiroshima and Nagasaki to explode. It deduced that the implosion method would be the most efficient and the rest is history.

It was able to work out calculations much faster than normal computers and with much greater accuracy and provided great service to Harvard and the USA until it was retired in 1959.