Colossus at wartime Bletchley Park. B. Jack Copeland.1 Table of Contents Introduction The Tunny machine A sample decrypt Central figures in the attack on Tunny Breaking the Tunny machine Turingery Tutte’s statistical method Heath Robinson Flowers, neglected pioneer of computing Colossus Misconceptions about Colossus Postwar Colossus and the modern computer Colossus and two operators from the Women’s Royal Naval Service, Dorothy Du Boisson (left) and Elsie Booker.2 The Lorenz Schlüsselzusatz (cip...