At last - the secrets of Bletchley Park's powerful codebreaking computers. This is a history of Colossus, the world's first fully-functioning electronic digital computer. Colossus was used during the Second World War at the Government Code and Cypher School at Bletchley Park, where it played an invaluable role cracking enemy codes. Until very recently, much about the Colossus machine was shrouded in secrecy, largely because the codes that were employed remained in use by the British security services until a short time ago. This book only became possible due to the declassification in the US of wartime documents. With an introductory essay on cryptography and the history of code-breaking by Simon Singh, this book reveals the workings of Colossus and the extraordinary staff at Bletchley Park through personal accounts by those who lived and worked with the computer. Among them is the testimony of Thomas Flowers, who was the architect of Colossus and whose personal account, written shortly before he died, is published here for the first time. Other essays consider the historical importance of this remarkable machine, and its impact on the generations of computing technology that followed.

Alan Turing is regarded as one of the greatest scientists of the 20th century. But who was Turing, and what did he achieve during his tragically short life of 41 years? Best known as the genius who broke Germany's most secret codes during the war of 1939-45, Turing was also the father of the modern computer. Today, all who 'click-to-open' are familiar with the impact of Turing's ideas. Here, B. Jack Copeland provides an account of Turing's life and work, exploring the key elements of his life-story in tandem with his leading ideas and contributions. The book highlights Turing's contributions to computing and to computer science, including Artificial Intelligence and Artificial Life, and the emphasis throughout is on the relevance of his work to modern developments. The story of his contributions to codebreaking during the Second World War is set in the context of his thinking about machines, as is the account of his work in the foundations of mathematics.

Alan Turing was one of the most important and influential thinkers of the 20th century. This volume makes his key writings available to a non-specialist readership for the first time. They make fascinating reading both in their own right and for their historic significance: contemporary computational theory, cognitive science, and artificial intelligence life all spring from this ground-breaking work.

During World War II Alan Turing's work on Colossus enabled the Allies to crack German ciphers. After the war he worked on the ACE, or automatic computing engine. This volume traces the genesis and development of ACE and examines how it became the forerunner of the modern computer.