From Turing Machine to Electronic Brain

This chapter1 analyses the relationships and differences between the various machines that Alan M. Turing invented, projected, created and programmed, in his work in fields ranging from logic and the theory of computability to cryptanalysis, computer science and artificial intelligence. Turing’s position in his article ‘On Computable Numbers’ was one of complete trust in the ability of a machine’s ‘table of instructions’ to achieve whatever result the ‘programmer’ desired. Nine years later, working on the design of the ACE project, he put forward a rather different view concerning the ability of the stored-program electronic computer to perform ‘intelligent’ tasks. The first surviving document to show Turing’s new attitude towards machines was his ‘Proposed Electronic Calculator’2. The machine that Turing proposed there, was different from both the universal Turing machine and the machine outlined in von Neumann’s ‘First Draft’.3 I compare Turing’s project with von Neumann’s in order to underline similarities and—above all—the differences.