Abstract: This introductory chapter discusses the development of Alan Turing's ‘universal computing machine’, better known as the universal Turing Machine. The earliest large-scale electronic digital computers, the British Colossus (1943) and American ENIAC (1945), did not store programmes in memory. In 1936, Turing came up with an idea for a machine with limitless memory, in which both data and instructions were to be stored. By 1945, groups in Britain and the US began developing hardware for a universal Turing machine. Turing headed a group at the National Physical Laboratory in London that designed the Automatic Computing Engine (ACE), the first relatively complete specification of an electronic stored-programme digital computer.

Keywords: universal computing machine, universal Turing Machine, computers, hardware, Automatic Computing Engine,