Notes on memory (1945)

This chapter presents fragments from Turing's draft of ‘Proposed Electronic Calculator’. This material is of interest chiefly because of its remarks concerning the universal machine of Turing's 1936 paper ‘On Computable Numbers’. In 1947, Turing described electronic stored-programme digital computers as ‘practical versions of the universal machine’ and it is clear that in designing the ACE, his aim was to replace the paper tape of the universal machine with a practical form of memory for holding instructions and data, and to replace the abstract ‘scanner’ of the universal machine by a ‘central pool of electronic equipment’.