Replica of the ‘Baby’ computer

The Small Scale Experimental Machine, nicknamed the ‘Baby’ computer, was developed as a research prototype to prove the concept of digital storage using the cathode-ray tube. It was not intended as a practical computer, but rather as a test-bed using changes on the screen to store data.

The machine’s ability to store programs within an electronic memory made it the first stored-program electronic digital computer in the world. It was designed by Professor Freddie Williams (1911-77), Tom Kilburn (1921-2001) and Geoff Tootill at the University of Manchester, using technology developed for Second World War radar and communications equipment.

‘Baby' had just seven instructions, and its programs were loaded bit by bit using a push-button ‘typewriter’. The machine ran the world’s first stored program at approximately 11.00 on 21 June 1948. Its development led to the construction of a more practical computer, the Manchester Mark 1, in 1949 and the Ferranti Mark 1 in 1951.