60th anniversary of the world's first programmable computer - "Baby"

Constructed by the Electrical Engineering department in a Manchester University laboratory in 1948, "Baby", officially known as the Small Scale Experimental Machine and sometimes referred to as the Mark I prototype, was the first computer, with only 128 bytes of memory, that allowed programs to be electronically stored. It was preceded by the top-secret Colossus machines used at Bletchley Park for decoding German signals during the second world war. The Colossus, originally constructed by Tommy Flowers and a team at a Post Office laboratory in Dollis Hill, London, was a pre-programmed machine, hard wired to solve only a small set of specific tasks. After the war the Colossus machines were broken up and buried on the orders of the then Prime Minister, Winston Churchill.

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The Manchester team successfully ran their first program on Baby – to determine the highest factor of a number – on 21 June 1948. In an interview with BBC News Geoff Tootill, one of the builders of Baby said recently "We were extremely excited," – "We congratulated each other and then went and had lunch in the canteen." Mr Tootill, and three other surviving members of the Baby team, will be honoured by the University and the British Computer Society at a ceremony in Manchester.

Professor M.H.A. (Max) Newman, later a member of the mathematics department at Manchester, had lectured at Cambridge to Tom Kilburn, Geoff Tootill and Alan Turing. Like Turing, Newman also worked at Bletchley during the war and having seen the potential for electronic computing there, he later in 1946 secured a substantial grant from the the Royal Society for the construction of "a projected calculating machine laboratory at Manchester University". Max Newman decided to build a similar machine to that planned by von Neumann at the Institute of Advanced Studies in Princeton, USA which was to use an RCA storage device called the Selectron. The Selectron was a large vacuum tube device that relied on the storage of electrostatic charge to store 4096 bits. Unfortunately RCA could not get the Selectron to work.

Meanwhile Freddie Williams and Tom Kilburn had joined the Electrical Engineering department at MU and they designed their own storage device, later known as the Williams-Kilburn CRT store. Williams had worked on this device in 1946 at the Telecommunications Research Establishment in Malvern. It was this that was used in the design of Baby, the machine constructed by Williams, Kilburn, Tootill and others in the MU Electrical Engineering department, funded by the Telecommunications Research Establishment. Max Newman did consult on the project, as did Turing, but was only peripherally involved.

A working replica of Baby is on display at the Museum of Science and Industry in Manchester.

(Terry Relph-Knight)

(trk)