The Hollerith Electronic Computer (HEC) was produced by the British Tabulating Machine Company (BTM) and was based on a design by Professor Andrew Booth of Birkbeck College, London.

[1] In 1950 John Womersley, who had previously led the team developing the Automatic Computing Engine (ACE) at the National Physical Laboratory (NPL), joined the Unit record equipment company, BTM.

He needed punched card input and output technologies and struck a deal with BTM,[2] whereby they supplied him with these in return for their copying the machine that he was developing, including its magnetic drum memory.

In March 1951,[3] BTM's Dr Raymond 'Dickie' Bird with Bill Davis and Dickie Cox were dispatched to Fenny Compton in Warwickshire where Booth lived and where, in a rotting barn, he was developing the prototype of his machine.

Seven or eight HEC 2M systems were delivered to customers who included GE Research Laboratories, Thorn, Esso, MoD Boscombe Down, Royal Aircraft Establishment and RAE, Bedford (they had two for wind tunnel applications) and the Indian Mathematical Institute.