Background

is that tape or what
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The first design for a program-controlled computer was Charles Babbage's Analytical Engine in the 1830s, with Ada Lovelace conceiving the idea of the first theoretical program to calculate Bernoulli numbers. A century later, in 1936, mathematician Alan Turing published his description of what became known as a Turing machine, a theoretical concept intended to explore the limits of mechanical computation. Turing was not imagining a physical machine, but a person he called a "computer", who acted according to the instructions provided by a tape on which symbols could be read and written sequentially as the tape moved under a tape head. Turing proved that if an algorithm can be written to solve a mathematical problem, then a Turing machine can execute that algorithm.[6]

is that tape or what
Image Redacted

The first design for a program-controlled computer was Charles Babbage's Analytical Engine in the 1830s, with Ada Lovelace conceiving the idea of the first theoretical program to calculate Bernoulli numbers. A century later, in 1936, mathematician Alan Turing published his description of what became known as a Turing machine, a theoretical concept intended to explore the limits of mechanical computation. Turing was not imagining a physical machine, but a person he called a "computer", who acted according to the instructions provided by a tape on which symbols could be read and written sequentially as the tape moved under a tape head. Turing proved that if an algorithm can be written to solve a mathematical problem, then a Turing machine can execute that algorithm.[6]

Public Information

Turing joined the National Physical Laboratory (NPL) in October 1945,[14] by which time scientists within the Ministry of Supply had concluded that Britain needed a National Mathematical Laboratory to co-ordinate machine-aided computation.[15] A Mathematics Division was set up at the NPL, and on 19 February 1946 Alan Turing presented a paper outlining his design for an electronic stored-program computer to be known as the Automatic Computing Engine (ACE).[15] This was one of several projects set up in the years following the Second World War with the aim of constructing a stored-program computer. At about the same time, EDVAC was under development at the University of Pennsylvania's Moore School of Electrical Engineering, and the University of Cambridge Mathematical Laboratory was working on EDSAC.[16]

The NPL did not have the expertise to build a machine like ACE, so they contacted Tommy Flowers at the General Post Office's (GPO) Dollis Hill Research Laboratory. Flowers, the designer of Colossus, the world's first programmable electronic computer, was committed elsewhere and was unable to take part in the project, although his team did build some mercury delay lines for ACE.[15] The Telecommunications Research Establishment (TRE) was also approached for assistance, as was Maurice Wilkes at the University of Cambridge Mathematical Laboratory.[15]

The government department responsible for the NPL decided that, of all the work being carried out by the TRE on its behalf, ACE was to be given the top priority.[15] NPL's decision led to a visit by the superintendent of the TRE's Physics Division on 22 November 1946, accompanied by Frederic C. Williams and A. M. Uttley, also from the TRE.[15] Williams led a TRE development group working on CRT stores for radar applications, as an alternative to delay lines.[17] Williams was not available to work on the ACE because he had already accepted a professorship at the University of Manchester, and most of his circuit technicians were in the process of being transferred to the Department of Atomic Energy.[15] The TRE agreed to second a small number of technicians to work under Williams' direction at the university, and to support another small group working with Uttley at the TRE.[15]