Skip to main content Skip to navigation

What has been digitised?

The Modern Records Centre holds the archives of the statistician John Simmons (1902-1985), including key material on the development of the pioneering LEO computers by J. Lyons & Company Ltd. during the 1940s and 1950s.

A selection of documents about the development of 'LEO I', the world's first business computer, have now been digitised and made available online:

  Electric machines: Report of a visit by Mr Booth and others to CambridgeLink opens in a new window November 1947
  Report on payroll preparation by electronic computerLink opens in a new window 16 January 1948
  Site for electronic computer (memorandum)Link opens in a new window 29 November 1948
  Electronic computer (report no.1)Link opens in a new window 4 February 1949
  Development of the electronic calculating machine (report no.2)Link opens in a new window 8 April 1949
  Lyons electronic computer (report no.3)Link opens in a new window 23 May 1949
  The development of EDSAC (report)Link opens in a new window 23 May 1949
  Lyons Electronic Office (report no.4)Link opens in a new window 14 June 1949
  Lyons Electronic Office (report no.5)Link opens in a new window 31 August 1949
  The layman's guide to LEO (computer manual)Link opens in a new window [1950?]
  LEO (report no.6)Link opens in a new window 31 January 1950
  Circulars relating to demonstration of LEOLink opens in a new window 2 March 1950
  Reactions to the demonstration of LEO on 7th and 8th March 1950Link opens in a new window 20 March 1950
  Notes on LEO and office managementLink opens in a new window 29-30 March 1950
  Notes on LEO and office managementLink opens in a new window February-June 1950
  Visit of Lord Halsbury (memorandum)Link opens in a new window 1 May 1950
  LEO (report no.7)Link opens in a new window 3 July 1950
  LEO (report no.8)Link opens in a new window 11 December 1950
  LEO (memorandum)Link opens in a new window 2 April 1951
  Demonstration of LEO (notes for talk)Link opens in a new window 17 April 1951
  Menu for dinner to celebrate the successful demonstration of clerical work performed by the calculator of LEOLink opens in a new window 16 May 1951
  LEO (report no.9)Link opens in a new window 18 June 1951
  LEO (report)Link opens in a new window 22 February 1952
  Development of LEO to link with a line-a-time printer (memorandum)Link opens in a new window 17 June 1952
  Modifications to LEO to make it independent of Standard's equipment (report)Link opens in a new window 3 October 1952
  LEO (report no.10)Link opens in a new window 27 November 1952
  Future policy for LEO (memorandum)Link opens in a new window 19 June 1953
  Memorandum regarding near-completion of LEOLink opens in a new window 7 December 1953
  LEO: Lyons Electronic Office (promotional leaflet)Link opens in a new window 16 February 1954
  Menu for dinner to celebrate the inauguration of LEOLink opens in a new window 27 May 1954
  LEO (report no.11)Link opens in a new window 30 June 1954
  LEO chronicle 1947-1954Link opens in a new window [1954?]
  Visit of T.R. Thompson and A.B. Barnes to the USA: General report to directorsLink opens in a new window 14 December 1955
  Photographs of LEOLink opens in a new window