By the 1960s, IBM had beaten all rivals and dominated the world computer market. But IBM came late to the race. From the 1930s to the 1960s, small, independent teams on four continents worked on the development of the first modern computers- practical, electronic, multi-purpose, digital machines with memory for data and programs. From interviews with surviving members of those original teams, the author builds up a picture of the eccentric men and women who laid the foundations for the computerised world we now live in, recreating the atmosphere of those early days. Some of the early projects, such as LEO, the Lyons Electronic Office, developed by the catering company J Lyons and Co in London in the 1940s, are now famous, others, such as the ABC, built in the basement of Iowa State College and abandoned when war broke out, and the RAND 409, constructed in a barn in Connecticut under the watchful eye of a stuffed moose, almost unknown. came and went in the years before IBM ruled the world, including the Phillips Hydraulic Economics Computer, or MONIAC, which perfectly demonstrated the workings of the economy by way of coloured water flowing through plastic tubes and the UNIVAC, which became a household name when, live on television, it correctly predicted the results of the 1952 US presidential election.