Ferranti builds a Nim-playing computer for a British exhibition

What happened

NIMROD was openly modeled on the American Nim machine of a decade earlier, with better engineering behind it. John Makepeace Bennett drew up the logic and Raymond Stuart-Williams built it at Ferranti, and the result filled a large panel with lamps that stood in both for the piles of counters and for the machine's own reasoning. Push buttons let a visitor take a turn, after which the lights traced what the machine was doing before it replied. Ferranti was at that point among the very few firms anywhere actually delivering computers to customers.

Bennett was explicit afterward about the intent, which was to teach the public that a machine could be set to follow rules and reach conclusions, using a game because the rules were short enough to print on a placard. The public drew a different lesson. Accounts from the exhibition, and from a later showing in Berlin, describe visitors far more interested in whether they could win than in the mathematics explained on the wall behind them. That gap between what an exhibit intends and what an audience wants has never really closed.

The world at the time

The Festival of Britain was a national exhibition staged in 1951 to project confidence after years of austerity, and its science section set out to explain new technology to ordinary visitors. Britain was then a leading center of computing, with machines running at Manchester and Cambridge and Ferranti building commercial versions. Almost nobody outside those circles had seen a computer of any kind.

What it changed

The cabinet was dismantled after its exhibition tour, though a replica built much later for a German museum has let people play it again. Its influence lies in the format rather than the hardware. Computer makers kept using games as public demonstrations, a habit that runs through chess programs, trade show attractions and the machines that companies later put in front of television cameras.