Bushnell and Dabney designed the game in 1970–71 to be a coin-operated version of "Spacewar!". After the pair were unable to find a way to economically run the game on a minicomputer such as the Data General Nova, they hit upon the idea of instead replacing the central computer with custom-designed hardware created to run just that game. While they were working on an early proof of concept, Bushnell found a manufacturer for the game in Nutting Associates. Working in partnership with Nutting, the pair completed the game and ran their first location test in August 1971, a few months prior to the display of a similar prototype called "Galaxy Game", also based on "Spacewar!". It was first shown to industry press and distributors at the annual Music Operators of America (MOA) Expo in October. With encouraging initial interest, though mixed responses from distributors, Nutting ordered an initial production run of 1,500 units, anticipating a hit game.