"Whether he (Nutting) had succumbed to Bushnell's salesmanship or simply believed in the project, Bill Nutting went on to make 1,500 Computer Space machines. Bushnell personally demonstrated the game to coin-op distributors at the 1971 Music Operators Association convention in Chicago." (page 33)
"The music operators at the convention saw little potential in Computer Space, and very few of them bought machines at the show. In the end, the game turned into a marginally expensive gamble for Nutting. The company didn't sell all of the original 1,500 machines and never built more." (page 33, continuing on to page 34)
There is a footnote on that second paragraph: * Arcade historian Keith Feinstein located sales and shipping documents proving that Nutting Associates began shipping Computer Space in 1971.