It is speculative but plausible to guess that the 1965 release of the PDP-8 might have instigated Gray’s own home computer project and the later creation of the ACS.

inspiration of

Experiment (Wikipedia) An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experimental studies.

From ACS to Altair: The Rise of the Hobby Computer (technichistory.com) A certain pattern of technological development recurred many times in the decades around the turn of the twentieth century: a scattered hobby community, tinkering with a new idea, develops it to the point where those hobbyists can sell it as a product. This sets off a frenzy of small entrepreneurial firms, competing to sell to other hobbyists and early adopters. Finally, a handful of firms grow to the point where they can drive down costs through economies of scale and put their smaller competitors out of business. Bicycles, automobiles, airplanes, and radio broadcasting all developed more or less in this way.