This essay investigates the historical role of play in computer history, drawing on the main studies on play conceived as an essential feature in human culture. The analysis of the relationship between play and forms of human-computer interaction falls into two main phases: phase 1 (1950-70), when computers were conceived by scientists as the main tool for the advancement of research and as an alternative intelligence to be educated, and phase 2 (1970-90), when computers were appropriated and domesticated through hacker cultures...