Toy subsequently enrolled in computer science at the University of California, Santa Cruz (UCSC) in the late 1970s. Working first on UCSC's PDP-11 and then its VAX-11, Toy began exploring what games were available over ARPANET, the predecessor of the current Internet. One game that intrigued him was "Colossal Cave Adventure" (also known as "Adventure") (1976) by William Crowther and Don Woods. "Adventure", considered the first text-based adventure game, challenged the player to explore a cave system through descriptions given by the computer and commands issued by the player. Toy was impressed by the game and started writing his own.