He started making games while studying playwriting at Pomona College in Claremont, California. In 1971 he developed the first-ever computer baseball game called Baseball as a turn-based simulation based purely on teleprinter input and output. It is now recorded in the Baseball Hall of Fame in Cooperstown. He also made the first mainframe computer role-playing game (1976). Near the end of the 1970s he was hired by Mattel to work on games for the new Intellvision console to compete against the Atari 2600. He developed the first sim game (Intellivision Utopia, 1982). After Mattel closed the Intellivision division, he became a producer at Electronic Arts.