Fonz and the Happy Days Gang (1980)

Based on the prime-time series "Happy Days." When Cup Cake, a girl from the twenty-fifth century, lands in Milwaukee in 1957, she befriends the main characters from "Happy Days" and takes them aboard her slightly defective time machine. During a demonstration, they become lost in time. The series depicts their adventures as they struggle to find their way back to 1957 Milwaukee.