Penny Marshall
Garry Marshall, creator and then part-time writer for "Happy Days", cast Marshall and Cindy Williams to guest on an episode of the show. The installment, titled "A Date with Fonzie", aired on November 11, 1975 and introduced the characters Laverne DeFazio and Shirley Feeney (played by Marshall and Williams, respectively). In that episode, Laverne and Shirley were a pair of wisecracking brewery workers who were dates for Fonzie (Henry Winkler) and Richie (Ron Howard). The pair were such a hit with the studio audience that Garry Marshall decided to co-create and star them in a successful spinoff, "Laverne & Shirley" (1976–1983). The characters of Laverne and Shirley appeared in five more episodes of "Happy Days". In 1982 at the beginning of "Laverne & Shirley"s eighth season, Williams left the show due to her pregnancy. Marshall continued with the show, but it was canceled after the season's final episode aired in May 1983.
Happy Days
Gould had originally been tapped to reprise the role of Howard Cunningham on the show. However, during a delay before the start of production he found work doing a play abroad and when he was notified the show was ready to begin production, he declined to return because he wanted to honor his commitment. Bosley was then offered the role.The first two seasons of "Happy Days" (1974–75) were filmed using a single-camera setup and laugh track. One episode of season two ("Fonzie Gets Married") was filmed in front of a studio audience with three cameras as a test run. From the third season on (1975–84), the show was a three-camera production in front of a live audience (with a cast member, usually Tom Bosley, announcing in voice-over, ""Happy Days" is filmed before a live audience" at the start of most episodes), giving these later seasons a markedly different style. A laugh track was still used during post-production to smooth over live reactions.