 The first episode of the series premiered on September 16, 1984 with the series concluding on May 21, 1989 after five seasons.Though the series concluded on May 21, 1989, NBC aired three more episodes after the series finale, and USA Network aired a fourth post-series finale episode, thus concluding the series on January 25, 1990.There are a total of 112 episodes, spanning five years (1984–1989) of the show's run.