ZOOM encouraged children to "turn off the TV and do it!" On the show, a rotating cast of seven kids (known as ZOOMers) performed various activities such as games, plays, poems, recipes, jokes, and science experiments, all suggested by viewer contributions. The mail-in request in both the 1970s and 90s versions became famous for its musical use of WGBH's zip code, 02134. There was also a language game on the show called Ubbi-Dubbi. ZOOM was a new kind of series when it premiered on January 3, 1972. Unlike other children's fare at the time, it was for the most part unscripted. Unlike Barney and Friends, the ZOOMers behaved like actual children rather than like child actors.