Plans to develop a Philadelphia-based SportsChannel network date back to 1986, when Rainbow Media announced plans to launch a regional sports network that would serve as a companion to the primarily movie-based premium channel PRISM, which would share the regional television rights to games from three of Philadelphia's major professional sports teams, the Philadelphia Phillies of Major League Baseball, the Philadelphia 76ers of the NBA and the Philadelphia Flyers of the NHL (the rights to the teams' road games were split at the time between independent stations WTAF-TV (channel 29, now Fox owned-and-operated station WTXF-TV), WPHL-TV (channel 17, now a MyNetworkTV affiliate) and WGBS-TV (channel 57, now CW owned-and-operated station WPSG), while PRISM carried home games involving all three franchises).
On January 23, 1990, the Phillies reached a four-year, $12 million contract with Rainbow/NBC, awarding SportsChannel Philadelphia and PRISM the regional cable television rights to the majority of the team's games.
By late September, the team announced plans to produce its home game broadcasts themselves and sell the local rights to individual cable providers if a deal was not struck.
[11][12] Then on October 4, 1996, the day before its season home opener, the Flyers reached a one-year contract extension with SportsChannel and PRISM, which would pay $5 million for the rights.
[18] On July 21, 1997, Comcast acquired the local television rights to the 76ers from SportsChannel and PRISM, opting out of its joint contract with the two networks that was set to run until the 1999–2000 season.