market also has areas of fairly rugged terrain—particularly in the eastern part of the state, which lies within the foothills of the Appalachian Mountains—which often created impairment issues with the over-the-air reception of UHF television stations. Both of these factors made prospective broadcasters skittish about launching a television station on one of the available UHF allocations. Although there were two other VHF channels in the market (channels 7 and 10), both had been allocated to Alabama Educational Television (now Alabama Public Television). This came after George Storer's company donated the two frequencies and accompanying transmitters to the Alabama Educational Television Commission (which were respectively signed on WCIQ and WBIQ on those channels in 1955) in a move that may have been an attempt to forestall future commercial competition in the market. As a result, while Birmingham had been large enough in terms of population to support three full network affiliates since the 1950s, it had a long wait for full-time service from all three networks. The Birmingham market would not get a third commercial broadcast television outlet until WBMG-TV (channel 42, now WIAT) began in October 1965. Although WBMG nominally had a CBS affiliation, the network allowed WAPI-TV to continue airing its higher-rated programs. This was largely because WBMG had launched only one year after the FCC's All-Channel Receiver Act went into law, requiring that television sets manufactured from 1964 onward include all-channel tuning; relatively few households in the area at the time had sets with built-in UHF tuning capability, or expensive converter boxes that enabled older television sets to pick up UHF signals. Compounding things, channel 42 operated at a comparatively low effective radiated power, producing a signal that was considerably weaker than that of either WAPI-TV or WBRC-TV. To fill out its schedule, WBMG aired some NBC programs that WAPI-TV turned down or otherwise had no room to broadcast on its schedule (such as The Tonight Show). Both stations listed "CBS/NBC" as their affiliation, as WBMG maintained a nominal secondary affiliation with the latter network. On April 3, 1967, WAPI-TV became the first television station in Birmingham to broadcast all of its programming in color, having acquired camera, projection and slide equipment to broadcast local and acquired programming in the format, in addition to carrying NBC and CBS programs available in color. In May 1970, WAPI-TV became the exclusive NBC affiliate for Birmingham, simultaneously resulting in the CBS