Teletext in Salt Lake City, Utah premiered a teletext service using Ceefax. They were followed by television network CBS, which carried out preliminary tests on both the British Teletext and the rival French Antiope system. One of the most prominent providers was the "Electra" teletext service, using World System Teletext (WST), broadcast from the early 1980s on American cable channel WTBS. Electra also carried another teletext service on its higher-numbered pages, a service called "Tempo". "Tempo" mainly carried sports (and other miscellaneous) information on its pages. At the time of Electra's closing in 1993, it was the only existing teletext service
Teletext systems mounted a large market trial in Los Angeles in partnership with NBC and Public Broadcasting Service (PBS) Public television. Services premiered simultaneously on station KNXT (now KCBS-TV), KNBC and KCET in Los Angeles. All three services included an array of local news and information services. KCET's service also included service components for use in schools. Later, an official North American standard of teletext, called NABTS (North American Broadcast Teletext Specification) was developed in the early 1980s by Norpak, a Canadian company. NABTS provided improved graphic and text capability over WST, but was quite short-lived. This was mainly due to the