Teletext systems the country being closed captioning, TV Guide On Screen, and Extended Data Services (XDS). A version of the European teletext standard designed to work with the NTSC television standard used in North America was first demonstrated in the US in 1978 by station KSL in Salt Lake City, Utah, premiered a teletext service using Ceefax. They were followed by American television network CBS, which decided to try both the British Ceefax and French Antiope software for preliminary tryouts for a teletext service, using station KMOX (now KMOV) in St. Louis, Missouri as a testing ground. CBS decided on Antiope and
Electra (teletext) operation. A few other services were offered by some large-market TV stations in the US throughout the 1980s, such as "Metrotext" from KTTV in Los Angeles and "KeyFax" from WFLD in Chicago. 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 in the USA. Electra (teletext) Electra was a teletext service in the United States that was in operation from the early 1980s up until 1993, when it was