List of teletext services
It offers a range of text-based information, typically including national, international and sporting news, weather and TV schedules.
A number of similar teletext services were developed in other countries, some of which attempted to address the limitations of the British-developed system, with its simple graphics and fixed page sizes.
In France, where the SECAM standard is used in television broadcasting, a teletext system was developed in the late 1970s under the name Antiope.
It had a higher data rate and was capable of dynamic page sizes, allowing more sophisticated graphics.
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.
Services premiered simultaneously on station KNXT (now KCBS-TV), KNBC and KCET in Los Angeles.
NBC discontinued their service in 1985 due to the cost of NABTS decoders not dropping to an affordable level for the consumer public.
When it was in operation, WaveTop's data was delivered on the VBI of local public TV stations affiliated with PBS through their PBS National Datacast[47] division, that the WaveTop software tuned the TV card to in order to receive the service.
There were several models of television sets made throughout the 90s by Thomson Consumer Electronics under the RCA and General Electric brands that had built-in Guide+ decoders.
Guide+ was an on-screen interactive program guide that provided current TV schedule listings, as well as other information like news headlines.
Some Guide+ equipped sets from RCA even had an IR-emitting sensor that could be plugged into the back of the TV, to control a VCR to record programs which could be selected from the on-screen Guide+ listings.
Guide+ in the United States was replaced by Gemstar with a similar service (delivered in the same fashion via VBI like Guide+), called TV Guide On Screen.
[citation needed] Similar to Guide+ was Star Sight,[51] with its decoders built into TVs manufactured by Zenith, Samsung, Sony, Toshiba, Magnavox, and others.
Almost all television sets sold in Europe since the early ’80s have built-in WST-standard teletext decoders as a feature.
Electra ran up until 1993, when it was shut down due to Zenith, the prominent (and only) American TV manufacturer at the time offering teletext features in their sets decided to discontinue such features, as well as a lack of funding and lagging interest in teletext by the American consumer.
Australian company Dick Smith Electronics (DSE) also offered through their US distributors a set-top WST teletext decoder kit.
The kit used as its core the same teletext decoding module (manufactured by UK electronics company Mullard) installed in most British TV sets, with additional circuitry to adapt it for American NTSC video, and to utilize it in a separate set-top box.
A significant reason for the demise of American teletext was when Zenith introduced built-in closed captioning decoders in TVs in the early '90s, as mandated by the FCC.
