Videotex is a system for sending of pages of text to a user in computer form, typically to be displayed on a television.Videotex in its broader definition can be used to refer to any such service; including the Internet, bulletin board systems, online service providers and even the arrival/departure displays at an airport. In a more limited definition, it refers only to two-way information services, as opposed to one-way services such as teletext. However, unlike the modern Internet, all traditional videotex services were highly centralized.
History
The first attempt at a general-purpose videotex service were created in the United Kingdom in the late 1960s. In about 1970 the BBC had a brainstorming session in which it was decided to start researching ways to send closed captioning information to audience. As the Teledata research continued the BBC became interested in using the system for delivering any sort of information, not just closed captioning. In 1972, the concept was first made public under the new name Ceefax. Meanwhile the General Post Office (soon to become British Telecom) was researching a similar concept since the late 1960s, known as Viewdata. Unlike Ceefax which was a one-way service carried in the existing TV signal, Viewdata was a two-way system using telephones. Since the Post Office owned the telephones, this was considered to be an excellent way to drive more customers to use the phones. Not to be outdone by the BBC, they also announced their service, under the name Prestel. ITV soon joined the fray with a Ceefax-clone known as ORACLE.
In 1974 all of the services sat down and created a standard for displaying the information. The display would be a simple 40x24 grid of text, with some graphics characters for constructing simple graphics. This standard was called CEPT1. The standard did not define the delivery system, so both Viewdata-like and Teledata-like services could at least share the TV-side hardware (which at that point in time was quite expensive). The standard also introduced a new term that covered all such services, teletext. Ceefax first started operation in 1977 with a limited 30 pages, followed quickly by ORACLE and then Prestel in 1979.
Prestel was somewhat popular for a time, but never gained anywhere near the popularity of Ceefax. This was due primarily to it delivering much the same content, yet requiring the user to pay for the terminal (today referred to as a set-top box), a monthly charge, and phone bills on top of that (even local calls are paid for in most of Europe). Although Prestel's two-way features (including e-mail) were interesting, the end-users appeared to be unwilling to pay much for such a service, not as much as it cost to run it at least. In the late 1980s the system was re-focused as a provider of financial data, and eventually bought out by the Financial Times in 1994. It continues today in name only, as FT's information service. A closed access videotex system based on the Prestel model was developed by the travel industry, and continues to be almost universally used by travel agents throughout the country.
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