Viewdata

Viewdata was an early interactive teletext service that allowed users to access information and services through their television sets. Developed in the 1970s, it combined elements of both broadcast teletext and interactive videotex. Unlike broadcast teletext, which was a one-way transmission, Viewdata was a two-way system, allowing users to make requests and receive responses.

The technology worked by using a modem to connect a specially equipped television or computer terminal to a telephone line. This line was then connected to a central computer or network of computers that stored the Viewdata pages. Users navigated through the information by selecting page numbers using a keypad. The pages themselves were typically text-based, often with simple graphics.

Viewdata services offered a wide range of information, including news, weather, financial data, and entertainment listings. They also enabled transactional services such as online shopping, banking, and ticket reservations. Major providers in the UK included Prestel, operated by the Post Office (later British Telecom), and services offered by private companies.

While Viewdata represented a significant step towards the internet and interactive services, its widespread adoption was limited by the cost of the specialized equipment and the relatively slow speed of data transmission. It laid important groundwork for later, more sophisticated online services and the eventual rise of the World Wide Web.