Teletext and viewdata systems and their possible extension to the USA

The UK teletext and viewdata systems are analysed as a basis for discussion of their suitability for incorporating in the North American NTSC television system. Methods for adapting to the different band width and display format requirements are described which indicate the feasibility of immediate implementation in the USA. An interim teletext test transmission system to assist in the choice of a suitable data rate and general system parameters is outlined. The cost implications of adopting the basic UK systems, which are already well established, are reviewed in some depth. The flexibility of the present teletext system and its potential for future extensions is discussed and it is shown that initial decoder designs will not be made obsolescent when these are implemented. It is concluded that, with a suitable choice of data rate and page format, the UK teletext and viewdata systems form a sound basis for the establishment of these services on the NTSC system in USA.