teletext decoder part 1

teletext decoder elektor october 1981 — 10-43 Teletext is information that is provided in the form of picture pages on a TV screen which the viewer is free to select. The pages consist of text blocks con- taining 24 lines of 40 characters, which may be partly replaced by illustrative graphic information (such as weather charts, etc.). In principle, the entire information package could be trans- mitted 24 hours a day by broadcasting stations along with the daily programs. This is possible, because use is made of two lines during field-blanking interval, so that the usual program material is unaffected. Up to 800 pages can be broadcast during an ordinary program and these are distributed as 8 "news- teletext decoder . . . that does not require modifications to the TV set Teletext is no longer a new word especially to our readers. It is also well known that a TV set requires a decoder in order to make use of the service. However, all the decoders available for home construction suf...