Teletext
More info
- Creator
- BBC (Ceefax), IBA (Oracle)
- Released
- 1974
- Type
- One-way text broadcast in the TV signal
News in forty characters per line, smuggled through the invisible lines of an analogue television picture.
An analogue TV picture contains lines that are never displayed, the vertical blanking interval between frames. In 1974 the BBC realised there was spare bandwidth in that gap and started transmitting pages of text in it under the name Ceefax. The receiver does not browse but waits: pages are broadcast in an endless carousel and the set picks out the one requested, which is why page 100 could take tens of seconds to appear.
The service was one-way, extremely cheap to run and for thirty years the obvious place for sports results, weather and news flashes. Ceefax went dark in 2012 when the UK switched off analogue transmission, while Sweden's SVT Text — on air since 1979 — lives on digitally and in an app, in the same blocky typeface.