BBC Television Ceefax, the first teletext service, launched on 23 September 1974. This service allowed BBC viewers to view textual information such as the latest news on their television. CEEFAX did not make a full transition to digital television, instead being gradually replaced by the new interactive BBCi service before being fully closed down on 22 October 2012. In March 2003 the BBC announced that from the end of May 2003 (subsequently deferred to 14 July) it intended to transmit all eight of its domestic television channels (including the 15 regional variations of BBC 1) unencrypted from the Astra 2D satellite. This
Teletext list of news headlines might appear on page 110; a teletext user would type "110" into the TV's remote control to view this page. The broadcaster constantly sends out pages in sequence. There will typically be a delay of a few seconds from requesting the page and it being broadcast and displayed, the time being entirely dependent in the number of pages being broadcast. More sophisticated receivers use a memory buffer to store some or all of the teletext pages as they are broadcast, allowing instant display from the buffer. This basic architecture separates from other digital information systems, such