Ceefax Wikipedia entry - http://en.wikipedia.org/wiki/Ceefax
History of Ceefax - http://iml.jou.ufl.edu/carlson/History/ceefax.htm
Ceefax, phonetic for 'See facts', is the BBC's Teletext service. Was the world's first teletext system. Went live in 1974 with thirty pages: compare to the hundreds today. Broadcast programmes (telesoftware) to BBC Micro from 1983 to 1989. Uses World System Teletext standard (was CEPT1).
The name "Teledata" was chosen and a patent application entitled "The Transmission of Alphanumeric Data by Television" was filed on Feb. 9, 1972 under the names of P. Rainger, I. Miller and F. Parker -- iml.jou.ufl.edu/Carlson/History/Ceefax.htm
There are television screenings of the service at set times in the week: these are becoming less common: in fact the BBC stopped the regular service long ago in favour of BBC News 24, whilst ITV ended their 'Nightscreen' transmissions in 2005. They are accompanied by a cheesy easy-listening tune and the pages tick over automatically. Meant for TVs without the Teletext decoder or for people who can't be bothered to lift their hands to get the remote. A screenshot to the left shows a typical screen from the service recorded on Christmas Day 1995. Note the cream background compared to the regular black colour.
The limited set of rolling pages shown on Pages from Ceefax (referred to as a "newsreel") are also accessible at any time of day via Ceefax page 152 (BBC1 or BBC2) on any analogue teletext television. -- en.wikipedia.org/Ceefax
BBC News 24 has seen a reduction in this service in recent times. There is now a television rather than text-based service so this usually screens in the early hours of the morning.
Ceefax on the Internet
Ceefax.tv is an online version of the Ceefax service which can be accessed by entering the desired number into the Google-style search box much like the TV decoded one. One benefit of this service is that it's much quicker than the television service itself, which has to download to the receiver. A broadband connection is more efficient in handling the data due to its greater technology compatibility.