Ceefax: Difference between revisions
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'''Ceefax''' (phonetic for "See Facts") is the [[BBC]]'s [[teletext]] information service transmitted via the [[analogue signal]], started in 1974. It |
'''Ceefax''' (phonetic for "See Facts") is the [[BBC]]'s [[teletext]] information service transmitted via the [[analogue signal]], started in 1974. It still runs regularly filling [[BBC2]]'s overnight schedule as ''Pages from Ceefax'', while the actual interactive service will run until 24 October 2012, in line with the [[digital switchover]].<ref name="ReferenceA">[[Pete Clifton]] Points of View 9 November 2008</ref><ref name="Test Cards and Ceefax">[http://www.bbc.co.uk/archive/testcards_ceefax.shtml?chapter=9 Test Cards and Ceefax] BBC Archive</ref><ref>[http://www.bbc.co.uk/news/magazine-17745100]</ref> |
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==History== |
==History== |
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Revision as of 02:25, 4 May 2012
| Ceefax | |
|---|---|
 Pages from Ceefax title card | |
| Country of origin | United Kingdom |
| Original language | English |
| Production | |
| Production company | BBC |
| Original release | |
| Network | BBC analogue (via "Text" button), BBC Two overnight |
| Release | September 23, 1974 – October 24, 2012 |
| Related | |
| Oracle (1974-1992), Teletext Ltd. (1993-) | |
Ceefax (phonetic for "See Facts") is the BBC's teletext information service transmitted via the analogue signal, started in 1974. It still runs regularly filling BBC2's overnight schedule as Pages from Ceefax, while the actual interactive service will run until 24 October 2012, in line with the digital switchover.[1][2][3]
History
During the late 1960s, engineer Geoff Larkby and technician Barry Pyatt were working at the Designs Department (Television Group) of the BBC on a text transmission system. Its object was to transmit a printable page of text during the nocturnal "close-down" period of normal television transmission. Sir Hugh Carleton Green, then Director General of the BBC, was interested in making farming and stock-market prices available as hard copy via the dormant TV transmitters. The remit received by BBC Designs Department was "the equivalent of one page of The Times newspaper to be transmitted during shut-down".
The first system employed a modified Muirhead drum facsimile transmitter, and hard-copy printer using pressure-sensitive "till-roll" paper passing over a drum with a raised helix of steel wire. This drum was synchronised with the transmission drum by means of the "frame" pulse inherent in the Muirhead system. Printing was effected by a hardened steel blade driven initially by loudspeaker moving coil, then by a printed-circuit coil, and finally by a special ceramic piezo element from Brush-Clevite. The combination of rotating helix and linearly moving blade, with the moving till-roll between them, enabled a raster to be drawn on the paper, without the smoke and smell of the Muirhead "sparking" system.
This early electro-mechanical system was called BEEBFAX - "Beeb" was the popular name for the BBC, and "fax" from the facsimile machine. Initial tests were conducted by sending scans of Christmas Cards over the internal telephone system.
The system was less than popular in the Designs Department laboratory, due to the clatter of the Muirhead facsimile, and the whining of the printer; the project was shelved. Barry Pyatt, who had designed the innovative receiving and decoding electronics, went on to propose several improvements using the then emergent integrated circuit digital technology, but the project died. Geoff Larkby retired, and Barry Pyatt left the employ of the Corporation.
The idea was later taken up once again, this time in digital and on-screen form, under the new name of CEEFAX.
The system was announced in October 1972, and following test transmissions in 1972-74, the Ceefax system went live on 23 September 1974 with thirty pages of information. Developed by BBC engineers who were working on ways of providing televisual subtitles for the deaf, it was the first teletext system in the world. James Redmond, the BBC's Director of Engineering at the time, was a particular enthusiast. Other broadcasters soon took up the idea, including the Independent Broadcasting Authority (IBA), who had developed the incompatible ORACLE teletext system, at around the same time. Before the internet (via the world wide web) become popular, Ceefax pages were often the first location to report a breaking story or headline.
After technical negotiations, the two broadcasters settled in 1976 on a single standard, different from both Ceefax and Oracle, which ultimately developed into World System Teletext, and which in 2012 is still in use for analogue broadcasts. The display format of 24 rows by 40 columns of characters was also adopted for the Prestel system.
The technology became the standard European teletext system and replaced other standards, including the Antiope system formerly used in France.
In 1983, Ceefax started to broadcast computer programs, known as telesoftware, for the BBC Micro (a home computer available in the United Kingdom). The telesoftware broadcasts stopped in 1989. A similar idea was the French C Plus Direct satellite channel which used different, higher speed technology to broadcast PC software.
The basic technology of Ceefax has remained compatible with the 1976 unified rollout; system elaborations since then have been made such that earlier receivers are still able to do a basic decode of pages, but will simply ignore enhanced information rather than showing corrupted data. For example, early receivers cannot process the FasText coloured-button hyperlinking data, but are able to ignore it.
Modern day
As of 2012[update], the BBC's Ceefax service is still providing information on a wide range of topics covering News, Sport, Weather, TV Listings and Businesses. The pages are still kept up-to-date. However, Ceefax is only available in areas where digital switchover has not taken place. The in-vision service Pages from Ceefax is still transmitted overnight until 06:00 on BBC Two.
In 2002, the BBC stopped broadcasting Ceefax on the digital satellite Sky Digital service, but later brought back a limited service including a TV schedule for BBC One and BBC Two; and subtitles.
The BBC has tried to reuse the old Ceefax page numbers where possible on the Freeview and digital satellite BBC Red Button Ceefax-replacement services.[4]
It has been announced that Ceefax will not be replaced when the analogue signal is switched off in October 2012.[1][2] The BBC Red Button service is seen as an alternative to Ceefax and since 2007[5] the number of regions with a Ceefax supported analogue signal has declined as digital switchover has progressed across the UK. As of the end of 2011 three quarters of the UK TV regions have completed or in the process of being switched over.[6]
Ceefax is the last remaining text service available via analogue TV transmissions in the UK, as ITV and Channel 4's Teletext service closed in December 2009. Channel 5's "five text" ancillary service closed in 2011. However, a limited analogue teletext service through ITV and Channel 4 is still available through terrestrial.
Technology
The Ceefax/ORACLE standard was internationalised in the 1980s as World System Teletext, which was adopted into the international standard CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System B. As with other teletext systems, text and simple graphics are transmitted in-band with the picture signal, and decoded by controller circuitry.
Pages from Ceefax
As of April 2012 limited Ceefax content can still be viewed overnight on BBC Two between 0415 and 0600, via the BBC's Pages from Ceefax slot, on both analogue and digital services. This consists of selected Ceefax pages (typically news) transmitted as an ordinary TV picture. As a result, although Pages from Ceefax can be viewed on any set, the interactive nature of the service is lost. Audio accompaniment typically consists of stock music or sometimes a discontinuous tone.
Pages from Ceefax is normally only shown in the absence of any other programming. Once a common filler during daytime (where it was also billed on-air as Ceefax in Vision or, in the case of the pre-Breakfast Time slot during the 1980s as Ceefax AM), it has been marginalised by the move towards a near-continuous service, where in recent years BBC News would be placed in late night/early morning gaps in schedules.
In a similar manner, Channel 4 also showed pages from Oracle until 1989 and 4-Tel On View until 1997.[citation needed]
The limited set of rolling pages shown on Pages from Ceefax (referred to as a "newsreel") was also accessible at any time of day via Ceefax page 152 (BBC Two only) on any analogue teletext television.
References
 |
- ^ a b Pete Clifton Points of View 9 November 2008
- ^ a b Test Cards and Ceefax BBC Archive
- ^ [1]
- ^ How we assign our page numbers BBC Blogs
- ^ http://www.guardian.co.uk/media/2007/nov/13/digitaltvradio.television
- ^ http://www.digitaluk.co.uk
 | This article needs additional citations for verification. (November 2008) |
External links
- BBC Ceefax at BBC Online
- BBC News article celebrating 30th anniversary of Ceefax
- Online representation of today's Ceefax
- "Pages from Ceefax" at Everything2
- More information and captures of CEEFAX pages
- View Ceefax on an Apple Mac using the Mac OS X Dashboard feature
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