ORACLE (teletext)

ORACLE (Optional Reception of Announcements by Coded Line Electronics) was a teletext service broadcast in the United Kingdom by ITV from 1978 to 1993, and then shared by ITV and Channel 4 until 31 December 2009. It was a system for delivering text-based information on television screens using spare bandwidth within the analogue television signal.

ORACLE allowed viewers with compatible television sets to access pages of information containing news, weather, sports, TV listings, travel information, and a range of other content. The data was transmitted in a cyclical broadcast stream; users would select a specific page number, and the teletext decoder in the TV would wait for that page to be broadcast again, capturing and displaying the data. The waiting time could vary depending on how many pages were being broadcast.

The service was originally developed by the Independent Broadcasting Authority (IBA) as a way to provide subtitles for the deaf and hard of hearing. However, it quickly evolved into a more comprehensive information service. ORACLE used a basic character-based graphics system with limited color palettes, making it distinct in its visual appearance. The content was organized into pages and subpages, accessed through a numerical navigation system.

ORACLE competed with the BBC's Ceefax teletext service. Following the Broadcasting Act 1990, the ITV network was fragmented, and ORACLE was operated by a separate company owned by the independent television companies. Ultimately, teletext services declined with the rise of the Internet and digital television services offering more advanced interactive features. The ORACLE service ceased broadcasting at the end of 2009 when the analogue television signal in the UK was switched off.