Teletext 2016, the Teefax teletext service was launched in the United Kingdom to coverage by the BBC, ITV and others. Using a Raspberry Pi computer card as a set-top box, it feeds its service to standard televisions. Teefax content is a mix of crowdsourcing, syndication and contributions from media professionals who contributed heavily to broadcast teletext services. Teefax is also syndicated to a web viewer. The systems were originally incompatible; Ceefax displayed pages of 24 lines with 32 characters each, while ORACLE offered pages of 22 lines with 40 characters each. In other ways the standards overlapped; for instance, both used
Teletext economic Teletext system with 1971 technology. However, as low cost was essential to the project's long term success, this obstacle had to be overcome. Meanwhile, the General Post Office (GPO), whose telecommunications division later became British Telecom, had been researching a similar concept since the late 1960s, known as Viewdata. Unlike Teledata which was a one-way service carried in the existing TV signal, Viewdata was a two-way system using telephones. Since the Post Office owned the telephones, this was considered to be an excellent way to drive more customers to use the phones. In 1972 the BBC demonstrated their system,