X free chat no subcrip hugh hefner dating advice
Teletext (or broadcast teletext) is a television information retrieval service created in the United Kingdom in the early 1970s by the Philips Lead Designer for VDUs, John Adams.
Teletext is a means of sending pages of text and simple geometric shapes from mosaic blocks to a VBI decoder equipped television screen by use of a number of reserved vertical blanking interval lines that together form the dark band dividing pictures horizontally on the television screen.
It offers a range of text-based information, typically including news, weather and TV schedules.
Paged subtitle (or closed captioning) information is also transmitted within the television signal.
In reality, there was no scope to make an 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.
This basic architecture separates from other digital information systems, such as the internet, whereby pages are 'requested' and then 'sent' to the user – a method not possible given the one-way nature of broadcast teletext.
In 1972 the BBC demonstrated their system, now known as Ceefax ("see facts", the departmental stationery used the "Cx" logo), on various news shows.It requires limited bandwidth; at a rate of perhaps a few words per second.However, it was found that by combining even a slow data rate with a suitable memory, whole pages of information could be sent and stored in the TV for later recall.Teletext is a means of sending text and simple geometric shapes to a properly equipped television screen by use of one of the "vertical blanking interval" lines that together form the dark band dividing pictures horizontally on the television screen.Transmitting and displaying subtitles was relatively easy.