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NABTS
NABTS, the North American Broadcast Teletext Specification, is a protocol used for encoding NAPLPS-encoded teletext pages, as well as other types of digital data, within the vertical blanking interval (VBI) of an analog video signal. It is standardized under standard EIA-516, and has a rate of 15.6 kbit/s per line of video (with error correction). It was adopted into the international standard CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System C. History NABTS was originally developed as a protocol by the Canadian Department of Communications, with their industry partner Norpak, for the Telidon system. Similar systems had been developed by the BBC in Europe for their Ceefax system, and were later standardized as the World System Teletext (WST, aka CCIR Teletext System B), but differences in European and North American television standards and the greater flexibility of the Telidon standard led to the creation of a new delivery mechanism that was tuned for speed. NABTS w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel. Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel. Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norpak
Norpak Corporation was a company headquartered in Kanata, Ontario, Canada, that specialized in the development of systems for television-based data transmission. In 2010, it was acquired by Ross Video Ltd. of Iroquois and Ottawa, Ontario. Norpak developed the NABTS (North American Broadcast Teletext Standard) protocol for teletext in the 1980s, as an improved version to the then-incumbent World System Teletext, or WST, protocol. NABTS was designed to improve graphics capability over WST, but required a much more complex and expensive decoder, making NABTS somewhat of a market failure for teletext. However, NABTS still thrives as a data protocol for embedding almost any form of digital data within the VBI of an analog video signal. Norpak's products, now part of and complementary to the Ross Video line, include equipment for embedding data in a television or video signal such as for closed captioning, XDS, V-chip data, non-teletext NABTS NABTS, the North American Broadcast Tel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World System Teletext
World System Teletext (WST) is the name of a standard for encoding and displaying teletext information, which is used as the standard for teletext throughout Europe today. It was adopted into the international standard ITU-R, CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System B. Development WST originally stems from the UK standard developed by the BBC and the UK Independent Broadcasting Authority in 1974 for teletext transmission, extended in 1976 as the Broadcast Teletext Specification. With some tweaks to allow for alternative Teletext character set, national character sets, and adaptations to the NTSC 525-line system as necessary, this was then promoted internationally as "World System Teletext". It was accepted by ITU-R, CCIR in 1986 under international standard CCIR 653 (now ITU-R BT.653) as one of four recognised standards for teletext worldwide (most commonly referred to as CCIR Teletext System B). WST in Europe Almost all television sets sold in Europe since the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JTES
JTES, the Japanese Teletext Specification, is a protocol used for encoding teletext pages, as well as other types of digital data, within the vertical blanking interval (VBI) of an analog video signal in Japan. It was adopted into the international standard CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System D. It supports the display of Chinese, Katakana and Hiragana characters. The service can be used to display subtitles, cyclic text pages or pseudo interactive programs. There's support for presentation of photographs, geometry or sound. History The development of teletext in Japan started in 1972, followed by the announcement of the world's first teletext system (Ceefax) by the BBC in the United Kingdom. Because Japanese characters are different from the western alphabets, Japan proceeded with research and development of a specific transmissions method. Called ''"pattern method"'', it sends scanning signals similar to a fax, at a rate 20 times faster than existing me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telidon
Telidon (from the Greek words τῆλε, ''tele'' "at a distance" and ἰδών, ''idon'' "seeing") was a videotex/teletext service developed by the Canadian Communications Research Centre (CRC) during the late 1970s and supported by commercial enterprises led by Infomart in the early 1980s. The CRC referred to Telidon as a "second generation" system, offering improved performance, 2D colour graphics, multilingual support and a number of different interactivity options supported on various hardware. With additional features added by AT&T Corporation, and 16 other contributors in North America and supported by the Federal Government, Telidon was redefined as a protocol and became the NAPLPS standard. Initially in multiple tests, Telidon failed to demonstrate compelling functionality, and the auxiliary equipment costs remained high. Although projects like GRASSROOTS for the Province of Manitoba, SOI for Venezuela, Compuserve, LA Times in California, EPIC for General Motors, NOVATE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NAPLPS
NAPLPS (North American Presentation Level Protocol Syntax) is a graphics language for use originally with videotex and teletext services. NAPLPS was developed from the Telidon system developed in Canada, with a small number of additions from AT&T Corporation. The basics of NAPLPS were later used as the basis for several other microcomputer-based graphics systems. History The Canadian Communications Research Centre (CRC), based in Ottawa, had been working on various graphics systems since the late 1960s, much of it led by Herb Bown.Cynthia Boyko"Telidon" Friends of the CRC, 14 October 1997 Through the 1970s they turned their attention to building out a system of "picture description instructions", which encoded graphics commands as a text stream. Graphics were encoded as a series of instructions (graphics primitives) each represented by a single ASCII character. Graphic coordinates were encoded in multiple 6-bit strings of XY coordinate data, flagged to place them in the print ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ExtraVision
ExtraVision was a short-lived teletext service created and operated by the American television network CBS in the early to mid-1980s. It was carried in the vertical blanking interval of the video from local affiliate stations of the CBS network. It featured CBS program information, news, sports, weather, even subtitling for CBS programming (much like page 888 in British/European teletext, and American closed captioning). ExtraVision could also have its pages customized by the local affiliate station carrying it, for such things as program schedules, local community announcements, and station promotions. ExtraVision was discontinued by CBS towards the end of the 1980s, due to the service using the NABTS protocol, which required a quite expensive decoder to receive the service. Also, most of the local CBS affiliates carrying the ExtraVision service did not bother to invest in the computer equipment required to customize pages to carry locally oriented information on the service. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NBC Teletext
NBC Teletext was a teletext service provided by the NBC, based on the NABTS standard. Initial trials started in Los Angeles in 1981. Transmissions started as a regular service on May 16, 1983 after FCC approval, in parallel with CBS similar '' ExtraVision'' service. Initially, the NBC Teletext was composed of a 50-page magazine, with the index page listing the following topics: Newsfront, Weather, Sports, Money, People, Your Body, Living, Your Stars, On the Soaps, Fun & Games, Kid's Korner, Partners, Credits. Graphics were reasonably detailed, allowing a detailed rendition of weather maps or movie posters. Since teletext provides real-time updates, it was expected that the service would attract advertisers like airlines, stores or businesses interested in constantly updating their rates and schedules. As there were no available standalone consumer decoders on the market, it was hoped that by launching the system manufacturers would soon built teletext capability into all televisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiope (teletext)
Antiope was a French teletext standard in the 1980s. It also formed the basis for the display standard used in the French videotex service Minitel. The term allegedly stood for ''Acquisition Numérique et Télévisualisation d’Images Organisées en Pages d’Écriture'', which could be loosely translated as ''Digital Acquisition and Remote Visualization of Images Organized into Written Pages''. Work on Antiope started in 1972 at CCETT, the newly merged French national research centre for television and telecommunications in Rennes, with first field trials in 1975. The system was officially launched in 1976 at Vidcom in Cannes, and simultaneously at the СПОРТ 76 exposition in Moscow. It was adopted into the international standard CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System A. Antiope ceased to be used for broadcast teletext in the early 1990s, before teletext became popular in France. It was replaced by European standard World System Teletext. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Blanking Interval
In a raster scan display, the vertical blanking interval (VBI), also known as the vertical interval or VBLANK, is the time between the end of the final visible line of a frame or field and the beginning of the first visible line of the next frame. It is present in analog television, VGA, DVI and other signals. In raster cathode ray tube displays, the blank level is usually supplied during this period to avoid painting the retrace line — see raster scan for details; signal sources such as television broadcasts do not supply image information during the blanking period. Digital displays usually will not display incoming data stream during the blanking interval even if present. The VBI was originally needed because of the inductive inertia of the magnetic coils which deflect the electron beam vertically in a CRT; the magnetic field, and hence the position being drawn, cannot change instantly. Additionally, the speed of older circuits was limited. For horizontal deflection, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Semigraphics
Text-based semigraphics or pseudographics is a primitive method used in early text mode video hardware to emulate raster graphics without having to implement the logic for such a display mode. There are two different ways to accomplish the emulation of raster graphics. The first one is to create a low-resolution all points addressable mode using a set of special characters with all binary combinations of a certain subdivision matrix of the text mode character size; this method is referred to as block graphics, or sometimes mosaic graphics. The second one is to use special shapes instead of glyphs (letters and figures) that appear as if drawn in raster graphics mode, sometimes referred to as semi- or pseudo-graphics; an important example of this is box-drawing characters. Semigraphical characters (including some block elements) are still incorporated into the BIOS of any VGA compatible video card, so any PC can display these characters from the moment it is turned on, even w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
