Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.
SECAM, also written SÉCAM, is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. It was one of three major analog color television standards, the others being PAL and NTSC. Like PAL, a SECAM picture is also made up of 625 interlaced lines and is displayed at a rate of 25 frames per second. However, due to the way SECAM processes color information, it is not compatible with the German PAL video format standard. This page primarily discusses the SECAM colour encoding system. The articles on broadcast television systems and analog television further describe frame rates, image resolution, and audio modulation. SECAM video is composite video because the luminance and chrominance are transmitted together as one signal.
NAPLPS 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.
Videotex was one of the earliest implementations of an end-user information system. From the late 1970s to early 2010s, it was used to deliver information to a user in computer-like format, typically to be displayed on a television or a dumb terminal.
Ceefax was the world's first teletext information service and a forerunner to the current BBC Red Button service. Ceefax was started by the BBC in 1974 and ended, after 38 years of broadcasting, at 23:32:19 BST on 23 October 2012, in line with the digital switchover being completed in Northern Ireland.
ISO/IEC 646 is a set of ISO/IEC standards, described as Information technology — ISO 7-bit coded character set for information interchange and developed in cooperation with ASCII at least since 1964. Since its first edition in 1967 it has specified a 7-bit character code from which several national standards are derived.
PALplus is an analogue television broadcasting system aimed to improve and enhance the PAL format by allowing 16:9 aspect ratio broadcasts, while remaining compatible with existing television receivers, defined by International Telecommunication Union (ITU) recommendation BT.1197-1. Introduced in 1993, it followed experiences with the HD-MAC and D2-MAC, hybrid analogue-digital widescreen formats that were incompatible with PAL receivers. It was developed at the University of Dortmund in Germany, in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. The system had some adoption across Europe during the late 1990s and helped introduce widescreen TVs in the market, but never became mainstream.
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.
NexTView was an electronic program guide for the analog domain, introduced in 1995 and based on Teletext Level 2.5 / Hi-Text.
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. It was adopted into the international standard CCIR 653 of 1986 as CCIR Teletext System C.
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.
Electra was a teletext service in the United States that was in operation from 1982 up until 1993, when it was shut down due to a lack of funding, and discontinuation of teletext-capable television sets by the only US television manufacturer offering teletext capability at the time, Zenith. It was owned, operated and maintained by Cincinnati-based Taft Broadcasting and Tulsa, Oklahoma-based Satellite Syndicated Systems (SSS), later known as Tempo Enterprises, in cooperation with cable/satellite TV station Superstation WTBS, who carried Electra's data on their vertical blanking interval. SSS's own TV network, the Satellite Program Network, carried the service before it was shut down in 1989. The service was also available to C-band satellite dish users via the Galaxy 1 and Satcom 3R satellites.
T.51 / ISO/IEC 6937:2001, Information technology — Coded graphic character set for text communication — Latin alphabet, is a multibyte extension of ASCII, or more precisely ISO/IEC 646-IRV. It was developed in common with ITU-T for telematic services under the name of T.51, and first became an ISO standard in 1983. Certain byte codes are used as lead bytes for letters with diacritics (accents). The value of the lead byte often indicates which diacritic that the letter has, and the follow byte then has the ASCII-value for the letter that the diacritic is on.
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.
YUSCII is an informal name for several JUS standards for 7-bit character encoding. These include:
CCIR System B was the 625-line VHF analog broadcast television system which at its peak was adopted by more than one hundred countries, either with PAL or SECAM colour. It usually associated with CCIR System G for UHF broadcasts.
625-line is a late 1940s European analog standard-definition television resolution standard. It consists of a 625-line raster, with 576 lines carrying the visible image at 25 interlaced frames per second. It was eventually adopted by countries using 50 Hz utility frequency as regular TV broadcasts resumed after World War II. With the introduction of color television in the 1960s, it became associated with the PAL and SECAM analog color systems.
This article covers technical details of the character encoding system defined by ETS 300 706 of the ETSI, a standard for World System Teletext, and used for the Viewdata and Teletext variants of Videotex in Europe.
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 of 1986 as CCIR Teletext System D.
