Teletext a plug in circuit board. It took another decade before the decoders became a standard feature on almost all sets with a screen size above 15 inches (teletext is still usually only an option for smaller "portable" sets). From the mid-1980s both Ceefax and ORACLE were broadcasting several hundred pages on every channel, slowly changing them throughout the day. The "Broadcast Teletext Specification" was published in September 1976 jointly by the IBA, the BBC and the British Radio Equipment Manufacturers' Association. The new standard also made the term "teletext" generic, describing any such system. The standard was internationalised as World
Teletext systems mounted a large market trial in Los Angeles in partnership with NBC and Public Broadcasting Service (PBS) Public television. Services premiered simultaneously on station KNXT (now KCBS-TV), KNBC and KCET in Los Angeles. All three services included an array of local news and information services. KCET's service also included service components for use in schools. Later, an official North American standard of teletext, called NABTS (North American Broadcast Teletext Specification) was developed in the early 1980s by Norpak, a Canadian company. NABTS provided improved graphic and text capability over WST, but was quite short-lived. This was mainly due to the