Teletext systems expensive cost of NABTS decoders, costing in the thousands of dollars upon their release to the public. NABTS, however, was adopted for a short while by American TV networks NBC & CBS throughout the early-to-mid 80s, CBS using it for their short-lived ExtraVision teletext service, which premiered after the early Antiope & Ceefax trials by CBS & KNXT, and NBC, who had a NABTS-based service called NBC Teletext for a very short time in the mid-1980s. NBC discontinued their service in 1985 due to the cost of NABTS decoders not dropping to an affordable level for the consumer public. The
BBC news and sport station. In 1997, BBC News 24, a rolling news channel, launched on digital television services and the following year, BBC Choice launched as the third general entertainment channel from the BBC. The BBC also purchased The Parliamentary Channel, which was renamed BBC Parliament. In 1999, BBC Knowledge launched as a multi media channel, with services available on the newly launched BBC Text digital teletext service, and on BBC Online. The channel had an educational aim, which was modified later on in its life to offer documentaries. In 2002, several television and radio channels were reorganised. BBC Knowledge