BBC teletext service, Ceefax, was introduced, created initially to provide subtitling, but developed into a news and information service. In 1978, BBC staff went on strike just before the Christmas of that year, thus blocking out the transmission of both channels and amalgamating all four radio stations into one. Since the deregulation of the UK television and radio market in the 1980s, the BBC has faced increased competition from the commercial sector (and from the advertiser-funded public service broadcaster Channel 4), especially on satellite television, cable television, and digital television services. In the late 1980s, the BBC began a process of
S-VHS can be recorded along with the normal video signal. As a result, this teletext data is also able to be decoded and displayed on-screen as an overlay of the conventional TV picture (though not on standard VHS machines). A suitably teletext-equipped receiver/decoder (TV, PC card, etc.) displays the recorded teletext data information as if the video were being viewed as a real-time live broadcast. S-VHS video cassette recorders (VCRs) and cassette tapes are nearly identical in appearance and operation, and backward compatible with VHS. Older VHS VCRs cannot play back S-VHS recordings at all, but can record onto an S-VHS