Ceefax

~ the eulogy ~

ceefax was uk-only at the broadcast layer. it lived inside the spare bandwidth of the analog bbc signal, in the few vertical blanking interval lines between video frames that turkish television never used. to get a ceefax page on a tv in ankara you would have needed a uk-spec teletext-capable set tuned to a uk transmitter. neither was within reach.

anyway, ceefax launched on 23 september '74 as a small experimental service run by the bbc engineering team, an idea from john adams and colin mcintyre to use the unused lines in the analog signal to carry news pages. it ran in trial mode until the late seventies when consumer tv sets with teletext decoders became affordable in the uk. by the eighties it had become the default way millions of british households checked the news, the weather, the sports scores, the flight delays.

the structure was a three-digit page number you typed on the remote. page 100 was the news index. page 300 was sport. page 400 was weather. page 888 carried subtitles for whatever program was on, which made ceefax the first major broadcast accessibility service in the uk. the carousel was the catch. pages cycled in sequence and you waited for yours to come back around, which could be eight seconds for a popular page or thirty for an obscure one.

the service died on 23 october '12 at 23:32 british summer time, when northern ireland completed the analog tv switch-off. the digital replacement was bbc red button, which was already a few years old by that point. dame mary peters, the belfast olympic gold medallist, turned off the last analog ni signal in a small public ceremony. ceefax went with it. the bbc kept a static memorial page on the red button service for a while, but the live thirty-eight-year continuous broadcast was over.

~ the dossier ~

~ how it actually worked ~

the technical idea was almost free. an analog tv signal has lines outside the visible frame that the receiver normally hides. teletext used those lines to transmit pages of text encoded in a low-bandwidth format. a teletext-capable tv had a small decoder chip that captured the lines as the signal arrived, stored them in memory, and rendered the requested page on screen as blocky characters and pseudo-graphics.

the carousel was the whole design. there was no two-way channel and no random access. the broadcaster just kept transmitting every page in order, over and over. your tv waited for the one you asked for. popular index pages were transmitted more often, deep sub-pages less so, which is why some pages felt instant and some felt like minutes. the rhythm of the wait was the rhythm of the medium.

~ what it carried ~

ceefax was a small distilled newspaper that updated continuously. headlines were rewritten by a small bbc team in white city around the clock. sports scores updated within seconds of a goal because the producer just changed the page in the master and the next carousel cycle picked it up. the football vidiprinter feel of saturday afternoon ceefax sport is what british people from a certain age remember best.

the subtitles on page 888 quietly became the most important part of the service. deaf and hard-of-hearing viewers in the uk used ceefax 888 for decades as the default subtitle channel for live broadcast. that single page is the reason a lot of accessibility advocates wrote angry letters when the analog switch-off date was set, because the digital subtitle handoff was not seamless in every region.

~ the day it died ~

this part i was not around for. anyway, the bbc had been winding ceefax down through the late 2000s as analog switch-off rolled across the uk region by region. each transmitter that went digital lost its ceefax signal that night. by october '12 only northern ireland still carried it. the final transmission countdown happened in belfast.

ian morse, then bbc head of program distribution, gave a short interview to the bbc news magazine the next morning. he said the service had been on air for fourteen thousand consecutive days. the last page transmitted was a goodbye message from the editorial team. by then most of the original engineers had retired or died. a few of them watched the final broadcast on a portable analog set in a belfast pub.

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