The initial path part of BBC urls (http://bbc.co.uk/this-bit/etc/etc) weren't allowed to contain an underscore, because they can't be displayed on Ceefax.
For those interested, Prestel was a great service too. Early days of investing and retriving historical data on companies via 4tel's Shares 3000 pages was the only way for private investors to get data freely. Investing could be done by dial-up using the prestel platform.
One of the nice things about Ceefax was that it managed to combine instant and delayed gratification. You knew you could get certain information by punching in the page number but at the same time you had to wait a short while for it to appear as the pages (and sub-pages) were transmitted in a certain order. I think it was this combination of access to information and a small price to pay in getting it that made it so addictive.
And the limited screen real-estate meant that the writing had to be short, simple and clear. The screen format was 24 x 40 and once headers and footers are taking into account a typical story might have 17 x 40 = 680 characters. Assuming an average English word length of 5 characters that's roughly 110 words. Add in blank lines for paragraph breaks and the format is very constrained.
Bit out of date that though (i.e. Sport on 302 has RVP still playing for Arsenal.)
I'll miss it, I used to watch football scores updating on Teletext for many many years...
And this reminds me of Mikefax on the BBC Micro that could be used to make your own teletext style pages. Control code 141 for double height Mode 7 chars?
Here's a lovely audio slideshow that captures the essence of Ceefax, complete with that cheesy music that accompanied everything:
http://www.bbc.co.uk/news/magazine-19996372
When I was young, I would sneak downstairs in the early morning on weekends to watch cartoons. If I was too early, nothing would be on apart from ceefax. I must have listened to that music for hundreds of hours.
The Ceefax-like service in the Netherlands is actually a much-installed iPhone/Android app. The limitation in information you can provide provides for a short, to the point, "curated" overview of things happening.
Teletext (Ceefax on Channel 4) had some games you could play 'through your TV!' :)
Bamboozle was a general knowledge, multiple choice quiz. A hacker at heart I noticed the correct choice (red/green/yellow/blue) went to a different page number to the rest. So if you quickly flicked through all the colours until you found the different one you could blaze through with 100% correct.
My sister was amazed when I could get every question right first time.
> Teletext (Ceefax on Channel 4) had some games you could play 'through your TV!' :)
Some broadcasters even had "apps" that you could "run" through an assigned Teletext page and your phone (using DTMF), including home banking and silly games.
If you picked up a random page in a certain interval you would actually see anonymized account data being broadcast around...
(also check ETS 300 706 and 708 for more fun stuff about teletext)
Lovely bit of legacy.