Date   : Wed, 25 Nov 2009 17:24:23 +0000
From   : robert@... (Rob)
Subject: Teletext receiver revisited

Nice!!!

On 25/11/2009, Philip Pemberton <philpem@...> wrote:
> does anyone know of
> a publicly-available spec for the usage of the VBI lines in BBC, ITV,
> Ch4 or Ch5 transmissions?

This looks like what you're asking for for the commercial channels:
http://www.ofcom.org.uk/tv/ifi/tech/codes_guidance/itu_r_teletext.pdf

Not sure for the Beeb, but I imagine they will be using similar
ranges.  I think the spec for teletext receivers is to assume that the
data could be almost anywhere...  I gather that some of the
closed-systems used for data had teletext data all the way down the
"screen" ,,

I remember having fun, once, years back in the days of analogue
satellite TV finding hidden data on MTV pages 1AA 1AB etc .. (had a tv
that allowed you to go "up" and "down" page numbers that included the
alphabetic pages!)