Date   : Mon, 18 Jul 1994 18:32:00 +0100
From   : jfid@... (James Fidell)
Subject: Re: Teletext graphics question...

Alan Hart wrote:

> As I remember, 'hold' causes all colour-change characters to appear as the
> previous graphics character [i.e. the one to the left] whilst still changing
> the colour. The purpose of this is to give continuous blocks of graphics
> which change colour, e.g. a narrow line changing colour along its
> [horizontal] length with no breaks. There was a game that used this on the 
> scores page!
> 
> Release reverts to normal mode.

Sounds like this shouldn't be too hard to implement.  Can you remember
how the hold character and the character on it's left appear on the screen ?

For example, do you get :

       <graphics character><space><lots more graphics characters>

where the hold character is displayed as the space, or :

       <graphics character><something else><more graphics characters>

If so, what's the <something else> ?

> > Also, there's a "conceal" display, which I assumes makes all characters
> > from that position onwards appear blank, but how is it turned off ?
> 
> I think you press the 'reveal' button on your remote control [oh dear, I 
> don't seem to have one] :)

It would appear that "conceal" is effectively useless in the context of
the beeb display, then ?

James.

-- 
 "Yield to temptation --             |
  it may not pass your way again"    |     jfid@...        
                                     |
        - Lazarus Long               |              James Fidell