Date   : Tue, 26 Feb 2002 12:21:06 -0000
From   : Chesterton Andrew-BLUW13 <andrew.chesterton@...>
Subject: Re: Circuits involving a SAA5050?

> -----Original Message-----
> From: owner-bbc-micro@...
> [mailto:owner-bbc-micro@...]On Behalf Of Michael Borcherds
> Sent: 25 February 2002 19:50
> To: bbc-micro@...
> Subject: Re: [BBC-Micro] Circuits involving a SAA5050?
>
>
> > For several years now I've been maintaining a RiscPC system with a
> teletext
> > decoder card in it. The card is being used to produce an
> 80x25 screen of
> > text as a composite video signal. Now, I need to replace
> this card, mostly
> > because the card has a TV tuner in it, and the property
> where the computer
> > is based does not have a TV licence. So, I'm looking to build my own
> > 'serverely simplified' version of the card. Using an
> SAA5050 chip seems to
>
> Why not rig up a serial/parallel link to a BBC B and use its
> composite video
> output?
>
> cheers,
>
> Mike
>
> (well if you will post to a BBC list :))))

>My main reason for posting here was that I figured here would reside the
>foremost experts on BBC innards. Yes, I'd thought of using an entire Beeb -
>it's just that that is quite a lot of hardware which I wouldn't be using.
>
>Looking at the BBC B circuit diagram again ... I still can't see what else
>is helping the 5050 produce the text. Anyone know?
>
>Cheers,

>Kris.

Mabe I am just getting confused, but how are you going to receive the teletext
information to decode if you don't have a TV signal demodulator to give you
the raw video data ?

however, If you don't need the demodulator, then why don't you take the circuit
for the podule that you are using at the moment and hack it to suit your
new requirement.

Changing the interface hardware to suit a different computer platform shouldn't
be to difficult.


Andrew.