[mythtv-users] Driving a PAL tv using Intel graphics

[Paul Gardiner]

On 23/08/2011 12:08, Alex Butcher wrote:
> On Tue, 23 Aug 2011, Paul Gardiner wrote:
>
>> On 23/08/2011 10:45, Alex Butcher wrote:
>>> On Tue, 23 Aug 2011, Paul Gardiner wrote:
>>>
>>>> On 22/08/2011 23:08, mlt at etruscott.co.uk wrote:
>>>>> I have just updated my motherboard+cpu to a sandy bridge combo,
>>>>> which is
>>>>> nice and quiet and low powered.
>>>>>
>>>>> however, at present i still have a SD crt TV; at present i am using a
>>>>> cheapo vga to s-video dongle thing that is pretty rubbish.
>>>>>
>>>>> Does anyone know of a better way than this? I have a vga and dvi
>>>>> connector so is there a solution that could use either of those? I had
>>>>> wondered about the apple dvi-s-video connector does this work for
>>>>> linux
>>>>> or is there a way of getting the graphics to drive a pal-tv directly?
>>>>
>>>> My first experiences of MythTV was use with an SD CRT. I was
>>>> disappointed with the results until I discovered this:
>>>> http://www.mythtv.org/wiki/RGB_Scart. No good to you if
>>>> your TV doesn't have a SCART socket, but great if it does.
>>>
>>> I'm a sometime contributor to that page, and I've been using Steve
>>> Hall's
>>> 'Nvidia cable' it documents since 2006. Works really well, providing
>>> your
>>> video card can output a 15.625kHz signal.
>>
>> Yes, that's what I used, plus an extra little circuit to hold the RGB
>> signalling wire high.
>
> I just used pin 9 of the VGA socket, through a resistor that, combined with
> the 50 ohm impedance of the TV input would give the appropriate voltage. I
> don't know how many TVs need it, though.
>
>>> If you don't fancy building one yourself (I think all my parts,
>>> including a
>>> case and some stripboard, cost about £15 from Maplin), Keene sell
>>> something
>>> similar:
>>> <http://www.keene.co.uk/electronic/keene-electronics/keene-sync-thingy-rgbhv-sync-transcoder/KST1.html>
>>>
>>
>> Coo. Nice. I don't think that existed when I built mine. I'd
>> have gone for that.
>
> I noted after I posted that the user questions say it was designed for a
> Radeon, which suggests it may not be the same as Steve Hall's circuit after
> all. It'd be a good, tidy base to hack from, though.

It says that it can take RGBHV in and output composite sync on pin 19
so should work fine with either ATI or nVidia. Nice that it also has
audio in, which I had to add to mine at a later date.

P.