RGB TV-out with a Matrox P750

[greinedo]

hi,

It's a great day for me because I think I'm very close to add the missed RGB TV-out feature to my Matrox P750.

Indeed the day Matrox gave up the RGB TV-out with the Parhelia was a bad day for me (and for Matrox). I had planned to buy a Parhelia but after that bad news I bought a G400DH for 20$ on ebay. This card gave me the very best output on TV, and a lot of pleasure.

Now I want to have the same quality and RGB TV-out features with the P750. It's perhaps possible :

I just downloaded the Matrox Monitor Manager. To my surprise, I could define a new res. corresponding to the PAL TV timings (720x576, interlaced).

I activated that res. on the 3rd head of the P750.

Then I tweaked a little bit the timings of that 3rd head with Powerstrip in order to have a true PAL signal on the HD15.

Then, after connecting the 3rd head on the TV with a home made cable, I saw a moving picture.

Here I must say that I have already in this PC a Radeon PCI graphic card, wich drives the TV with a PAL RGB signal (SCART). I compared both signals and the only difference is the sync signal.

In fact, on the radeon I have a composite sync signal (a mixture of horizontal and vertical syncs), and on the Matrox I have 2 separate sync signals : that is the only problem. If I uncheck 'composite sync' box in Powerstrip driving the ATI, I see on both cards, exactly the same, but moving picture.

'Composite Sync' is unfortunately greyed out in Powerstrip driving the P750, so I suppose I cannot solve that problem softwarewise.

I'm now on the way to build a sync converter that mixes the two separate sync. signals comming out from the HD15 into one composite sync signal. For those who are interrested, see that link :

http://www.hut.fi/Misc/Electronics/circuits/vga2rgbs.html

Sure, It must work !

[dZeus]

did you ask M about support for SCART-RGB in the drivers? I mean, they support it on their QID card, and composite sync was always supported on older Matrox cards. I'm sure both the driver code and hardware support is there. All we need now is getting Matrox to copy that code to the p-series drivers too (and maybe it'll work on the parhelia-512 too).

[greinedo]

I agree with you, there is no doubt to me, all Matrox cards are probably supporting composite sync. But how can we enable it ? The drivers doesn’t support that feature yet, and Matrox doesn’t want to publish the programming specs so a third party tool like Powerstrip is helpless.

At the Matrox forum, I saw Parhelia users requesting SCART RGB support but with no result. At Powerstrip Forum, I saw Parhelia users requesting better support, but that is not possible either because of the lack of technical data.

If you think that the Parhelia-LX chip have a different behaviour as the Parhelia chip, may be it’s worth to try an ask Matrox to add such a feature in the drivers. But do you think Matrox will do that additional job only for the P-series (until now Parhelia and Pxxx have the same drivers).

A simple way for Matrox could be to offer us a new feature in the “Matrox Monitor Manager” program (See my proposition in the picture). A “Composite Sync” check box, near the “Interlaced” check box. Doing so, tweakers and home theatre fans like me could be happy. And this prevents also, in case of fired monitor to show Matrox : “Incorrect monitor settings may cause some monitors to become unusable. Some monitors can be permanently damaged. No responsibility is assumed by Matrox” they said.

I must ask Matrox that feature. It must be easy to implement it.

Anyway, if no success, I’ll try the sync converter and I’ll post here the results.

Regards

[greinedo]

The very quick reply from Matrox states that the software developpement team was already asked in december 2003 about such a feature (composite sync option).

I still wonder if it's a positive or negative answer...

[Kurt]

lol

typical marketing answer...they don't know so they don't answer your question

enfin, qui sait?...