How to force ATI component out to do scaling rather than panning?

[TheManuel]

I finally received the DVI to YPbPr adapter for my ATI 9550 from monoprice.
I have to say that the image looks much better than s-video out.  The colors and definition are very crisp even if the red color still looks too orange.

Now I am struggling with my options for getting correct aspect ratio. 
I have the resolution set to 640x432 as recommended by many here.  I have two choices for getting the correct aspect ratio and filling the entire screen, either use D3D or Direct Draw with hardware stretch.
Hardware stretch introduces some blur although I admit it is a lot less notiecable than with s-video out and can be mitigated significantly by increasing the sharpness control in the TV but the end result is not quite as sharp as when using direct draw without hardware stretch.
The other option is to use D3D.  However, D3D ususally looks best when run at a high resolution (at least 1024x768).  Here is where the problem lies.  If I use that resolution or any other higher than 640x432, the image in the TV exceeds the visible area (when in Windows desktop mode, you can pan around with the mouse). 

What I would like to see is the image being scaled down to the TV resolution rather than over-expanding the image beyond the visible limits.  This is no different than when using s-video.  When you select 1024x768 whith s-video, the image gets scaled down and you see everything in the TV visible area.

Any ideas how I can do this?

[fjl]

I use component out with 1024x768 resolution. I have an ATi Radeon X1300 AGP card.

Perhaps its my TV that can support 1024x768. I haven't tried it with any other TV monitors. If I select 640x480 it also fits. But if I go for something lower it will have black borders/bars on the edges of the screen. And anything over 1024x768 doesn't fit on the screen.

[TheManuel]

That's really odd, that two or three different resolutions fit the screen  perfectly but the rest don't.
In my case, I am limited to 640x432.  Anything else either is too small or over-shoots the screen.

Are you using the component dongle set to 480i?

[Ummon]

I think there may be two things aiding here. One is the dongle settings for particular resolutions, and the other may be the card used, relative to scaling certain resolutions. I don't think there are geometry settings in video card display managers. You could look for service menu features on your TV.

[TheManuel]

Welll, if you are using a standard resolution TV like me, there is only one dongle setting you can use and that is 480i.  Anything else and the scan frequency will be too high for your TV and it won't work.
As for the card, there may be something there.  Maybe his card does scale while mine does not.
Oh well. 

[Ummon]

Something I forgot about are the image manipulation features in-game. Essentially, they're software geometry settings in mame itself. They induce artifacting if running native, but in D3D at (I think) VGA and above, they have no ill affect. Don't know how it would coincide with TV formats. And of course it doesn't help you with your fe.