> I do have a pivot lcd...
> What exactly do you mean? I can't achieve they look I want when the screen is
> pivoted ?
No :-), because it is an LCD screen.
To get the clearest possible picture, configure MAME to run everything in your LCD's native resolution, and use the stretch options in the D3D renderer to stretch and sharpen the image.
Forget everything I said about custom resolutions, they won't help you, since your LCD monitor will stretch and filter the image itself in order to make it match its own native resolution, which it is always running in anyway.