Psychtoolbox>Datapixx.{mex*} subfunction

The Datapixx has two independant analog video outputs, VGA1 and VGA2. There are
two ways in which these dual video outputs can be driven. In “mirror” mode, the
two outputs receive the same image. This could allow a tester to have his own
stimulus console during testing. In “split” mode, the left half of the image is
presented on VGA1, and the right half of the image is presented on VGA2. This
would create perfectly synchronized dual displays, ideal for applications like
haploscopes. The SetVideoHorizontalSplit “mode” can take on one of the following
0: MIRROR, VGA1 and VGA2 get identical images
1: SPLIT, VGA1/2 get left/right halves of image
2: AUTO (default value), Datapixx automatically switches to SPLIT when the
horizontal resolution is at least twice the vertical resolution.

###See also: SetVideoMode, GetVideoStatus