In your Colibri T20 datasheet you say: “Please contact Toradex if you plan to use Composite or S-Video Interface.” What’s special about these interfaces? I would like to use WinCE.
Basically this should work. We have not tested this since a while as it is not an often used feature. Give it a try by first modify the registry and set the BootUpStyle to either PAL or NTSC. See also here the detailed registry display settings.
For PAL the BootUpStyle needs to be set to 0x0000a . Eventually you also have to set the resolution to the standard PAL resolution ( 768 x 578). The PAL signal is on the VDAC_G (CRT_GREEN, on the extension connector) line.