In theory, you can directly push video into it if you have a pc capable of some strange frequencies - think Linux, XFree special config files, and probably some specific graphics card.

Getting the TV module means that you get simpler TV inputs through it and then it's easier to connect PC, DVD players, cameras, etc into the TV module.

TV and NAV can be together or either one alone. Both are capable of displaying the menus into the LCD (e.g. with NAV and TV, the tv displays the menus instead of nav).

Then there is an additional issue with the screen, which is how to open it up. I'm hunting down the I-BUS to see it the screen opens up via I-bus, via K-BUS, or via power. Check this thread.

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