Hi! I'm using a Canopus ADVC110 in a live video editing workshop for kids. I have two NTSC cameras and a video signal from a MacBook mini-DVI-to-video adapter going into three channels of a video switcher. The switcher outputs to the ADVC110, which is connected to the same MacBook via FireWire. The video is captured through FCP 6.0.6.

The image coming from the two NTSC cameras looks great. However the image coming from the MacBook has a black border around it. I want to make the image full screen. I've experimented with different display resolutions in System Preferences, but I can't figure out how to get either the MacBook or the ADVC110 to treat the MacBook's video signal as a full-screen NTSC image.

Essentially I want to recapture video from a MacBook going from mini-DVI-to-video into the ADVC110 and back into the MacBook via Firewire. How can I make the image full screen NTSC 640x480 without a black border?

I have attached two images: a sketch of the loop and an image of the video I am capturing with the black border.

You've created a video loop which won't work. Since your screen is significantly larger than 640X480 you get a black border in the 1:1 pixel mode. You can scale the image up (and lose resolution thru interpolation) using a screen recorder app in "full screen" mode.