the 4x3 override lets you select a format to display 4x3 SDTV content in. The motorola boxes let you set it to 480i, 480p, or off (1080i). Whatever setting you have it on, all 4x3 content will be converted to that particular resolution, ie if you have ti @ 480p, all SDTV will be shown in 480p. We needed this for our plasma downstairs because excessive black bars would probably resulkt in burn in. Unfortunately, our Samsung plasma does not have any sort of Zoom options in 1080i so the only option was to choose auto-pillarbox and the image was just stretched to fill the image and everyone looked like fat midgets (TNT-O-VISION). I needed the motorola's ability to out @ 480p so I could use the panorama/zoom features of my TV and have a decent 4x3 SDTV viewing experience.