What are you running?
If it's a PC, these ATSC resolutions roughly translate to their PC counterparts.
480p = 720x480
720p = 1280x720
1080i = 1920x1080i/1920x540p
1080p = 1920x1080
Also, these signals are available only over high bandwidth video connectors like Component (Y Pb Pr), VGA(RGBHV), DVI or HDMI etc.
RF, Composite, Y/C (s-video) are limited to 480i even when being output from a PC.
If it's a PC, these ATSC resolutions roughly translate to their PC counterparts.
480p = 720x480
720p = 1280x720
1080i = 1920x1080i/1920x540p
1080p = 1920x1080
Also, these signals are available only over high bandwidth video connectors like Component (Y Pb Pr), VGA(RGBHV), DVI or HDMI etc.
RF, Composite, Y/C (s-video) are limited to 480i even when being output from a PC.