How does screen resolution of a system affect what you see?

[1bigmig]

For example, the SMS has (according to the DP guide) a screen resolution of 240 x 226. Could someone tell me how this translates to what you see on the TV? If you had a TV with 600 lines of horizontal resolution, would it only use 240 of them? If you had two tv's of the same size and one had 300 lines and the other had 600 would the picture look the same? Any other info on this would also be appreciated. Thanks for your help.

[davidbrit2]

Okay, all NTSC televisions (should) support the same number of scan lines. HDTVs support considerably more, but display an NTSC image as you would expect to see it.

If a game has a high resolution interlaced display, which draws the even and odd scan lines in alternate fields 30 times per second, you'll get roughly 500 scan lines. With a non-interlaced display, which is what most every console used before the PSX/Saturn era, you get about 250 scan lines. Now, a system may or may not draw useful images on all 250 of those. For smaller images, you'll see a little bit of unused border space around the picture. The Commodore 64 is a good example. It has a border around the screen, which can be set to different colors. So the video hardware actually outputs a scan for the full television frame, but whether or not every single scan line is completely addressable for arbitrary graphics and such is another matter entirely. This is where resolution differences come in.

Horizontal resolution is a little more flexible, since the picture isn't confined to discrete lines.

[1bigmig]

Thanks, I didnt realize this question was in every audio/video faq on the net before I asked it. I should have looked first. Well, if anyone else is interested I found a very good page on this topic:
http://members.aol.com/ajaynejr/vidres.htm#QuickHor