But since only 224 lines would be visible on most TVs, most video games consoles up to the 2000s only had an active video resolution of 224/448 lines because anything more would be a waste of resources. To prevent you from seeing the end of the picture if the height temporarily decreased slightly, TV manufactures calibrated the sets so only around 448 lines were seen onscreen, while the rest is drawn outside of the CRT's visible area (overscan).Ĭonsole manufacturers used a technique that, to simplify, turned the 480 lines at 60 half frames per second video signal into 240 lines at 60 full frames per second. Depending on power fluctuations, those scanlines could be drawn further or closer apart from each other, resulting in increased or decreased vertical picture size. What happens is that analog TVs don't have pixels, they just draw scanlines from left to right at whichever point on the screen they want to, basically (contrary to popular belief, scanlines are the drawn lines, not the black lines inbetween). Some of those are used for blanking and whatelse, but there's still 480 lines left for video. NTSC signals (and PAL-M, for that matter) are made up of 525 interlaced lines.
Click to expand.This is not entirely true.
