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.
