1800 rpm in NTSC machines, exactly 1500 in PAL, each complete rotation corresponding to one frame of video. Source: Internet
352x240 (or SIF ) resolution was chosen because it is half the vertical and half the horizontal resolution of NTSC video. 352x288 is similarly one quarter PAL/SECAM resolution. Source: Internet
Accordingly, DVDs were labelled as PAL or NTSC (referring to the line count and frame rate) even though technically the discs do not carry either PAL or NTSC composite signal. Source: Internet
A minor drawback is that the vertical colour resolution is poorer than the NTSC system's, but since the human eye also has a colour resolution that is much lower than its brightness resolution, this effect is not visible. Source: Internet
Although incompatible with the existing NTSC standard, the new DTV standard would be able to incorporate many improvements. Source: Internet
Almost all other countries using system M use NTSC. Source: Internet