[johnwalkr]

All video games and consoles had separate NTSC and PAL versions until relatively recently. PAL, which is 50Hz was/is used in Europe most of the world except a handful of countries including USA and Japan.

Japan standardized on NTSC/60Hz well before the video game era, for both the 50Hz and 60Hz mains power regions. The frequency is decoupled from mains power frequency even though it was historically based on American 60Hz power.