[hot_gril]

Speaking of Japan and frequency differences, one funny indirect consequence of the power differences is the video game Super Smash Bros Melee having separate NTSC and PAL versions, one at 60Hz and another at 50Hz, and consequently running at 60fps or 50fps (unless you override this at start). For good players, 50fps changed the game a lot, so they'd always use NTSC or override to 60. But PAL Melee also had other gameplay changes.

[aeyes]

A lot of games on the Mega Drive / Genesis didn't properly adjust their speed for PAL/NTSC, for example Sonic 1. They'd just run slower/faster according to VDP clock.

[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.