Putting a 3-way region switch into a PAL Mega drive
The PAL Mega Drive can rather easily be modded with a switch that enables switching between PAL, NTSC-J and NTSC-US. It doesn’t require much skill, if you can do basic soldering, this one is for you. For proper instructions, take a look at this site.
Here’s a picture of my Mega Drive running at 50hz.