Please note: This is an advanced mod that requires soldering skills.
This little kit by borti will make your Mega Drive I / II / Genesis play any game from any region, at the correct speed.
No need to install switches, or modify your console shell at all. It makes use of the console's reset button to allow you to control the region of the cartridge you've connected. It will automatically switch to the right speed as well, 50Hz for PAL games and 60Hz for NTSC-U/NTSC-J cartridges!
The installation might be a little tricky though, as it requires soldering to traces, and cutting traces.
The installation is the same as the DIY kit shown on mmmonkey's website
Note: Due to the fragile nature and sensitivity of electronic components, we are unable to accept returns if the kit has been opened.