This instructable will tell you step-by-step how to modify your Model 1 Sega Genesis to it may play other region games with a simple toggle switch.
Step 1: Parts Needed
1. Model 1 Sega Genesis
2. Soldering Iron
4. Three small gauge wire
8. Philips head screw driver.
Step 2: Disassemble
In this step, we're going to completely dismantle the system.
Step 3: Locating the Proper Jumpers
Now that the board is exposed, you'll need to locate the proper jumpers labeled "JP1" and "JP2".
"JP2" has a bridge between it. Scratch this out using whatever you like.
Also, now would be a good time to heat up your soldering iron.
Step 4: The Wires
Take three different colored wires, preferably the same legenth. Strip the ends and add a bit of solder to the stripped ends. Braiding them is optional.
Step 5: The Switch
Find your switch, and add a bit of solder to the contact points.
Step 6: The Jumpers
Now, we're going to wire the jumpers.
Add a bit of solder to the jumpers, and then add the wire.
Please see the image notations below.
Step 7: The Switch (remix)
Solder the wires to the switch. Be mindful of which one is supposed to be on the center contact point of the switch.
Step 8: Cartridge Door.
Since there's a difference in cartridge size, the cartridge door will need to be modified as well. This is easy.
Again, follow the image notations.
Step 9: Finding a Home for the Switch
Now, you're going to have to bore out a space for the switch.
Follow the image notations.
Step 10: Re-Assemble!
Before you completely re-assemble this, you've probably noticed that the shield might be blocking the wires for the switch. Cut the shield. Don't cut it if you found a better placement.
After that, re-assemble it and bask in the glory of your Sega.