The other day I got a copy of the Japanese version of Metal Gear. It's still on route as I write this. And I was wondering, when it gets here, how would I know if it works? Metal Gear for the MSX is the only Konami game that's region locked and you need a Japanese MSX to make it work - and I don't own one.
Other than knowing if Metal Gear works, I'd actually would want to play it! And there's a whole bunch of other games that also change apearance or behaviour depending on the region of the MSX they're running on. Sounds like fun to be able to see that happening using the real cartridge! So, let's figure out if there's a workaround!
This region stuff is rather difficult to circumvent because the region code is set in the BIOS rom and there's just not much you can change about that. Unless you lift the hood and physically change the BIOS rom chip. Same goes for the game itself; It's burned on a rom chip and you can't easily make it do something other than what was basically set in stone somewhere in the 80's.
With the advent of cartridges like the MegaFlashRom however, it's much easier to get a foot in the door. The RegionSwap tool makes it possible to create a duplicate of the BIOS from your own MSX and modify it to look like a different region BIOS. This fake rom can then be run from the MFR and sneakily substitute the native BIOS for the duration of the game.
Once installed and booted from the MFR, you are given the choice between the original BIOS or the modified one. If you pick the latter, this new BIOS is selected and, before the system can swap back to the "real" one, the game is started. The game code will then hopefully be tricked into finding the region of your choice.
Even though this sounds all very convulted, I tried to make it as simple as possible and it's really a two step process now:
1 - Run the REGSWAP.BAS tool and wait until it's finished. You'll then have a file call REGSWAP.ROM in the same folder. If you have more than one MSX system, it might be a good idea to rename this file so you know to which it belongs. A rom file created on one MSX probably won't work on another!
2 - Burn the rom with OPFXSD REGSWAP.ROM /L to your MFR and restart the computer with the MFR in slot 1 and the game in slot 2.
Nothing should go wrong, but beware that it's your own risk. You're free to use this tool, but I'm not taking any responsibility for any negative side effect. If in doubt, don't use it.