For a long time now I've been wanting to replace a few ROM's in my EU MegaDrive games with the US ones, for those games that won't run in anything but 50Hz. I'm guessing some kind of EEPROM burner will be needed but I have no experience with any of that. I do have the basic soldering skills to remove the old ROM chip's and installing the new ones. How many types of ROM chips does MegaDrive cartridges use? The easiest thing would be if I could just get a bunch of the largest needed and for the small games fill the remaining space up with 0's or something As said I have never worked with these things before In the above picture it's pretty easy to spot what needs changing in the Mega Turrican cartridge The Soleil on the other hand might be more complicated? Soleil does work fine in 60Hz I just used it to show a difference between cartridges. Another thing that would be nice is getting RPG's like Langrisser 2 from Japan and replace the ROM with the fan translation. Or simply buy the cheaper and prettier Japanese versions of, for example, the Phantasy Star series and replace the ROM's with the English ones. Any chance that the Japanese cartridges will differ so much that simply replacing the ROM won't work? I have an EverDrive cartridge on the way so I could just use that to play the preferred versions of the games I already own, but it would be nice to use the original cartridges if possible. Is this a retarded idea and are there any downsides in doing this?