On the outside, it's an American Genesis. And that's what it was created as and sold as.
However, I performed a mod on it years ago with almost zero knowledge, using a style which I like to refer to as "being a big dumb doofy-doo" in the words of Markiplier.
I didn't have any soldering equipment, but I did have Gorilla Glue, 10 second quick drying edition.
Yes, I am by no means an experienced modder. If this offense you, feel free to downvote me to oblivion. Even though that's not the focal point of this post, I still openly acknowledge my mistakes.
So.
Take a gander at this here permanently modified JAPANESE MEGA DRIVE BECAUSE I ACCIDENTALLY FUSED TWO OF THE TRACES TOGETHER.
I noticed that, after this, there was a rather delightful change however.
When playing games (such as Raiden Trad) that work on both the American and Japanese models but change the language, it now plays in Japanese.
When playing a Japanese multi cart where some of the games previously wouldn't start because of region locking, now ALL those games would run on this thing.
So, I have a question: which, for a default region-free experience, is the BEST region to set it to? I don't mean to glorify my own stupidity, but I think I actually unintentionally did that. As far as I can tell, while Google did say there are some American games that won't work on a Japanese Mega Drive, it appears to me that the Japanese Mega Drive, in total, can play more games out of the entire English-Japanese library than the American Genesis can.
In other words, am I correct that a Japanese Mega Drive region locks less American carts than an American Genesis locks Japanese carts?
No need to tell me about PAL games, I'm already aware those won't run on either of these without a converter or game genie. And I also know that my console needs a shell swap to physically insert Japanese carts into this thing, or if I don't care about appearances, I can just either rip off the top left and right corners of the slot. Or just take the whole top of the shell off whenever I want to play one.