Super Mario Bros. 3 - NES

[MarioMania]

Why do some Game Genie Codes work on the Japanese version of it, but not others...Some off party codes like

Can Walk Anywheres On World Maps - OXKIPZOS

But the Debug Code - KKKZSPIU   won't work on the Japanese version, but it works on the PAL version

[UglyJoe]

Game Genie codes work by "changing" a value of the game ROM at a given address.  It's not a real change, since the ROM is read-only, but it kinda hijacks the ROM if you try to access the address and it gives you whatever value you specified in the code. 

The reason the codes aren't universal is because different versions of the games store some of their information at different ROM addresses.  For example, where the US version might store your initial number of lives at address 'A' (which you then replace with 255 using your code), the JA version may store your initial number of lives at address 'B'.  Your code would still be setting the value at address 'A' to 255, but that would have no effect on your lives.

[JC]

Interesting...I didn't know that. Is it possible that new codes still exist, or have gamers explored the ROMs thoroughly enough to find them all? I remember not too long back those hidden levels in SMB3 were discovered.

[FamicomFreak]

Interesting...I didn't know that. Is it possible that new codes still exist, or have gamers explored the ROMs thoroughly enough to find them all? I remember not too long back those hidden levels in SMB3 were discovered.

Yeah those were really interesting. I remember the game genie manual tells you how to create your own codes and I made some of them a couple of times like for metroid I could make it so that if you get hit one time you will die which I called super duper difficult mode. I know nowadays there are other ways to find codes so blah.

[UglyJoe]

Interesting...I didn't know that. Is it possible that new codes still exist, or have gamers explored the ROMs thoroughly enough to find them all? I remember not too long back those hidden levels in SMB3 were discovered.

Well, any code that you put in there does something.  It's just a question of what data you're replacing. 

The codes in the game genie book all replace values that have to do with lives or which level you start on or game physics (how high you can jump, etc) -- useful stuff.  If you just jam a code into it at random, you're more than likely going to alter either a tiny bit of graphics or, worse, an instruction or two of the game's source code -- stuff that'll garble the graphics or make the game freeze up.

NESDev has a neat article about it that explains how to translate the GG code to an address/value pair.

[133MHz]

AOSUZI  - the best gamegenie code EVER.

[JC]

Why?

[UglyJoe]

Apparently it lets you grab *any* tile off the map and kick it like it were a turtle shell.  You can plow through walls and stuff.  There's a couple vids of it in action on youtube.

[JC]

Sounds neat...I'll have to try it sometime. Is there any site that maintains every official Game Genie code for every game, plus codes discovered since the last code book was published?

[FamicomFreak]

Apparently it lets you grab *any* tile off the map and kick it like it were a turtle shell.  You can plow through walls and stuff.  There's a couple vids of it in action on youtube.

omg no way I have to see that!

[Jedi Master Baiter]

I just tried it!

Who discovered that? I am never going to get bored of this game

ever.

again.

[Jedi Master Baiter]

You can destroy water.

[133MHz]

And build yourself passages to explore around

[FamicomFreak]

Anyone have a youtube video for this? I'm too lazy to look there are just too many SMB3 videos...

[Jedi Master Baiter]

I can make one, but I'm too lazy to do it...