Lots of Effort, Too Few to Share It With

A friend of mine (the kind I can physically inflict my attentions on) asked me to try and find a ROM of the English release of Gyakuten Kenji 2 a.k.a. Ace Attorney Investigations: Miles Edgeworth: Prosecutor's Path for the Nintendo DS. His copy apparently crashes after the second case.

Digital adventure time! So first I have to figure out exactly what it is I'm looking for. Turns out there was never an English release of the game and Ace Attorney Investigations: Miles Edgeworth: Prosecutor's Path doesn't officially exist. What does exist is a fan translation work. Because legal Reasons^TM, the translation work can't release the translated game. What they can do is release patches for the ROM that change the original into the translated work. These patches were released in three stages. The first stage only translated the first two cases. The second stage translated the first three. And the final stage was the completed work which translated the entire game. My friend apparently had a ROM that had been patched with the first release.

So now that I know what I'm after, I have to actually find the darn thing. This seems straight forward until you realize that there are no shortage of bad actors. The first couple ROM sites offered appropriately sized and named downloads save for one little, very important detail: the offered files ended in ".exe". Nintendo DS ROMs should end in ".nds". I almost didn't catch it the first time. Anybody who lived through Napster can tell you the importance of a 40mb file that ends in ".exe". Basically it's Computer Cancer. NO TOUCHY!!!. So, having dodged that, I find a good ROM.

Now, to patch it. The official thread on the modder's forum where it was released is a good start. They've got instructions, release notes, and other goodies like links to the two commonly used patching programs. They also had dead download links for the patches. So I've got all the instructions and tools, I just don't have anything to use those tools on. Fortunately this was a little more straight forward. A quick internet search for the file names turned up a few likely candidates for alternative sources. Most were just links back to the original modder forum thread, but I did find one that had hosted the files locally. A quick site sign-up and I have my patches.

The final step (or so I thought) is to get an emulator to make sure it runs. Another quick internet search turns up a number of them. Hooray! The first three fail horribly. The first two are for 64bit operating systems (I have 32bit) and the third is a 32bit front end for 64bit emulators. Even visiting the emulators main pages isn't helping find other versions. Fortunately, the fourth emulator works. It starts the game. It gets through the splash screen (Yay! Shiny English words!). It starts spitting out random text. This... Is a problem. I try the unpatched ROM. It starts the game. It gets through the splash screen (Yay! Shiny Japanese kanji!). It starts spitting out random hieroglyphs. This... Is also a problem. To the release thread with instructions and notes!

So! It turns out that the copy protection on Gyakuten Kenji 2 makes it spit out random hieroglyphs if it detects that it's not being run from an official cartridge on an official DS. A patch is offered as well as some HEX code you could change. Patches are good. They're easy and straightforward and hard to mess up and the patch link is dead.

Poo.

HEX editor it is! I've not actually done this before. It'll be a learning experience and I' better back up anything even remotely connected to it. Okay, in reality, I just made a new copy of the ROM to work on. So what are my instructions? Ha. Hahaha. I said "instructions". I got

AP Patch reminder for old linkers (why wasn't this pre-patched ??)

0x00004640

00 00 9F E5 1E FF 2F E1 CF B3 00 00 00 00 9F E5
1E FF 2F E1 77 B1 00 00 07 40 2D E9 1C 00 9F E5
1C 10 9F E5 00 20 91 E5 02 00 50 E1 14 00 9F 05
00 00 81 05 0C 00 80 02 3C 00 81 05 07 80 BD E8
F0 32 0F 02 D4 1B 0F 02 40 27 00 02

0x000049F8
16 FF FF EA

Thank you, I have NO IDEA what that means. So after some hunting around I find what's purported to be an easy to use, but decently functional HEX editor. Now, I'm not a programmer, but from what I understand, this will allow me to edit the underlying binary that makes up the source code of the game, and the changes offered (whatever they are) will disable the copy protection. I fire up the editor and use it to open the ROM. After comparing the offered HEX code and the displayed code, the "0x00004640" refers to the hex line number where I'm supposed to start changing values. Note they are in groups of 16. Columns "0" through "F". So "0x000049F8" points to the hex location "line 49F0, column 8".

Still only running on "well, this might be right", I edit the values and save.

I open the edited ROM in the emulator.

It runs! Shiny splash screen!

It's still gibberish.

GAH!

It's late. I should be in bed. I go to bed.

This morning I wake up and try downloading the copy protection patch on my phone. The link wasn't dead after all! It just doesn't like my computer or some other digital voodoo. Maybe I need to start a bon fire and sacrifice some RAM sticks or something. I transfer the patch to my computer and attempt to apply it. It fails. I try to apply it using the other patching program. It fails. I try applying it to the English patched version. They fail.

In frustration I look for yet another emulator. I find a 32bit version of the first emulator I tried that the creator's site didn't have. Why it didn't have it? I DON'T KNOW! Whatever. I grab the copy. I install it. I run it. I load the game. It works flawlessly. In legible English. It was the emulator giving me trouble this whole time... *head desk*

So! If anybody wants a very well done (images and evidence and everything!) translated copy of Ace Attorney Investigations: Miles Edgeworth: Prosecutor's Path (never released outside Japan!) for the DS, let me know. I have a copy.