- A cartridge of Chrono Trigger DS
- A 3DS with A9LH and Luma3DS installed
- TWLSaveTool (install through the TitleDB menu in FBI)
- A ROM of Chrono Trigger DS (Since you already have a cartridge, you can just use Decrypt9/Hourglass9 to dump it. Select Gamecart Dumper, then Dump Cart (trim).)
- If you're doing this with a fresh cartridge of CTDS that doesn't have save data, you'll need to start the game once so that it will initialize its save data. Once it's going through logos and whatnot, you can exit back to your 3DS' home menu.
- With your CTDS cartridge in your 3DS, start TWLSaveTool. Don't remove your CTDS cartridge until after you finish this process.
- Press CHRONO_T.0.sav). It will end up in /TWLSaveTool/ on your SD card. to back up the save file, keeping the default name (
- When TWLSaveTool says it's done, press to exit it.
- Transfer CHRONO_T.0.sav from your SD card to your computer however you're used to transferring stuff to and from your SD card (microSD Management, an FTP server, SD card reader, whatever).
- If this is your first time using DeSmuME, create two folders inside the folder you extracted it to. Name one Roms, and name the other Battery.
- Put the ROM of Chrono Trigger DS into the Roms subdirectory, and put CHRONO_T.0.sav in the Battery subfolder.
- Start DeSmuME and load the ROM of CTDS. Let it initialize save data and start going through logos and whatnot before continuing.
- In DeSmuME's menu, go to File → Import Backup Memory...
- Select CHRONO_T.0.sav and click Open.
- On the next dialog that appears, select EEPROM 512kbit. Even if you have to use the manual selection dropdown.
- DeSmuME will reset and pause emulation, unpause the emulation. If the game still says "Initializing Save Data", you selected the wrong save size, and need to do it correctly this time. If it just goes straight to the logos, you're good to continue.
- Get to Chrono Trigger's main menu and load your save.
- Go into your inventory, get to the Accessories page, and press to sort the items. This will ensure that there are no empty spots in the middle of your accessories list.
- Pause the emulation.
- In DeSmuME's menu, go to Tools → View Memory.
- In the Address box, type in 02072ED4 and press Enter. Your cursor will be placed at the beginning of the Accessories table in memory.
- Set View mode to Words, and check the Big Endian checkbox so bytes stay in the order in which they appear in RAM. The inventory item structure happens to be four bytes long and properly aligned, so this makes it a lot easier to tell where one item ends and the next item begins.
- Depending on your game progress, there's going to be a different amount of data here. Click the first set of four bytes that's all zeroes and make a note of its address (shown in the lower left corner).
- I'll use my addresses (plus two I'm making up for the sake of completeness, they correspond to the two mirrors I already had and therefore didn't need to cheat in) for the purpose of this example, while they should technically work for you and just generate a hole in your accessories list, you can use your own to avoid said hole.
- Add the following cheats using the Internal button: (select 4 bytes for all of them, and leave Freeze Value checked)
Address Value Description 0x02072F78 471083 Nu Arcana 0x02072F7C 77868 Uranian Mirror 0x02072F80 77869 Pontic Mirror 0x02072F84 77870 Promethean Mirror 0x02072F88 77871 Hadean Mirror 0x02072F8C 77872 Aresian Mirror
The Nu Arcana code is different from the rest because it will give you seven of them (one for each character, since it can be equipped by anyone). You only need one of all the other items, so those codes only give you one. You're welcome.
- Once you've got all the cheats entered (double-check that you've entered everything correctly!), click Save and unpause the emulation. In the memory viewer, the data at those addresses should have changed. If something didn't change due to a bad address, or changed to an incorrect value; fix what's wrong, then reset DeSmuME and reload your save. The cheats are "sticky" due to our use of the Freeze Value option, and the areas of memory they affect will stay affected even after the cheats are disabled, so this is why you need to change them before resetting.
- Equip each of them on someone. The mirrors are character-specific, but the Nu Arcana can be equipped on anyone. In order for them to actually count for Item Encyclopedia completion, you need to equip them after hacking them in. This is because you aren't obtaining them legitimately, so the game won't know to add them to the Item Encyclopedia until you equip them. If you're doing this with a fresh cartridge that had no save data when you started, keep this in mind and do it later once you have all the characters recruited.
- Re-equip your normal accessories, or really any accessories as long as they're not one of the six items we just cheated in. Otherwise, you'll end up with duplicates later.
- Save the game, and soft reset back to the main menu. It's probably easier to use DeSmuME's reset than to press + + + to make the game soft reset.
- Select Extras, load your save, then select Item Encyclopedia.
- Select Accessories and scroll down, you'll eventually see all six of these annoyingly rare accessories are present in the list.
- In DeSmuME's menu, go to File → Export Backup Memory.... Type CHRONO_T.1.sav for the file name, and save. This way you still have a backup of the original (CHRONO_T.0.sav) should anything go wrong.
- Transfer your newly generated CHRONO_T.1.sav to /TWLSaveTool/ on your 3DS' SD card.
- On your 3DS, start up TWLSaveTool. Use the d-pad to change the filename to CHRONO_T.1.sav, and press to restore the save data.
- When TWLSaveTool says it's done, press to exit it.
- Start Chrono Trigger and inspect all the relevant menus to confirm that you have the mirrors and the Item Encyclopedia entries for them. Obviously, if this was fresh save data, you won't have the Item Encyclopedia entries yet, so remember to come back and equip these things once you have everyone recruited.
- You're done!
Edit (2017-03-29): I'm aware that some of the mirrors can be equipped by two people, and that in all likelihood you shouldn't actually check Freeze Value in step 3.9. I'll tweak the directions a bit once I've looked into things a bit more. Hopefully the tweaks will involve additional cheats to just add the entries to your Item Encyclopedia, if I can find that region of memory. It doesn't help that all the memory mapping efforts for Chrono Trigger have been for the SNES version. I'll see what I can accomplish with DeSmuME's tools.
Edit (2017-04-13): After a bit of poking around, I've figured out how to use DeSmuME's tools more better. Cheats will no longer be required, we can just edit the memory in-place and save as usual. Also, I did some slight revisions to the steps in this update, including splitting up the steps into their overarching tasks to hopefully make the process easier to follow.