catch-mew

Generates a save file for Japanese Pokémon Emerald that has the Old Sea Map Faraway Island event active.

TID/SID generation: Not all TID/SID pairs are valid because of the way Emerald generates them. Clicking the Randomize IDs or Generate save button with both ID fields blank attempts to generate a TID/SID pair by modeling the ID relationship on the method the game uses. You can override this behavior by manually entering a TID/SID pair or providing a save file from which the pair can be imported.

Usage

If you just want a save that you can use to catch Mew:

1. Enter a trainer name
2. Set the trainer gender
3. Leave both ID fields blank, or click Randomize IDs to preview a new pair
4. Click the Generate save button

If you have known trainer name, gender, TID, and SID you want to use:

1. Enter the known trainer name
2. Set the known trainer gender
3. Enter the known TID
4. Enter the known SID
5. Click the Generate save button

If you have an existing save file and want the same trainer name, gender, TID, and SID:

1. Click the Load from save button
2. Select your current save file

• 128 KiB save files in .sav or .srm format with or without a 16-byte RTC timestamp at the end of the save file. Save states are not supported.

3. Check the imported name preview and click the Generate save button

Trainer names

The preview shows how the trainer name will be rendered in game. Trainer names are limited to five characters after encoding and normalization. While leading, internal, and trailing spaces are preserved, a name cannot consist entirely of spaces. ASCII letters, digits, spaces, and ! ? . / : become their fullwidth equivalents. Dashes (- and −) are converted to the Japanese long-vowel mark ー. The ‥ and ⋯ characters are converted to …. Halfwidth kana and combining dakuten/handakuten are normalized where a matching game character exists.

Template save info

The template save has the following relevant flags and info set:

Property	Value
Starting location	Lilycove Pokemon Center 1F; map group 13, map 6; x=7, y=4
Game-clear flag (0x864)	Set
Faraway Island ferry flag (0x8D6)	Set
Old Sea Map received (0x13C)	Set
Old Sea Map shown (0x1B0)	Not set
Mew defeated (0x1C7)	Not set
Mew caught (0x1CA)	Not set
Old Sea Map (0x178)	One in the Key Items pocket

Save file format

The generated save file will be named OSM_Emerald_J.sav and be exactly 128 KiB (131,072 bytes). If you need a .srm file, you can simply rename the file extension.

What to do next

Travel to Faraway Island and catch Mew

1. Go to ミナモシティ (Minamo City, English: Lilycove City, between routes 121 and 124)
2. Go inside the harbor building (the most southwest building)
3. Talk to the NPC in front of the タイドリップ号 (Tiderip, English: SS Tidal)
4. After some dialog ハギ老人 (Old Man Hagi, English: Mr. Briney) will take you to Faraway Island
5. Walk through the trees and enter the encounter area, startling Mew
6. Chase Mew until you have it cornered and save before pressing A

Mew finder

This tool helps with RNG manipulation if you're looking for a Mew with specific stats.

Acknowledgements (in no particular order)

• Project Pokemon so much info
• PKHeX save file research
• PKHeXWC3Plugin event injection research
• JS-Finder Emerald TID/SID research
• Bulbapedia sprites, event research
• Emerald decomp more details about save files and TID/SID generation
• PokéFinder Method 1 static encounter model research