Creating a GCT File

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This is a tutorial on how to make a .gct file for use on Nintendont

Preliminary Information: Decrypting an AR code

Here is a list of the best source of ar codes, other than vanilla Dolphin (which is just half item modifier codes anyway)

You will notice that ar codes come in decrypted and encrypted form:

  • Encrypted form looks like XXXX-XXXX-XXXX for each line
  • Decrypted form looks like XXXXXXXX XXXXXXXX for each line

In order to make a .gct file, you need a decrypted ar code.

Method #1: Gcncrypt

Download: https://projects.sappharad.com/tools/gcncrypt_mac.html

To use: paste the encrypted ar code on the left side, select your region, and then decrypt. On the right side, the decrypted version should appear. The "verifier" line (the first line) should be omitted in the .gct file.

Method #2: Dolphin

Right click on the .iso -> Properties (on the bottom) -> AR codes tab On the bottom of the popup, click on “Add AR Code” Paste the encrypted version, and then add it. Click on the added AR code, and a decrypted version (without the verifier line) will be there.

Editing the .gct

This assumes that all your ar codes are decrypted. You also need a hex editor.

A .gct file is basically “00 D0 C0 DE 00 D0 C0 DE” < all of the ar code text here> “F0 00 00 00 00 00 00 00” .This is basically the formula of your desired ar code. Have the “header” in hex (not in text), then all of your desired ar codes (in hex, not in text), and then “F0 00 00 00 00 00 00 00”. In HXD, you can simply copy and paste the ar codes into the main display line by line.

This file should be named “GM4E01.gct” if playing on NTSC-U. For PAL, name the file "GM4P01.gct" You should put this file into the “cheats” folder on your Nintendont-playing storage space.