Savefile Manipulation

Terranigma uses two checksum to verify its save file, an ADD of all the bytes and a XOR of all the bytes.

Due this its vulnerable to moving values around in the save file as long as the byte is at the some align.

In the following POC three values are being moved around to achieve item duplication.

Before:

1. Equipped Item (0x4C)
2. Money (0x00)
3. First Slot ID Item (0x10)

After:

1. Equipped Item (0x00)
2. Money (0x10)
3. First Slot ID Item (0x4C)

Note: Terranigma automatically sorts the inventory but only when reentering the inventory screen.

Setup:

1. Get item you want to duplication and nine small heals, since they will always be left most in the inventory
2. Have 10 money
3. Save to second slot
4. Equip item you want to dupe and spent all your money
5. Save to first slot
6. Reset game
7. Load second save file
8. Unequip the item
9. Delete all the small heals
10. Reenter the item inventory screen
11. Save to first slot but as soon as the first slot item ID is written reset the system

Example: View