Grandia III PS2 Single-DVD9 Builder - Public Beta

Merges the USA Disc 1 and Disc 2 releases into one DVD9 ISO.

The script automatically patches the Disc 1 FIELD overlay so that:

the Disc 1 completion screen can return to the Main Menu;
the obsolete disc-swap message is replaced;
valid Disc 1 and Disc 2 saves can be loaded without a wrong-disc rejection.

Existing Disc 1 file payload LBAs are preserved where possible, and the original UDF data is not remastered.

Requires user-supplied Grandia III USA Disc 1 and Disc 2 ISO images.

Tested so far:

merged image boots;
Disc 1 saves load;
Disc 2 saves load;
Disc 1 -> Disc 2 -> Disc 1 saves can be loaded consecutively without changing images.

A complete start-to-finish playthrough has not yet been verified. Testing and bug reports are welcome.


Python 3 required

Usage:
py grandia3_single_dvd9.py "Grandia III Disc 1.iso" "Grandia III Disc 2.iso" -o "Grandia III Single DVD9.iso"
py grandia3_single_dvd9.py --help

Developed and tested by Yobonanakh, with code and reverse-engineering assistance from ChatGPT (GPT-5.6 Sol) (OpenAI).