About

A repository for reverse engineering and documenting the Paragon 5/GBASS sound driver

Feel free to reimplement, borrow or use this documentation for your own research and tools.

Several games used this driver. A few games worth noting:

• Godzilla: Domination!
• Shantae Advance (prototype/demo version, used Godzilla BGM as placeholders)
• Hardcore Pinball

Known/partially documented features

• Songs have internal names (no need to guess what they're called!)
• Has a super easy to scan for byte string that shows up right before the song table (00 00 00 00 01 01 00 00 XX 00 00 00) (XX is the engine version number)
• Each channel is assigned an instrument alongside the pointer to the sequence table for the said channel
• Each channel of a song is stored as several sub-sequences with a timer between each one (if a sequence is corrupted, the next one will always eventually start playing)
• Notes are played on a timer which appears to be done in frames. Each frame advanced on the GBA will generally decrease the timer value in RAM by 1. Lag will also generally slow the engine down.

Currently known command list

• 0000 - End of sequence
• 0X, 00XX - Note off event for X amount of time
• 1X - Unknown
• 20-2C - Note (subtract 0x20 from it and add the note base pitch value * 0xC to it)
• 30-4F - Unknown
• 50-58 - Set note base pitch (subtract 0x50 from it for the value)
• 84, 85 - Pitch bends (how they work is unknown)

Using PFivetoMIDI

Be sure that the Python mido library is installed and double click the script before navigating to your ROM.

Double click your ROM and the sequences should be converted to MIDI files in a folder named "/(ROM name)/" in the same folder as the ROM.

To-do list:

• Find out why the script is escaping the sequences in almost every single case (all of them have been confirmed to end on 0000, but the script reads past that and continues parsing data)
• Find out how pitch bends work
• Fix an issue where some sequences are way faster or slower than intended - possibly caused by a command that sets the tempo
• Improve the sequence table handling
• Add better variable names (this script is based off of an older script I made back in 2022)