Jam Editor is a texture editor for the Grand Prix 2 and Grand Prix 3 games.

I decided to try and make an up to date editor as the old Jam Editor source codes are no longer available. I had Trevor Kellaway's code for the decrypting of the Jam files but not HW Jam files, so had to do a bit of digging to get this to work.

Not had chance since August 2025 to move forward with the project, so releasing 'as-is' along with source code in case anybody is interested in it.

Main features are batch conversions and generating of 'proper palettes' for SW Jams. This can be hit and miss and can present weird results in game. A lot depends on the texture's flag settings and what is set within the track.

Some support for RCR jam viewing which is interesting. There is also a Jam browser.

Enjoy!

Thanks to:

Trevor Kellaway, Paul Hoad, Mal Ross, John Verheijen, René Smit