Ok, I managed to convert the Speccy extra stages "The stardrive" and "Laser platoon" so that they could be read by the "Saved Game" menu (like on Speccy). It seems that those 2 new maps have extra weapons not featured in previous maps.
The trick was only to change byte #2D to 'g' instead of 'e' (those letters are related to the menu entry number, which are not the same on MSX and Speccy...).
Packaging everything in a .ZIP file with some instructions (also unified the loader in a single file to make it simpler).
