I installed it on my SL-6000. The game starts up and shows me the Soduku grid, but every square just has a little box in it. It's the same box I usually see when I'm missing unicode characters, so I probably need to install a font. Which one do you use?
EDIT: it works if I switch my font set to the ones from the Japanese 6000 ROM, so I'll try and narrow down which one I'm missing.