After many months, I finally worked through the remaining issues with the Rygar core for MiSTer. I'm happy to announce that the public release is available for download.
The main issue holding things back was some SDRAM timing problems, which have now been fixed. I ended up putting so much time and research into my SDRAM controller that I have released it as a separate project. Hopefully this will give other core developers a headstart with their next arcade project.
There was also some clipping present in the audio when loud FM and PCM sounds were played together. I managed to fix this by writing an audio mixer, which uses fixed-point arithmetic to attenuate and sum the audio channels.
This turned out to be a bit trickier than I expected, so stay tuned for another blog post covering some of things I learned while researching fixed-point arithmetic.
Other than that, there's not much more to say.
Enjoy playing Rygar, I know I will.