The original sound hardware for Cosmo has been reverse engineered from schematics generated by The Guru of Mame fame and has been added to the core on MiSTer
The original hardware runs at 333Khz which is way too fast for the audio output on MiSTer (maximum 96Khz) and sounded wrong at the correct speed. (due to lost sample changes, and trying to resample it at different rates did not improve it much)
So I have changed this clock to 192Khz and averaged the output to the DAC over two samples.
This results in the effects being about 4 notes lower and slightly slower than the original, however in comparison to a video of the real thing I didn’t notice a difference!