Hi,
The standalone BlueMSX emulator has an option to Insert a “Special Cartridge” in Cartridge Slot 1 or Cartridge Slot 2. See attached picture.
So for example one could insert an “empty” SCC cartridge in slot 2, such that the Konami Sound chip can be used in scene demo’s or for example used for one of the many enhanced / patched games.
One specific case is that recently a number of Konami games have been patched with a lot of cool features. One of them is added voice synthesis to Salamander and Nemesis games (you can hear them when you pick-up a weapon) see for example these:
But for the voices to work one has to insert an SCC cartridge in the second slot. In the Libretro implementation this can unfortunately not be done right now, so no cool voiceset for us 
I was wondering whether someone capable of this could implement the “insert special cartridge” as a core option? I imagine the functionality is already there in the blueMSX code, but it needs to be hooked up.
@Tatsuya79 Possibly this is something you could look into?
Here are two example videos where the voice set can be heard:
These patched konami games with the voice synthesis are so cool, we need them to work in the Libretro core also 
