Modify the games. Add 8 to every value that this written to a bank select register. SD Snatcher works only with the SD cartridge. Values 8 - 15 select the memory. Loading ROM Files into Sound Cartridge Since the Sound Cartridge contains RAM, it is possible to load ROM files into it.
Documentation is in the zip file.
The fact that this is possible makes me think that this cartridge was used for testing Konami ROMs while they were in development. Of course, this is only speculation. It is much like a normal SCC, but now with RAM and an extra wave form. See megaROM mappers for more information on memory banks and bank select registers. Thus there are 16 memory areas of each 8Kb.