ISO doesnt work, it will most likely use CHD's anyway. A small fix to get the sound working in the last update is....
static ADDRESS_MAP_START( sound_readmem, ADDRESS_SPACE_PROGRAM, 8 )
AM_RANGE(0x0000, 0x7fff) AM_READ(MRA8_RAM)
AM_RANGE(0x8000, 0xbfff) AM_READ(MRA8_BANK5)
AM_RANGE(0xc000, 0xdfff) AM_READ(MRA8_BANK6)
AM_RANGE(0xe000, 0xefff) AM_READ(MRA8_BANK7)
AM_RANGE(0xf000, 0xf7ff) AM_READ(MRA8_BANK8)
AM_RANGE(0xf800, 0xffff) AM_READ(MRA8_RAM)
ADDRESS_MAP_END
static ADDRESS_MAP_START( sound_writemem, ADDRESS_SPACE_PROGRAM, 8 )
AM_RANGE(0x0000, 0xffff) AM_WRITE(MWA8_RAM) AM_BASE(&neocd_z80_ram)
ADDRESS_MAP_END