PORTIBM PC Portable (uses same BIOS as XT) 0604-060B - Windows Sound System Range: PORTIBM PC Portable (uses same BIOS as XT) 0530h-0537h,PORTIBM PC Portable (uses same BIOS as XT) 0604h-060Bh,PORTIBM PC Portable (uses same BIOS as XT) 0E80h-0E87h,PORTIBM PC Portable (uses same BIOS as XT) 0F40h-0F47h SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0530h"Sound System"