PORTIBM PC Portable (uses same BIOS as XT) 0530-0533 - Gravis Ultra Sound Daughter Card by Advanced Gravis Range: dipswitch selectable from PORTIBM PC Portable (uses same BIOS as XT) 0530h-0533h, PORTIBM PC Portable (uses same BIOS as XT) 0604h-0607h, PORTIBM PC Portable (uses same BIOS as XT) 0E80h-0E83h, and PORTIBM PC Portable (uses same BIOS as XT) 0F40h-0F43h SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0530h"Windows Sound System" 0530 RW address select (see #P0895) 0531 RW data (selected by PORTIBM PC Portable (uses same BIOS as XT) 0530h) 0532 RW status 0533 RW PIO data