SCB_NEXT
ahd_outw(ahd, SCB_NEXT, SCB_LIST_NULL);
next = ahd_inw_scbram(ahd, SCB_NEXT);
ahd_outw(ahd, SCB_NEXT, next);
ahd_inw_scbram(ahd, SCB_NEXT),
ahd_inw_scbram(ahd, SCB_NEXT),
ahc_outb(ahc, SCB_NEXT, i+1);
ahc_outb(ahc, SCB_NEXT, SCB_LIST_NULL);
ahc_outb(ahc, SCB_NEXT, SCB_LIST_NULL);
next = ahc_inb(ahc, SCB_NEXT);
next = ahc_inb(ahc, SCB_NEXT);
next = ahc_inb(ahc, SCB_NEXT);
next = ahc_inb(ahc, SCB_NEXT);
next = ahc_inb(ahc, SCB_NEXT);
ahc_outb(ahc, SCB_NEXT, next);
ahc_outb(ahc, SCB_NEXT, ahc_inb(ahc, FREE_SCBH));
next = ahc_inb(ahc, SCB_NEXT);
ahc_outb(ahc, SCB_NEXT, next);
scb_index = ahc_inb(ahc, SCB_NEXT);
scb_index = ahc_inb(ahc, SCB_NEXT);
scb_index = ahc_inb(ahc, SCB_NEXT);