SCB_NEXT_COMPLETE
ahd_outw(ahd, SCB_NEXT_COMPLETE, comp_head);
next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);