SEECTL
ahd_outb(ahd, SEECTL, SEEOP_READ | SEESTART);
ahd_outb(ahd, SEECTL, SEEOP_EWEN | SEESTART);
ahd_outb(ahd, SEECTL, SEEOP_WRITE | SEESTART);
ahd_outb(ahd, SEECTL, SEEOP_EWDS | SEESTART);
sd.sd_control_offset = SEECTL;
sd.sd_status_offset = SEECTL;
sd.sd_dataout_offset = SEECTL;