DAC_INDX_LO
p9100_ramdac_write(sc, DAC_INDX_LO, DAC_CURSOR_CTL);
p9100_ramdac_write(sc, DAC_INDX_LO, DAC_CURSOR_COL_1);
p9100_ramdac_write(sc, DAC_INDX_LO, 0);
p9100_ramdac_write(sc, DAC_INDX_LO, off & 0xff);
p9100_ramdac_write(sc, DAC_INDX_LO, off & 0xff);