BT848_E_VSCALE_HI
btwrite(0x20, BT848_E_VSCALE_HI);
btor(BT848_VSCALE_COMB, BT848_E_VSCALE_HI+off);
btand(~BT848_VSCALE_COMB, BT848_E_VSCALE_HI+off);
btaor((geo->vscale>>8), 0xe0, BT848_E_VSCALE_HI+off);