CFREG_CRT_VNDISP
cfxga_write_2(sc, CFREG_CRT_VNDISP, 39 | (8 << 8));
cfxga_write_2(sc, CFREG_CRT_VNDISP, 25 | (8 << 8));
while ((cfxga_read_1(sc, CFREG_CRT_VNDISP) &