CR40
unsigned char CR40, CR41, CR42, CR43, CR45;
reg->CR40 = vga_in8(0x3d5, par) & ~0x01;
vga_out8(0x3d5, reg->CR40, par);
reg->CR40 = vga_in8(0x3d5, par);
vga_out8(0x3d5, reg->CR40, par);