CR51
unsigned char CR50, CR51, CR53, CR55, CR58, CR5B, CR5D, CR5E;
reg->CR51 = (0x300 & width) >> 4;
vga_out8(0x3d5, reg->CR51, par);
reg->CR51 = vga_in8(0x3d5, par);
vga_out8(0x3d5, reg->CR51, par);