SR15
unsigned char SR10, SR11, SR12, SR13, SR15, SR18, SR29, SR30;
reg->SR15 = 0x03 | 0x80;
vga_out8(0x3c5, reg->SR15, par);
vga_out8(0x3c5, reg->SR15, par);
reg->SR15 = vga_in8(0x3c5, par);
vga_out8(0x3c5, reg->SR15, par);
{VIASR, SR15, 0x02, 0x02},
{VIASR, SR15, 0x02, 0x02},
{VIASR, SR15, 0x02, 0x02},
{VIASR, SR15, 0x02, 0x02},
{VIASR, SR15, 0x02, 0x02},