rem: uint8 mode = in8(0x03c1) & 0xf7; out8(mode, 0x3c0);
add: uint8 mode = in8(VGA_ATTRIBUTE_READ) & 0xf7; out8(mode, VGA_ATTRIBUTE_WRITE);
context: vga_enable_bright_background_colors(void){	// reset attribute controller	in8(0x03da);	// select mode control register	out8(0x30, 0x03c0);	// read mode control register, change it (we need to clear bit 3), and write it back	uint8 mode = in8(0x03c1) & 0xf7;	out8(mode, 0x3c0);}