从VESA显卡的时代起VGA接口的几根空余口线被当作显示器ID接口,其定义如下: 管脚 名称 功能描述 1 RED Red Video (75 ohm, 0.7 V p-p) 2 GREEN Green Video (75 ohm, 0.7 V p-p) 3 BLUE Blue Video (75 ohm, 0.7 V p-p) 4 ID2 Monitor ID Bit 2 5 GND Ground 6 RGND Red Ground 7 GGND Green Ground 8 BGND Blue Ground 9 KEY Key (No pin) 10 SGND Sync Ground 11 ID0 Monitor ID Bit 0 12 ID1 or SDA Monitor ID Bit 1 13 HSYNC or CSYNC Horizontal Sync (or Composite Sync) 14 VSYNC Vertical Sync 15 ID3 or SCL Monitor ID Bit 3