Motherboard and operating system capable of outputting image data

A motherboard capable of outputting image data and disposed in a case, comprising:

• a basic input/output system (BIOS);
• an image transmission port configured to receive an external image signal;
• an on-board video graphics array (VGA) card configured to provide an internal image signal;
• a switching circuit selectively using the external image signal or the internal image signal as the image data according to a selection signal;
• a control circuit selectively using the image data or Ethernet network data as output data;
• and
• a first network connection port configured to transmit the output data via a network cable,
• wherein:
• the network cable is directly connected between the first network connection port and an electronic device,
• in response to the control circuit using the image data as the output data, the electronic device displays an image according to the output data,
• the selection signal is provided by a switch or the BIOS, and the switch is disposed outside of the case.