To provide a user friendly display device and a method capable of visually and easily understandably displaying the various operating states of a computer.

This display device is constituted of a controller 16 for outputting control signals for reading data signals, analyzing the data signals when they are inputted and generating and outputting display signals corresponding to the operating state of the computer, an interface 14 for storing the data signals inputted from a system bus and then outputting them to a local bus when the control signals are inputted from the controller, a driver 18 for outputting grade driving signals and segment driving signals corresponding to the display signals when they are inputted from the controller and a display panel 20 for driving an icon and/or a message for indicating the operating state of the computer corresponding to the grade driving signals and the segment driving signals.