Patent ID: 8704833

Claim:
A method for displaying a video signal on a display of a first computer system, comprising: receiving a signal to switch from displaying a video signal from an internal video source of the first computer system to displaying a video signal from an external video source of a second computer system, wherein the second computer system is separate from the first computer system, wherein the internal video source of the first computer system and the external video source of the second computer system are coupled to a bi-directional video port of the first computer system, wherein the external video source of the second computer system is configured to generate an input video signal to the bi-directional video port, and wherein the bi-directional video port comprises an external port of the first computer system configured to couple the second computer system to the first computer system; determining whether the external video source of the second computer system is coupled to the bi-directional video port based at least in part on whether an indicator signal received on the bi-directional video port is asserted or deasserted; coupling the external video source to the display of the first computer system when the external video source is coupled to the bi-directional video port; determining whether the external video source is a valid video source; displaying the video signal from the external video source on the display of the first computer system when the external video source is valid; and when the first computer system is turned off and the external video source of the second computer system is coupled to the bi-directional video port, activating components of the first computer system comprising the display and internal control and processing circuits configured to display the video signal of the external video source of the second computer system on the display, wherein internal components of the first computer system that are not used for displaying the video signal of the external video source of the second computer system on the display remain turned off.