Abstract: An audio/visual server is described that can be used to store and play audio/visual data. A removable hard disk (or other media) is connected to a dock that is in communication with a computer. While the removable hard disk is connected to the dock, audio/visual data can be transferred from the computer to the hard disk. After the hard disk is removed from the dock and connected to the audio/visual server, the server can access and play the audio/visual data. In one embodiment, the audio/visual server stores and plays music, emulates a disc changer, and communicates with an automobile stereo head unit. The interface with the head unit is programmable so that multiple head units can be supported.

Abstract: A play list manager is disclosed that can be used to create and update play lists. The play lists can be used for audio information, visual information, or a combination of audio and visual information. The user of the play list manager creates a play list and specifies certain criteria for automatically adding tracks to the play list. When a new track is added to the environment, the system tests whether the track's properties satisfy the criteria for the play list. If so, the new track is automatically added to the play list. In one alternative, a user can select a predefined play list, whose criteria has already been created. Upon selection of the predefined play list, the play list manager accesses each track and adds the track to the play list if the track's properties satisfy the criteria for the predefined play list.