Abstract: A portable digital audio/video device is provided to work with a computer device, or removed from the computer device and work as an independent audio/video playing device. The portable digital audio/video device includes a disk interface connector and a USB port connector for engaging the corresponding connectors on the access slot of the computer device. The portable digital audio/video device includes a data type identification circuit for identifying the data format stored on a compact audio/video disk, and at least a data processing circuit. Each data processing circuit is designed to process, decode and output audio/video signals of a specific format.