A
multimedia notebook or
laptop personal computer (PC) has an enhanced audio
system. An external audio controller in a
docking station is connected to the
laptop PC's audio
system using a digital-audio link. The digital-audio link uses digital signals that have high
noise immunity. The high
noise immunity allows the digital-audio signals to be routed through the inexpensive docking connector, which has many other noisy, high-speed signals. Dedicated, expensive,
noise-prone, and difficult-to-connect analog-audio connectors between the
laptop PC and the
docking station are eliminated. Analog-
digital converter audio CODEC's are placed in both the
docking station and in the laptop PC. A master mixer in the laptop PC mixes
digital audio from the external audio controller in the docking
station with
digital audio from an external audio controller inside the laptop PC. The master mixer also connects to a
zoom-video audio port and to an internal PCI
bus for storing and retrieving audio clips. Audio from external docking-
station sources and from internal sources can be freely mixed with the master mixer connected to local mixers in the audio controllers. Audio can be simultaneously played to both internal and external docking-
station speakers.