A surround sound system for personal computer includes a control card and a PC surround decoder. The control card is a PC interface card for interfacing to the personal computer and draining the 5 VDC and .+-.12 VDC power from the personal computer as power source for both the control card...http://www.google.com/patents/US5841993?utm_source=gb-gplus-sharePatent US5841993 - Surround sound system for personal computer for interfacing surround sound with personal computer 
