A peripheral device is connectable to a computer having one of a first interface and a second interface. The first interface communicates with the peripheral device over a differential data connection having a first data conductor and a second data conductor. The second interface communicates with the...http://www.google.com/patents/US6795949?utm_source=gb-gplus-sharePatent US6795949 - Method and apparatus for detecting the type of interface to which a peripheral device is connected
