A universal card will support either a 5V or 3.3V adapter. What I do not understand is the Vi/o signal on PCI bus. In PCI 2.2 spec there is a signal called Vi/o whose equivalent pin in 5 Volt only & 3.3 volt only cards are 5V & 3.3V respectively. Is this signal routed to different power rail depending on the what is plugged into it? Thanks