An Introduction to PCI Technology

What are universal PCI cards?

In the days of yore, the PCI bus used 5 V signaling on the PCI connector. Some PCI buses, including many of today’s newest PC’s use 3.3 V signaling. A keyed notch in the card prevents it from being plugged into the wrong version of the bus. If you buy a 5 V PCI card, it won’t fit into a 3.3 V bus, and a 3.3 V PCI card won’t fit into a 5 V bus. A situation fraught with peril for the casual customer! Not to worry, all of the PCI cards in the following pages follow the Universal PCI specification, officially termed PCI V2.3. As you might guess, Universal PCI is compatible with both 3.3 V and 5 V systems. To tell if your card is Universal PCI, look for two keyed notches in the bus connector, indicating that it will fit (and work!) in any PCI system.

What about the ISA bus?

Need serial cards for the ISA bus? We’re happy to say that B&B Electronics continues to stock and support ISA cards (to be honest, some of us even feel an emotional attachment to these cards).