Apple Mac Pro (Early 2008) - Manual (Page 31)

Chapter 2 Life with Your Mac Pro 31
PCI Express expansion slots (3)
Expand your Mac Pro by installing up to three Peripheral Component Interconnect (PCI)
Express cards in the covered slots labeled 2, 3, and 4.
£ DVI display ports
Connect displays that use a Digital Visual Interface (DVI) connector to the DVI display
ports. Connect an Apple display, such as the 20-, 23-, or 30-inch Apple Cinema Display,
to either port. You can also connect displays that use a video graphics array (VGA)
connector using the Apple DVI to VGA Display Adapter that came with your Mac Pro.
Optical digital audio in and audio out ports
Connect to decks, receivers, digital instruments, and 5.1 surround-sound speaker systems
using standard TOSLINK cables or fiber-optic cables with a 3.5 mm plastic or nylon
optical plug. You can transfer stereo or encoded 5.1 audio using the S/PDIF (Sony/Philips
Digital Interface) protocol and TOSLINK cables.
, Analog audio line-in port
Connect self-powered microphones, MP3 and CD players, and other devices with analog
capability.
- Analog audio line-out port
Connect self-powered analog speakers and other devices with analog capability.