Hardware Reference
In-Depth Information
FIGURE 4.18
FireWire ports on a PC
Photo credit: Copyright ® 2001-2011 Cybernet Manufacturing, Inc. All Rights Reserved.
Figure 4.19 shows both ends of a FireWire cable; the smaller end plugs into a peripheral
device. At the computer end, a FireWire port looks like a small rectangle with one end
beveled, and it has six circuits (pins) inside. This is called a FireWire Alpha connector.
FIGURE 4.19
A FireWire cable. The plug on the right connects to the computer.
FireWire is commonly used with video-capture and -transfer devices, such as high-end
video cameras, because of its speed and effi ciency at moving data. The original FireWire
specifi cation, also called FireWire 400, is the most commonly used type (see Figure 4.18
and Figure 4.19). It transfers data at up to 400 Mbps. USB 2.0 is just as fast as the original
FireWire, the most common type in use today, so there is no real necessity for devices that
transfer a lot of data to use FireWire; it's simply a matter of product development and
marketing decisions on the part of the peripheral manufacturers.
Two newer and faster FireWire specs have been released, but they use different cables and
connectors and so aren't port-compatible with the standard FireWire Alpha ports unless you use
an adapter plug. FireWire 800 uses a nine-pin FireWire Beta connector and transfers data at up
to 786 Mbps. FireWire S800T uses Cat5e Ethernet cable and transfers data at up to 800 Mbps.
PS/2
PS/2 is an obsolete type of round connector that older systems used for keyboard and
mouse connections. You may still see this port on the back of an older computer. These
ports were typically color-coded, with purple being used for wired keyboard connections
