Specifications

CHAPTER 3
118
All About Motherboards
Even more rare is an ACR (Advanced Communications Riser) slot. It looks like a PCI
slot, but it sits a little closer to the rear of the motherboard than does a PCI slot and the
notch in the slot is in a different position than the notch in a PCI slot. ACR cards might be
used for wireless or wired networking, FireWire, or modems.
ON-BOARD PORTS AND CONNECTORS
In addition to expansion slots, a motherboard might also have several on-board ports and
internal connectors. Ports coming directly off the motherboard are called on-board ports or
integrated components. Almost all motherboards have two or more USB ports and sound
ports. Boards might also offer a network port, modem port, FireWire (IEEE 1394) port,
video port, keyboard port, mouse port, parallel port, serial port, one or more eSATA ports
(for external SATA hard drives), and a port for a wireless antenna. Figures 3-21, 22, and 23
show ports on three motherboards. Figure 3-21 shows an older motherboard. Figure 3-22
shows a current low-end motherboard, and Figure 3-23 shows a current high-end
motherboard. We’ll discuss how to use all these ports in Chapter 7.
When you purchase a motherboard, the package includes an I/O shield, which is the plate
that you install in the computer case that provides holes for these I/O ports. The I/O shield is
PS/2 mouse port
PS/2 keyboard port
S/PDIF port (for
audio coaxial cable)
S/PDIF port (for
audio optical cable)
Four USB
ports
Wireless LAN
antenna port
Six sound ports
Network port
FireWire port
Parallel port
Figure 3-21 A motherboard provides ports for common I/O devices
Courtesy: Course Technology/Cengage Learning
PS/2 keyboard
port
PS/2 mouse
port
Analog
video port
Serial port
Four USB
ports
Three sound
ports
Network port
Figure 3-22 Ports on a value Biostar motherboard
Courtesy: Course Technology/Cengage Learning
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220-701
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