Chapter 11: Expansion Cards^243
Setting System Resources
Every expansion card installed in a PC must be assigned some system resources, typically
an IRQ and an I/O address. In most cases, the expansion card is configured to work with a
certain set of system resources. However, most cards can be configured to work with other
resources if their default resources are unavailable. System resources are configured on an
expansioncardintwoways:physicallyonthecardthroughDIPswitchesorjumperblocks,
or through software. The software used to assign a card to a set of system resources may be
a dedicated installation program or a configuration interface, such as the BIOS setup
program or an operating system feature, like the Windows Device Manager.
A DIP switch block has either four or eight slide switches that can be moved between
two settings (representing on and off or 0 and 1). The documentation with the expansion
card should specify the settings for a card’s physical configuration for a particular PC
type. The same is true of jumper blocks. The jumper is set to cover two pins (on), one pin
(off), or no pins (neutral). A three-pin jumper can be set to represent eight values, each of
which designates a different system resource setting for the card. The values for a card’s
switches or jumpers are typically in its documentation.
If the expansion card comes with installation software, the system resources will be
automatically set. However, if system resource conflicts result, you can use the Windows
Device Manager (assuming a Windows system) to check on the resource settings. These
settings can also be modified in the BIOS setup program.Plug and Play
Plug and Play (PnP) enables expansion boards to be automatically configured, including
system resource settings, by the BIOS and operating system on a PC. Windows 98/2000
supports PnP out of the box, but Windows NT only supports some devices. Understand
that PnP does not mean hot-swappable. If you remove or install a PnP device, you may
need to reset the system before the PC will recognize it.Working with Expansion Cards
The rest of this chapter contains a number of procedures that can be used to install and
troubleshoot expansion cards. As with any PC component, nothing is more valuable than
the component’s documentation for the process that should be used to install, configure, or
troubleshoot it. The procedures included in this chapter are meant as general guidelines.Installing an Expansion Card
Follow this general procedure to install an expansion card in a PC (assuming that you are
strictly following the ESD protection guidelines outlined in Chapter 14):- Create a backup of the hard disk’s contents. Typically, installing an expansion
card should not have any effect on the hard disk, but you never know.