Jumper Settings
Older adapter cards, especially video or network interface cards, use jumper blocks to set
their IRQ settings. The position of the jumper, like those shown in Figure 13-4 on a NIC card,
determines which of usually two alternative IRQs the card will use. Cards that use jumpers
to set their system resources are usually preset to a default setting but offer one or more alter-
native settings using different positions of the jumper block. A two-position jumper (one
with two pins) can be set to four different values, and a three-position jumper can be set to
eight different values.
DIP Switches
Another means used to configure the system resources of an expansion card is a DIP
(dual inline packaging) switch. A DIP switch is a block of typically four or eight switches
(as illustrated in Figure 13-5) that are used, like a jumper, to represent a binary value by
moving the switches to on or off positions, also referred to as open or closed positions. A
card that uses DIP switches to set its system resource settings should also have a manual
or other documentation that specifies the switch settings to use for each resource value.
Proprietary Installation Software
Another common means of configuring the system resource settings for an expansion
card is a proprietary installation program that comes with the card on a diskette or
CD-ROM. Some diskettes may only include a startu p program that downloads the instal-
lation software from the manufacturer’s Web site. This ensures that the latest system re-
source setting values and device drivers are used to install the device.
Chapter 13: System Resources^289
Figure 13-4. A set of jumper blocks on an expansion card