Datasheet

58 Chapter 1
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Hardware
Remember that most of the dollars spent on systems are for labor. If you
spend an hour cleaning a $12.00 keyboard, then you have probably just
cost your company $20.00. Knowing how to fix certain things doesn’t nec-
essarily mean that you should fix them. Always evaluate your workload,
the cost of replacement, and the estimated cost of the repair before decid-
ing on a course of action.
Similarly, most mouse problems, such as the pointer failing to move in one direction or
the other, or the pointer jumping around onscreen, are due to dirt building up inside the
mouse. To clean a standard mouse, remove the plate on the bottom of the mouse that holds
the ball in place; then remove the ball, and clean the inside chamber with an alcohol-dipped
cotton swab. Clean the ball itself with mild soap and water. Don’t use alcohol on the ball,
because it tends to dry out the rubber.
Rather than being ball-driven, many mice today are optical. This simplifies
cleaning, in that the only thing you need to do is wipe dust away from the
optical sensor.
Peripheral Ports and Connectors
In order for a PC to be useful, there of course must be a way to get the data into and out of
the computer. To accomplish this, several ports are available. The four most common types
of ports are the serial, parallel, USB, and game ports. Figure 1.21 shows some typical ports
built into an ATX motherboard.
FIGURE 1.21 Built-in ports on a motherboard
These ports are connected to the motherboard using small ribbon cables on an AT system,
or they’re built directly into the side of the motherboard on an ATX system.
Adapter Cards
Adapter cards are also known by many other names, including circuit boards/cards and
expansion boards/cards. In all cases, adapter cards are circuit boards that fit into expansion
slots in the motherboard. They can include modems, network interface cards, sound cards,
and many other types of devices.
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