• Choose a category
• All
• Classic-Fiction

Figure 3-36 CPU with fan

Although only a few manufacturers of CPUs have existed, those manufacturers have made hundreds of models of CPUs. Some of the more common models made over the past few years have names such as Core 2, Core i7, Celeron, Athlon, and Phenom.

Finally, CPUs come in a variety of packages. The package defines how the CPU looks physically and how it connects to the computer. Intel CPUs currently use a package type called land grid array (LGA), and AMD likes pin grid array (PGA). Every CPU package type has a number of versions and each type is designed to fit into a particular connection called a socket. Sockets have such names as Socket AM3 or Socket B. Figure 3-37 shows a CPU with its matching socket.

Figure 3-37 CPU and matching socket

Chapter 5, “Microprocessors,” goes into great detail on CPUs, but for now remember that every CPU has a make, a model, and a package type.

RAM

Random access memory (RAM) stores programs and data currently being used by the CPU. The maximum amount of programs and data that a piece of RAM can store is measured in units called bytes. Modern PCs have many millions, even billions, of bytes of RAM, so RAM is measured in units called megabytes (MB) or gigabytes (GB). An average PC will have from 1 to 4 GB of RAM, although PCs may have more or less RAM. Each piece of RAM is called a stick. One common type of stick found in today’s PC is called a dual inline memory module (DIMM). Figure 3-38 shows two examples of DIMMs used in PCs.

Figure 3-38 Two DIMMs

Your PC takes only one type of DIMM, and you must know the type so you can add or replace RAM when needed. Chapter 6, “RAM,” covers everything you need to know to work comfortably with RAM.

* * *

CAUTION Some parts of your PC are much more sensitive to ESD than others. Your CPU and RAM are very sensitive to ESD. If you touch the metal parts of your CPU or RAM and you have even the tiniest amount of charge, you can destroy them.

Motherboard

You can compare a motherboard to the chassis of an automobile. In a car, everything connects to the chassis either directly or indirectly. In a PC, everything connects to the motherboard either directly or indirectly. A motherboard is a thin, flat piece of circuit board, usually green or gold, and often slightly larger than a typical piece of notebook paper (see Figure 3-39).

Figure 3-39 Typical motherboard

A motherboard contains a number of special sockets that accept various PC components. The CPU and RAM, for example, plug directly into the motherboard. Other devices, such as floppy drives, hard drives, CD and DVD drives, connect to the motherboard sockets through short cables. Motherboards also provide onboard connectors for external devices such as mice, printers, joysticks, and keyboards.

All motherboards use multipurpose expansion slots in which you can add adapter cards. Different types of expansion slots exist for different types of cards (see Figure 3-40).

Figure 3-40 Placing a card into an expansion slot

Power Supply

The power supply, as its name implies, provides the necessary electrical power to make the PC operate. The power supply takes standard electrical power and converts it into power your PC can use. Most power supplies are about the size of a shoebox cut in half and are usually a gray or metallic color (see Figure 3-41).

Figure 3-41 Power supply

A number of connectors lead out of the power supply. Every power supply provides special connectors to power the motherboard and a number of other general-use connectors that provide power to any device that needs electricity. Check out Chapter 10, “Power Supplies,” for more information.

Floppy Drive

The floppy drive enables you to access removable floppy disks (diskettes). The floppy drive used in PCs today is a 3.5-inch floppy drive. Floppy drives only store a tiny amount of data and have all but disappeared from PCs.

The floppy drive’s data connection to the computer is via a ribbon cable, which in turn connects to the motherboard. The connection to the motherboard