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Basic Computer Hardware

Computer systems include hardware, software, and firmware. Hardware is something you can touch and feel, like the physical computer and the parts inside the computer. The monitor, keyboard, and mouse are hardware components. Software interacts with the hardware. Windows, Linux, macOS, Microsoft 365, Google Chrome, Adobe Acrobat Reader, Intuit TurboTax, and WordPerfect are examples of software.

Without software that directs the hardware to do something, a computer is useless. Every computer needs an important piece of software called an operating system, which coordinates the interaction between hardware and software applications. The operating system also handles the interaction between a user and the computer. Examples of operating systems include Windows 10 and 11, macOS, and various Linux systems, such as Red Hat and Ubuntu.

A device driver enables the operating system to recognize, control, and use a hardware component. Device drivers are hardware and operating system specific. For example, a printer requires a specific device driver when connected to a computer that used to have Windows 7 installed. The same printer might require a different device driver when using Windows 10 or 11. That Windows print driver would not work on an Apple computer. Each piece of installed hardware requires a device driver for the operating system being used. Figure 1.9 shows how hardware and software must work together.

Figure 1.9

Figure 1.9 Hardware and software

Notice in Figure 1.9 the operating system kernel. The kernel is the central part of an operating system. The kernel is the connection between hardware and the applications being used.

A PC typically consists of a case (chassis), a keyboard that allows users to provide input into the computer, a monitor that outputs or displays information (shown in Figure 1.10), and a mouse that allows data input or is used to select menus and options. Figure 1.10 shows a computer monitor, which may also be called a flat panel, display, or screen.

Figure 1.10

Figure 1.10 Computer monitor

When the computer cover or side is opened or removed, the parts inside can be identified. The easiest part to identify is the power supply, which is the metal box normally located in a back corner of a case. A power cord connects the power supply to a wall outlet or surge strip. One purpose of the power supply is to convert the outlet AC voltage to DC voltage used internally in the PC. The power supply distributes this DC voltage using cables that connect to the various internal computer parts. A fan located inside the power supply keeps the computer cool to prevent damage to the components.

A PC usually has a device to store software applications and files. Two examples of storage devices are the hard drive and optical drive. The hard drive, sometimes called the hard disk, is a rectangular box normally inside the computer’s case that is sealed to keep out dust and dirt. The hard drive has no external opening. The computer must be opened in order to access an internal hard drive. An optical drive holds discs (compact discs, or CDs), digital versatile discs (DVDs), or Blu-ray discs (BDs) that have data, music, video, or software applications on them. The front of the optical drive has a tray that ejects outward so a disc may be inserted. Figure 1.11 shows the major components of a tower computer. Figures 1.12 through 1.14 show components as they would look before being installed. Figure 1.12 shows a hard drive. Figure 1.13 shows an optical drive. Figure 1.14 shows a power supply. Figure 1.15 shows a tower computer case.

Figure 1.11

Figure 1.11 Tower computer

Figure 1.12

Figure 1.12 Hard drive

Figure 1.13

Figure 1.13 DVD or optical drive

Figure 1.14

Figure 1.14 Power supply

Figure 1.15

Figure 1.15 Tower case

The motherboard is the main circuit board inside a PC and contains the most electronics. It is normally located on the bottom of a desktop or laptop computer and mounted on the side of a tower computer. Other names for the motherboard include mainboard, planar, or system board. External devices connect directly to the back of the motherboard or ports on the front of the computer. Figure 1.16 shows a motherboard when it is not installed inside a computer as well as memory and an adapter, which are covered next.

Figure 1.16

Figure 1.16 Computer motherboard

The motherboard holds memory modules. Memory modules hold applications, part of the operating system, and user documents. Random-access memory (RAM) is the most common type of memory on the motherboard and is volatile; that is, the data inside the module is lost when power is removed. When a user types a document in a word processing program, both the word processing application and the document are in RAM. If the user turns the computer off without saving the document to removable media or the hard drive, the document is lost because the information does not stay in RAM. (Note that some applications have the ability to periodically save a document, but this is not a guarantee that it has the latest information.) Figure 1.17 shows memory modules when they are not installed into the motherboard memory slots. Memory is covered in great detail in Chapter 6, “Memory.”

Figure 1.17

Figure 1.17 Memory modules

A device may have a cable that connects the device to the motherboard. Other devices require an adapter. An adapter is an electronic card that plugs into an expansion slot on the motherboard. Other names for an adapter are controller, card, controller card, circuit card, circuit board, and adapter board. Adapters allow someone to add functionality or an enhancement that is not provided through the ports on the motherboard, such as better sound or video graphics or additional ports of some type in order to connect external devices. Figure 1.18 shows an adapter. Notice how the contacts at the bottom are a particular shape. Chapter 3, “On the Motherboard,” goes into more detail about the types of expansion slots and adapters. You can also look back to Figure 1.16 to see a video card/adapter installed into a motherboard expansion slot.

Figure 1.18

Figure 1.18 Adapter

The following are the generic steps for installing adapters:

  • Step 1. Always follow the manufacturer’s installation directions. Use an antistatic wrist strap when handling adapters. Electrostatic discharge (ESD) can damage electronic parts. (See Chapter 5, “Disassembly and Power,” for more details on ESD.)

  • Step 2. Be sure the computer is powered off and unplugged.

  • Step 3. Remove any brackets from the case or plastic covers from the rear of the computer that may prevent adapter installation. Install the adapter in a free expansion slot and reattach any securing hardware.

  • Step 4. Attach any internal device cables that connect to the adapter, as well as any cables that go to an external port on the adapter.

  • Step 5. Attach any internal or external devices to the opposite ends of the cable, if necessary.

  • Step 6. Power on any external devices connected to the adapter, if applicable.

  • Step 7. Reattach the computer power cord and power on the computer.

  • Step 8. Load any application software or device drivers needed for the devices attached to the adapter.

  • Step 9. Test the device connected to the adapter.

See Figure 1.19 for an illustration of a motherboard, expansion slots, memory, and an adapter in an expansion slot.

Figure 1.19

Figure 1.19 Motherboard with expansion slots and an adapter

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