How Computers Work

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• Chapter 1
• How Computers Work

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Objectives

• In this chapter, you will learn
• That a computer requires both hardware and
  software to work
• About the many different hardware components
  inside and connected to a computer

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Hardware Needs Software to Work

• Hardware the computers physical components
• Software the set of instructions that directs
  hardware to accomplish a task
• Software uses hardware for input, processing,
  output and storage
• All letters and numbers are stored in a computer
  as a series of bits

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Hardware Needs Software to Work (continued)
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Hardware Needs Software to Work (continued)
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Hardware Needs Software to Work (continued)
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PC Hardware Components

• Hardware Used for Input and Output
• Hardware Inside the Computer Case
• The Motherboard
• The CPU and the Chip Set
• Storage Devices
• Motherboard Components Used for Communication
  Among Devices

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PC Hardware Components (continued)

• Interface (Expansion) Cards
• The Electrical System
• Instructions Stored on the Motherboard and Other
  Boards
• Motherboard Configuration Settings

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PC Hardware Components (continued)

• Hardware input, output and storage devices all
  require the following elements
• A method for the CPU to communicate with the
  device
• Software to instruct and control the device
• Electricity to power the device

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Hardware Used for Input and Output

• Communication through wireless connection or
  cables attached at a port
• Most popular input devices
• Keyboard
• Mouse
• Most popular output devices
• Monitor
• Printer

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Hardware Used for Input and Output (continued)
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Hardware Used for Input and Output (continued)
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Hardware Used for Input and Output (continued)
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Hardware Inside the Computer Case

• A motherboard containing the CPU, memory, and
  other components
• A floppy drive, hard drive, and CD-ROM drive for
  storage
• A power supply and power cables
• Circuit boards used to communicate with devices
  inside and outside the case
• Cables connecting devices to circuit boards and
  the motherboard

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Hardware Inside the Computer Case (continued)
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The Motherboard

• The largest and most important circuit board
• Also called the main board
• Contains the CPU, where most processing takes
  place
• All devices
• Communicate with the motherboard
• Are either installed directly on it or linked by
  a cable

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The Motherboard (continued)

• Processing CPU and the chip set that supports
  the CPU
• Storage RAM and cache memory
• Communication traces, expansion slots and the
  system clock
• The electrical system the power supply
• Programming and setup data Flash ROM, CMOS

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The Motherboard (continued)
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The Motherboard (continued)
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The CPU and the Chip Set

• CPU a chip inside the computer that performs
  most of the actual data processing
• Chip set microchips on the motherboard
• Control the flow of data and instructions to and
  from the CPU

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The CPU and the Chip Set (continued)
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The CPU and the Chip Set (continued)
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Storage Devices

• Temporary and permanent
• CPU uses temporary storage to hold both data and
  instructions while processing
• When data and instructions are not being used,
  they are kept in permanent storage

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Storage Devices (continued)
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Primary Storage

• Provided by devices called memory or Random
  Access Memory (RAM)
• Types include SIMMs, DIMMs, and RIMMs
• Information stored here is lost when the computer
  is turned off

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Primary Storage (continued)
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Primary Storage (continued)
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Primary Storage (continued)
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Secondary Storage

• Data and instructions permanently stored on
  devices such as CDs, hard drives, and floppy
  disks
• Cannot be processed by the CPU until copied into
  primary storage

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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Secondary Storage (continued)
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Motherboard Components Used for Communication
Among Devices

• Traces, or circuits, enable data, instructions
  and power to move between components
• The bus is a system of pathways, protocols, and
  methods used for transmission
• Data path size is the width of the bus
• System clock is on the bus and is dedicated to
  timing the activities on the motherboard

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Motherboard Components Used for Communication
Among Devices (continued)
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Motherboard Components Used for Communication
Among Devices (continued)
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Motherboard Components Used for Communication
Among Devices (continued)
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Motherboard Components Used for Communication
Among Devices (continued)
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Motherboard Components Used for Communication
Among Devices (continued)

• Three types of expansion slots
• PCI for high-speed input/output
• AGP for a video card
• ISA for older or slower devices

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Interface (Expansion) Cards

• Mounted in expansion slots on the motherboard
• Enable the CPU connection to an external device
  or to a network
• Technology to access device is embedded on the
  card itself
• Technology to communicate with the slot, the
  motherboard and the CPU also embedded
• Port configuration can identify card function

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Interface (Expansion) Cards (continued)
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Interface (Expansion) Cards (continued)
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Interface (Expansion) Cards (continued)
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The Electrical System

• Converts and reduces energy to a voltage that the
  computer can handle
• 110 to 20 AC power from wall outlet is converted
  to a much lower DC voltage
• Older style 5 or 12 volts DC
• Newer style 3.3, 5, 12 volts DC
• Runs fan to keep temperature under 185F

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The Electrical System (continued)
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The Electrical System (continued)
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Instructions Stored on the Motherboard and Other
Boards

• ROM (Read Only Memory) Chips
• BIOS Basic input/output system
• System BIOS
• Startup BIOS
• CMOS BIOS
• Flash ROM allows for overwriting software on the
  chip

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Instructions Stored on the Motherboard and Other
Boards (continued)
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Advanced Configuration and Power Interface (ACPI)

• Supports power-saving features
• Standards developed by Intel, Microsoft, Toshiba
• ACPI allows for powering up a system by an
  external device such as a keyboard

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Plug and Play

• A standard allowing for easier installation of
  new hardware
• Begins the process of configuring hardware
  devices in the system
• Passes information on to the operating system

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Motherboard Configuration Settings

• CMOS configuration chip, CMOS setup chip or the
  CMOS RAM chip
• Contains a very small amount of memory
• Holds configuration or setup about the computer
• Remembers current date and time, hard drive and
  floppy drive information and port configuration,
  and more

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Motherboard Configuration Settings (continued)
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Motherboard Configuration Settings (continued)
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Motherboard Configuration Settings (continued)
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Summary

• A computer requires both hardware and software to
  work
• Input, Output, Processing, Storage of data
• Motherboard is the most important component
  inside the computer
• Many components inside the computer are required
  for execution of the four functions of the
  microcomputer