COMPUTER COMPONENTS AND TYPES
Chapter Two
Discovering Computers Fundamentals, 2012 Edition
Chapter 1
1
What Is a Computer?
• A computer is an electronic device, operating
under the control of instructions stored in its own
memory
Collects
data
(input)
Processing
Produces
information
(output)
Information Processing Cycle
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Discovering Computers Fundamentals, 2012 Edition
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The Components of a Computer
• A computer contains many electric, electronic, and
mechanical components known as hardware
Input Device
Output Device
System Unit
Storage Device
Communications
Device
Pages 4 - 7
• Allows you to enter data and instructions into a computer
• Hardware component that conveys information to one or more people
• Case that contains the electronic components of the computer that
are used to process data
• Holds data, instructions, and information for future use
• Enables a computer to send and receive data, instructions, and
information to and from one or more computers or mobile devices
Discovering Computers Fundamentals, 2012 Edition
Chapter 1
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The Components of a Computer
Page 5
Figure 1-3
Discovering Computers Fundamentals, 2012 Edition
Chapter 1
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Categories of Computers
Personal computers
Mobile computers and mobile devices
Game consoles
Servers
Mainframes
Supercomputers
Embedded computers
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Discovering Computers Fundamentals, 2012 Edition
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Personal Computers
• A personal computer can perform all of its input,
processing, output, and storage activities by itself
Pages 15 - 16
Figures 1-13 - 1-14
Discovering Computers Fundamentals, 2012 Edition
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Mobile Computers and Mobile Devices
Mobile
Computer
Pages 16 - 18
Mobile
Device
Personal computer you
can carry from place to
place
Computing device small
enough to hold in your
hand
Examples include
notebook computers,
laptop computers,
netbooks, and Tablet
PCs
Examples include smart
phones and PDAs, ebook readers, handheld
computers, portable
media players, and
digital cameras
Discovering Computers Fundamentals, 2012 Edition
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Game Consoles
• A game console is a mobile computing device
designed for single-player or multiplayer video
games
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Figure 1-21
Discovering Computers Fundamentals, 2012 Edition
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Servers
• A server controls access to the hardware,
software, and other resources on a network
– Provides a centralized storage area for programs, data,
and information
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Figure 1-22
Discovering Computers Fundamentals, 2012 Edition
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Mainframes
• A mainframe is a large, expensive, powerful
computer that can handle hundreds or thousands
of connected users simultaneously
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Figure 1-23
Discovering Computers Fundamentals, 2012 Edition
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Supercomputers
• A supercomputer is the fastest, most powerful
computer
– Fastest supercomputers are capable of processing
more than one quadrillion instructions in a single
second
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Figure 1-24
Discovering Computers Fundamentals, 2012 Edition
Chapter 1
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Embedded Computers
• An embedded computer is a special-purpose
computer that functions as a component in a
larger product
Consumer Electronics
Home Automation Devices
Automobiles
Process Controllers and Robotics
Computer Devices and Office
Machines
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Discovering Computers Fundamentals, 2012 Edition
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Inputs
What Is Input?
• Input is any data and instructions entered into the
memory of a computer
Pages 258 – 259
Figure 5-1
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What Are Input Devices
An input device
is any hardware
component that
allows users to
enter data and
instructions into
a computer
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The Keyboard
• A keyboard is an input device that contains keys
users press to enter data and instructions into a
computer
• It could be wired or wireless
• It has many different types and styles.
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Figure 5-2
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Pointing Devices
Examples
1. Mouse
2. Trackball
3. Touchpad
4. Pointing stick
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Touch Screens and Touch-Sensitive Pads
• A touch screen is a touch-sensitive display device
Page 266
Figures 5-12 – 5-13
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Pen Input
• With pen input, you touch a stylus or digital pen on a flat
surface to write, draw, or make selections
Page 268
Figure 5-16
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Voice Input
• Voice input is the process of entering input by
speaking into a microphone
• Audio input is the process of entering any sound
into the computer
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Figure 5-22
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Scanners and Reading Devices
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Figure 5-27
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Biometric Input
• Biometrics authenticates a person’s identity by
verifying a personal characteristic
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Outputs
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What Is Output?
• Output is data that has been processed into a
useful form
Pages 304 – 305
Figure 6-1
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What Is Output?
• An output device is any type of hardware
component that conveys information to one or
more people
Display devices
Interactive
whiteboards
Page 305
Printers
Speakers,
headphones,
and earbuds
Force-feedback
game
controllers
Discovering Computers 2012: Chapter 6
Data projectors
Tactile output
25
Display Devices
• A display device visually
conveys text, graphics,
and video information
• A monitor is packaged
as a separate peripheral
– LCD monitor
– Widescreen
Pages 306 – 207
Figures 6-2 – 6-3
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Display Devices
• Liquid crystal display (LCD) uses a liquid
compound to present information on a display
device
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Display Devices
• Plasma monitors are display devices that use gas
plasma technology and offer screen sizes up to
150 inches
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Figure 6-8
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Printers
• A printer produces
text and graphics on
a physical medium
– Printed information
is called a hard copy,
or printout
– Landscape or portrait
orientation
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Figure 6-11
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Printers
Page 315
Figure 6-13
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Printers
• A nonimpact printer forms characters and
graphics on a piece of paper without actually
striking the paper
Ink-jet
printers
Photo
printers
Mobile
printers
Label and
postage
printers
Page 315
Laser
printers
Thermal
printers
Plotters
Largeformat
printers
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Printers
• An ink-jet printer forms characters and graphics by
spraying tiny drops of liquid ink onto a piece of paper
– Color or black-and-white
– Printers with a higher dpi (dots per inch) produce a higher
quality output
Pages 316 – 317
Figure 6-15
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Printers
A photo printer produces color
photo-lab-quality pictures
• Most use ink-jet technology
• PictBridge allows you to print photos
directly from a digital camera
• Print from a memory card and preview
photos on a built-in LCD screen
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Printers
Highspeed
Blackandwhite
Laser
printer
Highquality
Color
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Printers
• A multifunction peripheral (MFP) is a single
device that prints, scans, copies, and in some
cases, faxes
– Sometimes called an all-in-one device
Pages 320 – 321
Figure 6-20
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Printers
• A thermal printer generates images by pushing
electrically heated pins against the heat-sensitive
paper
Thermal wax-transfer
printer
Dye-sublimation
printer
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Figure 6-21
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Printers
• A mobile printer is a
small, lightweight,
battery-powered printer
that allows a mobile
user to print from a
notebook computer,
smart phone, or other
mobile device
Page 321
Figure 6-22
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Printers
• A label printer is a small printer that prints on
adhesive-type material
• A postage printer prints postage stamps
– Postage also can be printed on other types of printers
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Figure 6-23
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Printers
• Plotters are used to produce high-quality
drawings
• Large-format printers create photo-realistic
quality color prints on a larger scale
Page 322
Figure 6-24
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Printers
• Impact printers form characters and graphics on a
piece of paper by striking a mechanism against an
inked ribbon that physically contacts the paper
Dot-matrix
printer
Pages 322 - 323
Line
printer
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Printers
• A dot-matrix printer
produces printed
images when tiny wire
pins on a print head
mechanism strike an
inked ribbon
• A line printer prints an
entire line at a time
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Figure 6-25
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Speakers, Headphones, and Earbuds
• An audio output device produces music, speech,
or other sounds
Most computer users attach
speakers to their computers to:
• Generate higher-quality sounds for playing
games
• Interact with multimedia presentations
• Listen to music
• View movies
Page 323
Figure 6-26
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Speakers, Headphones, and Earbuds
• Headphones are
speakers that cover or
are placed outside of
the ear
• Earbuds (also called
earphones) rest inside
the ear canal
Page 324
Figure 6-27
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The components of the system unit
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The System Unit
• The system unit is
a case that
contains
electronic
components of
the computer
used to process
data
Page 210
Figure 4-1
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The System Unit
• The inside of the system unit on a desktop
personal computer includes:
Drive bay(s)
Power supply
Sound card
Video card
Processor
Memory
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Figure 4-2
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The System Unit
• The motherboard is the main circuit board of the
system unit
– A computer chip contains integrated circuits
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Figure 4-3
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Processor
• The processor, also called the central processing
unit (CPU), interprets and carries out the basic
instructions that operate a computer
– Contain a control unit and an arithmetic logic unit
(ALU)
Multi-core
processor
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Dual-core
processor
Discovering Computers 2012: Chapter 4
Quad-core
processor
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Processor
Page 213
Figure 4-4
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Processor
• The control unit is the component of the
processor that directs and coordinates most of
the operations in the computer
• The arithmetic logic unit (ALU) performs
arithmetic, comparison, and other operations
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Processor
• For every instruction, a processor repeats a set of
four basic operations, which comprise a machine
cycle
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Figure 4-5
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Processor
The processor contains registers, that
temporarily hold data and instructions
The system clock controls the timing
of all computer operations
• The pace of the system clock is called the clock
speed, and is measured in gigahertz (GHz)
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Data Representation
Analog signals are continuous and vary in
strength and quality
Digital signals are in one of two states: on
or off
• Most computers are digital
• The binary system uses two unique digits (0 and 1)
• Bits and bytes
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Expansion Slots and Adapter Cards
• With Plug and Play, the computer automatically
can configure adapter cards and other peripherals
as you install them
Pages 230 – 231
Figure 4-27
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Ports and Connectors
A port is the point at which a peripheral attaches to or
communicates with a system unit (sometimes referred
to as a jack)
A connector joins a cable to a port
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Ports and Connectors
• A USB port can connect up to 127 different
peripherals together with a single connector
– You can attach multiple peripherals using a single USB
port with a USB hub
Page 234
Figure 4-32
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Ports and Connectors
• Other types of ports include:
Firewire
port
Bluetooth
port
SCSI port
eSATA
port
IrDA port
Serial port
MIDI port
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Buses
• A bus allows the various
devices both inside and
attached to the system
unit to communicate with
each other
– Data bus
– Address bus
• Word size is the number
of bits the processor can
interpret and execute at a
given time
Page 237
Figure 4-36
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Buses
• Expansion slots connect to expansion buses
• Common types of expansion buses include:
PCI bus
PCI Express
bus
USB and
FireWire bus
Page 238
Accelerated
Graphics Port
PC Card bus
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Storage
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Storage
Storage holds data, instructions, and
information for future use
A storage medium is the physical
material on which a computer keeps
data, instructions, and information
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Storage
Pages 352 – 353
Figure 7-1
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Storage
• Capacity is the number of bytes a storage medium
can hold
Page 354
Figure 7-2
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Storage
• A storage device is the computer hardware that
records and/or retrieves items to and from
storage media
Reading is the process
of transferring items
from a storage medium
into memory
Writing is the process of
transferring items from
memory to a storage
medium
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Memory
• Memory consists of electronic components that
store instructions waiting to be executed by the
processor, data needed by those instructions, and
the results of processing the data
• Stores three basic categories of items:
The operating
system and other
system software
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Application
programs
Discovering Computers 2012: Chapter 4
Data being
processed and the
resulting
information
65
Memory
• The system unit contains two types of memory:
Volatile memory
Nonvolatile memory
Loses its contents when
power is turned off
Does not lose contents
when power is removed
Example includes RAM
Examples include ROM,
flash memory, and
CMOS
Pages 223 - 224
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Memory
• Memory cache speeds the processes of the computer
because it stores frequently used instructions and data
Page 227
Figure 4-22
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Memory
Read-only memory (ROM) refers to memory chips
storing permanent data and instructions
• Firmware
A PROM (programmable read-only memory) chip is
a blank ROM chip that can be written to
permanently
• EEPROM can be erased
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Hard Disks
• A hard disk contains one or more inflexible, circular platters
that use magnetic particles to store data, instructions, and
information
Page 355
Figure 7-5
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Hard Disks
An external hard disk is a separate freestanding hard disk that connects to your
computer with a cable or wirelessly
A removable hard disk is a hard disk that
you insert and remove from a drive
Internal and external hard disks are available
in miniature sizes (miniature hard disks)
Pages 360 – 361
Figures 7-14 – 7-15
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Hard Disks
• A disk controller consists of a special-purpose chip and
electronic circuits that control the transfer of data,
instructions, and information from a disk to and from the
system bus and other components of the computer
Pages 361 - 362
SATA
EIDE
SCSI
SAS
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Cloud Storage
• Cloud storage is an Internet service that provides
storage to computer users
Page 368
Figure 7-23
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Optical Discs
• An optical disc consists of a flat, round, portable
disc made of metal, plastic, and lacquer that is
written and read by a laser
• Typically store software, data, digital photos,
movies, and music
• Read only vs. rewritable
Page 370
Figure 7-25
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Optical Discs
A CD-ROM can be read from but not written to
• Read from a CD-ROM drive or CD-ROM player
A CD-R is a multisession optical disc on which
users can write, but not erase
A CD-RW is an erasable multisession disc
• Must have a CD-RW drive
Pages 372 – 373
Figure 7-29
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Optical Discs
A DVD-ROM is a high-capacity optical disc on
which users can read but not write or erase
• Requires a DVD-ROM drive
A Blu-ray Disc-ROM (BD-ROM) has a storage
capacity of 100 GB
DVD-RW, DVD+RW, and DVD+RAM are highcapacity rewritable DVD formats
Pages 375 – 376
Figure 7-29
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Other Types of Storage
Page 376
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Other Types of Storage
• Tape is a magnetically coated ribbon of plastic capable of
storing large amounts of data and information
• A tape drive reads and writes data and information on a
tape
Page 376
Figure 7-35
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Other Types of Storage
• A magnetic stripe card
contains a magnetic
stripe that stores
information
• A smart card stores
data on a thin
microprocessor
embedded in the card
Page 377
Figure 7-36
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Other Types of Storage
• Microfilm and microfiche store microscopic
images of documents on a roll or sheet film
Page 378
Figure 7-37
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Other Types of Storage
• Enterprise storage stores huge volumes of data
and information for large businesses
– Uses special hardware for heavy use, maximum
availability, and maximum efficiency
Page 379
Figure 7-39
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Computer Software
• Software, also called a program, tells the
computer what tasks to perform and how to
perform them
System Software
• Operating system
• Utility program
Application Software
Pages 11 - 12
Figures 1-8 – 1-9
Discovering Computers Fundamentals, 2012 Edition
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Computer Software
A program is a series of related instructions
that tells a computer what tasks to perform
and how to perform them
Programs respond to commands that a
user issues
A user response is an instruction a user
issues by replying to a question displayed
by a program
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Application Software
• Application software consists of programs
designed to make users more productive and/or
assist with personal tasks
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Application Software
• Available in a variety of forms:
Packaged
software
Custom
software
Web
application
Open source
software
Shareware
Freeware
Public-domain
software
Pages 142 – 143
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System Software
• System software serves as the interface between
the user, the application software, and the
computer’s hardware
– Utility programs
Page 143
Figure 3-2
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