Computers Are
Your Future
© 2005 Prentice-Hall, Inc.
Computers Are Your Future Chapter 5
Computers Are Your Future
Chapter 5
Input/Output and Storage
© 200 Prentice-Hall, Inc
Slide 2
Computers Are Your Future Chapter 5
What You Will Learn About
 The purpose of special keys and the most frequently
used pointing devices
 Input devices used to get audio and digital data into the
computer
 The characteristics of a monitor’s quality and the various
types of monitors
 The two major types of printers
 The difference between memory and storage
© 200 Prentice-Hall, Inc
Slide 3
Computers Are Your Future Chapter 5
What You Will Learn About




The categories of storage devices
The performance characteristics of hard drives
How data is stored on both hard and floppy disks
The various optical storage media available for
personal computers
© 200 Prentice-Hall, Inc
Slide 4
Computers Are Your Future Chapter 5
Input
 Input is any data entered into the computer’s
memory.
 Types of input include:
 Data – Unorganized information (words, numbers,
images, or sounds) that the computer converts to
meaningful information
 Software – Programs transferred from storage devices to
the computer’s memory
 Commands – Instructions that tell the computer what to
do
 Responses – Prompts requiring user feedback
© 200 Prentice-Hall, Inc
Slide 5
Computers Are Your Future Chapter 5
Input Devices: Giving Commands
Keyboard
Mouse
Other Pointing
Devices
© 200 Prentice-Hall, Inc
Slide 6
Computers Are Your Future Chapter 5
Audio Input
 Computers can accept input from a microphone.
 An expansion card called a sound card records and
plays back sound files.
 Sound files contain digitized sound data.
 Popular sound file formats include:
 Windows WAV
 Moving Pictures Expert Group (MPEG)
 MP2 and MP3
 Musical Instrument Digital Interface (MIDI)
© 200 Prentice-Hall, Inc
Slide 13
Computers Are Your Future Chapter 5
Audio Input: Speech Recognition
 Speech recognition is a type
of input in which the
computer recognizes words
spoken into a microphone.
 Special software and a
microphone are required.
 Latest technology uses
continuous speech recognition
where the user does not have
to pause between words.
© 200 Prentice-Hall, Inc
Slide 14
Computers Are Your Future Chapter 5
Digital Input: Digital Cameras and
Digital Video
Digital Cameras
Digital Video
Click on the
picture to play
the video.
© 200 Prentice-Hall, Inc
Slide 15
Computers Are Your Future Chapter 5
Alternative Input Devices
Scanners
Flatbed
© 200 Prentice-Hall, Inc
Fax Machines
Barcode reader
Slide 16
Computers Are Your Future Chapter 5
Output Devices: Engaging our Senses
 Output devices are peripheral devices that enable us
to view or hear the computer’s processed data.
 Visual output – Text, graphics, and video
 Audio output – Sounds, music, and synthesized speech
© 200 Prentice-Hall, Inc
Slide 19
Computers Are Your Future Chapter 5
Monitors
CRT
LCD
 A monitor is a peripheral device which displays
computer output on a screen.
 Screen output is referred to as soft copy.
 Types of monitors:
 Cathode-ray tube (CRT)
 Liquid Crystal Display (LCD or flat-panel)
© 200 Prentice-Hall, Inc
Slide 20
Computers Are Your Future Chapter 5
Monitor Specifications
 Screen size – The diagonal measurement of the screen surface
in inches (15, 17, 19, 21)
 Resolution – The sharpness of the image determined by the
number of horizontal and vertical dots (pixels) that the screen
can display (800 x 600, 1024 x 768, 1600 x 1200)
 Refresh rate – The speed at which the screen is redrawn
(refreshed) and measured in Hertz (Hz) (60Hz, 75Hz)
© 200 Prentice-Hall, Inc
Slide 23
Computers Are Your Future Chapter 5
Printers
A printer is a peripheral
device that produces a
physical copy or hard
copy of the computer’s
output.
© 200 Prentice-Hall, Inc
Slide 24
Computers Are Your Future Chapter 5
Types of Printers
Inkjet
 Inkjet printer, also called a
bubble-jet, makes characters
by inserting dots of ink onto
paper
 Letter-quality printouts
 Cost of printer is inexpensive
but ink is costly
© 200 Prentice-Hall, Inc
Laser
 Laser printer works like a
copier
 Quality determined by dots
per inch (dpi) produced
 Color printers available
 Expensive initial costs but
cheaper to operate per page
Slide 25
Computers Are Your Future Chapter 5
Plotter
 A plotter is a printer that uses a pen that moves over a
large revolving sheet of paper.
 It is used in engineering, drafting, map making, and
seismology.
© 200 Prentice-Hall, Inc
Slide 26
Computers Are Your Future Chapter 5
Audio Output: Sound Cards and Speakers
 Audio output is the ability of the computer to output
sound.
 Two components are needed:
 Sound card – Plays contents of digitized recordings
 Speakers – Attach to sound card
Click an icon
to play
music.
Try clicking on
Cheers while
playing music.
Click the icon
WMA
again to stop
Beethoven
playing.
1:15 min
© 200 Prentice-Hall, Inc
MIDI
Rocky
2:56 min
MP3
Hornsby
48 sec
WAV
Cheers
15 sec
Slide 27
Computers Are Your Future Chapter 5
Memory vs. Storage
Hard Drive – storage
RAM – memory
 Storage, also known as mass media or auxiliary storage,
refers to the various media on which a computer system can
store data.
 Storage devices hold programs and data in units called files.
 Memory is a temporary workplace where the computer
transfers the contents of a file while it is being used.
© 200 Prentice-Hall, Inc
Slide 28
Computers Are Your Future Chapter 5
Why Is Storage Necessary?
 Storage devices:
Retain data when the computer is turned off
Are cheaper than memory
Play an important role during startup
Are needed for output
© 200 Prentice-Hall, Inc
Slide 29
Computers Are Your Future Chapter 5
Storage Devices
 Storage devices are categorized by:
The type of operations they perform
The method they use to access the information
The technology they use
Their location in the storage hierarchy
Their capacity and speed
© 200 Prentice-Hall, Inc
Slide 30
Computers Are Your Future Chapter 5
Sequential vs. Random Access Storage
Tape Drive –
sequential storage
Floppy Disk Drive –
random-access storage
Hard Disk –
random-access storage
 Sequential – Storage devices that read and write data
in a serial (one after the other) fashion
 Random-Access – Storage devices that read and
write data without going through a sequence of
locations
© 200 Prentice-Hall, Inc
Slide 31
Computers Are Your Future Chapter 5
Storage Technologies: Magnetic and Optical
Magnetic Storage
Optical Storage –
CD/DVD drive
 Magnetic – Storage devices use disks or tapes that
are coated with magnetically sensitive material
 Optical – Storage devices that use laser beams to
read patterns etched into plastic disks
© 200 Prentice-Hall, Inc
Slide 32
Computers Are Your Future Chapter 5
The Storage Hierarchy
 The three levels of storage hierarchy are:
 Online storage – Also called primary storage, it is made
up of the storage devices that are actively available to the
computer system. User action is not required.
 Near-online storage – Also called secondary storage, it is
not readily available to the computer system. The user
performs an action, such as inserting a disk, to make it
available.
 Offline storage – Also called tertiary storage or archival
storage, it is not readily available to the computer system.
Devices such as tape backup units store data for archival
purposes.
© 200 Prentice-Hall, Inc
Slide 35
Computers Are Your Future Chapter 5
Storage Capacity and Speed
Floppy Disk
Capacity – 720 KB to
1.44 MB
Access Time – 100ms
Hard Drive
Capacity – Up to 80 GB
Access Time – 6 to 12ms
CD ROM / DVD
Capacity – CD-ROM 650
MB; DVD 17 GB
Access Time – 80 to 800ms
 A storage device’s performance is measured by:
 Capacity – The number of bytes of data that a device can hold
 Access Time – The amount of time, in milliseconds (ms), it takes
the device to begin reading data
© 200 Prentice-Hall, Inc
Slide 36
Computers Are Your Future Chapter 5
Hard Disks
Platter
Read/Write
head
 Hard disks are high-speed, high-capacity storage devices.
 They contain metal disks called platters.
 They contain two or more stacked platters with read/write
heads for each side.
 Hard disks can be divided into partitions to enable computers
to work with more than one operating system.
© 200 Prentice-Hall, Inc
Slide 37
Computers Are Your Future Chapter 5
Factors Affecting a Hard Disk’s Performance
 Seek time or positioning performance – How
quickly the read/write head positions itself and
begins transferring information. It is measured in
milliseconds (ms).
 Spindle speed or transfer performance – How
quickly the drive transfers data. It is measured in
rotations per minute (RPM).
© 200 Prentice-Hall, Inc
Slide 38
Computers Are Your Future Chapter 5
Floppy and Zip Disks and Drives
Floppy Drive
Zip Drive
Click on the
picture to see it
work.
 A disk or diskette is a portable storage medium.
 High-density floppy disks that are commonly
used today store 1.44 MB of data.
 Disks work with a disk drive.
 Zip disks store up to 750 MB of data and are not
downwardly compatible with floppy disks.
© 200 Prentice-Hall, Inc
Floppy Disk
Slide 39
Computers Are Your Future Chapter 5
CD-ROM Discs and Drives
 CD-ROM stands for Compact DiscRead Only Memory.
 CD-ROM drives can not write data
to discs.
 They are capable of storing 650 MB
of data.
 They are used for storing operating
systems, large application programs,
and multimedia programs.
© 200 Prentice-Hall, Inc
Slide 40
Computers Are Your Future Chapter 5
CD-R and CD-RW Discs and Recorders
CD-R
CD-RW
 Discs can be read and
written to
 Discs can be read and
written to
 Discs can only be
written to “once”
 Discs are erasable
 CD-R drives are capable
of reading and writing
data
© 200 Prentice-Hall, Inc
 Discs can be written to
many times
 CD-RW drives are
capable of reading,
writing, and erasing data
Slide 41
Computers Are Your Future Chapter 5
DVD-ROM Discs and Drives
 DVD stands for Digital Video Disc.
 DVD technology is similar to CDROM technology.
 DVDs are capable of storing up to
17GB of data.
 The data transfer rate of DVD drives is
comparable to that of hard disk drives.
 DVD-R and DVD-RW drives have the
ability to read/write data.
© 200 Prentice-Hall, Inc
Slide 42
Computers Are Your Future Chapter 5
Solid State Storage Devices
 Solid state storage devices use nonvolatile memory
chips to retain data.
 They do not have moving parts.
 They are small, lightweight, reliable, and portable.
© 200 Prentice-Hall, Inc
Slide 43
Computers Are Your Future Chapter 5
Solid State Storage Devices
Smart
Card
Flash
Memory
PC
Card
© 200 Prentice-Hall, Inc
Memory
Stick
Compact
Flash
Memory
Micro
Drive
Slide 44
Computers Are Your Future Chapter 5
Chapter 5 Summary
• Input is the software, data, and information that is entered into
the computer’s memory.
• Input devices such as the keyboard, mouse, and trackball enable
the user to enter data.
• A pointing device enables the user to control movements of an
on-screen pointer.
• Speech recognition software enables the user to enter data into
a computer by speaking into a microphone.
• Video and images can be entered into a computer by way of
digital cameras, scanners, and fax modems.
• Monitors enable the user to view the computer’s processed
data. The output is known as soft copy.
© 200 Prentice-Hall, Inc
Slide 45
Computers Are Your Future Chapter 5
Chapter 5 Summary (continued)
• The two types of monitors are the CRT and the LCD.
• A monitor’s quality is measured by screen size, resolution, and
refresh rate.
• Printers produce permanent versions (hard copies) of the
computer’s output.
• The two basic types of printers are the inkjet and laser.
• Memory makes software and data available for the CPU’s use.
• Storage devices are categorized by:
Data access (sequential or random-access)
Technology (magnetic, optical, or solid state)
Hierarchy (online, near-online, or offline)
Operations (read-only or read/write)
© 200 Prentice-Hall, Inc
Slide 46
Computers Are Your Future Chapter 5
Chapter 5 Summary (continued)
• A hard disk’s performance is measured by its positioning
performance and transfer rate.
• Optical storage devices include:
CD-ROM– Read-only
CD-R– Record once
CD-RW– Erasable, write repeatedly
DVD-ROM– Read-only
DVD-R– Read/write
• Solid state storage devices include:
PC cards
Flash memory cards
Smart cards
© 200 Prentice-Hall, Inc
Slide 47