Slide 1

Input Devices Output Devices Storage Devices
Slide 2


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
Slide 3


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
Slide 4


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
Slide 5

• Input device captures information and translates it into a form that can be processed and used by other parts of your computer.
 Keyboards
 Pointing devices
 Game controllers
 Scanners
 Styluses
 Microphones
 Digital cameras
 Web cams p. 5.130 Fig. 5-1 Slide 6

The keyboard is the most common input device. Types of keyboards include:
Ergonomic
Enhanced / Extended
Keyboard
Keyboard

Enhanced or Extended keyboard
– Typically 101 keys laid out in the QWERTY fashion; connected to the computer by a cable

Cordless keyboard – Uses infrared or radio wave signals
 Ergonomic keyboard – Designed to help prevent cumulative trauma disorder (CTD) or damage to nerve tissues in the wrist and hand due to repeated motion

SimNet Concepts Support CD: “Keyboards” p. 5.131 Fig. 5-2 Slide 7


Alphanumeric Keys

Numeric Keys

Function Keys

Arrow Keys

Combination Keys
Keys (Ctrl, Alt, Shift)

Special Keys
Slide 8

p. 5.131 Fig. 5-2 Slide 9

 Various pointing devices are available
 Types of pointing devices:
•
•
•
• Mouse
 Mechanical mouse
 Optical mouse
 Wireless mouse
Trackball
Touchpad
Pointing stick

SimNet Concepts Support CD: “Mice” p. 5.132 & P. 5.133 Fig. 5-3 & Fig 5.4
Slide 10

 Game controllers are used mainly to play games
 Types of gaming devices
• Gamepads
• Joysticks
• Gaming wheels
• Force feed p. 5.134 Fig. 5-5 Slide 11

 Other types of input devices include:
• Scanners
• Styluses
• Microphones
• Digital cameras
• Web cams p. 5.135 Fig. 5-6 Slide 12

Flatbed
Scanners
Barcode reader
Fax Machines
Slide 13

• Scanner is a light sensitive device that helps you copy or capture images, photos, and artwork that exist on paper. Types of scanners include:
 Flatbed

SimNet Concepts Support CD: “Scanners”
Slide 14

•
•
Stylus is an input device consisting of a thin stick that uses pressure to enter information or to click and point
Styluses are used with:
 PDAs
 Tablet PCs
 Graphics tablets p. 5.135 Fig. 5-6 Slide 15

•
•
•
Microphones are used to input audio
Three main types of microphones are:
 Desktop microphones
 Headsets
 Directional microphones
Speech recognition is increasingly being included in application software
Slide 16




Digital cameras are used to:
•
• Download images to a computer
Post pictures to the Web
• Produce videos
Resolution is measured in megapixels
Higher the resolution, better the image quality, but the more expensive the camera

SimNet Concepts Support CD: “Digital Cameras”
Slide 17

• Web cam is a video camera that can be used to take images for uploading to the Web
Slide 18


Output devices take information within your computer and present it to you in a form that you can understand

Main output devices:

Monitors
 Printers

Speakers
 SimNet Concepts Support CD:
“Overview of Output Devices”
Slide 19

Trackball
Touch
Screen
Pointing
Stick
Joystick
Pen
Touch Pad
Slide 20


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)
Slide 21

 The image’s light falls on a charge-coupled device
(CCD) which transforms the light’s patterns into pixels (individual dots).

Images are stored in the camera using flash memory.
The most popular types are CompactFlash and
SmartMedia.

Photo-editing programs enable the user to edit the images.
Slide 22


A video capture board transforms analog video into digital video.

Digital video cameras use digital technologies to record video images.

A Web cam is a low resolution video camera.
Web cam
Digital video camera
Slide 23


Output devices take information within your computer and present it to you in a form that you can understand

Main output devices:

Monitors
 Printers

Speakers
 SimNet Concepts Support CD:
“Overview of Output Devices”
Slide 24

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)

LED: Light Emitting Diode

Plasma
Slide 25


Resemble televisions

Use picture tube technology

Less expensive than a LCD monitor

Take up more desk space and use more energy than LCD monitors
Slide 26


Cells sandwiched between two transparent layers form images

Used for notebook computers, PDAs, cellular phones, and personal computers

More expensive than a CRT monitor
 Take up less desk space and use less energy than CRT monitors

Types of LCD monitors:

Passive-matrix LCD

Active-matrix LCD

Gas plasma display
 Field emission display
Slide 27


Screen size measured as a diagonal line across the screen – from corner to opposite corner (15,17,20)

Resolution the number of pixels displayed on the screen (the higher the resolution, the closer together the dots) 600*800

Pixels ( or picture element) dots that make up the image on your screen

Dot pitch is the distance between the centers of a pair of likecolored pixels
 Refresh rate the speed with which a monitor redraws the image of the screen, and is measured in hertz
Slide 28


A printer is a peripheral device that produces a physical copy or hard copy of the computer’s output.
Slide 29

Inkjet
Laser

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

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 30


Dot Matrix 
InkJet

Laser
1. Very Cheep
2. Less quality
3. 20-30 sec-A4
4. Less
Maintenance cost
1. More cost than
Dot
2. Good quality
3. 5-10 Sec-A4
4. High
Maintenance cost
1. High Cost
2. Excellent quality
3. 1-2 Sec-A4
4. Low
Maintenance cost
Slide 31


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.
Slide 32

RAM – memory
Hard Drive – storage

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.
Slide 33

Memory

Volatile

Cheep

Less Space(2-8GB)

Faster
Storage

Non Volatile

More cost

More Space(1 TB)

Slower than Memory
Slide 34

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
Slide 35

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
Slide 36

Sector

A disk is formatted ; it is divided into tracks and sectors , and a file allocation table (FAT) is created.

Track
– circular band

Sector
– pie shaped section

Cluster
– two or more adjacent sectors

FAT
– keeps track of specific locations of files
Track
Cluster
Slide 37

Disk surface magnified
Cross-section of a disk

Microscopic indentations called pits scatter the laser beam’s light. A light-sensing device receives no light from the pits. A signal is sent to the computer corresponding to a 0 in the binary system.

Flat, reflective areas, called lands , bounce the light back to the light sensing device, which sends a signal corresponding to a 1.
Slide 38


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.
Slide 39

Floppy Disk
Hard Drive CD ROM / DVD
Capacity – 720 KB to
1.44 MB
Access Time – 100ms
Capacity – Up to 80 GB
Access Time – 6 to 12ms
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
Slide 40

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.
Slide 41


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).
Slide 42

Zip Drive
Floppy 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.
Floppy Disk
Slide 43

Slide 44


CD-ROM stands for Compact Disc-
Read 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.
Slide 45

CD-R

Discs can be read and written to

Discs can only be written to “once”

CD-R drives are capable of reading and writing data
CD-RW

Discs can be read and written to

Discs are erasable

Discs can be written to many times

CD-RW drives are capable of reading, writing, and erasing data
Slide 46


DVD stands for Digital Video Disc.

DVD technology is similar to CD-
ROM 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.
Slide 47