1. Computer Skills 1400 TQN Level 1
Chapter 7 and 8
Input/Output and Storage

2. Input Devices
Output Devices
Storage Devices

3. 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

4. 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

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

6. Input Devices Keyboards Pointing devices Game controllers Scanners
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
Good Exercise: Ask students if they can name any other input devices. A hard drive can be classified as both an input device and an output device.
p Fig. 5-1

7. Input Devices
The keyboard is the most common input device. Types of keyboards include:
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
Ergonomic Keyboard
Enhanced / Extended Keyboard
                               
                               
SimNet Concepts Support CD: “Keyboards”
p Fig. 5-2

8. Keyboard Alphanumeric Keys Combination Keys Keys (Ctrl, Alt, Shift)
Function Keys
Arrow Keys
Combination Keys Keys (Ctrl, Alt, Shift)
Special Keys

9. Types of Input Devices
                               
                               
p Fig. 5-2

10. Pointing Devices 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 & P Fig. 5-3 & Fig 5.4

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

12. Specialized Input Devices
Other types of input devices include:
Scanners
Styluses
Microphones
Digital cameras
Web cams
p Fig. 5-6

13. Alternative Scanners
Fax Machines
Scanners
Flatbed
Barcode reader

14. Scanner
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”

15. Styluses
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 Fig. 5-6

16. Microphones 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
                                                                   
                               
                               

17. Digital Cameras 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”

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

19. Output Devices
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”

20. Other Types of Pointing Devices
Touch Screen
Trackball
Pointing Stick
Joystick
Pen
Touch Pad

21. 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)

22. Digital Cameras
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.

23. Digital Video
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.
Digital video camera
Web cam

24. Output Devices
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”

25. 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)
LED: Light Emitting Diode
Plasma

26. Cathode-ray tube (CRT)
Resemble televisions
Use picture tube technology
Less expensive than a LCD monitor
Take up more desk space and use more energy than LCD monitors

27. Liquid Crystal Display (LCD)
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

28. Monitor Specifications
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 like-colored pixels
Refresh rate the speed with which a monitor redraws the image of the screen, and is measured in hertz

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

30. Types of Printers
Laser
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
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

31. Difference Between Dot.Matrx, Inkjet and Laser Printer
Dot Matrix
Very Cheep
Less quality
20-30 sec-A4
Less Maintenance cost
InkJet
More cost than Dot
Good quality
5-10 Sec-A4
High Maintenance cost
Laser
High Cost
Excellent quality
1-2 Sec-A4
Low Maintenance cost

32. 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.

33. Memory vs. Storage
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.

34. Difference Between Memory & Storage
Volatile
Cheep
Less Space(2-8GB)
Faster
Non Volatile
More cost
More Space(1 TB)
Slower than Memory

35. Sequential vs. Random Access Storage
Hard Disk – random-access storage
Tape Drive – sequential storage
Floppy Disk Drive – 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

36. Storage Technologies: Magnetic and Optical
Optical Storage – CD/DVD drive
Magnetic Storage
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

37. Magnetic Disk Storage
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

38. Optical Disk Storage
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.

39. 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.

40. Storage Capacity and Speed
Floppy Disk
Hard Drive
CD ROM / DVD
Capacity – CD-ROM 650 MB; DVD 17 GB
Access Time – 80 to 800ms
Capacity – 720 KB to 1.44 MB
Access Time – 100ms
Capacity – Up to 80 GB
Access Time – 6 to 12ms
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

41. Hard Disks Hard disks are high-speed, high-capacity storage devices.
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.

42. 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).

43. Floppy and Zip Disks and Drives
Zip Drive
Floppy Drive
Click on the picture to see it work.
Floppy Disk
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.

44. Performance Enhancement for HD

45. CD-ROM Discs and Drives
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.

46. CD-R and CD-RW Discs and Recorders
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

47. DVD-ROM Discs and Drives
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.