This chapter discusses computer input and output devices. It describes common input devices like keyboards, mice, and touch screens. It explains how monitors use pixels and refresh rates to display images. Mouse components and maintenance techniques are covered. The chapter also details inkjet, laser, and dot-matrix printers; factors that affect printer choice; and serial, parallel, and SCSI interfaces that allow devices to connect to computers. Learning objectives review key input/output devices, monitor display processes, mice, printer types and characteristics, and interface types.

1. Chapter 3
Peter Norton’s Introduction to Computers
Interacting with Your
Computer

2. Learning Objectives:
• List at least three common input and output devices.
• Name the processes a video monitor uses to displays images.
• Name the components of a mouse and list the common
techniques used to maintain a mouse.
• Name three types of printers and list the advantages and
disadvantages of each.
• Explain how input and output devices communicate with the
other parts of the computer.

3. Input Devices:
• Keyboard
• Mouse
• Trackball
• Trackpad
• Pen
• Touch Screen
• Bar Code Reader
• Image Scanner
• Microphone
• Video

4. Right
click
The mouse is a fairly
intuitive input device.
When it gets sluggish, turn it
over and remove the cover plate.
Carefully clean the ball and rollers.
Left
click

5. Parts of a Keyboard:
• Alphanumeric Keys
• Modifier Keys
• Numeric Keypad
• Function Keys
• Cursor-movement Keys
• Escape Key
• Special-purpose Keys

7. Factors Affecting
Monitors:
• Size
• Resolution
• Refresh rate
• Dot pitch

8. Size is measured
diagonally.
Resolution = no. of pixels
(i.e. 1024 x 768)
Refresh rate = number of
frames in one second
The picture is scanned
from left to right and
from top to bottom.
One complete set of scan
lines is called a frame.
1 pixel in a color monitor

9. Flat-Panel Monitors:
• LCD (Liquid Crystal Display)
•Passive Matrix
•Active Matrix
(Notebooks use LCD displays)

10. Types of Printers:
• Ink Jet
• Laser
• Dot-Matrix
• Thermal-Wax
• Dye-Sub
• Fiery
• IRIS
• Plotter

11. Ink jets are popular because of their
relatively low cost and color capability.

12. Paper is given a
static charge
Laser beam
Heat roller bonds
toner to paper
Toner transferred
from drum to paper
Rotating
mirror
Laser transfers
image to drum
Laser printers are faster and capable of high resolution.

13. Printer Criteria:
• Image Quality
• Speed
• Initial Cost
• Cost of Operation

14. Types of Interfaces:
• Serial
• Parallel
• Centronics
• SCSI

15. Bit 0
Start bit
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Stop Bit
UART
RS232
Driver
To modem
Transmitter
Receiver
Control Serial data transmission
is relatively slow!
The serial ports transfer data one bit at a time.

16. PIA
Transmitter
Receiver
Control
To printer
The parallel port transfers data one byte at a time.
Drivers

17. A SCSI card can be plugged
into an expansion slot. SCSI
devices can be daisychained.

18. Learning Objectives:
Chapter 3 Review
• List at least three common input and output devices.
• Name the processes a video monitor uses to displays images.
• Name the components of a mouse and list the common
techniques used to maintain a mouse.
• Name three types of printers and list the advantages and
disadvantages of each.
• Explain how input and output devices communicate with the
other parts of the computer.