The document discusses various types of computer input devices. It describes how keyboards allow users to enter text and instructions through keys. Mice and other pointing devices like trackballs and joysticks enable users to control the cursor position on screen. Data scanning devices can directly input data from source documents into computers. Touchscreens and pen-based devices allow input through touching or writing on the display screen.

1. Muhammad Luqman (UOS)

2.  Input is any data and instructions entered into the
memory of a computer
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3.  As shown in Previous Figure , people have a variety of
options for entering data and instructions into a
computer
 Data is a collection of unprocessed items, including
text, numbers, images, audio, and video
 Once data is in memory, the compute interprets and
executes instructions to process the data into
information
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4.  When a programmer writes a program, he or
she enters the program into the computer by
using a keyboard, mouse, or other input
device
 The programmer then stores the program in
a file that a user can execute (run)
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5. 1. Keyboard
2. Point and Draw devices
3. Data Scanning devices
4. Digitizer
5. Electronic cards based devices
6. Speech recognition devices
7. Vision based devices
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6. Muhammad Luqman (UOS)

7.  An input device is any hardware component that
allows users to enter data an instructions (programs,
commands, and user responses) into a computer
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8.  A keyboard is an input device that contains keys users
press to enter data an instructions into a computer
 All desktop computer keyboards have a typing area
that includes the letters of the alphabet, numbers,
punctuation marks, and other basic keys
 Many desktop computer keyboards also have a
numeric keypad on the right side of the keyboard
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9.  Most popular keyboard used today is the 101-keys
QWERTY keyboard
 An enhanced keyboard has twelve or more function
keys along the top; it also has two ctrl keys, two alt
keys, and a set of arrow and additional keys between
the typing area and the numeric keypad
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10. Muhammad Luqman (UOS)

11.  Function keys, which are labeled with the letter F
followed by a number, are special keys programmed
to issue commands to a computer
 The command associated with a function key may
vary, depending on the program with which you are
inter acting
◦ For example, the F3 key may issue one command to
an operating system and an entirely different
command to a word processing program
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12.  All Keyboard’s have toggle keys
 A toggle key is a key that switches between two states each
time a user presses the key
 When you press the num lock key, for example, it locks the
numeric keypad so that you can use the keypad to type
numbers. When you press the num lock key again, the
numeric keypad unlocks so that the same keys can serve to
move around a document
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13.  Keyboards with media control buttons allow you to
control your media player program, access the
computer’s optical disc drive, and adjust speaker
volume
 Internet control buttons allow you to open an e-mail
program, start a Web browser, and search the Internet
 Some keyboards have USB ports so that you can plug a
USB device directly in the keyboard instead of in the
system unit
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14.  Interacting with computer was initially restricted mainly to text
mode
 It was soon realized that interacting with computers in text-
mode is time consuming
 A new type of interface called Graphical User Interface (GUI)
was devised for interfacing with computers
 A GUI provides a screen with graphical icons and allow a user to
make rapid selections from them to give instructions to
computers
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15.  A pointing device is an input device that allows a user
to control a pointer on the screen
 In a graphical user interface, a pointer is a small
symbol on the screen whose location and shape
change as a user moves a pointing device
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16.  Mouse is most popular point and draw device
 Mouse is a pointing device that fits under the palm of
your hand comfortably
 The mouse is the most widely used pointing device on
desktop computers
 Generally, you use the mouse to move the pointer on the
screen to an object such as a button, a menu, an icon, a
link, or text
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17.  Most desktop computer users today have some type of
optical mouse, which uses devices that emit and sense
light to detect the mouse’s movement
 Some use optical sensors, and others use a laser
 A mouse connects to a computer in several ways. Many
types connect with a cable that attaches to a USB port
or a mouse port on the system unit
 What are the types of Mouse ?
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18.  A wireless mouse, or cordless mouse, is a
battery-powered device that transmits data
using wireless technology, such as radio
waves (Bluetooth) or infrared light waves
(IrDA).
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19.  A Trackball is a pointing device similar to a
roller-ball mouse
 It has roller-ball placed on the top along with
buttons
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20.  To move graphical cursor on the screen ball is rolled
with hand
 Trackball is a device of choice in Computer Aided
Design area
 In designing track ball is preferred because hand
movement is mostly sufficient to move the graphical
cursor and does not require any movement of cursor
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21.  A joystick is a pointing device that works on
the same principle as a trackball
 A user move the spherical ball by the
attached stick with hand
 The stick can be move forward, backward, left
or right
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22.  It is a pen based point and draw device
 User holds the pen in his/her hand and point with it
directly on the screen to select from the displayed
menu items or icons
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23.  Touch screen is the most simple, intuitive, and easiest
to use of all input devices
 A Touch screen enable a user to choose from available
options by simply touching the desired icon or menu
item displayed on the screen
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24.  Data scanning devices are input devices used for direct
data entry into a computer system from source
document
 Some of them also capable of recognizing marks or
characters
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25.  They eliminate the need for manual entry of data by
human beings
 Automatic entry of data with their use improves data
accuracy and increase timeliness of the information
processed
 They demand high quality of input document because of
direct date entry from source documents, documents are
typed properly
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26.  Form design and ink specification usually becomes
more critical with the use of these devices than
keyboard devices are used to key in data from forms
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27.  An image scanner is an input device that translates
paper documents into an electronic format that can be
stored in a computer
 The Input document may be typed text, pictures,
graphics, or even handwritten material
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28.  When image scanners are used for inputting
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