1. Introduction to computers in year.ppt

these are notes for computer application students

1. Computer Application
COS 1101
Lecture 1
Introduction to Computers
Matovu Muhammed

2. Definition of a computerDefinition of a computer
By definition, a computer is an electronic device that processes data,
converting it into information that is useful to people.
Computers are controlled by programmed instructions that transform
the data into meaningful information.
Generally a Computer is an electronic device that accepts input,
processes it, stores data, and produces output.

3. Merits/characteristics of computers
Speed - Computers perform operations at an extremely high speed and
executes millions of instructions in a short time.
Accuracy -very high as long as they are fed with instruction. Error detecting
and correcting techniques will prevent false results
Diligence - Computers do not suffer from human limitations such as tiredness,
lack of concentration, boredom e.t.c.
Versatility - performs various tasks ranging from simple calculation to
complex, Can receive data in various forms i.e. text, sound, video, graphics etc.
Storage capacity -. can store and retrieve data immediately – large data

4. …
Consistency, you always get the same result for the same process
when using a computer. For example if you created a document on one
computer, you can open it on another without making any special
adjustments. 
Automation - Ability to perform various operations with little or no
human intervention.
Connection with Internet, With the Internet, you can
communicate faster with people across the globe

5. Demerits of computers
May take longer to learn how to use applications that may decrease
productivity.
Unlike human it can’t take decision on its own.
They are expensive.
Have taken place of human labor.
Health Risk, Improper and prolonged use of a computer might lead
to disorders or injuries of the elbows, wrist, neck, back, and eyes.

6. …
Violation of Privacy, When using the Internet on your computer,
you run the risk of leaking your private information.
Impact on Environment, When computer junk is discarded in
open grounds, they release harmful chemicals like lead and
mercury to the environment. 

7. Personal and Home Uses of Computers
Computers allow people with
disabilities to do normal activities.
Shopping online
Playing games with other people
Work from home
Entertainment such as listening to
music, watching videos etc.
Enable communication through the
use of (electronic mails) e-mails ,
chats etc.

8. Business Uses of Computers
Computers allow companies to keep large
amounts of information at hand.
Databases
Makes ordering and tracking resources
quicker and easier.
Allows people to have meetings from
different locations.
Helps in information management which
eases the process of decision making .
Computers allow people across the world
to communicate easily.

9. Educational Uses of Computers
The Internet allows access to
hundreds of online research
materials.
Allows colleagues to
correspond quickly about
ongoing research.
Eases the process of analyzing
research data.

10. Information Processing Cycle
The basic working principle of computers
Input
Processing
Output
Storage

11. Input
Input: Data provided to the computer by a person, the environment, or
another computer.
Examples of Input
words and symbols
numbers
pictures
audio signals from a microphone
signals from another computer
temperature, speed, pressures, etc. from sensors

12. Processing
Processing - manipulation of data.
Data are symbols that represent raw facts, objects, and ideas
about people, places, events, and things that are of importance in
an organization.
A computer program or software is a series of instructions
that tell a computer how to carry out a processing task.
Examples of Processing
Arithmetic calculations
Sorting a list
Modifying pictures
Drawing graphs

13. Output
13
Output - the result produced by a computer after processing the
data.
Examples of Output
images on a monitor
printed documents
sounds
signals to device controllers

14. Memory and StorageMemory and Storage
Memory - the area of a computer that temporarily holds data that is
being processed or waiting to be processed, stored, or output.
Storage - The area where data can be left on a permanent basis while
it is not needed for processing.
Examples of Storage
magnetic disks i.e HDD
CD-ROM (Compact Disk Read-Only Memory)
Flash disks

15. Proper care of computers
oComputers are used to store data and information
oIt is important to take care of your computer so that it will
function well.
oIf you take care of your computer, you will not experience
difficulties in retrieving data stored in it.

16. Proper care of computers cont.…
1.Place your computer in a cool dry place
2.Don’t put your computer under direct heat
3.Clean your computer regularly. Use a clean damp cloth to clean the
computers external casing
4.Don’t eat and drink while using your computer. Small particles of
food might on your computer and entice insects to feed on them.
Liquids when spilled on your computer, might destroy it.

17. Proper care of computers cont.…
5. Cover your computer when not in use. This will prevent dust from gathering on your
computer
6. Use an uninterrupted power supply (UPS) to give your computer a few minutes of power during
power failure. This allows you to save your work and properly shutdown.
7. Frequent saving and backups, It is good practice to save your work at regular intervals. This
prevents data loss resulting from a power cut or a system error.
8. Usernames, passwords and access rights, To protect information and access on a computer or multi-
user network, usernames and passwords are used.
9. Make sure your PC has the latest anti-virus software installed, and regularly update its data files so
that it can recognize new viruses to keep your PC safe from viruses.

18. Health Effects of Computers
1. Eye-Strain
One health issue that can occur after using computers for a long time is eye-
strain (tiredness of the eyes). 
This is caused by looking at a monitor which is a constant distance away.
The muscles that focus your eyes do not move, and so get tired and painful. Eye-
strain can also cause headaches.
2. Back and Neck Ache
Many people suffer from back and neck pain after working at a computer for a
long time.
This is usually due to them having a bad sitting posture

19. 3. Repetitive Strain Injury (RSI) in Wrists and Hands
Any repetitive movement (same movement over and over
again) can result in a health problem called repetitive strain
injury (RSI). 
In particular, typing and using a mouse for long periods are
common causes of RSI in the wrist (it is often called carpal-
tunnel syndrome)

20. Safety Issues with Computers
You wouldn't imagine that using computers could be dangerous,
but there are a few situations that can result in accidents.
1. Trailing Cables
Computer equipment is often connected
to lots of cables: power, network etc.
If these cables are laying on the floor,
they can cause people to trip over them
Solution: Place cables inside cable ducts,
Or under the carpet / flooring

21. ...
2. Spilt Drinks  or Food
If any liquids are spilt on electrical equipment,
such as a computer, it can result in damage to
the equipment, or an electric shock to the user.
Solution: Keep drinks and food away from
computers

22. 3. Overloaded Power Sockets
Plugging too many power cables into a socket
can result in the socket being overloaded,
overheating, and a fire starting.
Solution: Never plug too many cables into
a socket. Always make sure there are fire
extinguishers nearby

23. ...
4. Heavy Objects  Falling
Many items of computer equipment are very heavy:
CRT monitors, laser printers, etc. Heavy items
can cause serious injury if they fall on people.
Solution: Make sure equipment is placed
On strong tables / shelves