1. Computers are used everywhere at work, school, and home for tasks like email, research, games, communication, and entertainment. 2. A computer is an electronic device that can accept data as input, process it, produce output, and store results. It uses hardware components like a CPU and memory to perform calculations at high speeds and store large amounts of information. 3. Key components of a computer system include input devices like keyboards and mice, a central processing unit (CPU) with an arithmetic logic unit (ALU) and control unit, and primary memory (RAM and ROM) as well as secondary memory like hard disks and optical disks for long-term storage.

1. Introduction to Components of
Computer System
Subject: Programming for Problem Solving
Subject code: KCS-201

2. Computers are everywhere
At work
•e-mail messages
•Memos
• letters
•manage calendars
•calculate payroll
•track inventory
• generate invoices.
At school
• teachers use computers
to assist with classroom
instruction.
•research genealogy
At Home
•play games
•to communicate
• purchase goods online
•listen to music or radio
broadcasts
•watch or create videos
and movies
• read books and
magazines
• share stories
,

3. Definiton
• The word “computer “ comes from the word “compute”,
which means to calculate.
• A computer is an electronic device, operating under the
control of instructions stored in its own memory.
• It can accept data (input), process the data according to
specified rules (process), produce results (output), and
store the results (storage) for future use.
• Generally, the term is used to describe a collection of
electric, electronic, and mechanical components known
as hardware.

4. • Very fast speed of calculation
• Store large amount of information for future
purpose in short time
• Great ability to enhance the communication
system
• Accuracy of calculation is very high

5. • Computer and communication system
• Manufacturing, construction engineering and
project management
• Military, space applications
• Logistic, distribution and supply chain
management
• Business process, healthcare management,
research in different sector

6. Computer Classification
• Personal Computer : A small, single-user
computer based on a microprocessor. In addition
to the microprocessor, a personal computer has a
keyboard for entering data, a monitor for
displaying information, and a storage device for
saving data.
• Workstation: A powerful, single-user computer. A
workstation is like a personal computer, but it has
a more powerful microprocessor and a higher-
quality monitor.

7. • Mini-computer: A multi-user computer capable
of supporting from 10 to hundreds of users
simultaneously.
• Mainframe Computer: A powerful multi-user
computer capable of supporting many hundreds
or thousands of users simultaneously.
• Super Computer: An extremely fast computer
that can perform hundreds of millions of
instructions per second.

8. Anatomy of Computer

9. • Input devices are the part of hardware to
provide human understanding information to
a computing system in digital form.
• Input is any data or instructions entered into
the memory of a computer
• Any hardware component allows user to
enter data and instructions in to a computer.
Input Device

10. Keyboard
• Used to enter information into the computer and
for giving commands.
• A standard computer keyboard is called a
QWERTY keyboard

11. Ball Mouse
• An input device operated
• by rolling its ball across a
• flat surface. The mouse is
• used to control the
onscreen
• pointer by pointing
• and clicking,
doubleclicking,
• or dragging objects
• on the screen.

12. Optical Mouse
• It is an advanced
computer pointing
device.
• It uses Light-Emitting
Diode(LED) in place of
the traditional mouse
ball.
• Movement is detected by
sensing changes in
reflected light.

13. Examples of input devices
1. Keyboard: Alphanumeric Keyboard, MIDI keyboard
2. Pointing Devices: Mouse, touchpad, trackball
3. Speech Recognization : Microphone( using voice speech recognition
or biometric verification)
4. Biometric system: Fingerprint scanner
5. Smart Card Reader: ATM, employee, business card, Punch card
reader
6. Digital camera and digital camcorder.
7. Medical instruments: ECG, EEG, X-ray, CT scan, and ultrasound
images
8. Finger (with touch screen or Windows Touch).
9. Gamepad, joystick
10. Light gun, Light pen, Magnetic ink (like the ink found on checks), Pen
or stylus

14. Central Processing Unit (CPU)
• This is the central part of computer which is
responsible to produce output for a
particular input or sometime automatic
system production.
• A CPU is brain of a computer. It is responsible
for all functions and processes. Regarding
computing power, the CPU is the most
important element of a computer system.

15. CPU comprises of :
• Control Unit (CU)
• Arithmetic Logic
Unit(ALU)
• Memory

16. Control Unit
• controls and co-ordinates computer components.
• Read the code for the next instruction to be executed.
• Increment the program counter so it points to the next
instruction.
• Read whatever data the instruction requires from cells
in memory.
• Provide the necessary data to an ALU or register.
• If the instruction requires an ALU or specialized
hardware to complete, instruct the hardware to
perform the requested operation.

17. Arithmetic & Logic Unit (ALU)
• It executes arithmetic operation as addition,
subtraction, multiplication, division.
• It performs logical operations as comparison,
combinational logic (AND, OR, NOT, XOR,
XNOR).
• Registers :Stores the data that is to be
executed next, "very fast storage area".

18. Memory
• Executable data are stored in primary memory.
• Access of primary memory is very fast and
volatile in nature (except ROM).
• Data is stored temporally while program is
running – Main Memory.
• To store data for long-term, to preserve programs
and data while not in use – Backing Storage.
• Primary and secondary memory

19. Primary Memory
• Temporary area for holding data.
• To store the program currently being executed
• To hold data produced while the programme
is running.
• Primary Memory are of two types
1. RAM 2. ROM

20. RAM(Random Access Memory)
• Major portion of the Primary Memory
• Memory that is used by the program in
execution
• If the computer gets turned off, RAM will lose
all the data.
• Static RAM & Dynamic RAM

21. STATIC RAM
• The memory retains as long
as power remains applied.
• Uses Flip Flop circuitory.
• Is more faster.
DYNAMIC RAM
• Need continues Refreshing
in order to maintain the
data.
• It uses transistors and
capacitors in circuits
• Slow and consumes more
power

22. ROM (Read Only Memory)
• Memory which we can only read but cannot write
on.
• Non-volatile.
• Used to store some firmware programs.
• PROM – Programmable Read Only Memory
• EPROM – Erasable and Programmable read Only
Memory.
• EEPROM – Electrically Erasable and
Programmable read Only Memory

23. Secondary Memory
• Permanent memory of the system.
• More storage capacity.
• It is the Backing Store.
Magnetic Disk & Optical Disk

24. Magnetic Disc
• Stored data in the form of Magnetic
directions.
Hard Disk & Floppy Disk

25. Hard Disk
• Access to data is far faster
than access to data in floppy
disks.
• Read/Write Head is
positioned close to the disk.
• Disk is attached to a spindle.
• Spindle is rotated by a
motor.
• Speed of disk depends on
the speed of motor.

26. Floppy Disk
• Consists of a plastic disk
coated with iron oxide.
• Disk access mechanism is
arranged as a hardware unit
called disk drive.
• Drive contains motor,
Read/Write Head etc.
• Head comes in contact with
the disk through the data
access area.
• Disk is rotated to pass the
sectors through the head

27. Optical disk
• It is an electronic storage medium.
• Read operation is done using low powered laser beam.
• A laser read the dots and then the data is converted to an
electrical signal .
• The output form of this devise is in audio and visual format
 CD-ROM – Compact Disk-Read Only Memory.
 CD – R – Compact Disk – Recordable.
 CD-RW – Compact Disk – Rewritable
 DVD – ROM – Digital Versatile Disk – Read Only Memory
 DVD – RAM - Digital Versatile Disk – Random Access
Memory