Information technology

1. Designed By : Arunava Bera
Guided By : Mrs. Chetna
Class : IX ‘B’
Roll No. : 14

2. Introduction
What Is A Computer?
 An electronic device that receives data,
processes data, stores data, and
produces a result (output).
 Classified by size, speed and
application
 Uses hardware and software
 Comes in different types

3. Typical Personal Computer
System
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4. Computer Systems
 All computer systems, no matter how
complex, consists of the following:
 At least one CPU
 Memory to hold programs and data
 I/O devices
 Long-term storage
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5. CPU: Central Processing Unit
 ALU: arithmetic/logic unit
◦ Performs arithmetic and Boolean logical
calculations
 CU: control unit
◦ Controls processing of instructions
◦ Controls movement of data within the CPU
 Interface unit
◦ Moves instructions and data between the CPU
and other hardware components
◦ Bus: bundle of wires that carry signals and
power between different components
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6. Memory
 Also known as primary storage, working
storage, and RAM (random access
memory)
 Consists of bits, each of which hold a
value of either 0 or 1 (8 bits = 1 byte)
 Holds both instructions and data of a
computer program (stored program
concept)
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7. Software Component
 Applications
 Operating System
◦ API: application
program interface
◦ File management
◦ I/O
◦ Kernel
 Memory management
 Resource scheduling
 Program
communication
 Security
◦ Network Module
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8. Modern Computer Development
 1937: Mark I is built (Aiken, Harvard University, IBM).
◦ First electronic computer using relays.
 1939: ABC is built
◦ First fully electronic digital computer. Used vacuum tubes.
 1943-46: ENIAC (Mauchly, Eckert, University of Pennsylvania).
◦ First general purpose digital computer.
 1945: Von Neumann architecture proposed.
◦ Still the standard for present day computers.
 1947: Creation of transistor
◦ (Bardeen, Shockley, Brattain, Bell Labs).
 1951: UNIVAC.
◦ First commercially available computer.
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Early Computers
Babbage’s Analytical Engine ENIAC

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Latest Computers

11. Computer performs all the functions according to input output
processing cycle (IPO Cycle)
Input Process Output
Computer is an electronic device which take some input after
processing provide output.
Input
unit
Central processing
unit (CPU)
Output
unit
Main memory Secondary memory (Hard Disk)

12. Input unit take the input and converts it into binary form so that
it can be understood by the computer. For example:- Key board,
mouse, magnetic ink character reader (MICR), optical mark
reader (OMR), optical character reader (OCR), Joystick etc.
Output unit take the programs in the form of electronic binary
signals coming from the CPU and convert into human
understandable language. So it can be easily understood by the
human beings. For example :- Visual Display Unit (VDU),
Printer, Plotter, Speech Synthesizer and Coder etc.
It is a control center for a computer. It guides , directs and governs
its performance. It is the brain of the computer.

13. Output Devices
 Monitor: screen that displays information
such as text, numbers, and
 Printer: gives you information pictures.
◦ Softcopy
◦ from the computer in printed form.
◦ Hardcopy
 Speakers: allow you to hear voice, music,
and other sounds from your computer.

14. Processing Device
 Central Processing Unit (CPU)
– known as the heart or
“brain” of the computer and is
responsible for processing the
information that has been
entered into the computer

15. Storage Devices
 Hard Disk Drive: used
to store data inside of
the computer.
◦ Magnetic platter that
holds a large amount
of information in a
form the computer
can understand.
◦ Floppy Disk: flat circles
of iron oxide-coated
plastic enclosed in a
hard plastic case.
◦ Most are 3 ½ inches
and have a capacity to
hold 1.44 MB or more
of data.
 CD ROM Drive: a
compact disk that reads
only memory.
 CD-RW: a device that
allows you to read and
write to a compact disk

16.  Input
Enters data into the
computer
 Processing
Changes data into
usable form
 Output
Sends data out of
the
computer
 Storage
Saves for use later
CONCLUSION

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Bibliography
 Encyclopedia
 www.wikepedia.com
 NCERT Computer Book
 www.google.com

18. Thank You
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