INTRODUCTION TO COMPUTERS
A computer is an electronic device
capable of manipulating numbers and symbols under the control of a set of
instructions known as computer program. They are different stages of computers
(generation)
1. First Generation Computers
a.
Vacuum
tubes were used which produce more heat
b.
Speed
of computing was measured in milliseconds
c.
Limited
storage capacity
d.
punched
cards were used for I/O operation
2. Second – Generation
Computers
a.
Transistors
and diodes were used.
b.
Speed
of computing was measured in microseconds
c.
Consider
about reduction of heat
d.
Remarkable
improvement in reliability
e.
Storage
capacity was increased
f.
Magnetic
tapes were used instead of punching cards.
3. Third Generation Computers
a.
Integrated
Circuits were used.
b.
Speed
is measured in nanoseconds
c.
Occupied
less space.
d.
devices
like visual display unit for I/O devices
4.
Fourth
– Generation Computers
a.
Use
of micro processor chip
b.
Speed
was measured in nano and picoseconds
c.
Occupied
less space
d.
Commonly
available as personal computers
e.
Mini
& micro Computers are developed from micro-processor
5. Fifth – Generation
Computers:
a.
Use
of super large-scale integration (SLSI) chip in computer (super computers)
b.
Capable
of performing millions of instructions per seconds (MIPS)
c.
Processing
speed is high.
d.
Use
of RICS (reduced instructions set computing) for processing
e.
Super
computers are expensive.
Types of Computers
1.
Mainframe
Computers
2.
Mini
Computers
3.
Micro
Computers
4.
Super
Computers
Mainframe Computers work at a high
speed, and have a high storage capacity Mini Computers are medium and powerful
Computers. Micro Computer are the commonly used as general purpose Computer.
Data Storage in a Computer
1.
4bits
= 1 Nibble
2.
8bits
= 1 byte
3.
1024
bytes = 1k or 1kb (kilobyte)
4.
1024KB
= 1MB (mega byte)
5.
1024MB
= 1GB (Gega byte)
6.
1024GB
= 1TBC Terabytes
Organization of Computer:
1.
Arithmetic
and Logical unit
2.
Memory
unit
3.
Control
unit
4.
Input
unit
5.
Output
unit
The Input and Output units are used to
receive and display Inputs & Solutions Common i/p & o/p devices :
Keyboard, mouse, monitor, printer .
The CPU (Central Processing Unit) Consists
of.
1.
ALU
(Arithmetic Logic Unit)
2.
CU
(Control Unit)
3.
MU
(Memory Unit)
1. The
Control Unit Controls all the activities of the Computer. It sends commands and control signals and finds the sequence of instruction to be executed.
2. Memory Unit is the place where all
input data and results are stored. Computer memory is also available in the
form of Random Access Memory (RAM)
3. ALU Consists of CKTs for arithmetic
operations(+,-,*,/) and logical operations (<,>,>=,<=,==,!=)
Connected components of CPU are called peripherals
Input devices Output devices
1. Keyboard 1. Printer
2. Mouse 2. Monitor
3. Joystic 3. Dot Matrix
Printer
4. Laser printer
5.LCD
4. Laser printer
5.LCD
Storage Devices :
1.
Floppy
disk
2.
Hard
disk
3.
Compact
disk
Computer Main Memory : Primary memory RAM (Random
Access memory) Secondary memory ROM (Read only memory) Hard disk RAM : It is a
temporary storage medium in a computer. The data to be processed by the
computer are transferred from a storage devices or a keyboard to RAM results
from a executed program are also stored in RAM. The data stored will be erased
when the computer is off. ROM (Read only Memory) : This is a non-volatile or
data storage medium which stores start up programs (operating systems). This essentially
stores the BIOS (Basic Input Operating System) Note : Basically Computer System
components communicate it binaries as (0‟s & 1‟s, 0 refers OFF state,1
refer ON state)
Languages of different Generation Computer.
1. First – Generation Language :
All the instructions are in the binary form and are referred to as machine
level or low level language (LLL). It is very difficult to read the
instructions written in binary
Eg : 00110101011101110001,
101100001010101
2. Second – Generation Language:
all the instruction are in the forms of mnemonics. The symbolic instruction
language called as Assembly Language. All the symbolic instructions are
converted into binaries with the help of translator called Assembles.
ASCII (American Standard Code For Information
Interchange) is commonly used for translation of source Program into object
program
Source Program Eg : ADD A, B, R,
More
R,S
Assembler Translated by Assemble
Object Program 0101 101010100100
00001101
3. Third – Generation Language:
These are written in English with symbols and digits. Then are known as High
level language (HLL). common high level languages are c,c++, COBOL, BASIC,
FORTRAN, PASCAL, etc.
For execution the program is
translation into binary form by compiler or interpreter.
4. Fourth
– Generation Language (4GL‟s): is a programming language or programming environment
designed with a specific purpose in mind, such as the development of commercial
business software. In the history of computer science, the 4GL followed the 3GL
in an upward trend toward higher abstraction and statement power. The 4GL was
followed by efforts to define and use a 5GL.
Seven Wonder's in Modern Era
Great Wall of China
This newly elected
world wonder was built along China's northern border over many centuries to
keep out invading Mongol tribes. Constructed between the fifth century B.C. and
the 16th century, the Great Wall is the world's longest human-made structure, stretching some 4,000 miles (6,400 kilometers). The best
known section was built around 200 B.C. by the first emperor of China, Qin Shi
Huang Di.
Petra, Jordan
Perched on the edge of the Arabian
Desert, Petra was the capital of the Nabataean kingdom
of King Aretas IV (9 B.C. to A.D. 40). Petra is famous for its many stone
structures such as a 138-foot-tall (42-meter-tall) temple carved with classical
facades into rose-colored rock. The ancient city also included tunnels, water
chambers, and an amphitheater, which held 4,000 people. The desert site wasn't
known to the West until Swiss explorer Johann Ludwig Burckhardt came across it
in 1812.
Christ the Redeemer
The 105-foot-tall
(38-meter-tall) 'Christ the
Redeemer' statue in Rio de Janeiro, Brazil, was among the "new
seven wonders of the world" announced July 7, 2007 following a
global poll to decide a new list of human-made marvels. The
winners were voted for by Internet and phone, American
Idol style. The other six new wonders are the
Colosseum in Rome, India's Taj Mahal, the Great Wall of China, Jordan's
ancient city of Petra, the Inca ruins of Machu Picchu in Peru, and the ancient
Maya city of Chichen Itza in Mexico.
Machu Picchu, Peru
One of
three successful candidates from Latin America,
Machu Picchu is a 15th century mountain settlement in the Amazon region of Peru. The
ruined city is among the best known remnants of the Inca civilization, which flourished
in the Andes region of western South America. The city is thought to have been
abandoned following an outbreak of deadly smallpox, a disease introduced in the
1500s by invading Spanish forces.
Chichen Itza, Mexico
Chichen Itza is
possibly the most famous temple city of the Mayas, a pre-Columbian civilization
that lived in present day Central America. It was the political and religious
center of Maya civilization during the period from A.D. 750 to 1200. At the
city's heart lies the Temple of Kukulkan (pictured)-which rises to a height of
79 feet (24 meters). Each of its four sides has 91 steps-one step for each day
of the year, with the 365th day represented by the platform on the top.
The Colosseum, Rome, Italy
The only finalist from Europe to make it into the top
seven—the Colosseum in Rome, Italy-once held up
to 50,000 spectators who came to watch gory games involving gladiators, wild
animals, and prisoners. Construction began around A.D. 70 under Emperor
Vespasian. Modern sports stadiums still resemble the Colosseum's famous design
Taj Mahal, India
The Taj Mahal, in
Agra, India, is the spectacular mausoleum built by Muslim Mughal Emperor Shah
Jahan to honor the memory of his beloved late wife, Mumtaz Mahal. Construction
began in 1632 and took about 15 years to complete. The opulent, domed mausoleum,
which stands in formal walled gardens, is generally regarded as finest example
of Mughal art and architecture. It includes four minarets, each more than 13
stories tall. Shah Jahan was deposed and put under house arrest by one of his
sons soon after the Taj Mahal's completion. It's said that he spent the rest of
his days gazing at the Taj Mahal from a window.
Important Days - National and International
Important Days in January
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Jan 1
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Army Medical Corps Establishment Day
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Jan 8
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African National Congress Foundation Day
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Jan 10
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World Laughter Day
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Jan 9
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Pravasi Bharatiya Divas
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Jan 11
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Death anniversary of Lal Bahadur Shastri
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Jan 12
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National youth Day (Birth Day of Swami
Vivekanand)
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Jan 15
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Army Day
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Jan 23
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Netaji Subhash Chandra Bose's birth
anniversary
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Jan 25
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International Customs Duty Day, India Tourism
Day, Indian Voter Day
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Jan 26
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Republic Day
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Jan 28
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Birth anniversary of Lala Lajpat Rai
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Jan 30
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(Martyr's day) Mahatma Gandhi's Martyrdom Day;
World Leprosy Eradication Day
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Jan 31
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World Leprosy Eradication Day
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Inportant Days in February
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Feb 2
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World Wetlands Day
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Feb 4
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National Day of Srilanka
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Feb 5
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Kashmir Day (Organised by Pakistan)
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Feb 13
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Sarojini Naidu's Birth Anniversary
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Feb 14
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St. Valentine's Day
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Feb 24
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Central Exise Day
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Feb 28
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National Science Day
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Important Days in March
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Mar 3
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National Defence Day
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Mar 4
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National Security Day
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Mar 8
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International Women's Day
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Mar 9
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CISF Raising Day
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Mar 12
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Mauritius Day; Central Industrial
Security Force Day
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Mar 15
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World Consumer Day
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Mar 16
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National Vaccination Day
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Mar 21
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World Forestry Day
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Mar 22
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World Day of Water
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Mar 23
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World Meterological Day
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Mar 24
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World TB Day
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Mar 26
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Bangaladesh Liberation Day
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Important Days in April
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April 1
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Orissa Day
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April 5
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Natinal Meritime Day
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April 7
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World Health Day
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April 13
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Jallianwallah Bagh
Massacre Day (1919)
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April 14
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B.R. Ambedkar
Remembrance Day
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April 18
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World Heritage Day
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April 22
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World Earth Day
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April 23
|
World Books Day
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Important Days in May
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May 1
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International Labour
Day, Maharashtra Day
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May 3
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International Energy
Day
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May 8
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International Red
Cross Day (It is celebraed to commemorate the birth anniversary of the
founder of the Red Cross Organization Jean Henry Dunant)
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May 11
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National Technology
Day
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May 15
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International Family
Day
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May 17
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World Telecom Day
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May 24
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Commonwealth Day
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May 31
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World No Tobacco Day
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Important Days in June
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June 5
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World Environment Day
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Important Days in July
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July 1
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Doctor's Day
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July 4
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American Independence Day
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July 11
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World Population Day
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July 26
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Kargil Victory Day
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Important Days in August
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Aug 6
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Hiroshima Day
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Aug 9
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Quit India Movement
Day
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Aug 12
|
International youth
Day
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Aug 14
|
Pakistan's
Independence Day
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Aug 15
|
India's Independence
Day
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Aug 19
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World Photography Day
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Aug 20
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Sadbhavana Diwas
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Aug 29
|
National Sports Day
of India (Dhyanchand's Birth Day)
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Aug 30
|
Small Industry Day
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Important Days in September
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Sept 5
|
Teacher's Day (Dr.
Radhakrishnan's Birth Day)
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Sept 7
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Forgiveness Day
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Sept 8
|
International Literacy
Day
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Sept 14
|
Hindi day,World First
Aid Day
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Sept 15
|
International Day of
Democracy
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Sept 16
|
World Ozone Day
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Sept 21
|
International Day of
Peace, World Alzheimer's day
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Sept 25
|
Social Justice Day
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Sept 27
|
World Tourism Day
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Important Days in October
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Oct 1
|
International Day for
the Elderly(UN)
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Oct 2
|
Gandhi Jayanti, International
Day of Non-Violence
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Oct 3
|
World Nature Day,
World Habitat Day
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Oct 4
|
World Animal Day
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Oct 5
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World Teacher's Day
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Oct 6
|
World Wildlife Day,
World Food Security Day
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Oct 8
|
Indian Airforce day
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Oct 9
|
World Postal Day
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Oct10
|
World Mental Health
day; National Post Day
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Oct 12
|
World Sight day
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Oct 13
|
World Calamty Control
Day(UN)
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Oct 14
|
World Standard Day
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Oct 15
|
World White cane
day(guiding the blind)
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Oct 17
|
International poverty
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Oct 20
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National Solidarity
Day (China attacked India on that day)
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Oct 24
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United Nations Day
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Oct 30
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World Thrift Day
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Oct 31
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National Integration
Day (In memory of Idira Gandhi)
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Important Days in November
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Nov 7
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Infant Protection day;
World Cancer Awareness Day
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Nov 9
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Legal Service Day
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Nov10
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Transport Day
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Nov 14
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Children's day/ World
Diabetics day
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Nov 17
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Guru Nanak Dev's Birth
Anniverrsary
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Nov 26
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Law Day
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Nov 30
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Flag Day
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Important Days in December
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Dec1
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World AIDS Day
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Dec 3
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World Disability Day
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Dec 4
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Navy Day
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Dec 7
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Armed Force Flag Day
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Dec 10
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Human Rights day
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Dec 11
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UNICEF Day
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Dec 14
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National Energy
Conservation Day
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Dec 19
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Goa's Liberation day
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Dec 23
|
Kisan Divas (Farmer's
Day)
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