basic concepts of computers p repared b y : b ajaj c oaching c enter r ohtak bcc 2000. com
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BASIC CONCEPTS OF
COMPUTERS PREPARED BY:
BAJAJ COACHING CENTER ROHTAKBCC2000.COM
COMPUTER
The word computer comes from the word “compute”, which means, “to calculate”
Thereby, a computer is an electronic device that can perform arithmetic operations at high speed
A computer is also called a data processor because it can store, process, and retrieve data whenever desired
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DATA PROCESSING
The activity of processing data using a computer is called data processing
Data
Capture Data
Manipulate Data
Output Results
Information Data is raw material used as input and information is
processed data obtained as output of data processing
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EVOLUTION OF COMPUTERS Blaise Pascal invented the first mechanical
adding machine in 1642 Charles Babbage is considered to be the
father of modern digital computersHe designed “Difference Engine” in 1822He designed a fully automatic analytical
engine in 1842 for performing basic arithmetic functions
His efforts established a number of principles that are fundamental to the design of any digital computer
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SOME WELL KNOWN EARLY COMPUTERS The Mark I Computer (1937-44) The Atanasoff-Berry Computer (1939-42) The ENIAC (1943-46) The EDVAC (1946-52) The EDSAC (1947-49) Manchester Mark I (1948) The UNIVAC I (1951)
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COMPUTER GENERATIONS “Generation” in computer talk is a step in
technology. It provides a framework for the growth of computer industry.
Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software
Till today, there are five computer generations
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First generation computer
Period : 1945 – 1956
Inviter : Lee de Forest
Main processing device : Vacuum tubes
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Vacuum tubesB
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Punched curdsB
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Large punched cards
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. First generation computerAdvantages :
. It was only electronic device
. First device to hold memory
Disadvantages :
. Too bulky i.e. large in size
. Vacuum tubes burn frequently
. They were producing heat
. Maintenance problems
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Too bulky i.e. large in sizeB
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Vacuum tubes burn frequentlyB
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Maintenance problemsB
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. Second generation computer
Period : 1956 – 1963
Inviter : William Shockley
Main processing device : Transistor
Storage media : Magnetic disc
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Transistor
1 2
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Second generation computer
Advantages :
. Size reduced considerably
. The very fast
. Very much reliable
Disadvantages :
. They over heated quickly
. Maintenance problems
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Third generation computer
Period : 1964 – 1971
Inviter : Jack Kilby
Robert Noyce
Main processing device : IC (integrated circuit)
Storage media : Floppies
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IC (integrated circuit)B
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Third generation computer
Advantages :
. ICs are very small in size
. Improved performance
. Production cost cheap
Disadvantages :
. ICs are sophisticated
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. Fourth generation computer
Period : 1971– present
Inviter : Ted Hoff
Main processing device : ICs with VLSI
(Very Large Scale Integration)
Storage media : Floppies, CDs.
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ICs with VLSI(Very Large Scale Integration)
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. Fifth generation computer
Period : present and beyond
Main processing device : ICs with parallel processing
Storage media : Video disksAdvantages : . Artificial intelligence . Expert system
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. First generation computer. Second generation computer
. Third generation computer. Fourth generation computer
. Fifth generation computer
Vacuum tubes
Transistors
ICs ICs with VLSI
ICs with parallel processing
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Computer is a group of electronic devices used to process the data.
The characteristics of a computer are:
4. Accuracy5. Automation 6. Functionality 7. Tirelessness
1. Speed 2. Reliability 3. Memory capacity
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Characteristics Of A Computer
1.Speed: computer process the data at an unimaginable speed. The speed of the computer ranges up to Nano seconds.
2. Reliability: The next important characteristic of a computer is its reliability. we can always rely on the information given by a computer.
3. Memory capacity: The memory capacity of a computer is measured in in bits and bytes. Large amount of the data can be stored in computer and retrieved. Memory capacity of the computer ranges in Giga bytes.
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4. Accuracy: Accuracy of the computer is very high it performs calculation with greater accuracy
in less time.
5. Automation: a computer allows automation for any process designed in the from of a program. A program can be executed any number of times to repeat the process.
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6. functionality: computer can performs many kinds
of jobs. They not process the data but also can be
Used for plying music, movies, and printing jobs.
It finds its applications in all most all the fields.
7. Tirelessness: A computer never gate tired.
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