b asic c oncepts o f c omputers bajaj coaching center, rohtak for more such slides visit bcc2000.com
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BASIC CONCEPTS OF COMPUTERS
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For more such slides visit bcc2000.com
COMPUTERThe 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.
Data is a raw material used as input to data processing and information is processed data obtained as output of data processing.
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 computers.He designed “Difference Engine” in 1822He designed a fully automatic analytical engine in
1842 for performing basic arithmetic functionsHis efforts established a number of principles that are
fundamental to the design of any digital computer.
SOME WELL KNOWN EARLY COMPUTERS
The Mark I Computer (1937-44) – also known as Automatic Sequence
Controlled Calculator.
The Atanasoff-Berry Computer (1939-42)
The ENIAC (1943-46)- The Electronic Numerical Integrator and
Calculator was the first all electronic computer.
The EDVAC (1946-52)- Electronic Discrete Variable Automatic
Computer.
The EDSAC (1947-49)- The Electronic Delay Storage Automatic
Calculator.
The UNIVAC I (1951)- Universal Automatic Computer.
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 : 1942 – 1955
Main processing device : Vacuum tubes
All data and instructions were fed into the system from punched cards.
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Vacuum tubes
Punched cards
Large punched cards
First generation computer
Advantages :
. 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 Bajaj Coaching Center, Rohtak
Too bulky i.e. large in size
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Vacuum tubes burn frequently
Maintenance problems
Second generation computer
Period : 1955 – 1964
Inviter : William Shockley
Main processing device : Transistor
Storage media : Magnetic disc
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Transistor
1 2
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Second generation computerAdvantages : • Size reduced considerably
• Faster than first generation computers
• Very much reliable.
• Consumed less power and dissipated less heat.
• Easier to program and use than the first generation computers.
Third generation computer
Period : 1964 – 1975
Inviter : Jack Kilby
Robert Noyce
Main processing device : IC (integrated circuit)
Storage media : Floppies
IC (integrated circuit)
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 : 1975– present
Inviter : Ted Hoff
Main processing device : ICs with VLSI
(Very Large Scale Integration)
Storage media : Floppies, CDs.
ICs with VLSI(Very Large Scale Integration)
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 Microprocessors
ICs with parallel processing
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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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.
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.
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. Bajaj Coaching Center, Rohtak