Basics of computer

1. Basics Of Computers
-By Atharva Suresh Patil

2. INDEX
1. Introduction
2. What is a Computer ?
3. Characteristics of Computer
4. Classification of Computer
5. Classification of Computer based on size
6. Classification of Computer based on
purpose
7. Functions of Computer
8. Generations of Computer (1)
9. Generations of Computer (2)

3. Introduction
A computer consists of four major parts: the input, output, CPU (central processing
unit), and memory. Input consists of anything you will add into the computer
(microphone, keyboard, mouse, scanner), and output is how the computer gives back
to you (think screen, speakers, etc.). The CPU or central processing unit is located on
the motherboard and is the part of the computer where all that input/output
information gets sent to the proper place. Memory, commonly referred to as RAM
(random access memory), as you may already know, is where the information is
stored.
There are three major pieces of hardware in a computer. The motherboard is the most
important part of a computer and contains many subsystems such as the central
processor (CPU), input/output chips as well as memory and application controllers. An
Expansion Card fits into the expansion slot in a computer and is where you can add
additional capabilities such as for video or graphic performance. Finally, and very
importantly, is the power supply which supplies electric power to the electrical load of
a computer.

4. What is a Computer ?
A computer is a programmable electronic device that accepts raw data as input and processes it with
a set of instructions (a program) to produce the result as output. It renders output just afar
performing mathematical and logical operations and can save the output for future use. It can
process numerical as well as non numerical calculations The term "computer" is derived from the
Latin word "computars" which means to calculate A computer is designed to execute applications
and provides a variety of solutions through integrated hardware and software components. It works
with the help of programs and represents the decimal numbers through a string of binary digits. It
also has a memory that stores the data programs, and result of processing. The components of a
computer such as machinery that includes wires bantistors, crcuts, hard disk are called hardware
Whereas the program and data are called software It is believed that the Analytical Engine was the
first computer which was invented by Charles Babbage in 1837 it used punch cards as read-only
memory.The first computers were used primarily for numerical calculations. However, as any
information can be numerically encoded, people soon realized that computers are capable of
general-purpose information processing. Their capacity to handle large amounts of data has
extended the range and accuracy of weather forecasting. Their speed has allowed them to make
decisions about routing telephone connections through a network and to control mechanical
systems such as automobiles, nuclear reactors, and robotic surgical tools.

5. Characteristics of Computer
The characteristics of the computer system are as follows −
Speed: A computer works with much higher speed and accuracy
compared to humans while performing mathematical calculations.
Computers can process millions (1,000,000) of instructions per second.
The time taken by computers for their operations is microseconds and
nanoseconds.
Accuracy: Computers perform calculations with 100% accuracy. Errors
may occur due to data inconsistency or inaccuracy.
Diligence:A computer can perform millions of tasks or calculations with
the same consistency and accuracy. It doesn’t feel any fatigue or lack of
concentration. Its memory also makes it superior to that of human
beings.
Versatility:Versatility refers to the capability of a computer to perform
different kinds of works with same accuracy and efficiency.
Reliability: A computer is reliable as it gives consistent result for similar
set of data i.e., if we give same set of input any number of times, we will
get the same result.

6. Classifications of Computer
Classifications of Computer Based
On
Historical
Development Purpose
Size and
Capacity
Technology
Digital
Computers
Hybrid
Computers
Analog
Computers
Special
Purpose
General
Purpose
1st Generation
2nd Generation
5th Generation
4th Generation
3rd Generation
Mini
Computers
Mainframe
Computers
Super
Computers
Micro
Comput
ers

7. Classification based on size
Super Computers : They are biggest in price and most
expensive in price. They can process trillions of instructions
in a second and are especially used by Governments
Mainframe Computers: They are another giant computers
which can process millions of instructions per second . This is
used in big hospitals, airline reservation company, etc
Minicomputers: These computers offers less work and
performance. They are mostly preferred by small business
individuals, colleges, etc.
Personal Computers: These computers are computers of daily
usage which mostly everyone have. Example: Desktop
Notebook Computers: These can be carried anywhere
because of its small size . This computer has the same
memory as that of personal computer.
Classification based on size
Super
Computers
Mainframe
Computers
Mini
Computers
Personal
Computers
Personal
Computers

8. Classification based on purpose
General Purpose Computers: General purpose computers are
the computers that can be used for all general needs of all
environments and users. These are the versatile computers
that can perform a variety of jobs for a variety of
environments The programs or instructions are fed to them.
At the time of execution, these computers process these
instructions and produce meaningful results.
Special Purpose Computers: Special purpose computers are
the computers that are specially designed to perform a
specific task of a specific environment. These are designed for
performing a particular task and cannot perform other tasks.
In this way, these computers are not versatile. The
instructions used by these computers are permanently stored
in the system or machine. These computers are generally
embedded in various automatic devices.
Classification based on
purpose
General
Purpose
Computers
Special Purpose
Computers

9. Function of Computer
The functions of computers are numerous as modern
computers are capable of completing simple to complex
tasks with ease. Computer technology and related
devices or components are becoming more advanced
over time. In this way, it is very difficult to classify the
functions of a computer. However, some basic functions
are performed by every computer system irrespective of
its size, power, capability, or modernity.Taking data and
instructions from a user, processing the data as per
instructions, and displaying or storing the processed
data, are the four major functions of a computer. These
functions are also known as the input function, process
function, output function, and storage function,
respectively.

10. Generations of Computer
1st Generation: The first generation of computers (1942-1955)
had computers which were very bulky in size, had limited
commercial use, was highly unreliable , had a very costly
commercial production and was extremely difficult to use. It
was made using basic machine and assembly languages. It
had components such as vacuum tubes, electromagnetic relay
memory, punched cards, etc.
2nd Generation: the second generation (1955-1964) had
computers which were more faster, smaller, more reliable
and easy to program, however, commercial production was
still costly. High level programming, batch operating system
were used for programing. Components such as transistors,
magnetic core memory, magnetic tapes, and disks secondary
storage were used in manufacturing .
Generations Of Computer
1st Generation 2nd Generation
3rd Generation 4th Generation
5th Generation

11. Generations of Computer
3rd Generation: The third generation (1964-1975) had
computers which were faster, smaller, more reliable, easier
and cheaper to use commercially, and easier to upgrade than
previous generations. Time sharing operating system, high
level programming languages were used. It had components
such as ICs with SSI and MSI technologies, larger magnetic
core memory, etc
4th Generation: The fourth generation (1975-1989) had
computers wich were small, affordable, reliable and easy to
use. It had components with Ics and VLSI technology,
microprocessor, semiconductor memory, etc.
5th Generation: The fifth generation(1989-Present) had
portable and more powerful computers. It had larger
memory, optical disks, powerful mainframe, Internet
support, World wide web, powerful desktop PCs and Laptops,
etc.
Generations Of Computer
1st Generation 2nd Generation
3rd Generation 4th Generation
5th Generation
5th Generation