Computer

• It is an electronic device that accepts the data as input, processes

the data in a pre-determined way and then communicates the
result as output on the screen.
• Components of Computer:
– CPU
– I/O Devices
– Memory
 Characteristics of Computer
• Speed:
– works faster and more accurately than human.
– Ability to process so many millions of instructions per second.
• Reliability
– output results never differ unless the input varies
• Automation
– Executing jobs automatically, this computer feature replaces thousands
of workers.
• Accuracy
– When a computer performs a computation or operation, the chances of
errors occurring are low.
• Versatility
– capacity of computer.
– Computer perform different types of tasks with the same accuracy and
efficiency.
• Diligence
– A human cannot work for several hours without resting, yet a computer
never tires.
• Uses of Computer:
– Accounts
– Games
– Educational
– On-line banking
– Smart ID cards
– Supermarkets
– Working from home (Tele-working)
– Internet
 Generations of computers
Computer generations are based on when major
technological changes in computers occurred, like
the use of vacuum tubes, transistors, and the
microprocessor.
As of 2020, there are five generations of the
computer.
Review each of the generations below for more
information and examples of computers and
technology that fall into each generation.
 First generation (1940 - 1956)

Second generation (1956 - 1963)

Third generation (1964 - 1971)

Fourth generation (1971 - 2010)

Fifth generation (2010 to present)

Sixth generation (future generations)

 First generation (1940 - 1956)
The first generation of computers used vacuum tubes as a
major piece of technology. Vacuum tubes were widely
used in computers from 1940 through 1956. Vacuum tubes
were larger components and resulted in first-generation
computers being quite large in size, taking up a lot of
space in a room. Some of the first-generation computers
took up an entire room.
The ENIAC is a great example of a first-generation
computer. It consisted of nearly 20,000 vacuum tubes,
10,000 capacitors, and 70,000 resistors. It weighed over
30 tons and took up a lot of space, requiring a large room
to house it. Other examples of first-generation computers
include the EDSAC, IBM 701, and Manchester Mark 1.
 Second generation (1956 - 1963)
The second generation of computers saw the use
of transistors instead of vacuum tubes. Transistors
were widely used in computers from 1956 to 1963.
Transistors were smaller than vacuum tubes and
allowed computers to be smaller in size, faster in
speed, and cheaper to build.
The first computer to use transistors was the TX-0
and was introduced in 1956. Other computers that
used transistors include the IBM 7070, Philco
Transac S-1000, and RCA 501.
 Third generation (1964 - 1971)
The third generation of computers introduced the
use of IC (integrated circuits) in computers. Using
IC's in computers helped reduce the size of
computers even more than second-generation
computers, and also made them faster.
Nearly all computers since the mid to late 1960s
have utilized IC's. While the third generation is
considered by many people to have spanned
from 1964 to 1971, IC's are still used in computers
today. Over 45 years later, today's computers have
deep roots going back to the third generation.
Fourth generation (1971 - 2010)
The fourth generation of computers took
advantage of the invention of the microprocessor,
more commonly known as a CPU.
Microprocessors, with integrated circuits, helped
make it possible for computers to fit easily on a
desk and for the introduction of the laptop.
Some of the earliest computers to use a
microprocessor include the Altair 8800, IBM 5100,
and Micral. Today's computers still use a
microprocessor, despite the fourth generation
being considered to have ended in 2010.
 Fifth generation (2010 to present)
The fifth generation of computers is beginning to
use AI (artificial intelligence), an exciting technology
with many potential applications around the world.
Leaps have been made in AI technology and
computers, but there is still room for much
improvement.
One of the more well-known examples of AI in
computers is IBM's Watson, which was featured on
the TV show Jeopardy as a contestant. Other better-
known examples include Apple's Siri on the iPhone
and Microsoft's Cortana on Windows 8 and Windows
10 computers. The Google search engine also utilizes
AI to process user searches.
 Sixth generation (future generations)
As of 2022, most still consider us to be in the fifth
generation as AI continues to develop. One possible
contender for a future sixth generation is the quantum
computer. However, until quantum computing
becomes more developed and widely used, it is still
only a promising idea.
Some people also consider nanotechnology to be part
of the sixth generation. Like quantum
computing, nanotechnology is largely still in its
infancy and requires more development before
becoming widely used.
With a new generation of computers it's also
possible how we interact with a computer may
also change. New ways of how we may interact
with the next generation of computers include only
using our voice, AR (augmented reality), VR
(virutal reality), or MR (mixed reality).
 Types of Computers
A computer is a device that transforms data
into meaningful information. It processes the
input according to the set of instructions
provided to it by the user and gives the
desired output. Computers are of various
types and they can be categorized in two ways
on the basis of size and on the basis of data
handling capabilities.
So, on the basis of size, there are five types of
Computers:
Supercomputer
Mainframe computer
Minicomputer
Workstation
PC (Personal Computer)
And on the basis of data handling capabilities,
there are three types of computer:
Analogue Computer
Digital Computer
Hybrid Computer
Now let us discuss each type of computer in detail:
1. Supercomputer:
When we talk about speed, then the first name that comes
to mind when thinking of computers is supercomputers.
They are the biggest and fastest computers(in terms of
speed of processing data). Supercomputers are designed
such that they can process a huge amount of data, like
processing trillions of instructions or data just in a second.
This is because of the thousands of interconnected
processors in supercomputers. It is basically used in
scientific and engineering applications such as weather
forecasting, scientific simulations, and nuclear energy
research. It was first developed by Roger Cray in 1976.
Characteristics of supercomputers:
Supercomputers are the computers which are the
fastest and they are also very expensive.
It can calculate up to ten trillion individual
calculations per second, this is also the reason
which makes it even more faster.
It is used in the stock market or big organizations
for managing the online currency world such as
bitcoin etc.
It is used in scientific research areas for
analyzing data obtained from exploring the solar
system, satellites, etc.
2. Mainframe computer:
Mainframe computers are designed in such a way that it
can support hundreds or thousands of users at the same
time. It also supports multiple programs simultaneously.
So, they can execute different processes simultaneously.
All these features make the mainframe computer ideal for
big organizations like banking, telecom sectors, etc.,
which process a high volume of data in general.
Characteristics of mainframe computers:
It is also an expensive or costly computer.
It has high storage capacity and great performance.
It can process a huge amount of data (like data involved in
the banking sector) very quickly.
It runs smoothly for a long time and has a long life.
3. Minicomputer:
Minicomputer is a medium size multiprocessing
computer. In this type of computer, there are two or
more processors, and it supports 4 to 200 users at one
time. Minicomputers are used in places like institutes
or departments for different work like billing,
accounting, inventory management etc. It is smaller
than a mainframe computer but larger in comparison
to the microcomputer.
Characteristics of minicomputer:
Its weight is low.
Because of its low weight, it is easy to carry
anywhere.
less expensive than a mainframe computer.
It is fast.
4. Workstation:
Workstation is designed for technical or scientific
applications. It consists of a fast microprocessor,
with a large amount of RAM and high speed
graphic adapter. It is a single-user computer. It
generally used to perform a specific task with
great accuracy.
Characteristics of Workstation:
It is expensive or high in cost.
They are exclusively made for complex work
purposes.
It provides large storage capacity, with better
graphics, and a more powerful CPU when
compared to a PC.
It is also used to handle animation, data
analysis, CAD, audio and video creation, and
editing.
5. PC (Personal Computer):
It is also known as a microcomputer. It is
basically a general-purpose computer and
designed for individual use. It consists of a
microprocessor as a central processing
unit(CPU), memory, input unit, and output
unit. This kind of computer is suitable for
personal work such as making an assignment,
watching a movie, or at office for office work,
etc. For example, Laptops and desktop
computers.
Characteristics of PC (Personal
Computer):
In this limited number of software can be
used.
It is smallest in size.
It is designed for personal use.
It is easy to use.
6. Analogue Computer:
It is particularly designed to process analogue data.
Continuous data that changes continuously and
cannot have discrete values is called analogue
data. So, an analogue computer is used where we
don’t need exact values or need approximate
values such as speed, temperature, pressure etc. It
can directly accept the data from the measuring
device without first converting it into numbers and
codes. It measures the continuous changes in
physical quantity. It gives output as a reading on a
dial or scale. For example speedometer, mercury
thermometer, etc.
7. Digital Computer:
Digital computers are designed in such a way that
it can easily perform calculations and logical
operations at high speed. It takes raw data as an
input and processes it with programs stored in its
memory to produce the final output. It only
understands the binary input 0 and 1, so the raw
input data is converted to 0 and 1 by the computer
and then it is processed by the computer to
produce the result or final output. All modern
computers, like laptops, desktops including
smartphones are digital computers.
8. Hybrid Computer:
As the name suggests hybrid, which means made
by combining two different things. Similarly, the
hybrid computer is a combination of both analog
and digital computers. Hybrid computers are fast
like an analog computer and have memory, and
accuracy like a digital computer. So, it has the
ability to process both continuous and discrete
data.
For working when it accepts analog signals as
input then it converts them into digital form
before processing the input data. So, it is
widely used in specialized applications where
both analog and digital data is required to be
processed. A processor which is used in petrol
pumps that converts the measurements of fuel
flow into quantity and price is an example of a
hybrid computer.
 Computer - Memory Units
Memory unit is the amount of data that can be stored in
the storage unit. This storage capacity is expressed in
terms of Bytes.
The following table explains the main memory storage
units
Unit & Description
Bit (Binary Digit): A binary digit is logical 0 and 1
representing a passive or an active state of a
component in an electric circuit.
Nibble: A group of 4 bits is called nibble.
Byte: A group of 8 bits is called Byte. A byte is the
smallest unit, which can represent a data item or a
character.
Word: A computer word, like a byte, is a group
of fixed number of bits processed as a unit,
which varies from computer to computer but is
fixed for each computer.
The length of a computer word is called word-
size or word length. It may be as small as 8 bits
or may be as long as 96 bits. A computer stores
the information in the form of computer words.
The following table lists some higher storage units −

Unit & Description

Kilobyte (KB)
1 KB = 1024 Bytes
Megabyte (MB)
1 MB = 1024 KB
GigaByte (GB)
1 GB = 1024 MB
TeraByte (TB)
1 TB = 1024 GB
PetaByte (PB)
1 PB = 1024 TB