1.5 INTEGRATED CIRCUITS
Our world is full of integrated circuits (semiconductor devices with several transistors
built into one physical component). It is an electronic circuit which involves thousands or
millions of interconnected components like transistors, diodes and resistors. They are
usually called ICs. We can find several of them in computers. For example, most people
have probably heard about the microprocessor. The microprocessor is an integrated
circuit that processes all information in the computer.
It keeps track of what keys are pressed and if the mouse has been moved. It counts
numbers and runs programs, games and the operating system. The first integrated circuits
(ICs) were based on small scale integration (SSI) circuits, which had around 10 devices
per circuit (or „chip‟), and evolved to the use of medium-scale integrated (MSI) circuits,
which had up to 100 devices per chip. Integrated circuits are also found in almost every
modern electrical device such as cars, television sets, CD players, cellular phones, etc.
The main benefits of ICs are lower costs, high reliability and smaller space requirements.
But what is an integrated circuit and what is the history behind it?
1.5.1 Electronic Circuits
The integrated circuit is nothing more than a very advanced electric circuit. An electric
circuit is made from different electrical components such as transistors, resistors,
capacitors and diodes, which are connected to each other in different ways. It is an
unbroken loop of conductive material that allows electrons to flow continuously. If a
circuit is “broken”, its conductive elements will no longer form a complete path and
continuous electron flow cannot occur. The transistor acts like a switch. It can turn
electricity on or off, or it can amplify current. It is used for example in computers to store
information.
The resistor limits the flow of electricity and gives us the possibility to control the
amount of current that is allowed to pass. For example resistors are used, among other
things, to control the volume in television sets or radios.
The capacitor collects electricity and releases it all in one quick burst. The diode stops
electricity under some conditions and allows it to pass only when these conditions
change. This is used in, for example, photocells where a light beam that is broken triggers
the diode to stop electricity from flowing through it.
The flashlight is an example of electric circuits. It contains electrical energy (dry cells) as
a source, a load (the bulb) which changes the electrical energy into light and a switch to
control the energy delivered to the load.
1.5.2 The Transistor vs. the Vacuum Tube
The transistor is the most important one for the development of modern computers.
Before the transistor, engineers had to use vacuum tubes. Just as the transistor, the
vacuum tube can switch electricity on or off, or amplify a current. So why was the
vacuum tube replaced by the transistor? There are several reasons. The vacuum tube looks
and behaves very much like a light bulb; it generates a lot of heat and has a tendency to
burn out. Also, compared to the transistor it is slow, big and bulky. When engineers tried
to build complex circuits using the vacuum tube, they quickly became aware of its
limitations. The first digital computer ENIAC, for example, was a huge monster that
weighed over thirty tons, and consumed 200 kilowatts of electrical power. It had around
18,000 vacuum tubes that constantly burned out, making it very unreliable. When the
transistor was invented in 1947 it was considered a revolution. Small, fast, reliable and
effective, it quickly replaced the vacuum tube.
1.6 OPERATING SYSTEM
All computers need some sort of hardware platform to run the software; these platforms
are called Operating System (OS). Operating system is a program that acts as an interface
between user of computer and the computer hardware. The purpose of an operating
system is to provide an environment in which user can execute program in a convenient
and efficient manner. Operating system is an important part of almost every computer
system. It manages all resources of computer system. Operating system is installed in
secondary memory, while it‟s some part are stored permanently in read only memory.
Some part of the operating system resides in random access memory and the computer
begins to execute this part of the system.
The majority of modern home computers use some form of Microsoft's operating
systems. The original Microsoft operating system was called DOS (Disk Operating
System) though most computers use Windows. Windows comes in various versions
beginning with version 3.x then 95, 98, XP and currently Windows 7. A few computers
use IBM's O/S2. Apple's Mac use their own operating system beginning with OS 1
though most modern Macs use version 8.x or 9.x. Apple's latest version is OS 10.1.x.
Some computer professionals, Internet Service Providers (ISP) and mainframe computer
users use an operating system such as UNIX, Windows NT or 2000 or server based
operating systems. The operating system controls the input and output or directs the flow
of information to and from the CPU. Much of this is done automatically by the system. In
short, we can say that an Operating System is one of the most important components of
the computer software which is essential to operate a computer. When computer is
turned on, it first needs to load the operating system sometimes referred to a booting up.
It checks all its components and will usually display a message if there is a problem. It is
also known as Power on Self Test (POST). Loading the system is usually automatic.
Once the system is loaded, the user can start the application or program that he/she going
to us,
1.7 CURRENT APPLICATIONS OF COMPUTER
Some major applications of Computers are given below :
Banking : When there was no computer, every where manual system was followed
which was a very complicated and hard work but now with the arrival of computer, every
thing has become much more systematic and easy to use. Every bank is now using a
computerized system because it is very fast and user friendly. Personal Computer
banking lets us view our bank balance, request transfers between accounts and pay bills
electronically. Now-a-days, online banking is getting very popular which offers more
convenience and ease to the customers.
Traffic Light Control : In traffic light control, the computer is being employed to
orchestrate the traffic light. There are some programmed codes like turn off/on the red
light which control the traffic light and also to carry out other instructions.
Sports : Computers have revolutionized the sports industry. Computer is used to
maintain player records, track scores, create virtual playing field etc. The sports
equipment industry also relies heavily on computer-aided design (CAD).In sports,
computers are used in conjunction with video cameras. These are used to record the
motion of all the sports men. 3D programs are used to help the trainers see their
movements and could improve their styles of playing. Online games allow us to play with
other people regardless of their physical locations.
Schools and Colleges : There are many uses of computer in schools and colleges e.g.
every students details need to be stored so a computer program comes to help in.
Multimedia, animations, graphics and charts could be used to teach the students and
many boring topics can be made interesting using multimedia. Students could access
internet for online help and courses for more information. Computers are used in a
variety of ways in the educational field. Computers can be used in school management
such as budget, inventory, student records, communications, library circulation, and
library public access catalog.
Learning and Instruction : Computer applications can be used in education for learning
and for instruction. Instruction and learning can be divided into two major areas, teachercentered instruction and student-centered learning. Teacher-centered instruction
examined the computer as the object of instruction as well as a tool of instruction and the
management of instruction. With the advancement in the Technology and Internet,
Online Education, e-learning, m-learning are getting very popular which offers more
flexibility and convenience to the learners.
Student-centered learning views the computer as a tool for the student to use and create
access, retrieve, manipulate, and transmit information in order to solve a problem.
Understanding the concept of the computer as an information tool relies on accepting the
fact that the computer is a productivity tool for the student and the teacher alike.
Educational Research : Computers are used widely in all educational research.
Educational research includes functions relating to information gathering and processing.
The teacher/researcher may examine student performance data in new and revealing
ways. Bibliographic citations of studies performed by educators around the world can be
acquired and perused by the desktop computer.
Entertainment : Computers and Internet are a major source of entertainment. It is one of
the latest forms of entertainment for the modern society. It allows us to play computer
games, listen to music, watch videos and movies etc.
Agriculture : Computer usage among agronomists and farmers has risen rapidly in the
recent times. With the flow of information becoming faster and easier, the agricultural
sector is also getting benefited from computer. Computer allows the farmer to collect
adequate information related to prices, latest farming techniques, weather conditions,
cultivation of crops, farm machineries etc. which enhances the decision making
capability of the farmers.
Some of the other applications include Transport Management, Weather forecasting,
Industries etc.
1.8 LIMITATIONS OF A COMPUTER
The computer can outperform human beings in speed, memory and accuracy but still the
computer has limitations. Following are the limitations of computer.
Programmed and Supervised by Human : Though computer is programmed to
work efficiently, fast and accurately but it is programmed by human beings to do so.
Without a program, computer is nothing. Computer only follows these instructions. If the
instructions are not accurate the working of computer will not accurate. Without
supervision, computers will operate poorly when dealing with unexpected circumstances,
such as information or instructions that are incorrect or incomplete
No Intelligence : Although computers are faster, more diligent, accurate and versatile
than human beings, it cannot replace them. Unlike human beings, computers do not have
any intelligence. Its performance is depends on instructions given to it. It cannot carry
any task at its own and can‟t take any decision on its own.
Self Care : Computer can not care for itself like a human. A computer is dependent still
to human beings for this purpose.
Emotionless : Computers are emotionless. They do not have emotion and feelings. A
computer can not feel about something like a human. A computer can not compete
human in respect of relations. Computers are simply machines which work as per the
instruction given to them.
Thinking : Computer can not think itself. The concept of artificial intelligence shows
that the computer can think. But still this concept is dependent on set of instructions
provided by the human beings.
Retrieval of Memory : Computer can retrieve data very fast but this technique is linear.
A human being's mind does not follow this rule. A human mind can think randomly
which a computer machine can not.
1.9 SUMMARY
Computer is an electronic device that performs mathematical and non-mathematical
operations in order to achieve the results. Its‟ first generation used the vacuum tube. The
second generation used the transistors which were much smaller than vacuum tube.
Integrated circuits were used in third generations. VLSI comes in fourth generation
computer and now fifth generation growing towards parallel computing. The operating
system is an important component of modern computer. The two main objectives of
operating system are controlling the computer‟s hardware and providing an interactive
interface between the user and machine. Computer have enters almost in every field of
human life and found applications in various fields like medicine and health care,
business, science, technology, engineering, entertainment etc.
1.10 ANSWERS TO CHECK YOUR PROGRESS
Check Your Progress 1
1) A computer is an electronic device, which is used to accept, store, retrieve and
process the data at faster speed and with greater accuracy. It is also called as data
processor because it is mainly used for processing the input data given to it and
producing the desired result.
2) Evolution of computer can be divided into five generations: First Generation
(Vacuum tubes), Second Generation (Transistors), Third Generation (ICs), Fourth
Generation (Microprocessor), Fifth Generation (Artificial intelligence).
Check Your Progress 2
1) Microcomputer is at the lowest end of the computer range in terms of speed and
storage capacity. Its CPU is a microprocessor. The first microcomputers were built
of 8-bit microprocessor chips. The most common application of personal
computers (PC) is in this category. The PC supports a number of input and output
devices. An improvement of 8-bit chip is 16-bit and 32-bit chips. Examples of
microcomputer are IBM PC, PC-AT.
Mainframes computers are generally 32-bit microprocessors. They operate at very
high speed, have very large storage capacity and can handle the work load of many
users. They are generally used in centralized databases. They are also used as
controlling nodes in Wide Area Networks (WAN). Example of mainframes are
DEC, ICL and IBM 3000 series.
2) The five basic operations that a computer performs are accepting data as input,
storage of these data, processing of data, outputting the information and process
control.
3) As per technology variations computers can be classified into analog, digital and
hybrid computers.
