Computer history and General awareness of Computer system
1. INTRODUCTION
Computers
have made great inroads in our every day life and thinking. They are put to use for all sorts of application ranging
from complex calculations in the field or front-line research, engineering simulations
down to teaching, printing books and recreational games. The ease with
which computers can process data, store and retrieve it painlessly have
made them inevitable in office and business environments. The areas of applications of computers are
confined only by atically, can be performed
by a computer. Therefore, it is essential for every educated person
today to know about a computer, its strengths, its weaknesses and its internal
structure and that is what we are going
to explain in this chapter.
WHAT IS COMPUTER ?
It is
an electronic device or a flexible machine, which can manipulate data. These
manipulations may or may not be mathematical or more accurately a computer may
be defined as a device that operates upon data. Data can be anything like
bio-data of various applicants when the computer is used for recruiting
personnel, or the marks obtained by candidates in a competitive exams such as
medical entrance, engineering entrance, civil service examination etc. Data
comes in various shapes depending upon the type of computer application.
A
computer can store, process and retrieve data as and when required. Due to the
fact that computers process data is so fundamental that many people have
started calling it a data processor. Computers are so flexible that people feel
comfortable and equally at home while using them. A computer is programmable.
It means computer depends upon the program which is in use by it. No matter
which program a computer is using, the machine itself performs only four basic
operations.
3. The first Computer on Earth
The
first computer on Earth called ABACUS
is a tablet placed horizontally
on top of the capital of a column as an aid in supporting the architrave. We
are knowing ABACUS as name of
Slate (Thin layers of rock used for roofing) figures as given below :
Characteristics of computer
The
important factors that lead a person to use a computer are:
Speed
Accuracy
Storage
Versatility
Diligence
Reliability
Memory capability.
Speed
Computers
are very fast. They can process millions of instructions per second. Computers
can perform in minutes, tasks that would take a person year to complete. Today,
computers can perform 1000 million computations in 1 second. The speed of
computer is closely related to the amount of data it processes. Railway or
Airline reservation system illustrates frequency. Accuracy Computers are
accurate. They do not make mistakes in
calculations. The probability of computer
error is quite small and often traceable to faulty data. Computer can perform
all kinds of complex calculations accurately. The degree of accuracy of
computers depends upon their design. But, for a particular computer, each and
every calculation is performed with the same accuracy. Errors in computers are
not of technological nature but are mostly due imprecise thinking of the
programmer. The main examples in front of us are:
-
Space shuttles
-
Nuclear simulation reactions.
Storage
Computers
are having enormous storage capacity. Computers can store a vast amount of
information, which can be recalled at any time in fraction of seconds. The
information is stored in the form of files, but on disks and tapes. This helps
in easy and speedy retrieval of information. This storage is known as
electronic storage system. Now a days standard storage capacity of a computer
is in the range of 40 GB-512 GB.
Versatility
This
is one of the most wonderful things about the computer. Computers can do a
variety of jobs depending upon the instructions fed to them and their hardware
characteristics. Modern computers can be used in railways, air reservations
systems, process controls, nuclear reactors, manufacturing plants, scientific
laboratories, hospitals and hotels etc. They can also act as controlling
devices in children toys. Briefly, a computer is capable of performing any task
provided that the task can be reduced to a series of logical steps.
Diligence
Computers
are diligent in nature as they can perform complicated and respective tasks
very well with full concentration, without committing any error, for long
periods of time. Computers do not suffer from carelessness, boredom or
tiredness. Moreover, their efficiency does not decrease with age. If millions
of calculations are to be made with exactly the same accuracy even then
computer will not show any tiredness and commit any error.
Reliability
Computer
systems are widely accepted due to their exceptional reliability. Unlike human
beings they are capable of operating under the most adverse conditions for
extended periods of time without showing any sign of fatigue. They do not take
sick days and coffee breaks.
Computers
are very reliable. We can consider them as very faithful super servants of
humanity.
Memory Capability
Computer
systems have the capability to recall the total data instantly and an almost
unlimited capacity to store this data. A typical mainframe computer can have
billions of characters and thousands of graphic images stored and available for
instant recall.
The
above characteristics of computers enhance human capabilities of doing
analytical work at high speed. It is important to mention that inspite of all
wonderful characteristic of computers they had certain drawbacks. They have no
I.Q. They have no feelings and cannot work like human beings.
Advantages of Computer
Computers
are having advantages over other computing devices as they are fast, reliable,
accurate, can store massive amounts of information, can move information quickly
from one place to another and are versatile in nature.
The advantages of computers can be listed
out as below:
Perform
repetitive tasks. Are more accurate while dealing with large numbers. Work at
constant efficiency. Are used in almost
every field. Process millions of instructions in a fraction of a second. Are effective and efficient data storage and
retrieval. After having looked at the
characteristics of a computer, the advantages of using it become very obvious.
These are: The speed at which the computer carries out its operations. It’s
versatility, i.e. can be used in different fields. Enable
an individual or an organization to store and retrieve information as and when
required. Feeding of information is
required only once in one organisation or company and the same can be used by
different departments of the organisation of company. Instant recall of information is possible. Any
format of reports can be taken about individuals, group of individuals etc.
Limitations of computers
A)
Non-affordability
The
high cost of installation of computers puts a limit over its use. However, due
to the advent of PCs and super mini-computers and mini super computers, a
common man can also afford to buy a computer.
B)
Compatibility
Programs
and software written for one type of computer or microprocessor cannot be used
for other type of microprocessors.
C) Dependent upon human beings.
D) Have no imagination and intuition of their
own.
E) Tasks have to be described in detail.
F) Cannot detect flaw or error in logic.
G) Need of an expert programmer:
Today
a large number of computer languages are in use and also there are lots of
operating systems. Complete knowledge of system software (operating system)
along with application software is a must. Computers process data in a
step-by-step fashion according to the programs written for it. If any mistake
occurs in programming, then an error is bound to occur in processing the data,
which leads to wrong calculations in the output.
Applications of
Computers
Today,
computers have their utility in almost every sphere of life - particularly in
the areas where calculations are done at very fast speed. Computers now a day
are being used in almost every department to do the work at a greater speed and
accuracy. They can keep the record of all the employees and prepare their
salary bill in a matter of minutes. They can also keep checks on the stock of a
particular item. Big commercial houses and companies use software packages to
control and monitor their production system, dispatch system, account system
and many more. These packages need high
level of expertise to develop, use and maintain. These packages cost huge
amount of money.
These days computers can be used for
followings:
1.
Materials Management
2.
Production planning and control
3.
Purchase
4.
Credit and collection
5.
Warehousing
6.
Marketing information systems
7.
Manufacturing information systems
8.
Multimedia
9.
Science and technology
10.
Banks are using special software packages for monitoring their working. At any
point of time the concerned authority can have details of cash deposits, cheque
deposits, overdrafts, interest charges on the loan amount etc., in a matter of
minutes.
11.
Schools are using special software packages for fee administration, finance,
transport, time scheduling, payroll, record of students, performance of
teachers.
