Computer Science & Engg.

2. Programming Language

3. Q. What do you understand by
programming language?
Ans. Programming Language:
To write a computer program, a standard
programming language is used:
programming language is composed of set
of instructions in a language understood by
the programmer. Programming languages
may be divided into three broad categories:
1.Machine Language
2.Assembly Language
3.High level Language

4. (1) Machine language: The language
understood by machine is known
as machine language.
Programming is done at machine
level. The vocabulary of computer
consists of only 2 words 0 and 1,
i.e. digits of binary number system
where 0 indicates low voltage level
and 1 indicates high voltage level.
It is considered as 1st generation
language.

5. • Advantages:
It can be directly typed and executed.
No translator program is required.
• Disadvantages:
Difficult to remember machine instructions.
Difficult to understand modify and debug error.
Difficult to remember addresses of data and
instrument.
Each and every information is numerical.
Lack of portability program that runs on one
machine doesn't run on the other.

6. (2) Assembly language: To overcome
the drawbacks of machine level
language. Scientists developed a new
programming language which uses
symbolic instructions. This symbolic
instructions oriented programming
language is known as assembly level
language. This is Called second
generation language.

7. • Advantages:
1. Easy to remember operator codes.
Easy to understand the program.
Easy to write, modify and debug the program as
compared to machine language.
Need not remember addresses of operant (+,-,*)
and instruction.
• Disadvantages:
Not standardized.
Less efficient than machine language.
Memories are machine dependent. They differ
from computer to another.

8. (3) High level language: It is totally
machine dependent language.
COBOL, BASIC PASCAL, ADA, C is
all high level languages. The
programs written in any of these
languages can be executed on any
machine.

9. • Advantages:
1. Programs are portable.
2. Debugging is easier.
3. Most suited for software
Development.
4. Programs are not machine
dependent.

10. Q. Which was the first Electronic
Computer?
Ans. The first electronic computer was
the ENIAC (Electronic Numerical
Integrator and Calculator).

11. Q. Write the name of few different kinds of chips as
used in computers?
Ans. The following types of chips are used in
computers.
MEMORY CHIP
C.P.U. CHIP
MIRCOPROCESSOR CHIP
• Each of the above mentioned chips has special
circuits designed to do the particular job. Memory
Chips store the information others may work in the
arithmetic unit. Some chips can do all the work
which a computer is supposed to do and these are
called as microprocessors. Such chips are known
as Computer on a CHIP

12. Q. What do you understand by
programming? How high level
programming language is used for
systematic development of programs?
Ans. We know that that computer is
only a machine which requires a
series of instructions telling it what to
do. The set of sequenced instructions
which tell the computer to perform
certain particular task is called a
program.
• There are two types of program:

13. 1. System Programs: Programs that
control and direct the operations of
computer hardware are system
programs
2. Application Programs: Programs
that help the user and the system
programs to work together are
called application programs.

14. • Definition of Programming:
• Programming is a technique of
developing programs in order to
achieve the desired goals using
computers.

15. Methodology for Systematic
Development of Programs for High level
Language: A high level programming
language must contain the following
qualities for Systematic development of
programs
1. A program should be correct and
designed in accordance with the
requirement laid out during the analysis
of the program.
2. Program should be easy to understand
.It should be designed in such a way that
anyone can understand its logic.

16. 3. A program should be easy to
maintain and update.
4. It should be efficient in terms of
the speed and use of computer
resources such as primary storage
memory etc.
5. It should be reliable.
6. It should be flexible.

17. Q. Write the steps for designing and
implementation of correct, efficient and
maintainable programs?
Ans. Designing and implementation of
correct, efficient and maintainable
programs is done by a systematic way of
doing things. This consists of a set of
guidelines, rules, concepts and practices
which taken together are given the name
structured programming.
A good program can be developed by
following recommended series of steps

18. 1. Defining the problem
2. Designing the algorithm
3. Coding the Program
4. Testing and debugging the
program.
5. Implementing the program
6. Maintainable and upgrading the
program.

19. • Defining the Problem:
It involves
(i) Recognizing the problem.
(ii) Identifying exactly what the problem is.
(iii) Determining the available inputs and
desired output.
(iv) Deciding which configuration of computer is
required to problem . computer.

20. Designing the Algorithm
An algorithm is the finite set of step-by-step instructions that solve a
program.
After defining the problem,, algorithm can be designed by using design
aids which
are:
• Structure charts
• HIPO charts
• Pseudo code
• Flow charts

21. • Structure Charts
It is design aid in which the purpose of a
module, the relationship to other modules
and the overall program logic flow are
shown. Each module (a small segment of
a program) is represented by a box;

22. • HIPO (Hierarchy plus Input
Process Output) Chart:
HIPO chart can enhance a
structure chart by outline the
input, processing and output
needed by each module. With
respect to above structure chart
, HIPO cart is drawn:

23. It is a tool used to formulate the processing
steps of a program. Pseudo code uses
English phrases to describe the processing
steps of a program or module.
The logical control instructions within a
structured design are emphasized in a
pseudo
code. Thus, the following logical control
instructions arc always capitalized.

24. (I) PERFORM UNTI.. … END
PERFORM or DO WHILE………ENDDO
These are used to indicate a sequence
that will be executed until a specific
condition is met.
PERFORM UNTIL END PERFORM
is a COBOL expression; DO
WHILE…ENDDO is a FoxPro
expression.

25. (ii) IF - - - THEN - - - ELSe…….ENDIF
This is used to test a specific
condition. IF a condition exists THEN
perform some operation;
ELSE perform some other operation.
Illustrations of the pseudo code has
been discussed in detail in previous
chapters.

26. • Flow Chart:
It is a design tool comprising of standardized
symbols to show the components of a system
or the steps in solving a problem. It is the most
popular and commonly used design aid
A detail of the flowchart has been taken in
previous chapter.

27. • 4. Testing and Debugging the
Program:
After coding, the program must be
tested to ensure that it is correct and
contains no errors. Three types of
errors or bugs can be found which
are;
• Syntax error
• Logic error
• Run-Time error

28. Syntax error: Syntax is a set of rules by which a
programming language is governed.
Syntax error occurs when these rules are violated
while coding of the program.
Logic error: This type of computer program error is
caused by improper coding of either
In-dividual statements or sequences of statements, It
docs not stop program execution but
gives wrong results,
Run-Time error: This error in a computer program
stops its execution. It may be caused by entry of
Invalid data.
The process of finding any type of errors mentioned above
and correcting them is known as debugging

29. • 5. Implementing the Program:
After a program has been listed and debugged,
it can be installed and implemented.
Maintaining and Upgrading the Program:
After installation of a program, it needs to be
maintained for future use. A program once
developed and implemented can be upgraded
as per the requirements of the user. Maintaining
and upgrading the program is an ongoing
process.

30. • Q. What do you mean by dumb terminal and smart
terminal?
Ans. A dumb terminal consists of VDU and a
keyboard. It has no CPU of its own, and the
processing is done only by the central unit.
A smart terminal has its own CPU and
peripherals also and therefore it is capable
of doing its own processing at their end
also. So smart terminal can also work
independent of the central CPU too.
The advantage of this feature is that some
other OS can be loaded to its own hard disk
and connection to UNIX can be established
when required.

31. 1. Weight of the brain is about 1.5 kg.
2.The various parts of the brain like
Cerebrum, Cerebellum, Medulla
Oblongata etc. must stay together for
its functioning.
3. Intelligence is rated as I.Q. — the
level of human intelligence various
from 0 to 100.
4. The energy source is blood
glucose.
5. It needs a steady temperature.

32. 6. It is assumed that computing
elements in the brain are about a
hundred thousand million.
7.The memory recall can be rapid or
slow.

33. COMPUTER
(1)Weight of the computer varies from a few grams to a
few tones.
(2)The various parts can be placed at different places.
They can be linked by wires, satellites and laser
beams etc.
(3) I.Q. (Intelligence Quotient) is zero. It cannot think and
whatever intelligence we feel it has it is actually on
account of the efforts of the scientists and technocrats.
(4) Electricity is the energy source.
(5) It is less sensitive to heat or cold.
(6) It has about thousand million basic computing
elements and they are increasing day by day.
(7) The access speed to memory is limited.

34. Q. What are the characteristics of high level
languages?
Ans. The following four characteristics are
associated with the high level languages.
(1)Machine independence. Machine
independence means that a high level language
could be used on any of the computer systems
without making changes or at the most by
making minor changes.
(2)Use of a compiler. A compiler is a
program, similar to an assembler, which
translates the high level languages programes to
machine language. Thus the translation work is
done by the computer itself and the
programmers are not taxed with this translation
work.

35. (3)Self documentation. On account of this feature
the syntax errors, the errors caused on account
of improper use of high level language, are
automatically pointed out to the programmers.
This is done via an operational software. Once
these errors are known then programs can be
debugged.
(4) Standard language format. The standardized
language format provides level of uniformity to
the language. Manufacturers do add special
touches to standard versions to make them look
attractive to the buyers.

36. Q. What is bugs and debugging?
Ans. Mistakes in a program is called
"bugs" and correcting those
mistakes is known as "debugging".

37. Q. WHAT IS MACHINE LANGUAGE?
Ans. The Machine Language is the language directly
understood by a computer. In other words the binary
language (the language of O's and l's) is the machine
language. Any information or instruction in this
language is to be represented in terms of O's and 1's.
The symbol 0 standing for the absence of an electric
pulse and I for the presence of an electric pulse. As a
computer is able to recognize the presence or absence
of an electric pulse, so it enable to understand the
machine language. For example a sequence of O's and
1's such as 01110001 has a specific meaning for a
computer, although it may appear as an ordinary
binary number to us. This sequence may be fed to the
computer by electric pulses in different time cycles

38. Q. What is word processor?
Ans. Word processor is a microcomputer
operating with special purpose software
(e.g. WORD) which processes character
strings. It is commonly used for office
automation purpose for production of
documents such as reports, letters,
tenders, etc. Word processor accepts
text as input which can be edited and laid
out as desired. Word processors are
usually equipped with a floppy disk drive
and good quality printer.

39. Q. What do you mean by computer simulation
and what is its purpose?
Ans. In computer simulation mathematical model
of the process/equipment under study is fed into
the computer and the computer output
represents behavior of the process under
various operating conditions.
Simulation is used to study the performance of
system using a model and also for training
purpose. Such models can be physical (as air
plane placed in a wind tunnel) or mathematical
(series of equations describing a system as a
model of thermal power plant).

40. Q. Why was machine language discarded ?
Ans. The writing of programs in machine language is very
cumbersome and complicated task and it can be
accomplished only by the experts. Machine language
programming requires that all the information to be fed
to a computer must be in numeric form and that too in
binary language. Moreover, addresses of all the
locations storing instructions and data must be known
to the programmer and he should be able to address
these locations correctly. Thus instructions stored in
the computer in this manner are interpreted and
obeyed by the computer. In other words, writing of a
program in a machine language was a specialist's job
and common man could not do it. This language was
discarded due to these difficulties.

41. Q. What do you understand by bit, byte and word?
Ans. A Binary Digit (BIT) (0 or 1) is called bit. One bit
occupies one store location. A group or
combination of 8 bits is called a byte. A computer
word is a combination of one or more bytes
handled together as one unit for processing and
may thus be of 8, 16, 32 or 64 bite. The length of
word varies from machine to machine but it
predetermined for each machine.
In some computers, the grouping of bite, bytes or
words is flexible in design to meet the differing
storage requirements of numbers, alphanumeric
characters and instructions.
A computer reads and processes all the bits of the
word at a time.

42. Q. What do you understand by
Programming Environment?
Ans. Every one, who is ready to make a
program, has to choose a programming
environment that make to possible to
create and run the program. Different
types of programming environment is as
follows:
1.Batch processing environment:
2.Time sharing Environment
3.Client Server Environment
4.Distributed Computing Environment

43. 1.Batch processing environment: In this
programming environment data is
collected over a period of time and then
processed periodically. It is used for
office work like accounts, salary etc.
This type of environment is normally
used with general purpose computers for
applications, like preparation of bills,
accounting jobs etc. However this
environment is not useful with process
control

44. 2. Time sharing Environment: This
Environment provides the concurrent
use of a single computer by many
users. Each having his own
input/output device and accessibility
to computer at the same time.). The
computer in such cases gives each
user a small, but frequently repeated,
slice of the time, so that each user
gets almost immediate response.

45. 3. Client Server Environment: A client/server
programming environment splits the computing
functions between a central computer and users’
computers. The users are given personnel computer
at their own sitting place or workstation so that some
of the computation responsibilities can be moved or
shared from the central computer and assigned to the
workstations. In client/server environment, the users’
micro computers are called the client. The central
computer, which may be a powerful micro computer
known as server.
• Since the work is now shared between the users’
computers and the central computer, response time
and monitor display are faster and the users are more
productive.

46. 4. Distributed Programming
Environment: In a distributed
programming environment different
departments in an organization acquires
a computer of their own for their
applications but all these computers are
connected through a central computer
which can control other computers.
• -With this regard data is physically
located at different sites but logically
interconnected.

47. • It offers many advantages –
1.Better user acceptability
2.Better information processing as data is
captured by the computers at the respective
work sites within the user departments.
3.Fixing up of the responsibility by the users
4.Better computer availability.
5.Minimum communication cost as the data is
proceed locally.
6.More applications are put on the computers
due to better user experience, knowledge.

48. Q. Who, when and where this first electronic
computer was produced?
Write its characteristics also?
Ans. First Electronic Computer was produced in 1946
in the Moore School of Electrical Engineering at the
University of Pennsylvania. . It was extremely fast by
the standards of the day. It could multiply two 10 digit
decimal numbers in 3 milliseconds. A large team was
responsible for the design and construction of ENIAC.
• This computer did not have memory unit and did
not use stored program concept. The programming
had to the done manually by plugging and unplugging
sets of connecting wires. Data could be entered using
a punched card reader, and results output on punched
cards or on an electric type writer.

49. Q. What are touch sensitive screens?
Ans. There are some VDUs equipped with
touch sensitive screens. They allow data
to be input by touching the screen by
means of a LIGHT PEN, a GRAPHIC
PLOTTER and a GRAPHIC TABLET.
The screen surface consists of a number
of 'touch points' as defined by the
program in use. When touched, the
terminal sends the co-ordinates of these
points to the 'memory of the computer.

50. Q Explain Visual display unit (VDU)
Keyboard
Ans.Fig-5 This is another popular
input/output device for low volume
input and output. It consists of a key
board identical to a type writer key
board with some special keys and a
CRT (Cathode Ray Tube) screen
which displays the input and the
output.

51. • This device is very popular as it is not very expensive
and quite simple to operate. Micro-computers use this
device for input and output operations. One
disadvantage is that this device provides no hard copy
(a printed copy) of the output but it is possible to add a
printer to this device which can be attached to it for
getting a hard copy. However it is usually suited more
to those applications where hard copy is not needed. It
is more suited for on line activities like airline seat
reservations where speed is needed to handle
passengers' enquires. It is for this reason that VDUs
are fast becoming a part of office equipment.

52. Q. Write first four generations of computers
and in what way each generation was better
than earlier.
Ans. First generation computers developed during
the year 1951 to 1959 were based on vacuum
tubes. These computers were very slow in
operation (approximately 1000
instructing/second), big in size and unreliable.
Size of the memory was limited. These
computers consumed huge electric
power, generated lot of heat and needed much
air conditioning. UNIVAC 1 and IBM are
examples of first generations computers.

53. • Second generation computers developed during the years
1960-1965 were based on transistors. Transistors perform
the same function as vacuum tubes but are smaller, more
reliable, faster, consume less power and generate less heat
than vacuum tubes. As a result second generation
computers based on transistors were faster in operation
(approximately 106 operations/second), smaller is size and
much more reliable than the first generation computers.
New techniques such as operating system, time sharing
etc. also came to be used in second generation computers.
Auxiliary memory in the form of magnetic tape was also
introduced. With the ability to store large volume of
data, the data processing fraternity bagan to look with
interest at the possibility of using computers for commercial
applications and this resulted in phenomenal growth of
computers. UNIVAC 1107, IBM 7090, CDC
1604, Honeywell 800 are few example of second
generation computers.

54. • Third generation computers employing integrated
circuits (ICs) were introduced between 1965 and 1970
and are also being used presently. Integrated circuits
based on silicon technology are much smaller in size,
more reliable, faster and less expensive. Third
generation computers built around integrated circuits
are therefore, faster in operations (approximately 109
operations/second), smaller in size and more reliable
than second generation computers. These computers
employed higher capacity internal storage, and wide
range of peripherals came to be used. New concepts
e.g. multi higher capacity multi-processing use of high
level languages were used in these computers. Some
of the third generation computers are IBM-360/370,
Honeywell 6000.

55. • Fourth generation computers based
or VLSI (very large scale integration)
chips and microprocessors chips
were introduced in 70s. this
generations also includes
microcomputers, office automation
systems, distributed processing
systems. Computers in these
generations have become less
expensive, faster in operation and
more reliable.

56. Q. What do you understand by knowledge
information processing systems (KIPS)
or fifth generation of computers?
Ans. Computers based on Artificial
intelligence are termed as fifth generation
computers. These computers mark major
shift from the previous four generations of
computers as these are equipped with
reasoning and decision making capability
close to that of human being. These
computers are also called knowledge
information processing systems (KIPS).

57. Q. What are super computers and for
what purpose these are used?
Ans. Super computers are large general
purpose computers capable of executing
more than 100 millions instruction per
second and have a storage capacity of
millions of bits. The high speed in these
computers is due to use of a number of
processors working in parallel and high
storage densities are obtained by using
magnetic bubble memories and charge
coupled divides, weather forecasting etc.

58. Q. What is a microprocessor?
Ans. A microprocessor is a L.S.I (large
scale integration) chip which can
perform the function of central
processing unit (CPU) of digital
computer. Apart from computer
microprocessor are also used in
electronic calculators and many
house hold appliances viz. TVs.
VCRs, washing machines etc.

59. Q. What is the difference between a
microprocessor and a
microcomputer?
Ans. Microprocessor is a L.S.I chip which
performs the functions of central
processing unit (CPU) of a digital
computer. In order that a microprocessor
become full fledge microcomputer , main
memory unit, input and output devices,
auxiliary storage devices and a set of
operating system programs have to be
added to it.

60. Q. What do you understand by single-
chip microcomputer? For what
applications it is used?
Ans. A single chip microcomputer consists
of a single chip on which the central
processing unit input/output and memory
units are integrated. This is used for
industrial applications and also in pocket
calculators.
Its advantage is the reduction in cost and
size, increase in performance and
reliability.

61. Q. What do you understand by
“Computer Graphics”?
Ans. The term Computer Graphics refers
to the concept of man communicating
with a computer by means of graphical
symbols such as dots, lines corves,
alphabetical or numerical symbols, etc.
This mode of man machine
communication provides for a high rate of
information transfer. Examples of
computer graphics are bar charts,
graphs, curves, engineering drawings,
fashion patterns, etc.

62. Q. What led to the development of high level
languages?
Ans -Practically speaking the drawbacks
associated with machine and assembly
languages led to the development of high level
languages. Both these languages consumed to
much of time in writing a program. Correcting
errors took even more time. The writing of
programs in low/machine level languages is a
highly specialized job beyond the
comprehension of a layman. So the move
towards development of an easier computer
language led to the development of High Level
Languages.

63. Q.What do you mean by micro
computer and micro processor?
Ans. A micro-processor is a C.P.U. on
a single chip, where as the machine
which uses this chip is a micro
computer.

64. Q. WHAT ARE OPTICAL CHARACTER READER
(O.C.R) ?
Ans. Optical Character Reader (O.C.R.) is an
input device. It is so designed as to read,
numeric and alphabetic characters from printed
documents. However the recent OCRs can read
hand written characters with a rare rejection
rate. This is a photo-electric device as the shape
of the characters is recognized with the help of
light source which converts characters into
electrical signals and then these are analyzed
and identified. The speed of these readers can
be up to 6000 documents (of an average size)
per minute.

65. • Optical readers read the source documents
directly so it saves the time and money in
transferring the data from the source document
to the other input media. If the system is
developed further so as to recognize the
imperfectly written characters then these OCRs
will supercede all the existing" input methods of
key punch and key board. The optical character
reader is used in turn-around
documentation, such as processing of gift
coupons and puzzle solutions. Its use has
reduced the manual key stroke operation
required for preparing the source documents.

66. Q. In what way computers helps in engineering field?
Ans. Computers help engineers to solve complex problems
that could not have been solved by other methods.
• These relieve engineers of many tiring and time consuming
chores, thereby enabling them to spend more time on other
important aspects.
• These enable them to achieve higher standards of product
design and better meet tight development schedules.
• These enable to perform more rigorous analysis of design
problems.
• The characteristic of computer to store vast quantities of
information and retrieve the desired information
instantaneously can be best exploited to improve designs
and save time in searching for old piece of useful
information.
• In brief, computers enable engineers to over me problems
like short time schedules, growing complexity of products
process and higher standards of product design.

67. Q. How optical mark readers (OMR) are used?
Ans. Optical Mark Reader (OMR) is an input device
which interprets pencil marks on paper media which
can be a 80 column card or a full page. -Its main
application is in judging the I.Q. through multiple
choice or objective type questions. Here the candidate
is advised to put a dot with soft pencil in front of the
correct answer at a specified spot. Then these papers
are processed by an optical mark reader one by one.
A thin beam of light is projected on the paper. The
amount of light transmitted through the dot is less as
compared to its surrounding area and this leads to the
right answer being evaluated. About 10,000
documents can be processed just in one hour and this
enables the preparation of examination results in a
very short time.

68. Q. What type of organizations use MICR? How data
is processed? Why MICR was developed?
Ans.Magnetic Ink Character Readers (MICR) devices
were developed in the late 1950 to assist the
banking industry in automation of the processing
of input cards and paper documents which are written
with a magnetic ink which contains iron oxide particles
in it. The characters have a standard configuration
which makes them recognizable to humans and at the
same time provide signals produced by the read head
to electronic circuitry. These signals are analyzed to
sense the characters used and then these are
transmitted to the memory unit. MICR is an example
of pattern recognition technique and has successfully
replaced the time consuming and the expensive
punched card processing.

69. • Advantages: MICR has the following
advantages.
1.Reading of characters is accurate by
means of this input device.
2.The characters can easily be recognized by
the human beings.
3.The device is quite reasonable in cost.
• Disadvantage The less number of the
characters recognized by it makes its use
limited to the cheques only and so it cannot
be used for general purpose data
processing.

70. Q. Distinguish between source program
and object program.
Ans. A program written in any language
except that of machine language is
called a SOURCE PROGRAM. The
program in machine language is
known as OBJECT PROGRAM. For
example' a program written in „C‟
language/editor is a source program
and the computer transforms it to the
object program.

71. Q. How you can classify the various types of
computers?
Ans. There are several ways of classifying
computers.
(1) Depending on Generation.
i) First generation, based on vacuum tubes.
ii) Second generation, based on transistors.
iii) Third generation, based on small scale
integrated circuits.
iv) Fourth generation, based on large and very
scale integrated circuits (microprocessor based)
v)Fifth generation, having artificial intelligence.

72. (2) Depending on the principle of
working, these are classed as:
i)Digital Computers – In which mathematical
expression are represented as binary digits and
all operations are done using these digits at very
rate. These produce very accurate and precise
results.
ii)Analog Computers – These obtain continuously
varying signals and thus depend to a great
extent on accuracy of measurement of signal.
These are fast and best suited for solving
differential equations.
iii)Hybrid Computers – These use best qualities
of both analog and digital computers.

73. (3)Depending on the size of the
computer. These could be classified as:
i).Large Scale Computer – It may have
one or more CPUs for computation. The
main storage capacity may be several
million characters and the secondary
storage capacity ranges in billions of
characters. The terminals are connected
at several places for interaction with
computer by several users. The system
can typically work on a number of
different programs.

74. ii)Medium scale and small scale
computers – These have same
feature as large scale but the storage
capacity reduces. All these are
basically main frame computers, i.e.
whole of the CPU is concentrated at
one central place. In contrast to this.
Distributed arrangement is also
possible in which case CPU is
distributed physically and
computations are thus carried out
locally at several places.

75. iii)Minicomputer system- It is small in
size that is can be mounted on a rack
or put on a table. It is fast in the basic
operations but has a limited set of
instructions. Main memory is of the
order of 8 K 32 bytes, and number of
input/out put devices is also limited. It
is frequently dedicated to a specific
function

76. iv)Microcomputer or desk top
computer – With further reduction of
main memory and word length
smaller and smaller computer
systems have been produced. These
cost less and less.
Microcomputers are much more cost
effective than minicomputers.
Microcomputer CPU on a chip is
being used in a variety of
applications.

77. (4)Depending on the purpose for which they may be
classified as
i)General purpose computers which perform almost
unlimited variety of functions with the help of proper
programming. General purpose computer us used
mainly for processing complex numerical calculations
and accounting work.
ii)Special purpose computers which are designed for
some particular purpose. For instance, process control
computer is employed for controlling and monitoring
thermal power plants, steel plants, chemical plants,
etc.

78. iii)High intelligence machine com
machine computers (which are used
for remote and servo-controlled
applications, like robots, rocket
launching pads etc. )
iv)Knowledge information Processing
System (these have been developed
recently and these possess the ability
of reasoning, thinking and decision

79. (5)Depending on the processing
modes, these can be categorized as :
i)Batch processing mode: (First data is
collected over a period of time and then
processed periodically). It is used for
office work like accounts, salary etc.
ii)Real-time computers (each transaction
is processed as soon as it is
received, there being no waiting time for
accumulation of a batch of transactions).
It is used for on-line processes and
where immediate response is required.

80. iii)Dedicated to regularly scheduled jobs. (in
This mode only one request is considered
at a time)
iv)Time sharing mode (concurrent use of a
single computer by many users. Each
having his own input/output device and
accessibility to computer at the same time.).
The computer in such cases gives each
user a small, but frequently repeated, slice
of the time, so that each user gets almost
immediate response

81. Q. What does it mean that Computer
is automatic machine?
Ans. Computer is automatic means
that once the instructions are fed and
the process is begun, it would
continue without the need for human
intervention until completion.

82. Q. What is the advantage of using high level
language?
The high level language possesses many advantages
over low level language. A few of these advantages
are listed below:
1. The high level languages being similar to commonly
used languages in our day to day work are quite easy
to learn and use.
2. Since the syntax of these languages is similar to the
commonly used languages due to which the writing of
source programs becomes very easy.
3. The writing of source programs in these languages
does not require the knowledge of the internal
structure of the computer.
4. Allocation of memory locations for instructions and
data is done by the machine itself and the user is not
to bother about it.

83. 5. The number of instructions given to the machine are
greatly reduced as compared to number of instructions
required for an equivalent machine language or
assembly language program. Actually an instruction in
high level language may be broken down to a large
number of machine language instructions and
fortunately this job is performed by the computer and
not by the programmer. For example a single
instruction in a high level language may be split into 10
or more instructions in machine language.
6. These high level languages, unlike low level
languages which are machine oriented languages, are
problem oriental languages or procedure oriented
languages.
7. Modifications, if required, in programs written in these
languages are quite easy and straight forward.