COMPUTER AWARENESS
CHAPTER - 1
COMPUTER AWARENESS
1.1 Data, Information, Processing
1.2 Applications of Computers
1.3 Characteristics of Computers
1.4 Types of Computers
1.1 DATA, INFORMATION, PROCESSING
The electronic computer allows man to increase his productivity and permits him to do
tasks he would be unable to complete without the computer. A computer is a machine
capable of (1) accepting data; (2) performing described operations on the data, and (3)
providing the results of these operations. Thus the computer also permits man to improve
his output per unit of time, or productivity. We can say that the computer’s two most
important contributions as a productive tool are to increase (1) the speed of operation,
and (2) accuracy and quality of operation in terms of productivity.
Of course, when we consider these two factors, we realize that the computer enables us
to do tasks that we would probably never even attempt to do manually. For example, if
the number of input data is greater than million and the time necessary to accomplish a
task is more than fifty years, we would probably never attempt it. Yet it is such task that
we can ask the computer to accomplish.
Symbols are the basis of any language. The computer accepts and processes symbols in
an order to provide information. The symbols that today’s computers process are the
letters of the alphabet and numbers, as well as several useful algebraic and business
symbols.
The term electronic implies that the computer is powered by electrical and electronic
devices rather than by mechanical ones or those affected by heat or air pressure. Here
digital refers to discrete, noncontinuous quantities, as contrasted with continuous quantities.
For example, the computer accepts individual numbers, or signs, or other symbols. This
set of statements leads to the definition:( 2 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
Electronic Digital Computer is an information-processing device that accepts and processes
data represented by discrete symbols. It is constructed primarily of electric or electronic
devices.
Information processing is a series of planned actions and operations upon input data,
taken to obtain a desired result. The actions taken may be illustrated by a common data
processing operation which a person usually accomplishes manually, but which is
increasingly accomplished automatically by data processing service companies. This
processing work required:
(1) Data input
(2) Storage and retrieval of data, and instructions for data-processing actions
(3) Arithmetic steps
(4) Output of result
(5) Control of all above steps
Now, if we want to construct an automatic information-processor, we shall find it necessary
to carry out the same steps to complete the processing. A computer follows a similar
process. It is composed of five basic units, as shown in Figure The five basic units or
functions are:
1. An input unit which accepts the necessary input data and instructions.
2. A storage or memory unit in which computer instructions and the data as
well as intermediate results are stored.
3. An arithmetic unit in which numbers can be added, subtracted, compared in
size to other numbers, etc.( 3 )
COMPUTER AWARENESS
4. An output unit which provides the desired result in a suitable form, such as a
printed report or letter.
5. A control unit which controls the other four units, directs their order of operation
and supervises the overall excution of the computer
There are several devices which accomplish the function of input, output, and storage.
The arithmetic and control functions are accomplished by the central processing unit
located with storage in the system.
The basic unit of the computer is the arithmetic unit. It performs the arithmetic operations
accurately, reliably, and at high speed. However, the high-speed ability of the arithmetic
unit would be wasted if for each operation it had to go back to the input unit for the same
information at every step. The storage unit holds the data, the instructions and the
intermediate results of the calculations. (The incorporation of instructions in the storage
unit for ready and high-speed accessibility is the stored-program concept introduced by
John Von Neumann.) Since the instructions are in the memory, just as the intermediate
calculation results are, it is possible for the computer to modify the instructions themselves
as the calculation progresses.
The control unit supervises the flow of information and calculations and requests from
memory the instructions and data necessary at each stage in the calculation sequence.
The control functions are shown as dotted lines in Figure.
The input and output units serve as connections between the user and the machine.
1.2 APPLICATION OF COMPUTERS
Major technical innovations have always had a severe impact on the lives of individuals.
Same is true for computers also. Computers have entered every area of the society.
Society includes the organisations, where individuals work. The organisations are
educational, commercial, industrial, administrative, transport, medical, social, legal and
financial. Computers are being used in almost every sphere of activity ranging from home
to defence and entertainment to business and commerce. Let us see how computers are
used in various spheres of our life today.
Defence : Today, without computers, our defence is worthless. We may recall the recent
American-Iraq war in which the American Army used computers extensively to launch
missiles, track enemy air craft using radars, plan attacks and strategies etc. The entire
operation was conducted by commanders sitting in distant places.
Homes : Computers are increasingly becoming smaller in size, affordable and easy to
operate and use. These are finding their way into homes where they are used for keeping
accounts, study, sending mail playing games etc.
Science and Engineering : Here computers are used to solve complex mathematical( 4 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
and scientific calculations which would otherwise require years of effort. Before computers,
the launching of spacecraft and landing on the moon would have been distant dreams. In
addition to assisting in technical matters, computers aid the administrators to keep records,
accounts, maintain libraries of periodicals, journals, published papers etc.
Entertainment : Increasing use of computers is made in this field. The movies such as
“Jurassic Park” , “Independence Day”, “Terminator”, “Titanic” and “Jaws” have used
computers extensively to give special effects to the images. Today compact- disk (CDs)
used in record players are examples of computer technology having invaded this area.
Computers enable sound, audio and images to be combined to help film makers,
advertisement agencies to quickly produce films or advertisement clips. Animation films,
till recently were difficult to make, are now easily produced with the help of graphics or
computers.
Transportation : Transportation companies and agencies rely on computers. Railway
reservations are now done on computers. Apart from enabling quicker reservations, it
has enabled persons to plan journeys from any place to any other place with greater ease
and less worry. The cargo movement is also being computerised which will not only
impart efficiency to the handling but will also enable a consignor to know the exact status
of his consignment in a few moments. Air-lines & Railways had computerised their activities
much earlier, particularly reservations & now many state roadways have computerised
their reservations enabling passengers to book their journeys quickly and conveniently.
Business and Finance : No other sphere of activity has been as profoundly affected by
computers as banking and finance. The volume of business of banking after introduction
of computers has grown more than thousand fold. Right from automatic maintenance of
customer ledgers, identification of customers to payment of cash up to back office functions
such as balancing of books, MIS, funds transfer and reconciliation are all computerised.
Most banks abroad are fully dependent on computers for their functioning and even a
half-an hour halt in the computer functions cost them millions of dollars. Even in India,
private banks and co-operative banks have started fully computerised banking.
Hospitals and Medicine : As the number of patients keep growing, big hospitals have no
option but to computerise the records to enable them to track the patients’ history to help
doctors in diagnosing and administering medicine. Inventories of medicine are also
computerised so that availability of medicines are always known and stock-outs are avoided
by ordering replenishments well in advance. Similarly the administration of the hospitals
which is increasingly becoming a specialty is being done with the help of computers. With
the improvement of technology, electronics and computers are being used in increased
measures for diagnosing patients. Medical or Bioengineering is a fast developing branch
of science which uses computers every where. Pharma companies use computers in
various ways such as for designing experiments, analysing results of experiments and
even formulation of drugs.( 5 )
COMPUTER AWARENESS
Other Areas : Other spheres of activity where computers are being used are in schools
and education, by Govt., in maintenance of records, administration and decision-making
called e-governance by the tele-communication sector for switching, store and forward
facility, consumer billing & maintenance etc. the industry for production planning, inventory,
sales and purchase etc.
Commerce : It is the commercial world - shops, banks, insurance and credit companies
- which makes the maximum use of computers in a variety of applications. It will be very
difficult for the financial world to exist without the assistance of computers. The introduction
of micro-computers enable the offices to function faster and efficiently. A number of software
packages are used in business. Besides word processing, other packages used in the
offices are spread sheet, data base management system, presentation software etc.
Industry : Many industrial organisations such as steel, chemical, oil companies depend
upon computers not only for their own internal administration but also for the actual control
of the plant processes. The trend has increased with the advent of microcomputers. Many
assembling work of the industry are being undertaken by the processes controlled by
micro-computers.
Administration : Every organisation has its own internal administration, and the
administrative tasks are performed by computers.
Education : Although there is a very little impact of computers in the class-room of Indian
schools. In USA and UK, computer aided methods such as - Computer Assisted Learning
(CAL) and Computer Assisted Instructions (CAI) exist. Education is the area, where
computers have a major role to play, especially in Universities - more so in the science
and technology department.
1.3 CHARACTERISTICS OF COMPUTERS
What is so special about a computer? Yes, its characteristics, which separates it from rest
of the machines. The vital characteristics of the computer are as follows:
I. Speed : Computer works on electrical pulses, which travel at incredible speeds
and, because the computer is electronic device, its internal speed is instantaneous.
An arithmetic calculation can be performed in a thousandth, millionth, billionth or
even in a trillionth of second. It is capable of executing over ten thousand instructions
in a second.
MILLISEC ms = 1/1000 of second.
MICROSEC ms = 1/1,000,000 of second
NANOSEC ns = 1/1,000,000,000 of second
PICOSEC ps = 1/1,000,000,000,00O of second( 6 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
II. Storage : This is a very vital characteristic of the computer, which separates it from
rest of the machines. The smallest unit of storage is bit (acronym of Binary DigiT).
The speed with which a computer can perform, i.e. to input data and the instructions
for processing, is humanly impossible. The storage space available in the Central
Processing Unit, being limited ,large quantity of data and entire instructions of all
the required programs can not be stored in it. These are stored outside and read
into the memory of CPU at the time of processing.
BIT - the smallest unit of storage,
NIBBLE = 4 bits,
BYTE = 8 bits,
KB = 1024 bytes,
MB = 1024 KB,
GB = 1024 MB
III. Accuracy : Accuracy of computers is consistently high. Errors in computing are
due to machinery failure, imprecise programming logic, inaccurate data, poorly
designed systems. Precision is the degree of accuracy to which the computer give
the result. The precision of computers is phenomenal.
IV. Versatility : Computers seem capable of performing almost any task, provided the
task can be reduced to series of logical steps. It performs numeric and non-numeric
tasks equally well. An algorithm, a step-by-step procedure which applied to the
problem leads to solution. Programming is to convert these step-by-step procedures
as a set of instructions in computer language to solve the problem.
V. Automation : Once a program is in the computer’s memory, CPU follows the
instructions until it meets the last instruction. Once the process had begun, it would
continue without human intervention until completion.
VI. Diligence : Being a machine, a computer does not suffer from the human traits of
tiredness and lack of concentration. If three million calculations are to be performed,
computer performs all these calculations with the same speed and accuracy.
1.4 TYPES OF COMPUTERS
Computers are classified in to microcomputers, minicomputers mainframe Computers,
and supercomputers. Microcomputers may be either personal computers (PCs) or
workstations. PCs include desktop units, laptops, notebooks, subnotebooks, pocket PCs
(electronic organizers, palmtops, personal digital assistants), and pen computers.
Workstations are some sophisticated desktop microcomputers used for technical purposes.
Minicomputers are intermediate size machines that have become important as “servers,”
for holding databases and programs for many PCs.( 7 )
COMPUTER AWARENESS
Mainframes are the large size of computer and are used in large companies to handle
millions of transactions. The high-capacity minis called super computers are the fastest
calculating devices and are used for large-scale projects. Super computers have two
designs: vector processing and massively parallel processing.
Generally law says that , the larger the computer, the greater its processing power.
Computers are often classified into four sizes-small, medium, large, and extra-large, which
(though the sizes overlap) are given the following names.
n Microcomputers
n Minicomputers
n Mainframe computers
n Super computers( 8 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
I. MICROCOMPUTERS OR PERSONAL COMPUTERS : A small, relatively
inexpensive computer designed for an individual user is called personal computers
(PC) or Microcomputers. In price, personal computers range anywhere from a few
thousand rupees to over fifty thousand rupees. All are based on the microprocessor
technology that enables manufacturers to put an entire CPU on one chip. Businesses
use personal computers for word processing, accounting, desktop publishing, and
for running spreadsheet and database management applications. At home, the most
popular use for personal computers is for playing games.
Personal computers first appeared in the late 1970s. One of the first and most
popular personal computers was the Apple II, introduced in 1977 by Apple Computer.
During the late 1970s and early 1980s, new models and competing operating systems
seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal
computer, known as the IBM PC. The IBM PC quickly became the personal computer
of choice, and most other personal computer manufacturers fell by the wayside.
One of the few companies to survive IBM’s onslaught was Apple Computer, which
remains a major player in the personal computer marketplace.
Today, the world of personal computers is basically divided between Apple
Macintoshes and PCs. The principal characteristics of personal computers are that
they are single-user systems and are based on microprocessors. However, although
personal computers are designed as single-user systems, it is common to link them
together to form a network. In terms of power, there is great variety. At the high end,
the distinction between personal computers and workstations has faded. High-end
models of the Macintosh and PC offer the same computing power and graphics
capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and
DEC.
In general Microcomputers are considered to be of two types : personal computer( 9 )
COMPUTER AWARENESS
(PC) and workstations.
PERSONAL COMPUTERS (PC) : PC is the short name for personal computer or IBM
PC. The first personal computer produced by IBM was called the PC, and increasingly the
term PC came to mean IBM or IBM-compatible personal computers, to the exclusion of
other types of personal computers, such as Macintoshes.
Microcomputers or PC comes in various sizes, as follows :
(a) Desktop Models : A computer designed to fit comfortably on top of a desk, typically
with the monitor sitting on top of the computer. Desktop model computers are broad
and low, whereas tower model computers are narrow and tall. Because of their
shape, desktop model computers are generally limited to three internal mass storage
devices. Desktop models designed to be very small are sometimes referred to as
slim line models.
(b) Laptop Computers : A small, portable computer — small enough that it can sit on
your lap. Nowadays, laptop computers are more frequently called notebook
computers.
(c) Notebook Computers : An extremely lightweight personal computer. Notebook
computers typically weigh less than 6 pounds and are small enough to fit easily in a
briefcase. Aside from size, the principal difference between a notebook computer
and a personal computer is the display screen. Notebook computers use a variety
of techniques, known as flat-panel technologies, to produce a lightweight and nonbulky display screen.
In terms of computing power, modern notebook computers are nearly equivalent to
personal computers. They have the same CPUs, memory capacity, and disk drives.
However, all this power in a small package is expensive. Notebook computers cost
SPECIAL
CHAPTER - 1
COMPUTER AWARENESS
1.1 Data, Information, Processing
1.2 Applications of Computers
1.3 Characteristics of Computers
1.4 Types of Computers
1.1 DATA, INFORMATION, PROCESSING
The electronic computer allows man to increase his productivity and permits him to do
tasks he would be unable to complete without the computer. A computer is a machine
capable of (1) accepting data; (2) performing described operations on the data, and (3)
providing the results of these operations. Thus the computer also permits man to improve
his output per unit of time, or productivity. We can say that the computer’s two most
important contributions as a productive tool are to increase (1) the speed of operation,
and (2) accuracy and quality of operation in terms of productivity.
Of course, when we consider these two factors, we realize that the computer enables us
to do tasks that we would probably never even attempt to do manually. For example, if
the number of input data is greater than million and the time necessary to accomplish a
task is more than fifty years, we would probably never attempt it. Yet it is such task that
we can ask the computer to accomplish.
Symbols are the basis of any language. The computer accepts and processes symbols in
an order to provide information. The symbols that today’s computers process are the
letters of the alphabet and numbers, as well as several useful algebraic and business
symbols.
The term electronic implies that the computer is powered by electrical and electronic
devices rather than by mechanical ones or those affected by heat or air pressure. Here
digital refers to discrete, noncontinuous quantities, as contrasted with continuous quantities.
For example, the computer accepts individual numbers, or signs, or other symbols. This
set of statements leads to the definition:( 2 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
Electronic Digital Computer is an information-processing device that accepts and processes
data represented by discrete symbols. It is constructed primarily of electric or electronic
devices.
Information processing is a series of planned actions and operations upon input data,
taken to obtain a desired result. The actions taken may be illustrated by a common data
processing operation which a person usually accomplishes manually, but which is
increasingly accomplished automatically by data processing service companies. This
processing work required:
(1) Data input
(2) Storage and retrieval of data, and instructions for data-processing actions
(3) Arithmetic steps
(4) Output of result
(5) Control of all above steps
Now, if we want to construct an automatic information-processor, we shall find it necessary
to carry out the same steps to complete the processing. A computer follows a similar
process. It is composed of five basic units, as shown in Figure The five basic units or
functions are:
1. An input unit which accepts the necessary input data and instructions.
2. A storage or memory unit in which computer instructions and the data as
well as intermediate results are stored.
3. An arithmetic unit in which numbers can be added, subtracted, compared in
size to other numbers, etc.( 3 )
COMPUTER AWARENESS
4. An output unit which provides the desired result in a suitable form, such as a
printed report or letter.
5. A control unit which controls the other four units, directs their order of operation
and supervises the overall excution of the computer
There are several devices which accomplish the function of input, output, and storage.
The arithmetic and control functions are accomplished by the central processing unit
located with storage in the system.
The basic unit of the computer is the arithmetic unit. It performs the arithmetic operations
accurately, reliably, and at high speed. However, the high-speed ability of the arithmetic
unit would be wasted if for each operation it had to go back to the input unit for the same
information at every step. The storage unit holds the data, the instructions and the
intermediate results of the calculations. (The incorporation of instructions in the storage
unit for ready and high-speed accessibility is the stored-program concept introduced by
John Von Neumann.) Since the instructions are in the memory, just as the intermediate
calculation results are, it is possible for the computer to modify the instructions themselves
as the calculation progresses.
The control unit supervises the flow of information and calculations and requests from
memory the instructions and data necessary at each stage in the calculation sequence.
The control functions are shown as dotted lines in Figure.
The input and output units serve as connections between the user and the machine.
1.2 APPLICATION OF COMPUTERS
Major technical innovations have always had a severe impact on the lives of individuals.
Same is true for computers also. Computers have entered every area of the society.
Society includes the organisations, where individuals work. The organisations are
educational, commercial, industrial, administrative, transport, medical, social, legal and
financial. Computers are being used in almost every sphere of activity ranging from home
to defence and entertainment to business and commerce. Let us see how computers are
used in various spheres of our life today.
Defence : Today, without computers, our defence is worthless. We may recall the recent
American-Iraq war in which the American Army used computers extensively to launch
missiles, track enemy air craft using radars, plan attacks and strategies etc. The entire
operation was conducted by commanders sitting in distant places.
Homes : Computers are increasingly becoming smaller in size, affordable and easy to
operate and use. These are finding their way into homes where they are used for keeping
accounts, study, sending mail playing games etc.
Science and Engineering : Here computers are used to solve complex mathematical( 4 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
and scientific calculations which would otherwise require years of effort. Before computers,
the launching of spacecraft and landing on the moon would have been distant dreams. In
addition to assisting in technical matters, computers aid the administrators to keep records,
accounts, maintain libraries of periodicals, journals, published papers etc.
Entertainment : Increasing use of computers is made in this field. The movies such as
“Jurassic Park” , “Independence Day”, “Terminator”, “Titanic” and “Jaws” have used
computers extensively to give special effects to the images. Today compact- disk (CDs)
used in record players are examples of computer technology having invaded this area.
Computers enable sound, audio and images to be combined to help film makers,
advertisement agencies to quickly produce films or advertisement clips. Animation films,
till recently were difficult to make, are now easily produced with the help of graphics or
computers.
Transportation : Transportation companies and agencies rely on computers. Railway
reservations are now done on computers. Apart from enabling quicker reservations, it
has enabled persons to plan journeys from any place to any other place with greater ease
and less worry. The cargo movement is also being computerised which will not only
impart efficiency to the handling but will also enable a consignor to know the exact status
of his consignment in a few moments. Air-lines & Railways had computerised their activities
much earlier, particularly reservations & now many state roadways have computerised
their reservations enabling passengers to book their journeys quickly and conveniently.
Business and Finance : No other sphere of activity has been as profoundly affected by
computers as banking and finance. The volume of business of banking after introduction
of computers has grown more than thousand fold. Right from automatic maintenance of
customer ledgers, identification of customers to payment of cash up to back office functions
such as balancing of books, MIS, funds transfer and reconciliation are all computerised.
Most banks abroad are fully dependent on computers for their functioning and even a
half-an hour halt in the computer functions cost them millions of dollars. Even in India,
private banks and co-operative banks have started fully computerised banking.
Hospitals and Medicine : As the number of patients keep growing, big hospitals have no
option but to computerise the records to enable them to track the patients’ history to help
doctors in diagnosing and administering medicine. Inventories of medicine are also
computerised so that availability of medicines are always known and stock-outs are avoided
by ordering replenishments well in advance. Similarly the administration of the hospitals
which is increasingly becoming a specialty is being done with the help of computers. With
the improvement of technology, electronics and computers are being used in increased
measures for diagnosing patients. Medical or Bioengineering is a fast developing branch
of science which uses computers every where. Pharma companies use computers in
various ways such as for designing experiments, analysing results of experiments and
even formulation of drugs.( 5 )
COMPUTER AWARENESS
Other Areas : Other spheres of activity where computers are being used are in schools
and education, by Govt., in maintenance of records, administration and decision-making
called e-governance by the tele-communication sector for switching, store and forward
facility, consumer billing & maintenance etc. the industry for production planning, inventory,
sales and purchase etc.
Commerce : It is the commercial world - shops, banks, insurance and credit companies
- which makes the maximum use of computers in a variety of applications. It will be very
difficult for the financial world to exist without the assistance of computers. The introduction
of micro-computers enable the offices to function faster and efficiently. A number of software
packages are used in business. Besides word processing, other packages used in the
offices are spread sheet, data base management system, presentation software etc.
Industry : Many industrial organisations such as steel, chemical, oil companies depend
upon computers not only for their own internal administration but also for the actual control
of the plant processes. The trend has increased with the advent of microcomputers. Many
assembling work of the industry are being undertaken by the processes controlled by
micro-computers.
Administration : Every organisation has its own internal administration, and the
administrative tasks are performed by computers.
Education : Although there is a very little impact of computers in the class-room of Indian
schools. In USA and UK, computer aided methods such as - Computer Assisted Learning
(CAL) and Computer Assisted Instructions (CAI) exist. Education is the area, where
computers have a major role to play, especially in Universities - more so in the science
and technology department.
1.3 CHARACTERISTICS OF COMPUTERS
What is so special about a computer? Yes, its characteristics, which separates it from rest
of the machines. The vital characteristics of the computer are as follows:
I. Speed : Computer works on electrical pulses, which travel at incredible speeds
and, because the computer is electronic device, its internal speed is instantaneous.
An arithmetic calculation can be performed in a thousandth, millionth, billionth or
even in a trillionth of second. It is capable of executing over ten thousand instructions
in a second.
MILLISEC ms = 1/1000 of second.
MICROSEC ms = 1/1,000,000 of second
NANOSEC ns = 1/1,000,000,000 of second
PICOSEC ps = 1/1,000,000,000,00O of second( 6 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
II. Storage : This is a very vital characteristic of the computer, which separates it from
rest of the machines. The smallest unit of storage is bit (acronym of Binary DigiT).
The speed with which a computer can perform, i.e. to input data and the instructions
for processing, is humanly impossible. The storage space available in the Central
Processing Unit, being limited ,large quantity of data and entire instructions of all
the required programs can not be stored in it. These are stored outside and read
into the memory of CPU at the time of processing.
BIT - the smallest unit of storage,
NIBBLE = 4 bits,
BYTE = 8 bits,
KB = 1024 bytes,
MB = 1024 KB,
GB = 1024 MB
III. Accuracy : Accuracy of computers is consistently high. Errors in computing are
due to machinery failure, imprecise programming logic, inaccurate data, poorly
designed systems. Precision is the degree of accuracy to which the computer give
the result. The precision of computers is phenomenal.
IV. Versatility : Computers seem capable of performing almost any task, provided the
task can be reduced to series of logical steps. It performs numeric and non-numeric
tasks equally well. An algorithm, a step-by-step procedure which applied to the
problem leads to solution. Programming is to convert these step-by-step procedures
as a set of instructions in computer language to solve the problem.
V. Automation : Once a program is in the computer’s memory, CPU follows the
instructions until it meets the last instruction. Once the process had begun, it would
continue without human intervention until completion.
VI. Diligence : Being a machine, a computer does not suffer from the human traits of
tiredness and lack of concentration. If three million calculations are to be performed,
computer performs all these calculations with the same speed and accuracy.
1.4 TYPES OF COMPUTERS
Computers are classified in to microcomputers, minicomputers mainframe Computers,
and supercomputers. Microcomputers may be either personal computers (PCs) or
workstations. PCs include desktop units, laptops, notebooks, subnotebooks, pocket PCs
(electronic organizers, palmtops, personal digital assistants), and pen computers.
Workstations are some sophisticated desktop microcomputers used for technical purposes.
Minicomputers are intermediate size machines that have become important as “servers,”
for holding databases and programs for many PCs.( 7 )
COMPUTER AWARENESS
Mainframes are the large size of computer and are used in large companies to handle
millions of transactions. The high-capacity minis called super computers are the fastest
calculating devices and are used for large-scale projects. Super computers have two
designs: vector processing and massively parallel processing.
Generally law says that , the larger the computer, the greater its processing power.
Computers are often classified into four sizes-small, medium, large, and extra-large, which
(though the sizes overlap) are given the following names.
n Microcomputers
n Minicomputers
n Mainframe computers
n Super computers( 8 )
H3 – INTRODUCTION TO COMPUTER AND APPLICATIONS
I. MICROCOMPUTERS OR PERSONAL COMPUTERS : A small, relatively
inexpensive computer designed for an individual user is called personal computers
(PC) or Microcomputers. In price, personal computers range anywhere from a few
thousand rupees to over fifty thousand rupees. All are based on the microprocessor
technology that enables manufacturers to put an entire CPU on one chip. Businesses
use personal computers for word processing, accounting, desktop publishing, and
for running spreadsheet and database management applications. At home, the most
popular use for personal computers is for playing games.
Personal computers first appeared in the late 1970s. One of the first and most
popular personal computers was the Apple II, introduced in 1977 by Apple Computer.
During the late 1970s and early 1980s, new models and competing operating systems
seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal
computer, known as the IBM PC. The IBM PC quickly became the personal computer
of choice, and most other personal computer manufacturers fell by the wayside.
One of the few companies to survive IBM’s onslaught was Apple Computer, which
remains a major player in the personal computer marketplace.
Today, the world of personal computers is basically divided between Apple
Macintoshes and PCs. The principal characteristics of personal computers are that
they are single-user systems and are based on microprocessors. However, although
personal computers are designed as single-user systems, it is common to link them
together to form a network. In terms of power, there is great variety. At the high end,
the distinction between personal computers and workstations has faded. High-end
models of the Macintosh and PC offer the same computing power and graphics
capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and
DEC.
In general Microcomputers are considered to be of two types : personal computer( 9 )
COMPUTER AWARENESS
(PC) and workstations.
PERSONAL COMPUTERS (PC) : PC is the short name for personal computer or IBM
PC. The first personal computer produced by IBM was called the PC, and increasingly the
term PC came to mean IBM or IBM-compatible personal computers, to the exclusion of
other types of personal computers, such as Macintoshes.
Microcomputers or PC comes in various sizes, as follows :
(a) Desktop Models : A computer designed to fit comfortably on top of a desk, typically
with the monitor sitting on top of the computer. Desktop model computers are broad
and low, whereas tower model computers are narrow and tall. Because of their
shape, desktop model computers are generally limited to three internal mass storage
devices. Desktop models designed to be very small are sometimes referred to as
slim line models.
(b) Laptop Computers : A small, portable computer — small enough that it can sit on
your lap. Nowadays, laptop computers are more frequently called notebook
computers.
(c) Notebook Computers : An extremely lightweight personal computer. Notebook
computers typically weigh less than 6 pounds and are small enough to fit easily in a
briefcase. Aside from size, the principal difference between a notebook computer
and a personal computer is the display screen. Notebook computers use a variety
of techniques, known as flat-panel technologies, to produce a lightweight and nonbulky display screen.
In terms of computing power, modern notebook computers are nearly equivalent to
personal computers. They have the same CPUs, memory capacity, and disk drives.
However, all this power in a small package is expensive. Notebook computers cost
SPECIAL
1. The earlier computers, which were massive in size, were based on vacuum tubes.
2. Early computing machines, like the ENIAC, were actually meant to assist the armed forces.
3. The printers in pre-1950s were punch cards.
4. An improvement on the ENIAC, which pioneered 'stored program', was made possible with the help of the mathematician John von Neumann.
5. Before the 1950s, computers were mostly owned by universities and research labs.
6. The B-programming language was developed by Ken Thompson.
7. Famous people, associated with the ENIAC, EDVAC, UNIVAC computers are Eckert & Mauchly.8. The 1st commercially produced and sold computer (1951) was UNIVAC.
9. IBM was provided software for PCs by Microsoft.
10. Time-sharing, teletyping, were associated with mainframe computers.
11. The transformation from heavy computers to PCs was made possible using microprocessors.
12. The first microprocessor was developed in 1971 by Intel.
13. The term 'micro' (extremely small) denotes 10-6m.
14. The Harvard student, who chose to write computer programs and dropped studies was Bill Gates.15. A pentium 4 (P-4) employs roughly 40 million transistors.
16. Mark-1, Apple-1, and collossus were initial desktop computers.17. Binary digits are briefed as bit.
18. A collection of bits is called byte.
19. C++, is a computer language.
20. The process of eliminating programming faults is called debugging.
21. Starting up on operating system is called booting.
22. A program used to browse the web is called browser.
23. An error in software designing which can even cause a computer to crash is called bug.
24. Click and double-click are achieved using the mouse.
25. Java, C, ForTran, Pascal and BASIC are computer programming languages.26. The device which sends computer data using a phone line is called MODEM.
27. 'Worm' and 'virus' are actually programs.
28. A 'file' is a unit of information.
29. A megabyte has 106(million) bytes.
30. A small, single-site network is called LAN.
31. A processor that collects several data and sends them over a single line is called bridge.
32. 'Nano' stands for one billionth part.
33. The number of bit patterns using an n-bit code is 2n.
34. The part of a computer that works with the data/programs is called CPU.
35. To convert a binary number to a decimal, we have to express it in power of 2.
36. www stands for world wide web.
37. Mathematics employed in computers is called Boolean algebra.
38. A collection of 8 bits is called byte.
39. The first home computer (1977), which was sold in millions of units was Apple II.
40. 'PARAM' is a supercomputer.
41. A website containing periodic posts is called blog.
42. While cutting and pasting, the cutitem is temporarily stored in the clipboard.
43. http stands for hyper text transfer protocol.
44. The unwanted or non-requested emails are called "spam".
45. A computer framed to give various network services is called server.
2. Early computing machines, like the ENIAC, were actually meant to assist the armed forces.
3. The printers in pre-1950s were punch cards.
4. An improvement on the ENIAC, which pioneered 'stored program', was made possible with the help of the mathematician John von Neumann.
5. Before the 1950s, computers were mostly owned by universities and research labs.
6. The B-programming language was developed by Ken Thompson.
7. Famous people, associated with the ENIAC, EDVAC, UNIVAC computers are Eckert & Mauchly.8. The 1st commercially produced and sold computer (1951) was UNIVAC.
9. IBM was provided software for PCs by Microsoft.
10. Time-sharing, teletyping, were associated with mainframe computers.
11. The transformation from heavy computers to PCs was made possible using microprocessors.
12. The first microprocessor was developed in 1971 by Intel.
13. The term 'micro' (extremely small) denotes 10-6m.
14. The Harvard student, who chose to write computer programs and dropped studies was Bill Gates.15. A pentium 4 (P-4) employs roughly 40 million transistors.
16. Mark-1, Apple-1, and collossus were initial desktop computers.17. Binary digits are briefed as bit.
18. A collection of bits is called byte.
19. C++, is a computer language.
20. The process of eliminating programming faults is called debugging.
21. Starting up on operating system is called booting.
22. A program used to browse the web is called browser.
23. An error in software designing which can even cause a computer to crash is called bug.
24. Click and double-click are achieved using the mouse.
25. Java, C, ForTran, Pascal and BASIC are computer programming languages.26. The device which sends computer data using a phone line is called MODEM.
27. 'Worm' and 'virus' are actually programs.
28. A 'file' is a unit of information.
29. A megabyte has 106(million) bytes.
30. A small, single-site network is called LAN.
31. A processor that collects several data and sends them over a single line is called bridge.
32. 'Nano' stands for one billionth part.
33. The number of bit patterns using an n-bit code is 2n.
34. The part of a computer that works with the data/programs is called CPU.
35. To convert a binary number to a decimal, we have to express it in power of 2.
36. www stands for world wide web.
37. Mathematics employed in computers is called Boolean algebra.
38. A collection of 8 bits is called byte.
39. The first home computer (1977), which was sold in millions of units was Apple II.
40. 'PARAM' is a supercomputer.
41. A website containing periodic posts is called blog.
42. While cutting and pasting, the cutitem is temporarily stored in the clipboard.
43. http stands for hyper text transfer protocol.
44. The unwanted or non-requested emails are called "spam".
45. A computer framed to give various network services is called server.
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