Computer is an electronic machine that accepts information, processes it according to the specific instructions, and provides the results as new information.
To begin with, you most understand he impact of computer in the world today; Computers are affecting our lives in one-way or the other. Airlines, telephone and electricity bills, banking, medical diagnoses, and weather forecast...The list of services using computers is almost endless.
You must have noticed that some uses of computers, or applications of computers, have made life much easier for you-your air ticket is now issued in a mater of minutes and your credit card gets processed very fast. However, there is something about the computer that might make your fell a little uneasy. Perhaps, a feeling that is far more intelligent and informed and too complex to operate. You may be surprised to know that the computer can't perform any task without you. The computer needs to be instructed on exactly what it has to do.
The computer can store and manipulate large quantities of data at very high speed and even though, it can't think. It can make simple decisions and comparisons. For example, a computer can determine which two numbers is larger or which of two names comes first alphabetically and then act upon that decision. Although the computer can help to solve a wide variety of problems, It is merely a machine and can't solve problem on its own. It must be provided with instructions is the form of a computer program.
A program is a list of instructions written in a special language that the computer understands. It tells the computer which operations to perform and in what sequence to perform them.
In simply a computer is an electronic device that can accept input ands store data, process it and produce output.
Computer has basically three parts:
To begin with, you most understand he impact of computer in the world today; Computers are affecting our lives in one-way or the other. Airlines, telephone and electricity bills, banking, medical diagnoses, and weather forecast...The list of services using computers is almost endless.
You must have noticed that some uses of computers, or applications of computers, have made life much easier for you-your air ticket is now issued in a mater of minutes and your credit card gets processed very fast. However, there is something about the computer that might make your fell a little uneasy. Perhaps, a feeling that is far more intelligent and informed and too complex to operate. You may be surprised to know that the computer can't perform any task without you. The computer needs to be instructed on exactly what it has to do.
The computer can store and manipulate large quantities of data at very high speed and even though, it can't think. It can make simple decisions and comparisons. For example, a computer can determine which two numbers is larger or which of two names comes first alphabetically and then act upon that decision. Although the computer can help to solve a wide variety of problems, It is merely a machine and can't solve problem on its own. It must be provided with instructions is the form of a computer program.
A program is a list of instructions written in a special language that the computer understands. It tells the computer which operations to perform and in what sequence to perform them.
In simply a computer is an electronic device that can accept input ands store data, process it and produce output.
Computer has basically three parts:
Keyboard
System Unit (CPU) Central Processing Unit
Monitor (VDU) Visual Display Unit
A Keyboard is used to enter data, which is nothing but characters and numbers, into the computer. We can compare those keys of the typewriter. A system unit receives this data from the keyboard and holds on to it, until it is needed.
A monitor is like a TV screen where whatever is retrieved from the computer can be displayed.
System Unit (CPU) Central Processing Unit
Monitor (VDU) Visual Display Unit
A Keyboard is used to enter data, which is nothing but characters and numbers, into the computer. We can compare those keys of the typewriter. A system unit receives this data from the keyboard and holds on to it, until it is needed.
A monitor is like a TV screen where whatever is retrieved from the computer can be displayed.
History of Computer
Computers are developed as a result of man's search for a faster way to calculate. Computer is very fast because data and instructions are represented as pulses within electronic circuits and they travel at the speed of light. The inventions and ideas of many mathematicians and scientists led to the development of the computer.
The first mechanical calculating machines were invented during the 1600's. It was in 1642, that liaise Pascal developed the first mechanical calculating machine. The calculating machine could be used for addition and subtraction.
In 1671, Gottfried Leibniz's a German philosopher and mathematician constructed a calculator that was an improvement on Pascal's invention. This machine could add, subtract, multiply, divide and extract roots.
In the 1830's, an Englishman Charles Babbage devised the analytical engine, a kind of calculating machine. The analytical engine used axis and gears to computer values and store them and was designed to be a general purpose device that could be used to perform any mathematical operation automatically. The device includes memory, a central processing unit, input/output, and the use of programming language. All these are key elements in today's computers. That's why Babbage is often referred to as the father of the modern day Computer.
Lady Augusta add Lovelace was a mathematician, and a long time supporter of Babbage. Lovelace thought of way to program the machine, so that it would repeat the same set of instructions and carry out instructions, If certain conditions exist. These techniques are till in use today. These techniques are still in use today, to make computer programs more efficient. Because of her work, many consider Lovelace, to be the First programmer.
Computers are developed as a result of man's search for a faster way to calculate. Computer is very fast because data and instructions are represented as pulses within electronic circuits and they travel at the speed of light. The inventions and ideas of many mathematicians and scientists led to the development of the computer.
The first mechanical calculating machines were invented during the 1600's. It was in 1642, that liaise Pascal developed the first mechanical calculating machine. The calculating machine could be used for addition and subtraction.
In 1671, Gottfried Leibniz's a German philosopher and mathematician constructed a calculator that was an improvement on Pascal's invention. This machine could add, subtract, multiply, divide and extract roots.
In the 1830's, an Englishman Charles Babbage devised the analytical engine, a kind of calculating machine. The analytical engine used axis and gears to computer values and store them and was designed to be a general purpose device that could be used to perform any mathematical operation automatically. The device includes memory, a central processing unit, input/output, and the use of programming language. All these are key elements in today's computers. That's why Babbage is often referred to as the father of the modern day Computer.
Lady Augusta add Lovelace was a mathematician, and a long time supporter of Babbage. Lovelace thought of way to program the machine, so that it would repeat the same set of instructions and carry out instructions, If certain conditions exist. These techniques are till in use today. These techniques are still in use today, to make computer programs more efficient. Because of her work, many consider Lovelace, to be the First programmer.
Computer Generation
First Generation (1943-1958)
The storage media or memory used in the first generation computer was vacuum tube. ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general computer. It used vacuum tubes (18,000) and could do 300 multiplications per second.
Second Generation (1958-1965)
The computers using transistors as storage media were classified as second Generation computers. One transistor could do the task of 1000 vacuum tubes. Second generation computers were relatively smaller than the first generation computers. Computers were much faster and reliable. They had greater computing capacity.
Third Generations (1965-1973)
Third Generation computers were general-purpose computers. In 1964, International Business Machines (IBM) Corporation announced its system 360 family of mainframe computers. They are much faster as they used small chips containing thousands of parts integrated in them. Floppy disks. Hard disk, taps of card were used in this generation of computers. Large scale integration (LSI) about 20,000 transistors.
First Generation (1943-1958)
The storage media or memory used in the first generation computer was vacuum tube. ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general computer. It used vacuum tubes (18,000) and could do 300 multiplications per second.
Second Generation (1958-1965)
The computers using transistors as storage media were classified as second Generation computers. One transistor could do the task of 1000 vacuum tubes. Second generation computers were relatively smaller than the first generation computers. Computers were much faster and reliable. They had greater computing capacity.
Third Generations (1965-1973)
Third Generation computers were general-purpose computers. In 1964, International Business Machines (IBM) Corporation announced its system 360 family of mainframe computers. They are much faster as they used small chips containing thousands of parts integrated in them. Floppy disks. Hard disk, taps of card were used in this generation of computers. Large scale integration (LSI) about 20,000 transistors.
Fourth Generation (1973- Now)
While third generation computers saw the use of integrated circuits in building computers, the fourth generation is characterized by the increased number of circuits, allows more data to be stored on a memory chip. Lare Scale Integration (LSI) and very large scale integration (VLSI), allows memory chips having thousands of storage locations. Fourth generation computers have microprocessor, which have serial numbers. The serial numbers indicates the capability of computer and speed as well.
While third generation computers saw the use of integrated circuits in building computers, the fourth generation is characterized by the increased number of circuits, allows more data to be stored on a memory chip. Lare Scale Integration (LSI) and very large scale integration (VLSI), allows memory chips having thousands of storage locations. Fourth generation computers have microprocessor, which have serial numbers. The serial numbers indicates the capability of computer and speed as well.
Fifth Generation
There are three factors that are said to characterize the fifth generation of computers; mega-chip memories, advanced parallel processing, and artificial intelligence. A mega-chip can have more than one million storage locations. With parallel data processing thousands of instructions can be processed simultaneously. Fifth generation computers are expected to have artificial intelligence.
There are three factors that are said to characterize the fifth generation of computers; mega-chip memories, advanced parallel processing, and artificial intelligence. A mega-chip can have more than one million storage locations. With parallel data processing thousands of instructions can be processed simultaneously. Fifth generation computers are expected to have artificial intelligence.
The Personal Computer
The most popular form of the computer in use today is probably the PC or the personal Computer. The PC can be used for various applications. In fact, there are million of PCs already used by individuals and organizations. The PC us small in size but capable enough to handle large tasks. It can perform a divers range of functions, from keeping track of household accounts to keeping records of the stores of a large manufacturing company.
The most popular form of the computer in use today is probably the PC or the personal Computer. The PC can be used for various applications. In fact, there are million of PCs already used by individuals and organizations. The PC us small in size but capable enough to handle large tasks. It can perform a divers range of functions, from keeping track of household accounts to keeping records of the stores of a large manufacturing company.
Other Computer Systems
The PC is although the most popular computer system, there are other computer system too, which are categorized on the basis of size, cost; and performance.
Before we describe some of these computer systems. It is essential to understand the term, system. A system is a group of integrated parts that have a common purpose of achieving an objective. These parts or components of the PC system will be discussed in detail, later in the course. A popular system is the Mini-Computer, which is a small, general- Purpose computer. It can vary in size from a small desktop model to the size of a small filing cabinet. A typical mini system is more expensive than a PC and surpasses it in storage capacity and speed. While most PCs are oriented towards single users, mini systems are usually designed to simultaneously handle the needs of multiple users,, I.E. more than one person use a mini computer at the same time.
A mainframe is another form of a computer system that is generally more powerful than a typical mini system. Mainframe themselves may very widely in cost and capability. They are used in large organizations for large-scale jobs.
However, there is an overlap between the expensive Mini's and small Mainframe models in terms of cost and capability. Similarly, there is an overlap between the more powerful PC systems and the Mini Computer.
At the end of the size and capability scales are the Super Computers. There systems are the largest, fastest and the most expensive computers in the world. They are used for complex scientific and defense applications.
The PC is although the most popular computer system, there are other computer system too, which are categorized on the basis of size, cost; and performance.
Before we describe some of these computer systems. It is essential to understand the term, system. A system is a group of integrated parts that have a common purpose of achieving an objective. These parts or components of the PC system will be discussed in detail, later in the course. A popular system is the Mini-Computer, which is a small, general- Purpose computer. It can vary in size from a small desktop model to the size of a small filing cabinet. A typical mini system is more expensive than a PC and surpasses it in storage capacity and speed. While most PCs are oriented towards single users, mini systems are usually designed to simultaneously handle the needs of multiple users,, I.E. more than one person use a mini computer at the same time.
A mainframe is another form of a computer system that is generally more powerful than a typical mini system. Mainframe themselves may very widely in cost and capability. They are used in large organizations for large-scale jobs.
However, there is an overlap between the expensive Mini's and small Mainframe models in terms of cost and capability. Similarly, there is an overlap between the more powerful PC systems and the Mini Computer.
At the end of the size and capability scales are the Super Computers. There systems are the largest, fastest and the most expensive computers in the world. They are used for complex scientific and defense applications.
Benefits and Limitations of Computers
The fact that computers have made their impact of almost all aspects of life in today's world can hardly be questioned. The question that you may ask here is how do you benefit from using a computer.
The fact that computers have made their impact of almost all aspects of life in today's world can hardly be questioned. The question that you may ask here is how do you benefit from using a computer.
A computer provides three basic benefits:
Speed
Accuracy (Accurate work)
Diligence (care full hard work or toady effort)
Speed
Accuracy (Accurate work)
Diligence (care full hard work or toady effort)
Computers work at very high speeds and are much faster than humans. The human equivalent of an average computer would be one million mathematicians working 24 hours a day. A computer rarely makes mistakes. In fact, most computer errors are cusec by human facilities. Unlike human, computers simply do not get bother or tired. The monotony of repetitive works does not affect computer. Unanticipated situation arises, computer will either produce erroneous results or abandon the task altogether. They do not have the potential to work out and alternative solution.
Computer of a PC system -the Hardware.
Now that you know the benefits and limitations of computer. let us move on to identifying each component of the personal computer with which you will be working during the course. The until that resembles a TV screen is called the Monitor, or more commonly VDU, short form for visual Display Unit.
The component that closely resembles a typewriter is called the Keyboard. The box like structure that houses the necessary components to run the system is called the system unit.
The Printer, as the name suggests, is used to print the results of any operation.
The tiny device connected to the system unit through a cord, resembling a tail is called a Mouse. Moving the Mouse produces a corresponding movement of an arrowhead on the VDU.
These devices are collectively known as the Hardware. Thus hardware comprises of all the physical components of a PC system.
Now that you know the benefits and limitations of computer. let us move on to identifying each component of the personal computer with which you will be working during the course. The until that resembles a TV screen is called the Monitor, or more commonly VDU, short form for visual Display Unit.
The component that closely resembles a typewriter is called the Keyboard. The box like structure that houses the necessary components to run the system is called the system unit.
The Printer, as the name suggests, is used to print the results of any operation.
The tiny device connected to the system unit through a cord, resembling a tail is called a Mouse. Moving the Mouse produces a corresponding movement of an arrowhead on the VDU.
These devices are collectively known as the Hardware. Thus hardware comprises of all the physical components of a PC system.
How does a computer work ?
Most activities follow the basic principal of Input-Process-Output. Consider an automobile assembly line. The raw materials are forwarded to the assembling unit. This activity constitutes the Input part of the cycle. The process is the actual building of the automobile. There the process acts upon what has been the input and produces the Output, which in this case would be the finished automobile.
Like all other activities, a computer system follows the Input-Output process or I-P-O cycle. This can best illustrate by an example of an airlines reservation. A person who whishes to travel by air between Singapore and New York first has to fill in a request slip. This contains relevant data, I.E., details of name, age, place of destination, etc. The booking clerk keys in the data from the request slip into the computer. The process in this case includes examining the flight number, the date of the journey, the class requested and determining whether seats are available as per the reservation details. The output of this process is some information confirming the booking, if seats are available, otherwise, the computer turning down the request may issue message.
Let us see how each component of the PC system is related to the I-P-O cycle. The data in the request slip is input the input in computer is via the keyboard. Hence, the keyboard is an input device. The processing is performed by a component of the system unit called the Microprocessor. The information reading availability of seats is displayed on the VDU. Hence, the VDU is an Output Device. As mentioned earlier, the term hardware comprises the input and Output Devices along with the system unit.
Most activities follow the basic principal of Input-Process-Output. Consider an automobile assembly line. The raw materials are forwarded to the assembling unit. This activity constitutes the Input part of the cycle. The process is the actual building of the automobile. There the process acts upon what has been the input and produces the Output, which in this case would be the finished automobile.
Like all other activities, a computer system follows the Input-Output process or I-P-O cycle. This can best illustrate by an example of an airlines reservation. A person who whishes to travel by air between Singapore and New York first has to fill in a request slip. This contains relevant data, I.E., details of name, age, place of destination, etc. The booking clerk keys in the data from the request slip into the computer. The process in this case includes examining the flight number, the date of the journey, the class requested and determining whether seats are available as per the reservation details. The output of this process is some information confirming the booking, if seats are available, otherwise, the computer turning down the request may issue message.
Let us see how each component of the PC system is related to the I-P-O cycle. The data in the request slip is input the input in computer is via the keyboard. Hence, the keyboard is an input device. The processing is performed by a component of the system unit called the Microprocessor. The information reading availability of seats is displayed on the VDU. Hence, the VDU is an Output Device. As mentioned earlier, the term hardware comprises the input and Output Devices along with the system unit.
A closer Look at the Hardware
Keyboard:
The keyboard has already been identified as an input device. This is a component that closely resembles a typewriter console.
While working on the PC using a keyboard, you eill notice a flashing point on the VDU. This is the cursor. When you press a keyboard, a character is displayed at the point where the cursor is flashing and the cursor moves one position forward. The keyboard provides different keys to perform various operations. (Refer below table)
