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MACHINE LANGUAGE

INTRODUCTION OF COMPUTER MACHINE LANGUAGE

Computers can be programmed to understand many different computer languages. But there is only one language which does not require any translator program to convert the language into machine understandable form and this language is called machine language. This language can be understood by the computers without help of any translator. This is the fundamental language of a computer. It is written as strings of 1s and 0s. The circuitries of a computer are so designed that it can understand the machine language and convert it into the electrical signals. An instruction or data which is written in machine language has two parts. The first part of the instruction is called operation code or shortly written as (Operation Code) OPCODE. The operation code of the instruction tells the computer to perform functions. The second part, known as OPERAND, of the instruction contains the address or location where to store or find the data. Thus each instruction tells the control unit of CPU what to do and the length and location of the data field that are involved in the operation such as reading, adding, subtracting, writing, and so on. We know that computers use binary digits 0s and 1s to perform the internal operations. Machine languages consist of binary numbers and CUP can directly understand this. (more…)

HIGH LEVEL LANGUAGE

INTRODUCTION OF HIGH LEVEL LANGUAGE

As we are now familiar with machine language and assembly language and the requirement needed to write programs in these two languages is a programmer must to have intense knowledge of the internal structure of the hardware of the computer along with the knowledge of programming. Since in these languages writing a program is tedious because while writing a program in any of the these language a programmer need to remember the operation codes (OPCODE) and their operations executed by these operation codes in details and also their effects on the computer registers. An OPCODE tells the computer to perform the functions. Now for being a good programmer, a programmer needs to concentrate only on the logical side of the problem except giving more attention or value to the internal structure of hardware of the computer. Thus to overcome these problems high level languages were developed because high level languages are problem oriented rather than focusing on the internal structure of the computer. Programming in high level language does not require any internal knowledge of the computer system. High level languages give permission to the programmer to write their programs using English words which is more recognizable to the programmer. It also supports some mathematical instructions and notations or symbols to write program for evaluation of mathematical oriented problems. This property of high level languages felicitates the programmer to write his program easily. One another benefit of high level language is that for writing a program using high level languages, a programmer need not to be expert in programming or we can say a person having a little bit knowledge of the programming can be able to write programs. Let us have an example writing a program in one of the high level languages in FORTRAN, suppose we want to add or subtract two numbers namely FRST and SCND and to store the answer in ANSR. We can write the instruction just in one step as: (more…)

FORTRAN LANGUAGE AND IT’S GENERATION

INTRODUCTION OF FORTRAN LANGUAGE

FORTRAN is the abbreviation of formula translation. It is the one of the oldest high level language and its first version was developed by International Business Machine Corporation for 704 computers in 1957. 704 computers were also developed by the IBM Corporation itself. FORTRAN was also a popular language of its time. After 1957 several updated versions were developed by the IBM Corporation. The original FORTRAN language was soon followed by FORTRAN II. As the time passed its more advanced version FORTRAN IV was developed. FORTRAN IV was the first programming language which was standardized and it is done by the American National Standards Institute (ANSI) in 1966. One more property of FORTRAN was that programs written in FORTRAN IV could run in any computer and it did not matter in which computer the programs were actually written. In 1977 FORTRAN VI was developed and this version had some addition properties which were not in FORTRAN IV. The additional properties were character and file handling. FORTRAN VI was also known as FORTRAN 77. Subsequently, still more general purpose versions of the FORTRAN language FORTRAN 90 has been developed making FORTRAN a truly useful programming language.

FORTRAN was primarily developed for the evaluation of arithmetic and scientific oriented problems and was the most popular language of scientist and engineers during its time. But now FORTRAN language is not in use any more. This language is oriented towards the solving problems of mathematical and engineering nature. And this language has been designed as algebra based programming language. Any algebraic equation suppose a = b + c can be written as an instruction of FORTRAN. Example of a FORTRAN is given below:

SAMPLE FORTRAN PROGRAM

Problem: Find Sum and Average of successive odd positive integers up to 80?
n = 0
DO 10 i = 1, 79, 2
n = n + 1
10        continue
av = n / ((79 – 1)/2 + 1)
write(*,*)’sum = ‘,n, average=’, av
stop
end

TYPES OF COMPUTER

GENERAL PURPOSE AND SPECIAL PURPOSE COMPUTERS

A general purpose computer can store different program structures and offer fairly extensive instructions to write programs. General purpose computers can perform any kind of jobs either business oriented or scientific oriented with equal efficiency and speed. A special purpose computer is designed to perform special types of jobs and therefore instructions are inbuilt in these computers by the manufacturer company so that the given task is performed efficiently. These computers are often used to provide only specific functions such as controlling a manufacturing process, directing communication equipment etc.
On the basis of storage capacity and processing speed of data a computer can be classified as.
  1. Super computer
  2. Mainframe computer
  3. Mini computer
  4. Micro computer or Personal computer

SUPER COMPUTER

Super Computer PARAMIt is the most powerful and expensive computer. It has extremely large storage capacity and tremendous processing speed at least ten times faster than other computers. Inside the super computer there are several smaller computers connecting with one another. Each computer inside a super computer can work on different parts of a job simultaneously. They can be handled and maintained only by computer experts. It can calculate about 400 million numbers every second and can provide exact result. Super computers are used in weather forecasting, medical science, petroleum engineering and for creating computer graphics. Some of the super computers are: CRAY, AECK, SXII, Cyber 20, CDC STAR etc.
PARAM is the name of the super computer which is available in India and it is mainly used for weather forecasting.

MAINFRAME COMPUTER

Mainframe ComputerIt is a medium computer made by connecting several computer units together. A Mainframe computer is generally used in big organization and government sector for large-scale processing. In India railway reservation, airline reservation, are done with the help of mainframe computer. Mainframe computer can support all kind of high level languages. It can support all numbers of terminal up to 100 or more. It is capable of handling all types of problems whether it is scientific or commercial. It has sigh speed memory which enables it to process applications faster than mini and micro computers.

MINI COMPUTER

They are like small mainframe computers. They are consisted of a few separated computer units connected together. They can process information at the rate of 4 million bits per second. They are not so powerful as mainframe computers. They are generally applied to perform smaller works in commercial or government organization.

MICRO COMPUTER OR PERSONAL COMPUTER

Micro Computer or Personal ComputerA Micro computer is also known as personal computer is the smallest general purpose computer. It contains a small CPU which is also known as Central Processing Unit or micro processor. A micro processor is a complete CPU inside a single chip. Micro computer are being manufactured at large-scale as compared to others. Micro computers are easy to handle so they are continuously used in different sectors like business, engineering, school and for entertainment etc. they are used to the jobs which does not required critical computing. Micro computer can be used by a single user at a time so that it is named as personal computer.

GENERATION OF COMPUTERS

The term generation is used to distinguish between varying hardware and software technologies. The custom of referring computer era in term of generations came into wide use after 1964. There are five computer generations known till today. Each generations of computer has been discussed in details with their advantages and disadvantages here.

FIRST GENERATION COMPUTER (1942-1955)

Vacuum Tube Used in First Generation ComputerIn the evolution of computer topic, I have already told you about the early days computers ENIAC, EDVAC and EDSAC which were first generation computers. Full name of ENIAC is Electronic Numerical Integrator And Calculator. EDVAC is known as Electronic Discrete Variable Automatic Computer. And EDSAC is  known as Electronic Delay Storage Automatic Calculator. These machines and other of its time were designed using vacuum tubes. A vacuum tube was a fragile glass device that could control and amplify electrical signals. These computers were operated on Machine languages.

ADVANTAGES OF FIRST GENERATION COMPUTERS:

  1. Vacuum tubes were the only electronic components available during that time.
  2. Vacuum tube technology made possible to the invention of digital computers.
  3. They were the fastest calculating machine of their time.
  4. The computation time of that time computers were in milliseconds.

DISADVANTAGES OF FIRST GENERATION COMPUTERS:

  1. They were huge in size.
  2. They were not completely reliable.
  3. They needed air conditioning because thousands of vacuum tube generated a large amount of heat.
  4. Hardware failure was occurred frequently.
  5. They were non-portable.
  6. Their commercial use was limited because their production was difficult and costly.
  7. They needed continuous maintenance.
  8. Manual assembly of individual components was required.

SECOND GENERATION COMPUTER (1955-1964)

The second generation computers were designed using transistors except vacuum tubes. Transistors were invented during 1947. Transistors based computers were not produced on large-scale over a decade. In second generation computers, transistor were the brain of the computers. Transistor was used because they were smaller in size and more reliable than the vacuum tubes. And also they consume less power and generate less heat as compared to vacuum tubes. These computers were operated on assembly languages.

ADVANTAGE OF SECOND GENERATION COMPUTERS:

  1. They were smaller in size than first generation computers.
  2. They were more reliable than first generation computers.
  3. They draw less power and produce less heat than first generation computers.
  4. These computers can perform computation tasks in microsecond.
  5. Hardware failure was decreased as compared to first generation computer.
  6. They could be taken from one place to another. Thus they have portability property.
  7. Their commercial use was wider than first generation computers.

DISADVANTAGES OF SECOND GENERATION COMPUTERS:

  1. Second generation computers still needed air conditioning.
  2. Frequent maintenance was also required as in the first generation computers.
  3. Manual assembly of individual component into functioning was still required.
  4. Its commercial production was difficult and costly.

THIRD GENERATION COMPUTER (1964-1975)

IC or Integrated Circuit used in third Generation ComputerThird generation computers were designed using IC’s (Integrated Circuits). Micro electronic devices were invented with advancement in technology. With the help of microelectronic technology, it made possible to integrate a large number of circuit components into a single piece of silicon. This Silicon was known as chips. And this technology is called Integrated circuit or IC. This small chip contained several transistors in it. Third generation computers are operated on structured programming languages. Structured programming languages are C, FORTRAN and Pascal.

ADVANTAGES OF THIRD GENERATION COMPUTERS:

  1. With the invention of IC’s third generation computers were smaller than previous generations.
  2. Third generation computers were more reliable than previous generations.
  3. They generate less heat and consume less power than previous generations.
  4. The computation time was reduced from microsecond to nanosecond.
  5. Maintenance cost was low because hardware failure rarely occurred as compared to previous generations.
  6. They were portable.
  7. They were used widely in various commercial applications all over the world.
  8. Manual assembly of individual components was not required.
  9. Commercial production was easier and cheaper than previous generations

DISADVANTAGES OF THIRD GENERATION COMPUTERS:

  1. Air conditioning required in many cases.
  2. Highly sophisticated technology required for the manufacturing of IC chips.

FOURTH GENERATION COMPUTER (1975-1990)

Initially, an IC could have only about 10 to 20 components in it and this technology is known as Small-Scale Integration (SSI). Later, with the advancement of technology, it became possible to integrate more than 100 components in a single chip and this technology is known as Medium Scale Integration (MSI). Then came the era of LSI (Large-Scale Integration) and VLSI (Very large-scale integration). These technologies could integrate more than 30000 component into a single chip. The fourth generation computers used LSI chips. VLSI technology had million of components inside a single chip. LSI and VLSI technology had led to the development of very small and extremely powerful computer.

ADVANTAGE OF FOURTH GENERATION COMPUTERS:

  1. They are the Smallest in size because of their high component density.
  2. They are more reliable than the previous generations.
  3. They do not need air conditioning in most cases.
  4. They are much faster in computation than previous generations.
  5. Hardware failure is negligible hence minimum maintenance is required.
  6. Easy portable because of its size.
  7. They can be used in totally in general purpose.
  8. Commercial production was cheaper.

DISADVANTAGES OF FOURTH GENERATION COMPUTERS:

  1. Highly sophisticated and costly technology was required to manufacture the LSI and VLSI chips.

FIFTH GENERATION COMPUTERS (1990-ON WARDS)

The earlier VLSI technology has further advanced to ULSI (Ultra Large Scale Integration) technology in the fifth generation computers. This has resulted in the production of micro chips having 10 million electrical components. The fifth generation computer has brought more powerful super computers based on parallel processing technology. During fifth generation computer, there was tremendous growth of the computer network. In the area of operating system the fifth generation included multithreading and distributed operating systems. In the area of programming languages some of the concepts gained popularity during fifth generation like JAVA language, parallel programming languages etc.

ADVANTAGES OF FIFTH GENERATION COMPUTERS:

  1. Fifth generation computers are smaller than the previous generations.
  2. They are portable and handy.
  3. They are more powerful than fourth generation computers.
  4. Concept of parallel processing is introduced.
  5. Capabilities for solving complex problems.
  6. Fifth generation computers are general purpose computers.

COMPUTER EVOLUTION

Charles Babbage is considered to be father of modern computers. He was a professor at Cambridge University. During his time mathematical and statistical tables are made of a group of clerks. Even the out most care can not eliminate the human error in calculations. Babbage had to spend a lot time for checking these tables and soon be become exasperated of doing these types of works. So he started thinking of building a machine which can solve these problems having no error. In the year 1822 he built a Difference computer that can generate reliable tables. In 1842, Babbage came with a new idea of Analytical computer. The Analytical computer was totally automatic and it can perform any type of basic arithmetic at an average speed of 60 additions per minute. But unfortunately he was unable to produce a working model of this computer because precision engineering was not available at that time. However his efforts and principles laid to design the digital computers. We will now discuss about some of the well-known early computers.
  1. THE MARK I COMPUTER
  2. THE ATANASOFF-BERRY COMPUTER
  3. THE ENIAC
  4. THE EDVAC
  5. THE EDSAC
  6. MANCHESTER MARK I
  7. THE UNIVAC I

THE MARK I COMPUTER (1937-1944)

The MARK I computer is also known as Automatic Sequence Controlled Calculator was designed by the professor Howard A. Aiken of Harvard University in association with IBM corporation. This computer was the first automatic calculating machine. It was designed based on the punch card machinery which was already developed. This was very huge in size about 50 feet long and 8 feet high. And its design was very complex but this machine proved itself to be extremely reliable. It used over 3000 electrically actuated switches to control its operations. This machine was capable of performing five basic operations as addition, subtraction, multiplication, division and table reference. This machine took around 0.3 second to add two numbers and 4.5 numbers to calculate multiplication of two numbers. Thus this machine was too slow as compared to today’s computers. This computer was an electro – mechanical machine because it was designed with mechanical as well as electrical components. Although its operations were not controlled electronically, Aiken’s machine is often classified as computer because its instructions could be altered.

THE ATANASOFF-BERRY COMPUTER (1939-1942)

This machine was designed by Dr. John Atanasoff and his assistant Clifford Berry to solve certain mathematical equations. This computer was called Atanasoff-Berry Computer or ABC, after its inventor names. It used 45 vacuum tubes for internal logic and capacitor for storage.

THE ENIAC (1943-1946)

The ENIAC also known as the Electronic Numerical Integrator And Calculator was the first completely electronic computer. it was designed by the professor J. Presper Eckert and John Mauchly and by their team at the Moore school of engineering of the university of Pennsylvania, United State of America. It was developed for the military. The size of this computer was 20 X 40 square feet and it had 18000 vacuum tubes. It took 200 microsecond (2×10-4 second) to compute addition of two numbers and 2000 microseconds (2×10-3 seconds) to find multiplication of two numbers. The ENIAC was much faster than the MARK I computer.

Major Shortcomings of ENIAC:

There are two major shortcomings of this computer. First it could store and manipulate only a small amount of information and second its programs were wired on the boards. These shortcomings made it difficult to find errors and to change the program. Thus its use was limited. Except having these shortcomings it was used for years and it was used to solve ballistic problems.

THE EDVAC (1946-1952)

The EDVAC also known as Electronic Discrete Variable Automatic Computer was developed by Dr. John Von Neumann. In ENIAC the operation was seriously handicapped by the wiring board but this problem was overcome in this system. EDVAC was based on the concept of stored program. The idea behind stored program was that a sequence of instructions or data can be stored in the memory of the computer for the purpose of automatically flow of operations. Thus the stored program concept influenced for the development of the modern computers which uses the stored program concept. Von Neumann also introduced the idea of storing the information or data in the form of binary number system.

THE EDSAC (1947-1949)

As the EDVAC was developed in U.S.A. almost in the same time EDSAC was developed in Britain. The EDSAC is known as the Electronic Delay Storage Automatic Calculator. The machine was first started in May 1949. This machine took 1500 microsecond (15×10-4 seconds) to accomplish addition of two numbers. And it took 4000 microsecond (4×10-3 second) to accomplish multiplication of two numbers. This machine was developed by Professor Maurice Wilkes and his team at the Cambridge University.

MANCHESTER MARK I (1948)

This computer was a small experiment machine based on the stored program concept. It was designed at the Manchester University by a group of scientists headed by the Professor M.H.A. Newman. Its Storage capacity was only 32 words. This was too limited to store data and instruction. Hence the Manchester Mark I was hardly used.

THE UNIVAC I (1951)

The UNIVAC is known as Universal Automatic Computer it was the first digital computer which was not one of kind. Many UNIVAC machines were produced, the first of which was installed in the Census Bureau in1951and was used for continuously for 10 years. The first business use of a computer, a UNIVAC I, was by General Electric Corporation in 1954. In 1952 IBM Corporation introduced the 701 commercial computers. The commercially available digital computers that could be used for business and scientific applications had arrived.

COMPUTER DEFINITION

DESKTOP COMPUTER OR PERSONAL COMPUTER

The word computer has come from the word compute that means calculating. Thus it is an electronic device which performs arithmetic operations such as addition, subtraction, multiplication and division at high-speed. The main objective of inventing computers is to process large arithmetic calculation. But nowadays, it is used to process non-arithmetical as well as arithmetical data. Hence defining computers as calculating device is to ignore their rest of the work. More accurately, it may also be defined as a man-made electronic machine which can operate on a large amount of data or information. Here data or information can be numerical or non-numerical and it can be of any size or shape. Non-numerical data can be a list of bio-data of many applicants when the computer is used for recruiting personal, or to prepare result of many students who have obtained marks in different subjects, or to store details of a person while booking ticket on airline or railways reservation. Computers can store, read and process data and produce a meaningful data as output. Computers work very fast and do not make mistakes. it can also be defined as it is a collection of hardware or software component to accomplish many tasks.

CHARACTERISTICS OF A COMPUTER

Today computes are the backbone of every business and leisure of life. The most common properties of computers which make them powerful machines are as listed below.
  1. SPEED
  2. ACCURACY AND RELIABILITY
  3. DILIGENCE
  4. VERSATILITY
  5. HIGH STORAGE CAPACITY
  6. AUTOMATION
  7. POWER OF REMEMBERING

SPEED:

A computer is a very fast machine. It can do a job in few seconds or minutes for which a human being can take an entire year. The quick services we expect from bank, railway reservation, airline reservation, at the grocery store, at stoke exchange and while using Internet we are dependent on the speed of the computer. A powerful computer is capable of performing 3 to 4 million simple arithmetic per second. When we are taking about the speed of a computer, we do not talk in terms of second or millisecond. The unit of speed is microsecond or nanosecond or pico-seconds. The speed of a computer is measured in the following units of time:
Milli seconds
10-3 seconds
Micro second
10-6 seconds
Nano second
10-9 seconds
Pico-seconds
10-12 seconds
KIPS
Kilo instruction per second
MIPS
Million instruction per second

ACCURACY AND RELIABILITY:

Accuracy of a computer is consistently high and the degree of accuracy of a particular computer is dependent on its hardware design. A particular computer has same degree of accuracy for each and every calculation performed in it. It does not create any error while calculation itself. The errors appeared in any calculation are caused by humans. It may be possible that the programmer has written wrong code for calculation based application or it may also be possible that the data which is provided to the computer is not right or insufficient. Reliability of a computer is extremely high. We can be completely dependent on a computer to get fine and accurate result if the user had provided the right and sufficient data.

DILIGENCE:

A computer is free from monotony, physical and mental tiredness, and lack of concentration. Thus it can work for hours without stopping and can give accurate outputs. So that a computer scores over human being in doing routine type jobs that requires high accuracy. If a computer is ordered to process ten millions of calculation then it will calculate each with same speed and will provide output of each with same accuracy.

VERSATILITY:

A computer has its wide use of field. It can be used in commerce, daily life for entertainment, scientific application as well as in education. As for example, one person who is creating a list of job applicants at one moment, at the next moment he can use the same computer for booking tickets or after some time he can watch movie or listen songs. So it is clear that a computer can be used for different purposes at different times.

HIGH STORAGE CAPACITY:

A computer is capable of storing huge amount of data. We can store data of any size in a computer at any time and we can also retrieve it any time very quickly.

AUTOMATION:

When a process has been given to a computer and it is initiated then it does not need any person or help for functioning at each step of the process.

POWER OF REMEMBERING:

when a human being acquires new knowledge, the brain subconsciously selects what is important and retains it in its memory, and relegates unimportant details to the back of mind or just forgot them. With computers, this is not the case. It can store and recall any amount of information because of its secondary storage capability. Every piece of information can be retained by the user and can be recalled as and when required. Even after several years, the information recalled will be as accurate as on the day when it was fed to the computer. It forgets or looses certain information only when it is asked to do so. So it is entirely up to the user to make a computer retain or forget particular information.

LIMITATIONS OF COMPUTER

  1. NO I.Q.
  2. NO FEELING
  3. PRONE TO VIRUS
  4. DEPENDS ON ELECTRICITY

NO I.Q.:

A computer has no I.Q. a computer can not perform tasks that a human can. The difference is that it performs these tasks with unthinkable speed and accuracy. It has no intelligence of its own. It has to be instructed to do and in what sequence. Hence only a user can decides what task a computer will perform. It has no brain or intelligence regarding this.

NO FEELING:

Computer have no feelings or emotions because they are machines. Based on our feelings, taste, knowledge, and experience, we make our decisions in our daily life but it can not do these thing. Their decisions are based on the instruction we give them in form of codes.

PRONE TO VIRUS:

A virus can affect the performance of a computer. Sometimes they can destroy our computers.

DEPEND ON ELECTRICITY:

Computers cannot be operated without electricity.

APPLICATION OF COMPUTER

Today computers are used in various fields and these are as follows:

ENTERTAINMENT:

Computers are used for playing games, listing music and watching movies. They are also used to create movies and to make drawings.

EDUCATION:

Today computers are used in school for teaching, doing mathematical calculations and making computer projects.

BANKING:

In banking sector computers are used to store information of its account holders, it is also used to keep record of cash deposit and withdrawal it is also used by the ATM.

RAILWAY STATIONS AND AIRPORTS:

At railway stations and airports computers are used to check seat availability and for seat booking. It is also used to see timings trains and airlines and to see the arrival and departure of trains and airlines.

BUSINESS:

In business, computers are used to prepare documents, letters and to print them. They also help to store records of all employees and other details of the business. It is also used to send E mails to business colleagues.

DESIGNING:

Now computers are used to design magazines, newspapers, books and advertisements, they are also used for design clothes, preparing blue prints of a buildings and for auto mobile designing.

ADMINISTRATION:

Computers are used in administration at a large-scale for handling of all kind of works of administration.

PUBLICATION:

Computers are used for desktop publication.

SCIENTIFIC RESEARCH:

Different types of computers are used by the scientists for their different projects handling.

DEFENCE:

In Defence computers are used for designing weapons, controlling their functions and launching missiles and to store records of criminals. It is also used to connect soldiers with the operating base.

COMMUNICATION:

Computers are used in communication system.