Introduction of computer


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Introduction of computer

  1. 1. -1-Submitted by: NOUMAN RIAZSubmitted to: MISS: AYESHA ATTARoll No: 0147-BH-BAF-2011TOPIC…. Date: May 18, 2012 INTRODUCTION OF COMPUTER
  2. 2. -2-Computer technology has two branches .Computer Engineering and Computer Science.Computer Engineering concerned with the manufacture of the physical components of acomputer. In computer technology these components are collectively called ComputerHardware or simply Hardware. Computer Science is concerned with the use of computerto perform various function is called Software Engineering and the instruction themselvescalled Computer Software or simply Software’s. Software being a very important part ofthe computer technology is that is a general purpose machine. It can perform a multitudeof tasks and it is the software which controls a computer in all tasks. HISTORY AND DEVELOPMENT OF COMPUPTERThe history of computing is very old. It goes back to some 500 B.C., when Chinese usedto calculate with the help of an abacus.However, it was not the year 1812 when an English mathematicians from CambridgeUniversity. Charles Babbage designed a machine which he named as different Engine.This machine would be capable of calculating powers of numbers. Babbage also gave theidea of an analytical Engine, which was supposed to be general purpose machine havingthe ability to calculate a wide variety of arithmetic and algebraic formulae. Store data andprint results. He never converted his dreams into realities. However, his son was able tobuild a part of arithmetic unit. The analytical was to be composed of: 1. input in the form of punch card 2. A memory where arithmetic values could be stored 3. An arithmetic unit to perform calculations 4. A control section which could hold. Execute and modify stored instruction 5. Automatic output of answersThe Analytical Engine was not a successful machine but it gave birth to the research inthe field of computers. In 1946 John Mauchly and J. P Eckert developed an ElectronicNumerical Integrator and Computer (ENIAC) at the Moore School of Engineering andTechnology Pennsylvania USA. This was the first truly successful computers afterMark-1 developed at Manchester University. There were three major backs in theENIAC. 1. It used serial lines for processing 2. No storage facility was available
  3. 3. -3- 3. it used decimal numbers instead of binary number system These problems were successfully overcomes in John von Neumann Electronic Discrete Automatic Computer (EDVAC) development of these machines materialized the existence of computers and they became commercial entity used in many Government organization. GENERATION OF COMPUTERS It is quiet obvious that the development of computer is continuous process. However, the development of computers could be categorized into the following generation based on the technology used for the machine. 1. FIRST GENERATION All computers developed in the initial phase of computer development (ENIEL, EDVAL, BINAC, UNIVAC and Mark 1) belong to the First Generation of computers .These computers were mostly made between 1945 and 1950 . Computers develop in this generation used the electrical devices like vacuum tubes, capacitors and resisters. 2. SECOND GENERATION The first generations computers opened the gateway to the commercial development and sale of computers. Attempts were made to reduce the size and costs increase the speed and reliability of computers. A breakthrough was the invention of an electronic device called transistor. Transistors replaced vacuum tubes and gave birth to the second generation of computers like (UNIVAC II. IBM 1401 AND CDC 1604).Which improved the storage and processing capabilities of computers. 3. THIRD GENERATION In early 1960 the electronic technology of solid state was introduced. The development of integrated circuits is referred to as solid state technology. The integrated circuits are the collection of many electronic devices, like transistors, on a single chip (small piece) of silicon. The computer using this
  4. 4. -4- challenging electronic era of competition for speed and accuracy. The IBM 360. PDP 11 and HP 3000 are the computers developed in this generation. 4. FORTH GENERATION In 1970s integrated circuit technology was developed sufficiently to integrate all main function of a computer on a single chip called microprocessors. The introduction of microprocessors brought the computer age into Fourth Generation. A direct result in the development of microcomputers like IBM PC and Apple Macintosh which brought computer down from the organizational level to the personal level. 5. THE WAY FORWARD0 The progress in computer technology is still continued and active research is going in difficult fields of computer technology but there is no well categorization after the Forth Generation. The reason may be that now the developments are taking place in a variety of fields of Computer Hardware and Software as compared to the previous developments which mostly took place in the field of Electronics. As a result of that further grouping of computer developments is difficult. TYPES OF COMPUTERS
  5. 5. -5- Computers can be classified into three types. This classification is based on the hardware structure and the way physical quantities are represented in a computer.  Analog Computer  Digital Computer  Hybrid Computer 1- Analog Computers These computers represent physical quantities like speed, weight etc through an analogy with the electrical properties of current and voltage. Analog computers are the first computer being developed and provided the bases for the development of modern digital computers. These computers are mainly made of electrical devices like resisters, amplifiers and transistors. They are computers used for the calculation of observation of physical quantities or their measurement such as temperature, speed and height etc. In general Analog computers are very fast in processing and are used for real time simulation. 2-DIGITAL COMPUTERS Digital Computers represent physical quantities with the help of digits and numbers. These numbers are used to perform arithmetic calculations and
  6. 6. -6- also make logical decisions to each conclusion depending on the data they receive from the user. In general Digital Computers are easy to program and are general purpose in use. The IBM PC and others personal computers belong to this category. 3-HYBRID COMPUTERS There is another type of computer called the hybrids computer. A hybrid computer is the combination of Analog or Digital Computers. These computers consist partly of the components of a Digital Computer and partly of an Analog Computer to combine the characteristics of the two types. Although Analog Computers are still used in some defense and other real time applications the fast development and versatility of Digital Computers have almost eliminated the need and use of Analog computers. Now a day’s term computer, in general, means a Digital computer. Therefore, in rest of this book we will be discussing the Digital computer and the name, “Computer” will refer to a digital computer. Ref: Computer Science (professor Mehmood Ali Anjam) Ref:
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