Computer Basics | Computer Fundamental and Organization
- 2. Unit 1: Computer Basics
- 3. Agenda • Simple Model Computer • Characteristics of Computer • Generation of Computer • Stored Program concept: Vonn-Neumann architecture
- 5. Cont... • Input Unit – Input Unit is provided to read the algorithm and data to be processed by the algorithm • Memory Unit – Memory Unit stores the algorithm and computed values. • Processing Unit – Processing Unit interprets the instruction and carries them out. – It has the capabilities to perform arithmetic operations, character manipulation operations, and logical operations. • Output Units – Output Unit prints or displays computed values.
- 6. Characteristics of Computer • Computers are built to carry out a small variety of instructions. • Instructions are extremely simple; e.g., add, subtract, read a character, write a character, compute numbers, characters, etc. • Most instruction are carried out in less than a millionth of a second. • Instruction are carried out obediently with no questions asked. • Instructions are carried out without any mistakes. • Automatic – Works by itself without human intervention • Speed – Very fast device. It can perform in very few second, the amount of work that a human can do in entire year. – Not in a term of seconds, milliseconds but in terms of microseconds, nanoseconds and even picoseconds.
- 7. Cont... • Accuracy – It is fast but at same time it is very accurate – Errors are occur but due to human or technological weakness. • Diligence – Computer is free from monotony, tiredness, and lack of concentration. – Work for hours without any error or grumbling – Millions of calculation have to be performed, a computer will perform last one with exactly the same accuracy and speed of the first one. • Versatility – At one moment preparing result of examination, next moment it is busy to prepare electricity bill and in between helping an office secretary to trace an important letter in second. • Power of remembering – It contain important and unimportant data while human brain can do selection what is important and worth, retain in memory and other is removed.
- 8. Cont... • No I.Q – Computer is not magical device. It don’t have intelligence of its own. Its I.Q is zero till today. – It has to be told that what to do and in what sequence. – Computer can not take its own decision. • No feelings – Computer are devoid of emotions. They don’t have feelings because they are machine. – Computer will not do work as human heart and soul. – Based on our feelings, taste, knowledge, and experience we often make certain judgement in day-to-day life but computer can not make such judgement. – They make judgement based on instruction given to them in form of program which is written by human.
- 9. Generation of Computer • It provide framework for the growth of computer industry. • First Generation(1946-1955) – The first large electronic computer was completed in 1946 by a team led by Eckert and Mauchly at the University of Pennsylvania in U.S.A. – It is called as Electronic Numerical Integrator and Calculator(ENIAC) which used high speed Vacuum tube switching devices. • It had small memory and was designed to calculate the trajectories of missiles. It took about 200 microsecond to add two digit and about 2800 microsecond to multiply. – A major drawback of ENIAC was that its program were wired on boards that made it difficult to change the program. – Dr.John Von Neumann introduce “Stored Program Concept” which is used by Electrical Discrete Variable Automatic Computer (EDVAC) of USA. – At the same time U.K. Developed Electronic Delay Storage Automatic Calculator (EDSAC).
- 10. Cont... • In this machine addition operations took 1500 microsecond and multiplication operation took 4000 microsecond. • Commercial production of stored program machine in 50s and that is Universal Automatic Computer (UNIVAC I) build by Univac division of Remington Rand and delivered in 1951. – It also used Vacuum Tube. It used filament as a source of electron, they had limited life. – Computers typically used more than10,000 tubes so power dissipation was very high. • During this time programming was mainly done in machine language. • Initial application of this computer was in science and engineering.
- 11. Cont... • Characteristic of First Generation computers – They were the fastest calculating devices of their time. – They were too bulky in size, required large rooms for installation. – They used thousands of vacuum tubes that heat large amount of heat so the rooms in which these computers were located had to be properly air-conditioned. – Each vacuum tube consumes half a watt of power and it used more than 10,000 vacuum tubes, power consumption was very high. – As vacuum tube used filament, they had limited life and computer used thousands of vacuum tube they face frequent hardware failures. – Due to low mean time between failure, these computer required constant maintenance. – Commercial production of these computer was difficult and costly because thousands of individual component were assembled manually by hand in electronic circuits. – It had limited commercial use because it is difficult to program and used.
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- 13. Cont... • Second Generation (1955-1965) – John Bardeen, willian shockley, and Walter Brattain invented a new electronic switching device called transistor at Bell Laboratories in 1947. – Transistor proved to be better device than vacuum tube because, • They are easy to handle than tubes because they are made of germanium semiconductor material rather than glass. • They were highly reliable as compared to tubes because they had no parts like a filament. • They could switch faster than tube. • They consumed almost one tenth power consumed by a tube. • They were much smaller than tube. • They were less expensive. • They dissipated less heat as compared to vacuum tube. – Second generation computer emerged around 1955 transistor instead of Vacuum tube.
- 14. Cont... • Magnetic cores for storage was generated in this period, it was a tiny ring made up of ferrit and can be magnetized in either clockwise or anticlockwise direction to represent 0 and 1. • Memory capacity was about 100 KB. • Higher level programming language like FORTRAN, COBOL, Algol SNOBOL & operating System were developed during this generation. • International Business machine (IBM) 700 series computer emerged during second generation using batch oriented operating system. • Commercial application rapidly developed during this period. • More than 80% installed computer used in business and industry. • Payroll, inventory control, marketing, production planning and general ledger system were developed. • New professions in computing such as System Analyst and Programmer emerged during second generation.
- 15. Cont... • Characteristics of Second Generation – They are more than ten times faster than first generation. – They are smaller than first generation computer so require small space. – Consume less power and dissipate less heat than first generation. – More reliable and less prone to hardware failure than first generation. – They had faster and larger primary and secondary storage as compared to first generation. – They were easier to program. – Thousands of individual transistors had to be assembled manually by hand into electronic circuits making commercial production of these computer difficult and costly.
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- 17. Cont... • Third Generation (1965-1975) • In 1958, Jack St.Clair Kilby and Robert Noyce invented first integrated circuit (IC). • IC consist of transistors, resistors and capacitors. • Small scale integrated chip had about 10 transistor per chip, for medium scale 100 transistor per chip. • Switching speed of transistors went up by factor of 10, reliability increased by factor of 10, power dissipation reduced by factor of 10 and size also reduce by factor of 10. • The cumulative effect this was powerful CPUs with capacity of carrying out 1 million instruction per second. • Some new features like virtual memory, interrupt processor, base register become a part of a commercial computer. • Size of main memory reached about 4MB and Magnetic disk become 100 MB.
- 18. Cont... • This all things led to development of time shared operating system. It increased programmer productivity. • On-line system become feasible like Dynamic Production Control System, Airline Reservation System, Interactive Query System and real time closed loop process control system. • High level languages improved. FORTRAN IV and optimizing FORTRAN compiler were developed. • COBOL 68 was standardize by American National Standard Institute. • Characteristics of Third Generation – More powerful than second generation. Capable of performing about 1 million instruction per second. – Smaller than second generation so require small space. – They consume less power and dissipated less heat than second generation computer but still required proper air-conditioned.
- 19. Cont... • Less hardware failure than second generation so require lower maintenance cost. • They had faster and larger primary and secondary storage. • Used for both scientific and commercial application. • Did not require manual assembly of individual components into electronic circuits resulting in reduced human labour and cost involved at assembly stage so commercial production of these system was easier and cheaper highly sophisticated technology and expensive setup was required for manufacturing of IC chips. • Standard high level programming languages allowed programs written for one computer to be easily ported to and executed on another computer. • Timesharing Operating system comes in exist. • Unbundling of software from hardware gave users of the systems an opportunity to invest only in software of their need and value. • Minicomputers of third generation made computers affordable even by smaller companies.
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- 21. Cont... • Fourth Generation(1975-1989) • Average number of electronic components packed on a silicon chip doubled each year after 1965. • This progress soon led to era of the Large Scale Integration (LSI) with possible to integrate 30,000 electronic component on single chip & Very Large Scale Integration (VLSI) with possible to integrate about One Million electronic component on a single chip. This led to creation of Microprocessor. • Microprocessor contains all circuits needed to perform arithmetic logic and control functions, the core activities of all computer on a single chip. • It started new social revolution called Personal Computer (PC) revolution • Semiconductor memories replaced magnetic memory core memories. Hard disk become cheaper, smaller and larger in capacity. Floppy disk become very popular as a portable media for porting program and data from computer to another computer. • High speed computer network enable to enter connection of multiple computers to enable them communicate and share data. • Local Area Network (LAN) became popular for connecting computers within small organization or within campus.
- 22. Cont... • Wide Area Network became popular for connecting computers located at large distance. • Several new OS were developed during this period like MS-DOS, MS- Windows and etc. • Graphical User Interface (GUI) is developed for making computer more user friendly. It provides icons and menus that user can select with mouse. • Powerful word processing packages that allows easy development of document, spreadsheet packages that allowed easy manipulation and analysis of data in form of rows and columns, graphics packages that allowed easy drawing of pictures and diagrams. • Multiple windows on single terminal screen. • UNIX operating system and C Programming languages become very popular.
- 23. Cont... • Characteristics of Fourth generation computer • PCs were smaller and cheaper than mainframes or minicomputers of third generation. • Fourth generation mainframe required air-conditioning of the rooms/areas in which they were located, but no air conditions were required for PC. • Consumed less power than third generation computer. • More reliable and less prone to hardware failures than third generation computers.` • Had faster and larger primary and secondary storage as compared to third generation. • They were general purpose machine. • Did not require manual assembly of individual components into electronic circuits resulting in reduced human labour and cost involved at assembly stage so commercial production of these system was easier and cheaper highly sophisticated technology and expensive setup was required for manufacturing LSI and VLSI chips.
- 24. Cont... • Standard high level programming languages allowed programs written for one computer to be easily ported to and executed on another computer. • Graphical User Interface (GUI) enabled new user to quickly learn how to use computer. • PC-based application made PCs a powerful tool for both office and home usage. • Network of computers enabled sharing of resource like disks, printer, etc. among multiple computers and their users. Other application like involving interaction among computer users at geographically distant location. • PCs of fourth generation made computers affordable even by individuals for their personal use at home.
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- 26. Cont... • Fifth Generation (1989-present) • Small change in electronic components, increase in power of microprocessor and increase in capacity of main memory and hard disk continued during fifth generation. • VLSI became ULSI (Ultra Large Scale Integration) in fifth generation and chips having ten million electronic component. • Storage technology also increased during this fifth generation, optical disk also emerged as a popular portable mass storage media such as CD-ROM. • In fifth generation outgrowth of computer network, this trend is result in popularity of internet. Internet provide computer user to sitting across the globe to communicate with each other within a minutes using Electronic Mail. • Some application emerged during this time e.g. Electronic commerce, Virtual libraries, virtual classrooms, distance education. • Popular tool for wide range for multimedia (text, graphics, animation, audio, video) application because high processing power and storage capacity.
- 27. Cont... • The data size of multimedia application is much larger than textual information because representation of graphics, animation, audio, video. • Characteristics of fifth generation • Portable PCs (notebook) are much smaller than fourth generation, allow user to use its facility even while travelling. • Fifth generation computer require proper air conditioning of the room or area in which they are located. No air conditioning for notebook, desktop PC. • Consume less power than their predecessor. • More reliable and less prone to hardware failure than their predecessor. Requiring negligible maintenance cost. • Larger and faster primary storage as compared to their predecessors. • They are general purpose machines. • Did not require manual assembly of individual components into electronic circuits resulting in reduced human labour and cost involved at assembly stage so commercial production of these system was easier and cheaper highly sophisticated technology and expensive setup was required for manufacturing ULSI chips.
- 28. Cont... • Standard high level programming languages allowed programs written for one computer to be easily ported to and executed on another computer. • User-friendly interfaces with multimedia features make system easier to learn and use by anyone, including children. • More powerful application including multimedia application make system more useful. • Programs to be easily ported to and executed on another computer. • So many types of computer in all price range today.
- 29. Stored Program Concept: Vonn- Neumann Architecture • This concept is proposed in 1945 by John Von Neumann. • Main idea is storing program and processed data in same memory. • Storing program in in memory makes operation of computer automatic. • Basic operation of computer • Inputting: Process of entering data and instruction in computer. • Storing: storing data and instruction to make them available when required. • Processing: performing arithmetic operation or logical operation on data to convert them into useful information. • Outputting: processing of producing useful information or result for user. • Controlling: directing the manner and sequence in which the above operations are performed.
- 31. Cont... • Input Unit • Accept or read data and instruction for computation. • Data and instruction are depend upon the input device used. • Computer memory accept input in binary form so Input Interface transfer that input signal to binary code. • Functions of Input Unit: • It accepts instruction and data from outside world. • It converts these instruction and data in computer acceptable form. • It supplies the converted instruction and data to computer system for further processing. • Output Unit • Perform reverse operation of input unit. • Supplies processed data to outside world. • Result is always be in binary form so Output Interface transfer that binary data in human acceptable form.
- 32. Cont... • Functions of Output Unit: • It accepts the result produced by a computer, which are in coded form and hence, we cannot easily understand them. • It converts these coded result to human acceptable form. • It supplies the converted result to outside world. • Storage Unit • Data inserted by input unit have to be stored in the computer before actual processing start. Similarly computed result also have to be stored somewhere before being passed on to output unit. Moreover computer must also store intermediate result. • Storage Unit provide space for input data, output data and intermediate result. • Storage Unit holds: • Data and instruction required for processing. • Intermediate result of processing. • Result for output, before they are released to an output device.
- 33. Cont... • Two types of storage: • Primary Storage: • It also known as a main memory. • It stores piece of program instruction and data, intermediate results of processing, and recently produced results on which computer is currently working. • It hold information only while computer system is on. As soon as system switches off or resets, the information held in primary storage is erased. It has limited storage capacity because it is very expensive. • Secondary Storage: • It is also known as auxiliary storage. Secondary storage is much cheaper than primary storage so it takes care of the limitation of primary storage and it can contain information even when computer system switches off. • Magnetic disk is the most commonly used secondary storage medium.
- 34. Cont... • Arithmetic Logic Unit (ALU) • It is the place where actual execution of instruction takes place during processing. • Calculations are performed and all decisions are made in the ALU. • First of all data are stored in primary storage and, transfer it to ALU when it is needed after that again it is transferred to primary storage. This process happened many times within the completion of process. • ALU can perform four basic arithmetic operation (Add, Subtract, Division, Multiplication) and logical operations or comparisons such as less than, equal to. • Control Unit: • CU is acts as a central nervous system for other components of a computer system. • It manages and coordinate the entire computer system.
- 35. Cont... • Central Processing Unit (CPU): • CU and ALU of computer system are together known as the Central Processing Unit (CPU). It is a brain of computer system. • In computer system all major calculation comparisons takes place inside CPU and it is responsible for activating and controlling the operations of other units of computer system.
- 36. Any Question?