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Computer: A Placement Perspective Computer: A word computer comes from Latin word compute it means to calculate. A computer is an electronic device which receives and stores a large quantity of data in the form of symbols and numbers and processes them at a high speed as per the instruction given. Control set of instructions known as a program. Computer programme: A computer programme is a set of sequential instruction prepared by human being to direct the computer to solve a particular problem and give out the result. Advantage of computer:  Speed  Accuracy  Storage  Automation  Patience  Abacus: Earliest known computing device  Charles Babbage: Father of computer  Lady Ada Lovace: Mother of computer  I mainframe launched by IBM  HCL is pioneer in India in computer manufacture  TCS is pioneer in software in IT in India, Founded by Faquir Chand Kohli  Prof. Veer Raja Raman is the I professor of computer in India  Datum is Singular form and Data is Plural form  QWERT keyboard is the I keyboard  Japan is pioneer in Robot Technology  Prof. Raj Reddy is pioneer in Robotics  ENIAC: Electronic Numerical Integrator and Computer  EDVAC: Electronic Discrete Variable Automatic Computer  UNIVAC: Universal Automatic Computer  EDSAC: Electronic Delay Storage Automatic Calculator Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 1 Computer: A Placement Perspective  ASCII: American Standard Code for Information Interchange  JPEG: Joint Photographic Expert Group  USB: Universal Serial Bus  ARPANET: Advanced research project agency network  MILNET: Military Network  IP: Internet Protocol  TCP: Transfer Control Protocol  FTP: File Transfer Protocol  WWW: World Wide Web  CUG: Closed User Group  GUI: Graphical User Interface  GIST: General Information System Terminal  SOHO: Small Office Home Office  LAN: Local Area Network  WAN: Wide Area Network  MAN: Metropolitan Area Network  VPN: Virtual Private Network  Richard Brody: Author of MS World  First computer installed at Indian Statistical Institute, Kolkata  TCP/IP: Transfer Control Protocol / Internet Protocol  HTTP: Hyper Text Transfer Protocol  C is Structured programming language while C++ is an Object oriented programming language.  Open Source ERP: Apache OffBiz  Indian OS: Boss (Bharat Operating System Software) by C-DAC Defragmentation: Whenever data is scattered, we arrange these scattered data in an organized way and arrange some space is vacant, is called defragmentation. First Generation Computer: The computers, which were made with the use of vacuum tubes, are identified as the First generation computers. Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 2 Computer: A Placement Perspective Advantage: Vacuum Tubes technology made possible the designing of digital computer Disadvantage:  To bulky in size  Frequent failures  Slow processing  Highly heated Second Generation Computer: The computers, in which vacuum tubes were replaced by Transistors, are identified as the First generation computers. Advantage:  Small size than First generation computer  Less cost  Less heat generator  More faster Disadvantage:  Frequent maintenance  Commercial production was difficult and costly Third Generation Computer: IBM introduced the third generation computers around 1964. The computer using the Integrated Circuits came to be known as third generation computers. Example: IBM 360 etc. Advantages:  Smaller size compare to previous  Low maintenance cost  Widely used for commercial applications Disadvantages:  AC required in many cases  Highly advanced technology required for the manufacturing for the ICs Fourth Generation Computers: The computers builds with Microprocessor belongs to the fourth generation. Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 3 Computer: A Placement Perspective Advantage:  Smaller in size  Cheaper among all generations  Much faster in compilation Disadvantage:  Highly sophisticated technology Fifth Generation Computer: The fifth generation computer had a new technology called Artificial Intelligence incorporated in them. They will process non-numerical data such as pictures and graphics. These computers require new architecture, new memory organizations and new programming language. Hardware: The physical component of computer system that is the machine parts are known as hardware. The major components of the hardware are the microprocessor, input/output device, memory and various other devices connected to the computer. Software: Software refers to the programme written by the users for solving their problems and by the computer manufacturers for managing activities and the computer like operating system. There are primary two types of software: Application Software: It is a set of programs necessary to carry out the operations for a specified application. Example: processing examination results System Software: These programs written for the system which provide the environment to facilitate the using the application programs. Example: language translators like compilers and interpreters Block diagram of computer: Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 4 Computer: A Placement Perspective Control Unit Input Arithmetic and Logical Unit Memory Unit Output Central Processing Unit Input Device: A computer must receive both program statement and data to solve problems. The entry of program statements and data into a computer occurs by means of an input unit. Example: Keyboard, Mouse etc Central Processing Unit (CPU): The heart of the computer is the central processing unit. It is this unit that makes comparisons, performs calculations, needs, interprets and controls the execution of the instructions. It consists of three different units:  The control unit  The arithmetic and logical unit  Memory unit The Control Unit: The control unit, as the name indicate, supervise the operations of the entire computers, it selects the program statement from the storage unit, interprets the statement and sends the appropriate electronic impulse to the arithmetic/logic and storage units to cause these units to carry out the operations required. Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 5 Computer: A Placement Perspective Arithmetic and Logical Unit: It performs mathematical calculations, compares numeric and non-numeric values and makes decisions. The data flows between this unit and the storage unit during processing. Storage: The storage or primary memory section of the computer controls consists of the devise and to store the information that will be used for calculations. Output Devices: Output unit like input units are instruments of communication between the computer and the user. The most commonly used output devices are monitor, printer etc. Bit: A bit is the smallest memory location that can store “0” or “1”. Byte: Byte is a combination of 8 bits. 8 Bits = 1 Byte 1024 Bytes = 1 KB 1024 KB = 1 MB 1024 MB = 1 GB 1024 GB = 1 TB 1024 TB = 1 PB 1024 PB = 1 EB 1024 EB = 1 ZB 1024 ZB = 1 YB MS DOS: MS-DOS (Microsoft-Disk Operating System) or DOS as it is commonly known, is the most widely used, popular and easy to use operating system for the personal computers or micro computers. “Willian Gates” and “Poul Allen” developed MS-DOS Operating System: An operating system consists of programs, which control, coordinate and supervise the activities of various components of a computer. These Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 6 Computer: A Placement Perspective operating systems provide links between the users programs and the computer hardware. These programs confining the operating system are built with a computer and the supplied by the manufactures as standard packages. Types of Operating Systems: There are two types:  Single user Operating System: Example: MS-DOS  Multi User Operating System: Example: Unix Booting: The process of loading operating system into the memory is called Booting. Types of Booting:  Cold Booting: By switching on  Warm Booting: some times gets stuck then with the help of CTRL+ALT+DEL Office Automation: the term automation refers to all tools and methods that are applied to office activities which make it possible to process written, visual and sound data in a computer aided manner. Office automation almost always implies a network of computer with a variety of available programs. Office automation intended to provide elements which make it possible to simplify, improve and automate the organization of the activities of a company or a group of people. Considering that organization require increased communication, today, office automation is no longer limited to simply capturing handwritten notes. In particular it also includes the following activities:  Exchange of information  Management of administrative documents  Handling of numerical data  Meeting planning and management of work schedule Office automation does not always mean that the computer will do everything from start to finish by clicking a button. Many times the job still requires some human Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 7 Computer: A Placement Perspective intervention because computers can not make business decisions. Therefore, automation can be used to manage business process more efficiently and with fewer errors. Advantage:  Increased Efficiency  Employees business on core business functions  Increased output  By adding to the work process, the process is understood more clearly Intranet: An intranet is a private network that is contained with in an enterprise. It may consist of many interlinked local area networks and also use leased lines in the wide area network. The main purpose of an intranet is to share company information and computing resources among employees. It facilitates working in groups and for teleconferences. Secure intranets are now the faster growing segment of the internet because they are much less expensive to build and manage. Advantage:  Reduced cost  Saves time  Increased collaboration  Increased productivity and efficiency  Integrated and distributed computing environment  Rich in format Disadvantage:  Management can not control specific information  Security issue  Overload of information, difficult to find meaningful data Extranet: It is an intranet extended to outsiders to organization for specific purpose. An extranet is a B2B intranet that allows limited controlled secure access between a company’s intranet and designated, authenticated users from remote location. Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 8 Computer: A Placement Perspective Language Translators: Programming language can be divided in two major categories: Low level and High level. “Assemble language” and “Machine language” are called as low level language while BASIC, Visual Basic, JAVA are called as high level language. There are two types of language translators: Compiler: Compiler is a special program that process statements written in a particular programming language and converts them into machine language, a binary program or code that a computer processor uses. In this process, a programmer writes language statements in a language such as C, Pascal or C++ one line at a time using a tool called an editor. The edited file contains the source statements. The programmer then runs the appropriate language compiler, when executing the file, the compiler first analyzes all of the language statements syntactically in a sequential manner and then, in one or more successive passes, build the output code. Interpreter: An interpreter translates high-level instructions line by line and converts them into an intermediate form, which it then executes. An interpreter may be a program that either  executes the source code directly  translates source code into some efficient intermediate representation (code) and immediately executes this  explicitly executes stored precompiled code made by a compiler which is part of the interpreter system Utility Programs: Utility programs help manage, maintain and control computer resources. Some examples of utility programs include:  Virus scanning software  Backup software  Scan disk  Disk defragmenter Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 9 Computer: A Placement Perspective Application Programs: Application programs are programs, which the user uses to perform specific task. Example: word processor, spread sheet, database. Waterfall Model: Waterfall model was one of the first models to be proposed. Requirement Analysis System Design Program Design Coding Unit and Integration Testing System Testing Acceptance Testing Operation and Maintenance We follow a certain order to accomplish a task and they are followed I the same sequence each time. So a process can be defined as a sequence of ordered tasks. A series of steps involving activities, constraints and resources, which produce an intended output of some kind. From the figure we can imply that one development stage should be completed before the next begins. The waterfall model presents a very high level view of what goes on during development and it suggests to developers the sequence of events they should expect to encounter. Multitasking: It refers to the running of multiple independent computer programs on the same computer; giving the appearance that it is performing the tasks at the same time. Since most computers can do at most one or two things at one time, this is generally done via time sharing, which means that each program uses a share of the computers time to execute. Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 10 Computer: A Placement Perspective Hard Coding: It refers to the software development practice of embedding input or configuration data directly into the source code of a program. Soft Coding: It refers to obtaining a value or function from some external resources, such as a preprocessor macro, external constant, configuration file, command line argument or database table. It is the opposite of hard coding. Batch Processing: Batch processing is execution of a series of programs on a computer without human interaction. It allows sharing of computer resources among many users and programs. It shifts the time of job processing to when the computing resources are less busy. Absolute Addressing: In this, you specify the actual address (called the absolute address) of a memory location. It is used in programming and in spreadsheet application. Relative Addressing: An address specified by indicating its distance from another address called the base address. Example: B+15, B being the base address and 15 is the distance (called the offset) DBMS (Data Base Management System): DBMS is a collection of programs that enables us to store, modify and extract information from a database. Example: Computerized library system, Automated Teller Machine (ATM) RDBMS (Relational Data Base Management System): RDBMS is a type of DBMS that stores data in the form of related tables. Relational Data Base is powerful because they require few assumptions about how data is related or how it will be extracted from the database. ERP Evaluation: 2000s 1990s 1980s 1970s 1960s Extended ERP ERP MRP-II MRP Inventory Control Packages ERP Products: SAP(1972) ORACLE (1977) PeopleSoft (1987) Baan (1978) JD Edwards (1977) Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 11 Computer: A Placement Perspective Three Tier architecture of ERP: Presentation Layer Application Layer Database Layer Client Application Server Database Servers *****************************Best of Luck***************************** Mahendra K Patidar / PGDM BIF / 017 / IPE, HYD Page 12