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Kenneth silang

  2. 2. Chapter 3<br />THE COMPUTER SYSTEM<br />
  3. 3. SYSTEM<br />Is a collection of elements that work together to solve a specific problem. It can also be defined as a systematic sequence of operation to produce specific results.<br />A computer system is combination of six elements namely Hardware, Software, People ware, Data/Information, Procedures and Communication. A computer must be a part of a system to be useful.<br />
  4. 4. HARDWARE<br /> Refers to the physical components that perform the function of data presentation, data input, data manipulation, data storage and output data.<br />Hardware is categorized as Input, Output, Processing, Storage and Communications Hardware.<br />
  5. 5. INPUT HARDWARE<br />Consist of devices that take data and programs that people can read or comprehend and convert them to a form that computer can process.<br />
  7. 7. Keyboard<br />A device that converts letters, numbers and other character into electrical signals that are machine-readable data by the computer’s processor. The keyboard is also referred to as the main input peripheral used by all computers. The keyboard allows the user input and action with the computer. Much like many type writers, the keyboard has all the letters of the alphabet, numbers 0 - 9 and additional special operational keys.<br />
  9. 9. QWERTY Keyboard<br />Developed by Sholes in 1868 and is now the official standard of computer keyboards. The layout of the QWERTY keyboard was designed to help prevent stuck keys. Now with the new technology, stuck keys are no longer an issue; and with the position of the keys, the hands are held close together helping to cause Carpal Tunnel Syndrome. Given all the above problems, this is the most widely used keyboard because the lack of options, can be used without training, is used because of the difficulty of having to teach a different keyboard, and is cheap and is easy to find. <br />
  10. 10. DVORAK KEYBOARD<br />Developed by Dr. August Dvorak in 1936 as solution to the outdated QWERTY keyboard. The layout of the keys on this keyboard make it easier and faster to type on when compared to the other keyboard.<br />
  11. 11. CHICLET KEYBOARD<br />Very small keyboard that was introduced with the PC Jr. with small keys spread out.<br />
  12. 12. DIRECT-ENTRY DEVICE<br />
  13. 13. DIRECT-ENTRY DEVICE<br />Refers to many forms of data entry devices that are not keyboards. Direct entry devices create machine-readable data on a magnetic media or paper or feed it directly into the computer’s processor.<br />Pointing Device is any computer hardware component(specifically human interface device) that allows a user to input spatial(continuous and multi-dimensional) data to a computer. CAD systems and graphical user interfaces(GUI) allow the user to control gestures–point, click, and drag - typically by moving a hand–held mouse across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on the screen by movements of the mouse pointer (or cursor) and other visual changes.<br />
  14. 14. Direct Entry <br />Pointing Devices<br />
  15. 15. MOUSE<br />A device that is rolled about on a desktop to direct a pointer on the computer’s screen or display screen.<br />
  16. 16. TRACKBALL<br />Is a movable, on top of a stationery device, that is rotated with the fingers or palm of the hand. In the fact, the trackball looks like a mouse turned up-side down.<br />
  17. 17. JOYSTICK<br />Is a pointing device that consist of a vertical handle like a gearshift lever on a base with one or two buttons.<br />
  18. 18. TOUCH SCREEN<br />Is a video-display screen that has been sensitized to receive input from the touch of a finger. The screen is covered with a plastic layer, behind which are invisible beams of infra-red light.<br />
  19. 19. LIGHT PEN<br />Is a sensitive stylus, or pen-like device connected by a cable to a computer terminal. Light pens are used by engineers, graphic designers and illustrators.<br />
  20. 20. DIGITIZING TABLET<br />Consist of a tablet connected by a cable to a stylus. A stylus is a pen-like device with which the user “sketches” an image. Digitizing tablets are used primarily in design and engineering. Pen-based computer system uses a pen-like stylus to enter handwriting and marks into a computer.<br />
  21. 21. SCANNING DEVICES <br />These are device that translate images of text, drawings, photos, and the like info digital form. Scanning devices include:<br /><ul><li>Bar Code Reader
  22. 22. Imaging Systems</li></li></ul><li>BAR CODE READER<br />Are photoelectric scanners that translate the bar code symbols into digital forms. The price of a particular items is set within the store’s computer and appears on a sales-clerk’s point-of-sale terminal on your receipt.<br />
  23. 23. IMAGING SYSTEMS<br />IMAGE SCANNER or<br />GRAPHICS SCANNER<br />This devices converts text, drawings, and photographs into digital form that can be stored in a computer system and then manipulated. The system scans each image with the light and breaks into light dark dots, which are then converted to digital code.<br />
  24. 24. Mark-recognition and Optical Character Recognition Devices are other examples of scanning devices. There are three types that read marks or characters: <br /><ul><li>Magnetic-Ink Character Recognition (MICR)
  25. 25. Optical Character Recognition (OCR)
  26. 26. Fax Machines</li></li></ul><li>Magnetic-Ink Character Recognition (MICR)<br />Reads the strange-looking numbers printed at the bottom of checks. MICR characters, which are printed with magnetized ink, are read by MICR equipment , producing a digitized signal. This signal is used by a bank’s reader/sorter machine to sort checks.<br />
  27. 27. Optical Character Recognition (OCR)<br />Uses a device that reads special reprinted characters and converts them into machine readable form.<br />
  28. 28. Fax Machines<br />Also known as Facsimile Transmission Machine scans an images and sends it as electronic signals over telephone lines to a receiving fax machine, which re-creates the image on a paper. (Facsimile means “an exact copy”)<br />
  29. 29. TWO TYPES OF FAX MACHINE:<br /><ul><li>Dedicated Fax Machine
  30. 30. Fax Modems</li></li></ul><li>Dedicated Fax Machines<br />These are specialized devices that do nothing except send and receive fax documents. They are found not only in offices and homes but also along side regular phones in public places such as airports.<br />
  31. 31. Fax Modems<br />Are installed as a circuit board inside the computer’s system cabinet. It is a modem wit fax capability that enables you to send signals directly from your computer to someone else’s stand alone fax machine or internal fax.<br />
  32. 32. Smart Card<br />Is a wallet type card that contains a microprocessor and memory chips that can be used to input data. In some countries, telephone users may buy a smart card allowing a telephone calls until the programmed total cost is used up.<br />Optical Card<br />Is a plastic, credit card size using laser technology, like music compact disks, which can be used to input data.<br />
  33. 33. Voice Recognition System<br />Can convert a person’s speech into digital code. The system compares the electrical patterns produced by the speaker’s voice with the a set of pre-recorded patterns stored in the computer.<br />
  34. 34. Audio-Input Device<br />Record or play analog sound and translates it for digital storage and processing. The principal use of audio-input devices such as these is to provide digital input for multimedia PC’s. A multimedia system is a microcomputer that incorporates text, graphics, sound, video and animation in single digital presentation. <br />
  35. 35. Video-Input Devices<br />Convert video from analog to digital form. As with sound most film and videotape is in analog form, thus, to be used by a computer, the signals that come from VCR or a camcorder must be converted to digital form through a special video-card installed in the computer.<br />
  36. 36. Electronic Cameras<br />Capture images in electronic form, which can be manipulated by a computer, for immediate viewing on a television or computer display screen.<br />Two Types of Electronic Cameras:<br /><ul><li>Still-Video Camera
  37. 37. Digital Cameras</li></li></ul><li>Electronic-Video Cameras<br />These are like camcorders only that they capture a single video image at a time. This is because the cameras are meant to display images only on a television screen before it can be transferred to a computer. <br />
  38. 38. Digital Cameras<br />Uses light-sensitive processor chip to capture photographic images in digital form. The bits of digital information can be copied onto a computer’s hard disk for manipulation and printing.<br />
  39. 39. Sensor<br />Is a type of input device that collects specific kinds of data directly from the environments and transmits it to a computer. Although you may not see such input devices connected to a PC in an office, they exist all around us, often in invisible form. Sensors can be used for detecting all kinds of things: speed, movement, weight, pressure, temperature, humidity, wind, current, fog, gas, smoke and the like.<br />
  40. 40. Human-Biology Input Devices<br />Uses the characteristics of a human body as input to a system. These when interpreted by sensors, optical scanners, voice recognition , and other technologies, can become forms of input. Biometric systems, line-of-sight systems, cyber gloves and body suits, and brainwave devices fall in these category.<br /><ul><li>Biometric Systems
  41. 41. Line-of-sight Systems
  42. 42. Cyber Gloves and Body Suits
  43. 43. Brainwave Devices</li></li></ul><li>Biometric Systems<br />Biometric security devices identify a person through a fingerprint, voice intonation, or other biological characteristics. For example, retinal-identification devices use a ray of light to identify the distinctive network of blood vessels at the back of one’s eyeball. In short, passwords to identify people authorized to used a computerized system.<br />
  44. 44. Light-of-sight Systems<br />Enable a person to use his or her eyes to ”point” at the screen, a technology that allows physically handicapped users to direct a computer. This is accomplished by a video camera mounted beneath the monitor in front of the viewer.<br />
  45. 45. Cyber Gloves and Body Suits<br />Special gloves and body suits often used in conjunctions with “virtual reality” or the computer generated simulation of reality- use sensors to detect body movements. Similar technology is being used for human controlled robot hands, which are used in nuclear power plants and hazardous-waste sites.<br />
  46. 46. Brainwave Devices<br />Perhaps the ultimate input device analyze the electrical signals of the brain and translates the into computer commands. Experiments have been successful in getting users to move the cursor on the screen through sheer power of thought. Other experiments have shown users able to type a letter by slowly spelling out the words in their heads. Although there is a very long way to go before the brainwave input technology become practicable, the consequences could be tremendous, not only for the handicapped people.<br />
  47. 47. Processing Hardware<br />Retrieves and executes or interprets instructions or software provide to the computer. The main components of processing hardware are the Central Processing Unit (CPU) and main memory.<br /> <br />
  48. 48. Central Processing Unit (CPU)<br />Central Processing Unit (CPU) is the “brain” of the computer it follows the instructions of the software to manipulate data into information. <br />The CPU or microprocessor is made up of silicon. Silicon is an element that is widely found in clay and sand. It is used not only because not only because its abundance makes it cheap but also because it is a semiconductor. A semiconductor is a material whose electrical properties are intermediate between a good conductor of electricity and non-conductor of electricity.<br />
  49. 49. There are three (3) functional parts of the CPU, namely<br />There are three (3) functional parts of the CPU, namely<br />
  50. 50. Control Unit<br />the control unit of the CPU services or monitors the functions performed by the entire computer system according to conditions set forth by the stored program. It directs the movements of the electronic signal between main memory and the arithmetic logic unit. It also directs signal between main memory and the input and output devices.<br />
  51. 51. Arithmetic Logic Unit<br />Performs arithmetic operations and logical operations and controls the speed of these operations.<br />
  52. 52. Memory Unit<br />is the primary storage or main memory where the computer and data are stored during processing. The main memory has three tasks:<br /> <br />It holds data for processing;<br />It hold the instructions;<br />It holds data that has been processed.<br />
  53. 53. There are two important facts to know about the main memory.<br />
  54. 54. Its contents are temporary. Once the power of the computer has been turned off. This is why data must also be stored on disk and tapes – called secondary storage. Secondary storage (external storage or auxiliary) is a non-volatile memory physically separated from the computer. It is used to store large files or programs not being used for the meantime.<br />
  55. 55. Arithmetic Logic Unit<br />Its capacity varies in different computer. The size of main memory is important. It determines how much data can be processed at once and how big and complex a program may be used to process it.<br /> <br />How capacity is expressed:<br /> <br /><ul><li>Bit – each 1 or 0 is called a bit, which is short for binary digit
  56. 56. Byte – a group of 8 bits, and a byte represents one character
  57. 57. Kilobyte – (K, KB) is about 1000 bytes(actually 1024 bytes)
  58. 58. Megabytes – (M, MB) is about 1 million bytes (actually 1,048,576 byes)
  59. 59. Gigabytes – (G, GB) is about 1 billion bytes (1,073,741,824 bytes)
  60. 60. Terabyte – is 2 to the 40th power approximately a thousand billion bytes (that is, a thousand gigabytes).</li></ul>  <br />
  61. 61. How data and programs are represented in the computer?<br />
  62. 62. Electricity is the basis for the computers and communications. But how it is used to represent data? We start with a simple fact that electricity can either be on or off. The binary system has only two digits: 0 and 1. Thus, in the computer 0 can be represented by the electrical; current being off and the 1 by the current on.<br />
  63. 63. Storage Hardware<br />Refers to storing devices and storage media where media and instructions are stored before and after they are used to be processed. There are two types of storage, the primary storage and the secondary storage.<br />Primary Storage<br />(main memory) refers to the RAM, where both data and instructions are temporarily held for immediate access and use by the computer’s microprocessor. It is consider as a volatile form of storage, meaning that the data and instructions are lost when the computer is turning off.<br />
  64. 64. The process of entering data into the storage is called WRITING. The process of retrieving data from the storage is called READING.<br /> <br /> Most primary storage today is comprised of semiconductor technology.<br /> <br /> “Semiconductor Technology” is made by ‘etching’ electronic circuits into silicon chips.<br />
  65. 65. The two most common form of memory are Random-Access-Memory (RAM) and Read-Only-Memory (ROM)<br /> <br />Random-Access-Memory (RAM) is the part of the primary storage where programs and their instructions are held temporarily while being manipulated or executed.<br />Read-Only-Memory (ROM) contains permanently stored instructions that can only be read. Data cannot be written into it. ROM is usually set by the manufacturer and is consider non-volatile, meaning data are not lost when the computer is turned off.<br />
  66. 66. Secondary Storage<br />Any storage devices are designed to retain and instructions in a relatively different form. Secondary storage is non-volatile meaning the saved data and instructions remain intact when the media is turned off.<br />
  67. 67. Three of the most commonly used secondary storage media are magnetic tapes, magnetic disk and optical technology.<br />
  68. 68. Magnetic Tapes<br />Stores records or group of records sequentially. Tapes can store large amounts of data that are erasable, reusable and durable. Magnetic tapes come in form of tape reels and cartridges for minicomputers.<br />
  69. 69. Magnetic Disks<br />Is a metallic platter on which electronic data can be stored. Data files on the disk can be read sequentially or directly. Magnetic disk are manufactured in both floppy and hard disk styles.<br />
  70. 70. Floppy Diskette<br />Is a small, flexible disk on which data are stored. It is available in three sizes: 3 ½ “ microfloppy, 5 ¼ “ and 8”<br />Hard Disk<br />is not flexible and is made from materials such as aluminum. A hard disk is used to compensate for the limited space on the floppy diskette <br />
  71. 71. Optical Technology<br />involves the use of laser, highly concentrated beam of light. This technology includes optical laser disk, optical cards and optical tape. The optical storage technology used with computers consists of four types.<br />
  72. 72. CD-ROM Disk<br />Compact Disk-Read Only Memory is an optical technology capable of storing huge amounts of data on disk. The data is prerecorded on the disk by the manufacturer, so the user can only read it.<br />CD-R Disk<br />This stands for Compact Disk Recordable, is a CD format that allows you to write data into a specially manufactured disk that can then be used by standard CD-ROM drive.<br />
  73. 73. WORM Disk<br />Write Once-Read Many is an optical storage technology, like CD-ROM, except that the user can determine what the manufacturer record on the disk.<br />Erasable Optical Disk<br />Allows the user bothto record data on the optical discand to erase it. An erasable optical disk can store 281-3200 megabytes of data.<br />
  74. 74. Output Hardware<br />Consist of devices that translate information processed by the computer into a form that human can understand. <br />Output Devices translate information processed by the computer that human can understand. <br />
  75. 75. Two kinds of output: <br />hardcopy and softcopy<br />
  76. 76. Hard Copy<br />Refers to printed output. The principal examples are printouts, whether text or graphics, from printers. Hardcopy output can be produced using a printer or a plotter.<br />
  77. 77. Printer<br />Is an output device that prints characters, symbols and perhaps graphics on paper.<br />
  78. 78. Impact Printer<br />Has mechanisms resembling those of a typewriter. That is, an impact printer forms of character or images by striking mechanism such as print hammer or wheel against an inked ribbon, leaving an image on paper. Example: Daisy wheel printer, Dot matrix printer.<br />
  79. 79. Non-Impact Printer<br />Are faster and more quiet than impact computer because they have few moving parts. They form characters and images without making any direct physical contact between printing mechanism and paper. Example: Laser printer, Inkjet printer.<br />
  80. 80. Plotter<br />Is a specialized output device design to produce high quality graphics on a variety of colors. Plotter are specially useful for creating maps and architectural drawings, although they may also produce less complicated graphs and charts.<br />
  81. 81. Soft Copy<br />Refers to data that is shown on a display screen or is in audio or voice form. This kind of output is not tangible; it cannot be touch. The softcopy output hardware<br />
  82. 82. Cathode Ray Tubes (CRT)<br />Is a vacuum used in display screen in a computer or video display terminal. CTR’s are most common softcopy output devices used with computer systems; this technology is also used in TV sets.<br />
  83. 83. Flat-Panel Display<br />Are much thinner, weigh less and consume less power. They are better used for portable computer.<br /> <br />
  84. 84. Communications Hardware<br />Are commonly used in business applications. This includes modems, fax modems, multiplexer concentrator and front-end processors.<br />
  85. 85. Modem<br />Is a contraction of modulate and demodulate. A modem’s basic purpose is to convert digital computer signals to analog signals for transmissions over phone lines, then to receive this signals. A modem allows the user to directly connect the computer to the telephone wires.<br />
  86. 86. Fax Modem<br />Enables you to send data and scanned-in images directly from your computer to someone else’s fax machine or fax modems. Fax modems are installed inside portable computers, including pocket PCs, as well as desktop computers. <br />
  87. 87. Multiplexer<br />is a device that merges several low-speed transmissions into one high-speed transmission.<br />
  88. 88. Concentrator<br />Is a piece of hardware that enables several devices to share a single communications line. Concentrator collects data in a temporary storage area. It then forwards the data when enough has been accumulated to be sent economically.<br />
  89. 89. Front-End Processor<br />is a smaller computer that is connected to a larger computer and assists with communication functions. The front-end processor is itself a microcomputer or even a mainframe. It receives messages over the communication channels, corrects errors, and relieves the larger computer of routine computational task.<br />
  90. 90. Software<br />Refers to the collection of programsand operating aids associated with a computer to facilitate its programming and operation and extends its processing capability. <br />
  91. 91. Software can generally be divided into two categories namely Systems Software and Application Software.<br />
  92. 92. System Software<br />Is a program that aid in the operation of a computer regardless of the application that is being used.<br />
  93. 93. Several categories of System Software which are;<br />
  94. 94. Operating System<br />Consists of a master system of programs that manage the basic operations of computer. These programs provide resource management services such as running and storing programs and storing the process data.<br />
  95. 95. Also, OS performs the following task:<br /><ul><li>Coordinate processing
  96. 96. Manages the use of the main memory
  97. 97. Allocates the use of peripheral devices
  98. 98. Checks equipments malfunctions and display error messages</li></li></ul><li>Utility Programs<br />are generally used to support, enhance or expand existing programs in a computer system. Examples of utility programs are screen saver, data recovery programs, back up, virus protection, data compression, memory management and de-fragmentation.<br /> <br />
  99. 99. Screen Saver<br />Can prevent monitors display screen from being etched by an unchanging image by putting moving patterns on the screen.<br />
  100. 100. Data Recovery<br />Are programs are use to undelete a file or information that has been accidentally deleted.<br />Back-up<br /> Is making a duplicate copy of the information in your storage.<br />
  101. 101. Virus Protection<br />Refers to antivirus software program that scans for viruses<br />Viruses<br />Are hidden programming instructions that are buried within an application or system programs. They copy themselves to other programs causing havoc on files and computer system.<br />
  102. 102. Data Compression<br />Removes redundant elements, gaps and unnecessary data from computer’s storage space so that less space is required to store or transmit data.<br />Memory Management<br />Programs are determining how to efficiently control and allocate memory resources.<br />
  103. 103. De-Fragmentation<br />Programs rearrange the data so that the data units of each file are repositioned together on one location on the disk.<br />
  104. 104. Language Translator<br />is software that translates a program written by a programmer in a language which the computer can understand. There are three examples of language translators: Assembler, Compiler, and Translator<br />
  105. 105. Assembler<br />Are use in assembly language programs.<br />Complier<br />Interprets and checks the errors in a program one line at a time.<br />Translator<br />Interprets and checks the errors of the whole program.<br />
  106. 106. System Software programs are capable of performing the following task: multiprogramming, time sharing and multiprocessing<br />
  107. 107. Multiprogramming<br />Or multi tasking is the execution of two or more programs by one user currently on the same computer with one central processor.<br />
  108. 108. Time Sharing<br />Is a single computer processing of the task of several users at different workstations in a round robin fashion. Used when several users are linked by a communications network to a single computer.<br />
  109. 109. Multiprocessing<br />Is a processing done by two or more computers or processors linked together to perform work simultaneously.<br />
  110. 110. Application Software<br />Consists of programs designed to satisfy users specific needs and may be custom made or package. This can be divided into: Basic Software Tools and Advanced Software Tools.<br />
  111. 111. Basic Software Tools<br />are programs that can be found in most offices and campuses. The purpose is to make the users productive at performing general task. This includes word-processing, spreadsheets, database managers, graphic program, communication programs, and desktop accessories.<br />
  112. 112. Advance Software Tools<br />Are programs which are necessary in some occupations like publications. These include desktop publishing, project design/manufacturing (CAD/CAM).<br />
  113. 113. The Common types of Application Software are the following:<br />Word Processing, Desktop publishing, Electronic Spreadsheets, Database management, Graphic Software, Project management Software, CAD/CAM Software and Multimedia Software.<br />
  114. 114. Word Processing<br />Allows the user to create, edit, erase, store and print documents<br />Desktop Publishing<br />involves using the computer and mouse, scanner and a printer for mixing text and graphics to produce high quality printed output.<br />
  115. 115. Electronic Spreadsheets<br />Allows users to create tables and financial schedules by entering data into rows and columns arranged as grid on a display screen.<br />Database Management<br />Software consists of programs for storing, cross indexing, retrieving, and manipulating large amounts of data<br />
  116. 116. Graphic Software<br />enables users to produce many types of graphic creations, which come into two forms: Analytical graphics which are basic graphical forms used to make numerical data easier to understand like charts. Presentation graphics are graphics used to communicate or make presentation of data to others including artwork, animation or multimedia presentations.<br />
  117. 117. Communication Software<br />Includes programs that access software data and transmit data to a remote location.<br />Project Management Software<br />Programs which are used to plan, schedule and control the people, costs and resources required to complete a project on time.<br />
  118. 118. CAD/CAM<br />Enabled manufacturers to save much time and money because this allows product design to be inputted automatically into the system<br />Multimedia Software<br />is also called multimedia production tool or author-ware. This enables user to combine not only text and graphics but also animation, video, music, voice and sound as well.<br />
  119. 119. The common features of Application Software are Cursor, Scrolling, Menu Bar, Pull-down Menu, Help menu or screen, Dialog box, Macros, Object Linking and Embedding (OLE), and tutorials.<br />
  120. 120. Peopleware<br />Refers to the data-processing staff that performs numerous activities such as programming, systems analysis, computer operations, system maintenance and the like. <br />
  121. 121. Electronic Data Processing (EDP) and its Role in the Organization<br />The flow and availability of data has become necessary and an essential element of almost every organization. Transforming this data into complete and usable form needs people, planning, equipment and money. EDP plays a vital role in any firm because it serves as the service department. EDP department can be divided into 2 areas:<br /><ul><li>SOFTWARE AREA which consists of the following: system analysis, programming, and computer operations.
  122. 122. HARDWARE AREA focuses on Computer Engineers and Technicians.</li></li></ul><li>System Analysis<br />Is the scientific study of the systems operation which involves investigation of the input and output in order to find a better, more economical and more efficient means of processing. The processing starts from the time that the firm decides that some operation should be automated until the time the computer-based application is running.<br />
  123. 123. The Advantages of System Analysis are as follows:<br />Greater efficiency<br />Maximize profits<br />Maximum use of resources<br />Reduction of workloads or human efforts<br />Increases accuracy of data and information<br />Provide consistent operations and procedures<br />
  124. 124. Programming<br />I s the process of providing specific instructions that tells the computer what to do and what should be the expected result. Programming has different stages which include design or making decision on what the program should accomplish, coding or using a programming language to convert the instruction to machine language, testing and debugging in which errors are being corrected and documentation of the program listing.<br />
  125. 125. There are three (3) types of programmer, namely: <br />Application Programmer; Maintenance Programmer; System Programmer<br />
  126. 126. Application Programmer<br />Is a person who writes business application program like accounting system program such as payroll, inventory and the like,<br />Maintenance Programmer<br />Is the one responsible for making changes or modifications for the application program.<br />
  127. 127. System Programmer<br />Is in-charge of designing, developing and maintaining the complex system software packages. They maintain the system software environment for use by application programmers and computer operators.<br />
  128. 128. Computer Operation<br />The daily activities in the production of information in the data processing department are being referred to as COMPUTER OPERATION. These activities include preparation of data for processing, controlling, and scheduling of work done, operating the computer and other related equipment, storing the libraries of system and program documentation, output devices and other records essential to the system. To perform all these, data processing staff such as operations manager or supervisor, computer operator and other personnel is essential in operation.<br />
  129. 129. Data Encoders<br /> The main function of data encoder is to transfer data from source documents to a computer understandable form by keypunching. Encoders are required keyboard skills, at least average intelligence and alertness in order to recognize and correct errors encountered during the process. Not necessarily a graduate or degree holder but they should be trainable and careful to avoid errors.<br />
  130. 130. Computer Engineers and Technicians<br />A Computer Engineer is in charge of designing the computer components to fit the new development in the processor and the system requirements of the application programmers.<br /> A Computer Technician is tasked to maintain, upkeep and repair the peripherals. He is responsible in identifying the hardware problems of the machine and recommend further solutions.<br />
  131. 131. Distinction between a Computer Professional and a User<br />
  132. 132. Computer Professional is a person who had a formal education in the technical aspects of using computers. One best example is a computer programmer.<br />The user or end-user is someone without much technical knowledge of computers but who uses computers to perform professional or personal tasks, enhance learning, or to have fun.<br />
  133. 133. Becoming Computer Literate and Computer Competent<br />
  134. 134. Computer Literacy is having an understanding of what a computer is and how it can be used as a resource. Literacy, which refers to having a knowledge and understanding, needs to be distinguished from competency which refers to having a skill.<br />Computer competency is applying your skill with computers to meet information needs and provide productivity.<br />
  135. 135. Data Information<br />Data consist of raw facts and figures that are processed into information. Information summarized data or otherwise manipulated data.<br />
  136. 136. Data Processing<br />Refers to the transformation of data into meaningful and useful information. This involves performing operations on data usually by self-operating equipment in order to derived information. The computer-based manipulation of raw data to produce useful information; includes such processes as verifying summarizing, calculating, merging, sorting, comparing, classifying, refining, storing and retrieving.<br />
  137. 137. This block diagram illustrates the basic data processing cycle:<br />PROCESS<br />OUTPUT<br />INPUT<br />The block diagram shows the data processing operation which consist of three basic activities the INPUT, PROCESSING, OUTPUT.<br />
  138. 138. The first phase in the data processing is the input phase wherein, in this stage the date are being gathered and arranged in some form that is convenient to the user. Data must be recorded or captured in some form before they can be processed. They may be first recorded on source documents whether in paper form designed to accept input data or by means of keyboard and other machines, or any other direct input devices that accept input data in paperless, machine readable form. The next phase is the processing, which refers to the different data processing operations. <br />
  139. 139. Data processing operations involves the following task: <br />Recording; Duplicating; Classifying; Sorting; Calculating; Summarizing and Reporting; Merging; Storing and Retrieving;<br />
  140. 140. Recording<br />Is the process of transferring data into some forms or document. We can make use of the manual way of recording data or the computerized method of recording data. In manual operation the use of pencil/pen and log book or other legal form is being used in order to record this data, otherwise, the use of computer keyboard or other electronic/electromechanical devices is being used in the data recording process.<br />
  141. 141. Verifying<br />Is the process of carefully checking the recorded data for any errors.<br />Duplicating<br />is the process of reproducing the data into many forms or documents<br />Classifying<br />is the process of separating data into various categories.<br />
  142. 142. Sorting <br />Is the process of arranging data in specific order. After the data are classified, it is necessary to arrange or rearrange them into predetermined sequence to facilitate processing.<br />Calculating<br />involves arithmetic manipulations of data. It is consider as a crucial phase in data manipulation, because the outcome of this operation becomes part of the output.<br />
  143. 143. Summarizing and Reporting<br />In this operation, a collection of data is condense and certain conclusion from the data are presented in a meaningful format.<br /> Merging<br />This operation takes two or more sets of data, all sets having been sorted by the same key, and puts them together to form a singled set of data.<br />
  144. 144. Storing<br />is the process of placing similar into files for future reference, and this can be done in various forms. We can actually store data in manual form that is with the use of ledger/log book, the other form is being done electromechanically (punched cards), and the last methods is considered as the modern way of storing data and that is with the use of electronic storage devices such as magnetic tapes, disk, and main memory.<br />
  145. 145. Retrieving<br />Is the process of recovering stored data information when needed.<br />
  146. 146. The last phase in data processing is the output. Once the data has been captured and processed, these raw facts/data are transformed into useful and meaningful information. In this phase we can compare the outputs and the goals set in advance, and discrepancy is analyzed, corrected, and fed back to the proper stage in the processing operation.<br />
  147. 147. The following are Data Processing Objectives<br /><ul><li>Production of accurate, complete and timely information
  148. 148. Efficient retrieval and storage of data.
  149. 149. Faster and minimum number of processing operation.
  150. 150. Low processing cost</li></li></ul><li>The two (2) Areas of Data Processing are Business Data Processing (BDP), Scientific Data Processing (SDP)<br />
  151. 151. Business Data Processing (BDP)<br />It is characterized by the need to establish, retain, and process files or data to produce useful information. It involves a large volume of input data, limited mathematical operations and relatively large volume of output.<br />Scientific Data Processing (SDP)<br />In science, data processing involves a limited volume of input and variety of logical and arithmetic calculations. Unlike business problems, most of the scientific problems are non-repetitive, requiring a “one-time” solution.<br />
  152. 152. The following are methods of Data Processing: Batch Processing, On-line Processing, Real-time Processing and Distributed Processing.<br />
  153. 153. Batch Processing<br />Is a technique in which data to be processed or programs or programs to be executed are collected into groups to permit convenient, efficientand serial processing. It is the simplest form of data processing, with this method, Data is entered into the information flow in large volume or batches. That is, the processing is performed periodically at a specified time interval (weekly, monthly, and annually).<br />
  154. 154. On-line Processing<br />The term “on-line” refers to the equipment or devices under the control of the central processing unit (CPU) of the computer. An on-line operation is one which uses devices directly connected to the CPU either for data entry or inquiry purposes. With the aid of the terminal we can either enter data or inquire about the status of some record or file that is being stored by the computer. On-line processing has been developed for certain uses as an answer/solution to the batch processing deficiencies. On-line processing system features random and rapid input or transaction and immediate and direct access to records contents as needed. However, on-line processing and direct access of records require unique hardware and software, it also requires software security. <br />
  155. 155. Real-Time Processing<br />Is a method of data processing which has the capability of fast responses to obtain data from the activity or physical process performs computations and returns response rapidly enough to accept the outcome of the activity or process. Application of real time process: airline reservations, motel and hotel rooms, updating customer records in savings bank.<br />
  156. 156. Distributed Processing<br />This type of data is the most complex level which is generally consists of remote terminals linked to a large central computer system to help the user conduct inquiries about accounts, process jobs, or other operations. Distributed computer communication network is similar in some respects to public utilities such as telephones and electric companies. In distributed processing network a large number of computers are significant software resources is being shared among large number of users.<br />
  157. 157. Some are advantages of distributed processing<br />Central Processing idle time is reduce<br />Sophisticated computers and growing library of application program maybe immediately available to end user whenever needed.<br />Skilled professionals are available to help their own specialized applications.<br />Managers may be able to react more rapidly to new developments and interact with the system in order to seek solution to unusual problems.<br />
  158. 158. Some advantages of distributed processing<br />The reliability and cost of the data communications facilities, and the cost and quality of the computing service received, maybe disappointing in some cases.<br />Input/output are slow and efficient.<br />Provisions for protecting the confidentiality and integrity of the user program and data files generally ineffective against skilled hackers.<br />
  159. 159. Procedures<br />Are description of how things are done, steps for accomplishing result. Procedures for computer system appear in documentation manuals, which contain guidelines for using the hardware and software.<br />
  160. 160. Communication<br />Has become an important element of the computer system is set up to share data and information electronically with another computer system.<br />
  161. 161. COMPUTING TRENDS: <br />Connectivity, On-line Access and Interactivity<br />
  162. 162. Connectivity<br />Is the ability to connect computers and telephones by telecommunications lines to other devices and source of information<br />
  163. 163. Telecommuting <br />In standard commuting, one takes transportation from home to work and back. In telecommuting, one works at home and communicates to the office by phone, fax and computer.<br />
  164. 164. Tele-shopping <br />Microcomputerusers dial into a telephone-linked computer based shopping service that list prices and description of products, which may be ordered through the computer.<br />
  165. 165. E-mail and Voice-mail<br />E-mail or electronic mail is a system that links computers by wi8red or wireless connections. It allows users to post messages and read responses on their computer screens.<br />Voice-mails acts like a telephone answering machines. Incoming voice messages are digitized and stored for your retrieval later. Retrieval is accomplished by dialing into your “mailbox” number from any telephone.<br />
  166. 166. ONLINE INFORMATIOBN ACCESS: <br />The Examples of Databases Online Service and Networks, and BBSs<br />The term online or on-line refers to being connected via modern or network to the computers. That is you are “on the line” with them. Online connections are usually of the wired kind but rapidly becoming wireless also.<br /> The word access means the ability to connect to a particular database, network, online service, or electronic bulletin board system (BBS).<br />
  167. 167. Databases<br />A database may be large collection of data located within an unconnected microcomputer. Here, however, we are concerned with data bases located elsewhere. These are wireless connection and available to you through your microcomputer. A database is a collection of integrated or crossed reference which different people may access to use for different purposes.<br />
  168. 168. Computer On-line Services and Networks<br />A computer online service is a commercial information service that, for a fee makes, available to subscribers various services through e-mail to others using the service. Through a computer online service you may gain access to the INTERNET.<br /> The INTERNET is a network of approximately 11,000 local and regional computer networks that links computers at academic, industrial, and scientific institutions. Internet members are found in more than 200 countries.<br />
  169. 169. Electronic Bulletin and Board Systems<br />It is a centralized information source and message-switching system for a particular computer linked interest group.<br />
  170. 170. Interactivity<br />Means that the user is available to make an immediate response to what is going on and to modify the processes. That is, there is a dialog between the user and the computer or communication device. Video games, for example, are interactive allows user to be active rather than passive participant in technological process.<br />
  171. 171. Multimedia Computers<br />Multimedia refers to technology that presents information in more than one medium, including text, graphics, animation, video, music, and voice. “Multimedia” has become the buzzwords of the 90’s.<br /> Multimedia personal computers are fairly powerful microcomputers that include sound capability, run CD-ROM disk, and allow playing games or performing interactive task. The first, the MPC (for multimedia personal computers), was unveiled in 1991 by Tandy and Microsoft.<br />
  172. 172. TV/PC “smart boxes” and set-top boxes<br />Already envisioning a world crossbreeding among televisions, telephones, and computers enterprising manufacturers are bringing to market various forerunners of TV/PC “smart boxes”. A TV/PC is device that combines a television and a personal computer.<br />
  173. 173. Personal Digital Assistants<br />In 1988 handheld electronic organizers were introduced, which consisted of tiny keypads and barely readable screens. They were unable to do much more than store phone numbers and to daily “to do” list.<br /> In 1993, electronic organizers began to be supplanted by personal digital assistants. Personal digital assistants (PDAs) are small pen-controlled, handheld computers that, in their most developed form, can do two way wireless messaging. Instead of pecking at a tiny keyboard, you can use special pen to write out commands on the computer screen. The PDAs can be used to send and receive faxes and e-mail, to write memos, and to keep an appointment calendar.<br />