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Understanding Input and Output Devices in Information Systems

Discover the essential input and output devices in information systems, including keyboards, pointing devices, screens, printers, and more, their functions, and importance in enhancing user interaction and data processing efficiency.

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Understanding Input and Output Devices in Information Systems

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  1. Information System Hardware www.assignmentpoint.com

  2. Why information systems need hardware • Speed: computers provide fast processing of business transactions and information • Accuracy: computers ensure accuracy by not making mistakes as people do • Capacity: computers provide the ability to handle large amounts of data www.assignmentpoint.com

  3. Input & Output Devices • Input - keyboards, pointing devices, other • Output - screens, printer, other • Terminals (input and output combined) • Multimedia input and output • Virtual reality input and output www.assignmentpoint.com

  4. Input & Output Devices (cont’d) • Keyboards: • Most widely used input device • May be general layout or special purpose • Can cause repetitive strain injuries (RSI) • Carpal tunnel syndrome is an RSI • Keyboards can be specially designed to avoid problems using ergonomics www.assignmentpoint.com

  5. Input & Output Devices (cont’d) • Keyboards (cont’d) www.assignmentpoint.com

  6. Input & Output Devices (cont’d) • Pointing devices • Mouse • Trackball • Trackpoint • Touchpad • Purposes are to move the cursor and select what the computer does next www.assignmentpoint.com

  7. Input & Output Devices (cont’d) • Pointing devices (cont’d) www.assignmentpoint.com

  8. Input & Output Devices (cont’d) • Other input devices - Touch input • Touch screen • Pen input device • Touchpad • Light pen • Digitizer tablet www.assignmentpoint.com

  9. Input & Output Devices (cont’d) • Other input devices - Touch input (cont’d) www.assignmentpoint.com

  10. Input & Output Devices (cont’d) • Other input devices - Optical scanning • Bar code scanner (uses barcodes and UPC codes) • Image or Page Scanner (or scanner) • Optical character recognition or OCR • Mark sense www.assignmentpoint.com

  11. Input & Output Devices (cont’d) • Other input devices • Magnetic scanning • Magnetic strip reader • Magnetic ink character recognition/MICR • Voice input • Voice recognition and IVR systems • Requires training www.assignmentpoint.com

  12. Input & Output Devices (cont’d) • Screens • Characters and images are formed from picture elements or pixels • Resolution is the number of pixels that can be displayed on a screen at one time • Most common screen is a Cathode ray tube or CRT www.assignmentpoint.com

  13. Input & Output Devices (cont’d) • Screens (cont’d) • Monitors may vary in size • CRTs display images well, but are bulky • Flat panel screens are lighter weight and use liquid crystal displays • Ergonomic factors: brightness, contrast, tilt capabilities, glare screens www.assignmentpoint.com

  14. Input & Output Devices (cont’d) • Printers • Desktop or high-volume (stand-alone) • Impact vs. Non-impact • Serial: characters per second (cps) • Line: lines per minute (lpm) • Page: pages per minute (ppm) • Quality: draft, near-letter, and letter www.assignmentpoint.com

  15. Input & Output Devices (cont’d) • Printers (cont’d) • Desktop • Inkjet - nonimpact, sprays ink on paper • Laser - nonimpact, similar to a copier • Dot-matrix - impact, uses a ribbon to form an image with a group of dots www.assignmentpoint.com

  16. Input & Output Devices (cont’d) • Printers (cont’d) • High Volume • Line printers - impact, uses a ribbon, similar to a dot matrix, draft quality • Laser - nonimpact, 200 ppm, letter quality, used for large volume printing www.assignmentpoint.com

  17. Input & Output Devices (cont’d) • Printers (cont’d) • High Volume (cont’d) www.assignmentpoint.com

  18. Input & Output Devices (cont’d) • Other output devices • Plotters - graphics on paper • Voice output - text-to-speech synthesis • Sound output - can be tones, music, beeps, etc. www.assignmentpoint.com

  19. Input & Output Devices (cont’d) • Other output devices (cont’d) www.assignmentpoint.com

  20. Input & Output Devices (cont’d) • Terminals (input and output combined) • Also called a video display terminal/VDT • Dumb terminals can only send and receive data to and from a computer • Intelligent terminals can also do some basic processing • Can be a PC, ATM, cash register www.assignmentpoint.com

  21. Input & Output Devices (cont’d) • Multimedia input and output • Data in more than one form • still or moving pictures • voice, music, other sound • animation • Used in highly interactive presentations • Requires speakers or headphones www.assignmentpoint.com

  22. Input & Output Devices (cont’d) • Multimedia input and output (cont’d) • Input requirements depend on the presentation (e.g. touch screen kiosks) • Usage may require a keyboard and/or a pointing device • Creations requires audio/video equipment • Images and sounds are digitized www.assignmentpoint.com

  23. Input & Output Devices (cont’d) • Virtual reality input and output • Creates a non-real, virtual world through sight and sound • Uses a headset for sight, and headphones for sound • May use a glove for touch and a joystick to control and move in the virtual world www.assignmentpoint.com

  24. Input & Output Devices (cont’d) • Virtual reality input and output (cont’d) • Uses • Entertainment • Train doctors • Architecture • Criminal investigations, simulations, and courtroom re-enactments www.assignmentpoint.com

  25. Primary Storage • Primary storage structure • Data representation • Primary storage organization • Primary storage capacity www.assignmentpoint.com

  26. Primary Storage (cont’d) • Primary storage structure • Composed of silicon chips • Each chip has millions of electronic circuits that can be off or on (0 or 1) • Called volatile storage • Random access memory (RAM) • Read only memory (ROM) www.assignmentpoint.com

  27. Primary Storage (cont’d) • Primary storage structure (cont’d) www.assignmentpoint.com

  28. Primary Storage (cont’d) • Data representation • Binary representation: binary digits/bits • 2 main formats: • ASCII: American Standard Code for Information Interchange • EBCDIC: Extended Binary Coded Decimal Interchange Code www.assignmentpoint.com

  29. Primary Storage (cont’d) • ASCII • A character consists of 7 bits • 128 characters/combinations of 7 bits • Computers use 8 bits for 256 characters J O H N 1001010 1001111 1001000 1001110 www.assignmentpoint.com

  30. Primary Storage (cont’d) • EBCDIC • A character consists of 8 bits • 256 characters/combinations of 8 bits J O H N 11010001 11010110 11001000 11010101 www.assignmentpoint.com

  31. Primary Storage (cont’d) • Data representation problems • ASCII and EBCDIC computers cannot communicate without special HW/SW • 256 characters may not be enough in the future • Potential successor is 16 bit Unicode www.assignmentpoint.com

  32. Primary Storage (cont’d) • Primary storage organization • Bits are arranged into storage locations • Computers use 8 bits and store one character in each location, sometimes adding a parity bit • Byte: group of bits to store one character • Each location has a unique address www.assignmentpoint.com

  33. Primary Storage (cont’d) • Primary storage organization (cont’d) www.assignmentpoint.com

  34. Primary Storage (cont’d) • Primary storage capacity • Kilobyte = 1024 bytes (about 1 thousand) • Megabyte = 1,048,576 (about 1 million) • Gigabyte = about 1 billion • Terabyte = about 1 trillion www.assignmentpoint.com

  35. Central Processing Unit (CPU) • Structure • Compatibility • Speed • Common CPUs www.assignmentpoint.com

  36. CPU (cont’d) • Structure • Composed of one or more chips containing millions of electronic circuits • Composed of • Arithmetic Logic Unit (ALU)-performs calculations and compares values • Control Unit - analyzes and executes instructions in programs www.assignmentpoint.com

  37. CPU (cont’d) • Structure (cont’d) www.assignmentpoint.com

  38. CPU (cont’d) • Compatibility • Instructions in machine language (0 or 1) • Different CPUs use different machine languages • Various CPUs may not be compatible • CPUs are compatible if their machine languages are identical www.assignmentpoint.com

  39. CPU (cont’d) • Speed • Factors: • bits/second processing capability • amount of data transferred between CPU and primary storage • Data transfer speed is measured in fractions of a second (milli, micro, nano) www.assignmentpoint.com

  40. CPU (cont’d) • Speed (cont’d) • Clock speed is measured in megahertz, one million cycles (ticks) per second • Reduced Instruction Set Computing (RISC) systems - smaller instruction set • Faster • Less expensive www.assignmentpoint.com

  41. CPU (cont’d) • Common CPUs • Microcomputer • Uses a single chip - a microprocessor • First developed by Intel - 4004 • Now at Pentium II/Pro with MMX (multimedia enhanced capabilities) • Apple used a Motorola 68000 www.assignmentpoint.com

  42. CPU (cont’d) • Common CPUs (cont’d) • Microcomputer (cont’d) • Intel and Motorola chips are not compatible-different machine language • Computer manufacturers use chips from other companies (e.g Intel) • Many may use the same chip www.assignmentpoint.com

  43. CPU (cont’d) • Common CPUs (cont’d) • Mini- and mainframe computers • May use computer chips manufactured by the computer company • These computers are not usually compatible because of different chips • A DEC program can’t run on an IBM www.assignmentpoint.com

  44. CPU (cont’d) • Common CPUs (cont’d) • Supercomputers • Similar to mini- and mainframes • May use 64 or 128 bit chips • Multiprocessing - using several CPUs in the same computer at the same time • Massively parallel - many processors www.assignmentpoint.com

  45. Secondary Storage • Magnetic Disk • Optical Disk • Magnetic Tape www.assignmentpoint.com

  46. Secondary Storage (cont’d) • Magnetic Disk • Most widely used secondary storage type • Flat, round platter • Made of metal or plastic • Covered with metallic coating which can be magnetized at different spots • Each magnetized spot is a 0 or a 1 www.assignmentpoint.com

  47. Secondary Storage (cont’d) • Magnetic Disk (cont’d) • Bits are organized into concentric circles known as tracks • Bits are grouped in tracks to form bytes • Each byte represents one character • Capacity depends on the number of bytes per track and the total number of tracks www.assignmentpoint.com

  48. Secondary Storage (cont’d) • Magnetic Disk (cont’d) www.assignmentpoint.com

  49. Secondary Storage (cont’d) • Magnetic Disk (cont’d) • May store trillions of bytes • Disk is non-volatile storage • Several platters may form a disk pack • Sizes range from 2 inches to 14 inches • Common floppy size is 3 1/2 • Only form of storage for some computers www.assignmentpoint.com

  50. Secondary Storage (cont’d) • Magnetic Disk Drives • Stores data on magnetic disks • Retrieves data from magnetic disks • Rotates the disk at speeds from 300 to 7000 rpms depending on type www.assignmentpoint.com

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