Hardware: Input, Processing, and Output Devices

1. Hardware: Input, Processing, and Output Devices

2. Computer System Special subsystem of an organization's overall information system Integrated assembly of physical devices, centered around at least one processing mechanism utilizing digital electronics Used to input, process, store, and output data and information

3. Computer System Components

4. Central Processing Unit (CPU) Arithmetic/logic unit (ALU) Performs mathematical calculations Makes logical comparisons Control unit Sequentially accesses and decodes program instructions Coordinates flow of data in and out of the ALU, registers, primary storage, secondary storage, output devices Registers High-speed storage areas Temporarily hold small units of program instructions and data immediately before, during, and after execution by CPU

5. Primary Storage Holds program instructions and data immediately before or immediately after the registers Also called memory or main memory Closely associated with the CPU

6. Execution of an Instruction Instruction phase Step 1: Fetch instruction Step 2: Decode instruction Instruction time (I-time): The time to complete the instruction phase

7. Execution of an Instruction Execution phase Step 3: Execute instruction Step 4: Store results Execution time (E-time): The time to complete the execution phase

8. Execution of an Instruction

9. CPU Characteristics Machine cycle time Clock speed Wordlength and bus line width Physical characteristics Complex and reduced instruction set computing

10. Machine Cycle Time Measured in fractions of a second Millisecond - one thousandth of one second Microsecond - one millionth of one second Nanosecond - one billionth of one second Picosecond - one trillionth of one second Or in terms of instructions per second MIPS - millions of instructions per second

11. Clock Speed Predetermined rate at which the CPU produces a series of electronic pulses Microcode Predetermined internal instructions executed in accordance with clock speed Often measured in megahertz (MHz) or millions of cycles per second; ranges from 20 MHz to over 200 MHz for PCs

12. Clock Speed and the Execution of Microcode Instructions [Figure 3.3]

13. Wordlengthand Bus Line Width Bit A binary digit: 0 or 1 Wordlength Number of bits the CPU can process at any one time Bus lines Physical wiring that connects computer system components

14. Physical Characteristicsof the CPU Moore�s Law: The hypothesis that transistor densities on a single chip will double every 18 months

15. CISC and RISC Complex instruction set computing (CISC) Places as many microcode instructions into the central processor as possible Reduced instruction set computing (RISC) Reduces the number of microcode instructions built into a chip to an essential set of common instructions

16. Memory Storage capacity Byte = eight bits Kilo, Mega, Giga, Tera Types of memory Random access memory (RAM) Temporary and volatile Read-only memory (ROM) Permanent and non-volatile Cache memory High-speed, quicker access than main memory

17. Basic Types of Memory Chips

18. Cache Memory

19. Multiprocessing Processing that occurs using more than one processing unit Coprocessor A processor that speeds processing by executing specific types of instructions while the CPU works on another processing activity

20. Parallel Processing Speeds processing by linking several processors to operate at the same time

21. Parallel Processing Shared memory processing (SMP) Involves fewer processors and a common pool of main memory An independent task runs on each processor Massively parallel processing (MPP) Involves hundreds or thousands of microprocessor chips assigned to do the computing for a single program

22. Parallel Processing

23. Secondary Storage The portion of the computer that holds large amounts of data, instructions, and information more permanently than does main memory Also called permanent storage

24. Cost Comparison of Various Forms of Data Storage

25. Access Method Trade-Offs Direct access Process by which data and information are retrieved directly, without the need to pass by other data in sequence Sequential access storage device (SASD) Device used to sequentially access secondary storage media

26. Access Method Trade-Offs Direct access storage device (DASD) Device used to directly access secondary storage media

27. Secondary Storage Devices Magnetic tape Common secondary storage media Mylar film coated with iron oxide Magnetic disks Steel platters (hard disks) or Mylar film (floppy disks) coatedwith iron oxide

28. Secondary Storage Devices Redundant array of independent/ inexpensive disks (RAID) Generates extra bits of data from existing data so the system can create a �reconstruction map� to rebuild lost data Disk mirroring Provides an exact copy of data on drive

29. Secondary Storage Devices Optical disks A rigid disk of plastic onto which data is recorded by special lasers that physically burn pits into the disk Compact disk read-only memory (CD-ROM) A common form of optical disk on which data, once recorded, cannot be modified

30. Secondary Storage Devices CD-rewriteable (CD-R) Allows PC users to replace their diskettes with high capacity CDs that can be written upon and edited over Write-once, read-many (WORM) Allows businesses to record customized data and information onto an optical disk

31. Secondary Storage Devices Magneto-optical disk A hybrid between magnetic disks and optical disks Digital video disk (DVD) Looks like a CD-ROMdisk, but can store about 135 minutes of digital video

32. Secondary Storage Devices Memory cards Credit-card sized devices that can be installed in an adapter or slot in many personal computers Flash memory A silicon chip that is nonvolatile and keeps its memory when the power is shut off

33. Secondary Storage Devices Expandable storage Storage devices that use removable disk cartridges

34. Secondary Storage Devices Floptical disk Experimental storage device that is the same size as a diskette, but is able to hold many more times the data

35. Comparison of Secondary Storage Devices

36. Speed And Functionality The nature of data Human-readable data vs. machine-readable data Data entry and input Data entry: Human-readable data is converted into a machine-readable Data input: Machine-readable data is transferred into the system

37. Speed And Functionality Source data automation Automation of data entry and input where the data is created, thus ensuring accuracy and timeliness

38. Input Devices Personal computer input devices Keyboard Mouse Voice recognition devices  Digital computer cameras Terminals  Scanning devices Optical data readers Optical mark recognition readers Optical character reader

39. Input Devices Magnetic ink character recognition (MICR) devices Point-of-sale (POS) devices  Automatic teller machine (ATM) devices Pen input devices Light pens Touch-sensitive screens Bar code scanners

40. Sample Input Device: Digital Computer Camera

41. Sample Input Device: MICR Device

42. Output Devices: Monitors Display monitors Monochrome RGB (red, green, blue) Color graphics adapter (CGA) Enhanced graphics adapter (EGA) Video graphics array (VGA) Extended graphics array (XGA) Liquid crystal display (LCDs)

43. Output Devices: Printers, Plotters,and Microfilm Impact printers Letter-quality printers, dot-matrix printers, near-letter quality printers (NLQ) Non-impact printers Ink-jet printers and laser printers Plotters Computer output microfilm devices (COM) Special-Purpose Devices: Multifunction device A device that combines several input/output devices (e.g., printer, fax, scanner)

44. Classifying Computers Special-purpose computers Used for limited applications General-purpose computers Most common type of computers Used for a variety of applications

45. Types of Computer Systems Personal computers Network computers Workstations Midrange computers Mainframes Supercomputers

46. Types of Computer Systems Personal computers Relatively small and inexpensive Also called microcomputers

47. Computer System Types Network Computers Stripped-down personal computers Primarily used with network system and the Internet Workstations Fit between high-end microcomputers and low-end midrange computers in terms of cost and processing power

48. Computer System Types Midrange computers Systems that can accommodate several users at one time Formerly known as minicomputers Mainframes Large powerful computers often shared by hundreds of concurrent users connected to the machine via terminals Supercomputers Most powerful computer systems with the fastest processing speeds

49. Network Computer Processor speed 1-5 MIPs Amount of RAM 4-16 MB Approximate cost $500-$1,500 How used Supports data entry Connects to the Internet Example Oracle Network computer

50. Personal Computer Processor speed 5-20 MIPs Amount of RAM 16-128 MB Approximate cost $1,200-$5,000 How used Improves individual worker�s productivity Example Compaq Pentium computer

51. Workstation Processor speed 50-100 MIPs Amount of RAM 32-256 MB Approximate cost $4,000 to over $20,000 How used Engineering CAD Software development Example Sun Microsystems computer

52. Midrange Computer Processor speed 25-100 MIPs Amount of RAM 32-512 MB Approximate cost $20,00 to over $100,000 How used Meets computing needs for a department or small company Example Hewlett-Packard HP-9000

53. Mainframe Computer Processor speed 40-4,550 MIPs Amount of RAM 256-1,024 MB Approximate cost $250,000 to over $2 million How used Meets computing needs for a company Example IBM ES/9000

54. Supercomputer Processor speed 60 billion-3 trillion instructions per sec Amount of RAM 8,192MB+ Approximate cost $2.5 million-$3.5 million How used Scientific applications Marketing Customer support Product development Example Cray C90

55. Multimedia Computers Involves the marriage of sound, animation, and digitized video Multimedia standards Enable software and hardware vendors to build products that will work together to meet the needs of their customers

56. Multimedia Support Microsoft multimedia extension for Windows Multimedia PC Council (MPC) IBM Ultimedia Solution

57. Multimedia Support: Audio Musical Instrument Digital Interface (MIDI) Standard system for connecting musical instruments and synthesizers to computers Digital signal processor (DSP) A chip used by advanced sound systems to improved the analog-to-digital-to-analog conversion process

58. Multimedia Support: Video Video compression A process that uses mathematical formulas to reduce the number of bits required to present a single video frame

59. Hardware Components of Multimedia Computer System

60. Architecture and Upgrades: Responding to Change Computer system architecture The structure, or configuration, of hardware components of a computer system

61. Computer Standards Approved reference models determined by groups for building various products Common PC standards: Plug and play (PnP) Small Computer Systems Interface (SCSI) Multimedia extension (MMX)

62. Information Systems Principles Assembling an efficient computer subsystem requires an understanding of its relationship to the information system and the organization. The computer system objectives are subordinate to, but supportive of, the information system and the organization.

63. Information Systems Principles Components of information systems (input devices, people, procedures, goals) are interdependent. Because the performance of one system affects the others, all systems should be measured according to the same standards of effectiveness and efficiency.

64. Information Systems Principles When selecting computer subsystem devices, consider current and future needs. The choice of a particular computer system should allow for later improvements in the overall information system. Reasoned forethought is the hallmark of a true systems professional.

65. Information Systems Principles Determine hardware needs based on how the hardware will be used to support the objectives of the information systems and the goals of the organization. For PC users, this means knowing what software you want to run.

66. Information Systems Principles Do research to gain an understanding of the trade-offs between overall system performance, and cost, control, and complexity.