Principles of Information Systems Eighth Edition

1
Principles of Information SystemsEighth Edition

• Chapter 3
• Hardware Input, Processing, and Output Devices

2
Principles and Learning Objectives

• Assembling an effective, efficient set of
  computer hardware devices requires understanding
  their role in supporting the underlying
  information systems and the needs of the
  organization the computer hardware objectives
  are subordinate to, but supportive of, the
  information systems and the needs of the
  organization
• Describe how to select and organize computer
  hardware components to support information system
  (IS) objectives and business needs

3
Principles and Learning Objectives (continued)

• When selecting computer hardware, you must
  consider the current and future needs of the
  information systems and the organization your
  choice of a hardware device should always allow
  for later improvements to meet evolving
  organizational needs
• Describe the power, speed, and capacity of
  central processing and memory devices
• Describe the access methods, capacity, and
  portability of secondary storage devices

4
Principles and Learning Objectives (continued)

• Discuss the speed, functionality, and importance
  of input and output devices
• Identify popular classes of computer systems and
  discuss the role of each

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Why Learn About Hardware?

• Can improve productivity, increase revenue,
  reduce costs, and provide better service
• Managers are expected to know about hardware
• To help define business needs
• To ask questions and evaluate options when buying
  equipment

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Introduction

• Hardware any machinery (most of which use
  digital circuits) that assists in the input,
  processing, storage, and output activities of an
  information system
• When making hardware decisions, businesses must
  consider how the hardware can support
• Objectives of the information system
• Goals of the organization

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Computer Systems Integrating The Power of
Technology

• Choosing the right computer hardware requires
  understanding its relationship to the information
  system and needs of the organization
• Hardware objectives are subordinate to, but
  supportive of, the information system and the
  current and future needs of the organization

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Hardware Components

• Central processing unit (CPU)
• Input devices
• Output devices

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Hardware Components (continued)

• Communications devices
• Primary storage devices
• Secondary storage devices

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Hardware Components (continued)
Figure 3.1 Hardware Components
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Hardware Components in Action

• Step 1 Fetch instruction
• Step 2 Decode instruction
• Step 3 Execute instruction
• Step 4 Store results

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Hardware Components in Action (continued)
Figure 3.2 Execution of an Instruction
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Processing and Memory Devices Power, Speed, and
Capacity

• System unit
• Houses the components responsible for processing
  (the CPU and memory)
• All other computer system devices are linked
  either directly or indirectly into the system
  unit housing

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Processing Characteristics and Functions

• Machine cycle time is measured in
• Nanoseconds (1 billionth of a second)
• Picoseconds (1 trillionth of a second)
• MIPS (millions of instructions per second)

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Processing Characteristics and Functions
(continued)

• Clock speed series of electronic pulses produced
  at a predetermined rate that affects machine
  cycle time
• Often measured in
• Megahertz (MHz) millions of cycles per second
• Gigahertz (GHz) billions of cycles per second
• Microcode predefined, elementary circuits and
  logical operations that the processor performs
  when it executes an instruction

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Physical Characteristics of the CPU

• Digital circuits on chips
• Electrical current flows through silicon
• Moores Law transistor density of chips will
  double every 18 months

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Physical Characteristics of the CPU (continued)
Figure 3.3 Moores Law
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Memory Characteristics and Functions

• Main memory
• Located physically close to the CPU, but not on
  the CPU chip itself
• Rapidly provides data and instructions to the CPU

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Storage Capacity
Table 3.1 Computer Storage Units
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Types of Memory

• Random access memory (RAM)
• Temporary and volatile
• Types of RAM
• EDO (Extended Data Out)
• DRAM (Dynamic RAM)
• SDRAM (Synchronous DRAM)

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Types of Memory (continued)

• Types of nonvolatile memory
• ROM (read-only memory)
• PROM (programmable read-only memory)
• EPROM (erasable programmable read-only memory)
• Cache memory high-speed memory that a processor
  can access more rapidly than main memory

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Types of Memory (continued)
Figure 3.4 Basic Types of Memory Chips
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Types of Memory (continued)
Figure 3.5 Cache Memory
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Multiprocessing

• Multiprocessing simultaneous execution of two or
  more instructions at the same time
• Multiprocessing using coprocessors
• Coprocessor speeds processing by executing
  specific types of instructions while the CPU
  works on another processing activity

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Parallel Computing

• Parallel computing simultaneous execution of the
  same task on multiple processors to obtain
  results faster
• Massively parallel processing
• Speeds processing by linking hundreds or
  thousands of processors to operate at the same
  time, or in parallel
• Each processor has its own bus, memory, disks,
  copy of the operating system, and applications

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Parallel Computing (continued)

• Different approaches to achieving parallel
  computing
• Single instruction/multiple data (SIMD) parallel
  processors
• Multiple instruction/multiple data (MIMD)
  parallel processors
• Grid computing use of a collection of computers,
  often owned by multiple individuals or
  organizations, to work in a coordinated manner to
  solve a common problem

27
Secondary Storage

• Compared with memory, offers the advantages of
  nonvolatility, greater capacity, and greater
  economy
• Access methods, storage capacities, and
  portability required are determined by the
  information systems objectives

28
Access Methods

• Sequential access records must be retrieved in
  order
• Devices used are called sequential access storage
  devices (SASDs)
• Direct access records can be retrieved in any
  order
• Devices used are called direct access storage
  devices (DASDs)

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Devices

• Magnetic tapes
• Magnetic disks
• RAID
• Virtual tape
• Optical disks

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Devices (continued)

• Digital video disk (DVD)
• Holographic Versatile Disc (HVD)
• Memory cards
• Flash memory

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Enterprise Storage Options

• Attached storage
• Network-attached storage (NAS)
• Storage area network (SAN)

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Enterprise Storage Options (continued)
Figure 3.9 Storage Area Network
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Input and Output Devices The Gateway to Computer
Systems

• Through input and output devices, people provide
  data and instructions to the computer and receive
  results from it
• Selection of input and output devices depends on
  organizational goals and IS objectives

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Characteristics and Functionality

• Data can be human-readable or machine-readable
• Data entry converts human-readable data into
  machine-readable form
• Data input transfers machine-readable data into
  system
• Source data automation capturing and editing
  data where the data is initially created and in a
  form that can be directly input to a computer

35
Input Devices

• Personal computer input devices
• Keyboard
• Mouse
• Speech-recognition technology
• Digital cameras
• Terminals

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Input Devices (continued)

• Scanning devices
• Optical data readers
• Magnetic ink character recognition (MICR) devices
• Magnetic stripe card
• Point-of-sale (POS) devices

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Input Devices (continued)

• Automated teller machine (ATM) devices
• Pen input devices
• Touch-sensitive screens
• Bar-code scanners
• Radio Frequency Identification (RFID)

38
Output Devices

• Display monitors
• Liquid crystal displays (LCDs)
• Organic light-emitting diodes (OLEDs)
• Printers and plotters
• Digital audio player

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Special-Purpose Input and Output Devices

• Computer-based navigation systems
• Multiple function printers
• Eyebud screens

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Computer System Types, Selection, and Upgrading

• Special-purpose computers used for limited
  applications by military and scientific research
  groups
• General-purpose computers used for a wide
  variety of applications

41
Computer System Types

• Handheld computers
• Portable computers
• Thin client
• Desktop computers

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Computer System Types (continued)

• Workstations
• Servers
• Mainframe computers
• Supercomputers

43
Selecting and Upgrading Computer Systems

• Dispose of old equipment properly
• Consider factors such as speed, cost, and
  performance when upgrading
• Hard drive
• Main memory
• Printer
• DVD burners

44
Summary

• Hardware machinery that assists in the input,
  processing, storage, and output activities of an
  information system
• Hardware components central processing unit
  (CPU), input and output devices, communications
  devices, primary storage devices, and secondary
  storage devices
• Random access memory (RAM) temporary and
  volatile
• ROM (read-only memory) nonvolatile

45
Summary (continued)

• Multiprocessing simultaneous execution of two or
  more instructions at the same time
• Sequential access records must be retrieved in
  order
• Direct access records can be retrieved in any
  order
• Examples of secondary storage devices magnetic
  tapes and disks, DVDs, memory cards, etc.
• Enterprise storage options attached storage,
  network-attached storage (NAS), and storage area
  network (SAN)

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Summary (continued)

• Examples of input devices keyboards, mice,
  voice-recognition devices, terminals, scanning
  devices, and touch-sensitive screens
• Examples of output devices display monitors,
  liquid crystal displays (LCDs), printers, and
  plotters
• Computers can be classified as either
  special-purpose or general-purpose
• Computer system types handheld computers,
  portable computers, desktop computers,
  workstations, servers, etc.