Hardware: Input, Processing, and Output Devices

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Hardware Input, Processing, and Output Devices

• Chapter 3

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Principles and Learning Objectives

• Assembling an effective, efficient computer
  system 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 needs of the
  organization.
• Describe how to select and organize computer
  system components to support information system
  objectives and business organization needs.

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Principles and Learning Objectives

• When selecting computer devices, you also must
  consider the current and future needs of the
  information system and the organization.Your
  choice of a particular computer system device
  should always allow for later improvements.
• Describe the power, speed, and capacity of
  central processing and memory devices.
• Describe the access methods, capacity, and
  portability of secondary storage devices.
• 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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Hardware Components

• Central processing unit (CPU)
• Primary storage (main memory memory)
• Secondary storage
• Input devices
• Output devices

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Hardware Components
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Hardware Components in Action

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

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Hardware Components in Action
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Processing Memory Devices
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Processing Characteristics and Functions

• Machine cycle time is measured in
• Microseconds (1 millionth)
• Nanoseconds (1 billionth)
• Picoseconds (1 trillionth)
• MIPS (Millions of Instructions Processed per
  Second)

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Processing Characteristics and Functions

• Clock speed electronic pulses affecting machine
  cycle time
• Hertz one cycle (pulse) per second
• Megahertz (MHz) millions of cycles per second
• Microcode internal, predefined elementary
  operations in a CPU

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Clock Speed
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Wordlength and Bus Line Width

• Bits (Binary Digits) smallest form of data in a
  computer
• Word number of bits that can be processed as a
  unit
• Bus lines electrical paths of data flow

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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

• Superconductivity - property of certain metals
  that allows current to flow with minimal
  electrical resistance
• Optical processors - uses light waves instead of
  electrical current

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Moores Law
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Complex and Reduced Instruction Set Computing

• Complex instruction set computing (CISC) -
  places as many microcode instructions into the
  central processor as possible
• Reduced instruction set computing (RISC) -
  involves reducing the number of microcode
  instructions built into a chip to an essential
  set of common microcode instructions

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Memory Characteristics and Functions
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Storage Capacity
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Types of Memory
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Types of RAM

• EDO (Extended Data Out)
• DRAM (Dynamic RAM)
• SDRAM (Synchronous DRAM)

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Types of ROM

• ROM (read-only memory)
• PROM (programmable read-only memory)
• EPROM (erasable programmable read-only memory)

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Cache Memory
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Multiprocessing

• Speeds processing by linking hundreds and even
  thousands of processors to operate at the same
  time
• Can coordinate large amounts of data and access
  them with greater speed

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Massively Parallel Processing
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Secondary Storage
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Secondary Storage

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

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Secondary Storage
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Access Methods

• Sequential records must be retrieved in order
• Devices used are called sequential access storage
  devices (SASD)
• Direct 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
• Storage area networks (SAN)
• Optical disks
• Magneto-optical (MO) disks
• Digital versatile disks (DVDs)

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Types of Secondary Storage
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Magnetic Disks
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Storage Area Network
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Digital Versatile Disk
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Additional Devices and Media

• Memory cards
• Flash memory
• Expandable storage

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Expandable Storage
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Comparison of Secondary Storage Devices
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Characteristics and Functionality

• Data - can be human or machine readable
• Data entry - converts human readable data into
  machine-readable form
• Data input - transfers machine-readable data into
  the system
• Source data automation - capturing and editing
  data at its source

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Input and Output Devices
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Input Devices

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

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Digital Computer Cameras
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Magnetic Ink Character Recognition (MICR) Device
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Output Devices

• Display monitors
• Printers and plotters
• Music devices
• Liquid Crystal Displays (LCDs)
• Active matrix
• Passive matrix

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Printers
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Computer System Types
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Computer System Types
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Standards
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Standards
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Selecting and Upgrading Computer Systems

• Hard drive considerations
• Main memory considerations
• Printer considerations

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Price List
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Summary

• Hardware - includes any machinery that assists
  with the input, processing, and output activities
  of a CBIS
• Processing speed - often measured by the time it
  takes to complete one machine cycle
• Primary storage (memory) - provides working
  storage for program instructions and data
• Common forms of secondary storage - magnetic
  tape, magnetic disk, compact disk, digital video
  disk, and optical disk storage