Hardware and Software

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Chapter 3

• Hardware and Software

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Purpose

• To be an intelligent consumer of hardware
  products
• To ask intelligent question
• What is it?
• How can I use it?
• Is it the best choice?

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Agenda

• Computer
• Hardware
• Computer Data and Instruction
• CPU (Central Processing Unit) and Memory
• Computer Performance
• Software
• Computer Virus
• Discussion and Case Study

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Computer

• Components hardware and software
• Hardware electronic components and related
  gadgetry that input, process, output, and store
  data according to software
• Software instructions encoded in computer
  programs
• Types general purpose (desk top) and special
  purpose (cell phone)

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Hardware - I

• Input
• keyboard, mouse, document scanner, bar-code
  scanner, microphone, etc.
• Processing
• Central processing unit (CPU)
• CPU selects instructions, processes them,
  performs arithmetic and logical comparisons, and
  stores results of operations in memory
• CPU is vary in speed, function, and cost
• Special function cards to augment basic
  capabilities (video display card)

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Hardware - II

• Output
• video displays, printers, audio speakers,
  overhead projectors, etc.
• Storage
• Save data and program
• Magnetic disk, optical disk (CD, DVD), magnetic
  tape
• Communication
• Wire, bus, etc.

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Figure 3-9 Magnetic Disk Components
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Magnetic Disk

• Long-term and nonvolatile data storage
• Performance depends on type and size
• Recording data on magnetic disk in concentric
  circles
• Read/write head
• Data transfer speed
• Rotational delay
• Seek time
• Width and speed of the channel

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Optical Disk

• Type
• CD (compact disk)
• DVD (digital versatile disk)
• The differences are their capacity and speed
• Burning a pit into the photosensitive material
  using a low-power laser to represent data
• The presence of a pit causes light to reflect and
  signifies a one
• The absence of reflection signifies a zero
• Usage
• Playing music and video
• Nonvolatile

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Video Display

• Type
• CRT (cathode ray tubes)
• LCD (liquid crystal display)
• Illuminating small spots on the screen called
  pixels to display image
• CRT monitor
• The dot pitch the distance between pixels on the
  screen
• The smaller the dot pitch, the sharper and
  brighter the screen image
• LCD monitor
• The pixel pitch the distance between pixels on
  the screen
• The smaller the pixel pitch, the sharper and
  brighter the image will be
• Optimal resolution
• The size of the screen, the dot or pixel pitch,
  etc.

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Input, Process, Output, and Storage Hardware
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Computer Data and Instruction - I

• Binary digits (bits)
• Zero or one
• Closed or open of a switch
• Orientation of a magnetic field
• Light reflection of a optical media
• Represent data and instruction
• Byte 8-bit
• Numbers, characters, currency amounts, photos,
  recordings, or whatever

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Bits Are Easy to Represent Physically
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Important Storage-Capacity Terminology
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Computer Data and Instruction - II

• Instruction set a collection of instructions for
  directing computer process
• Microsoft Windows Intel instruction set by Intel
  Corporation
• Macintosh computers PowerPC instruction set
  using Powerful PC processor
• Macintosh computers either Intel or PowerPC
  processor starting 2006

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CPU and Memory - I

• Motherboard a circuit board mounted and/or
  connected with processing components
• Main memory
• RAM (random access memory)
• Volatile
• A set of cells holding bytes of data or
  instruction
• Each cell has a address for identification
• Speed and amount
• House OS, application programs, and data

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CPU and Memory - II

• Cache memory
• Very fast and expensive memory to improve overall
  throughput of the CPU
• Stores frequently used data, intermediate
  results, and the most frequently used computer
  instructions
• CPU reads instructions and data from main memory
  and writes data to main memory via a data channel
  (bus)
• CPU speed
• Cycles per second, or hertz (3.0 gigahertz or 3.0
  GHz or 3 billion cycles per second)
• Data transfer speed
• The speed of main memory
• The speed and width of the data bus
• The wider the bus (by no. of bits), the more data
  transferring

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Computer Performance

• Memory swapping
• A request to the operating system to store data
  in RAM and there is not enough free memory to
  store the requested data
• The operating system has to remove something to
  make space
• Slow down the performance
• Adding more main memory to substantially improve
  the computer performance

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Software

• Operating system (OS)
• Application software

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Operating System

• Types
• Windows for business users
• Mac OS for arts community
• Unix for scientific and engineering community
• Linux developed by open-source community for web
  servers
• Own versus License issue

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Application Software

• In terms of source
• Off-the-shelf
• Custom software
• in house or consultant
• Difficulty and risky
• In terms of capability
• Horizontal-market application software for all
  organization and industry
• Vertical-market application software for specific
  industry
• Firmware
• Software installed into the device
• Print server, communication devices, etc.

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Computer Virus

• A computer program that replicates itself,
  consumes the computers resources, take unwanted
  and harmful actions
• Payload the program code causing unwanted
  activity
• Type
• Trojan horse
• Macro virus
• Worm
• Prevention
• Download
• Email
• File extension
• Antivirus
• OS patch

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Discussion

• Security (53a-b)
• How to enforce employees to follow the antivirus
  policy and procedure in any organization?
• State your opinions related to the statement the
  viruses are developed by the antivirus software
  vendor.
• Opposing forces (57a-b)
• State your opinions related to the statement the
  new computer products are the conspiracy between
  hardware and software vendors to ripe off
  consumers.
• Ethics (61a-b)
• State your opinions about the major impacts in
  terms of social, entertainment, government, and
  business operations by implementing the TCG/NGSCB
  (Trusted Computing Group/Next Generation Secure
  Computing Base)

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Case Study

• Case 3-1 not 6 and 9 (69-70)
• Case 3-2 only 1 and 2 (70-71)

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Points to Remember

• Computer
• Hardware
• Computer Data and Instruction
• CPU (Central Processing Unit) and Memory
• Computer Performance
• Software
• Computer Virus
• Discussion and Case Study