Chapter 2 Hardware

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Chapter 2Hardware

• Trends in Computing Systems
• Generally classified into three groups
• Mainframe computers
• Midrange (mini) computers
• Microcomputers (PCs)

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MicrocomputerApplications

• Often referred to as personal computers
• Many uses, styles, purposes
• Workstations - High power PCs used for analytical
  processing, mathematical calculations,
  statistical analysis
• Network Servers - Used to manage resources on a
  network (usually a Local Area Network)

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Microcomputers (cont)

• Personal Digital Assistants - Highly specialized
  and mobile devises
• Use special software to allow for optical
  character recognition, touch pads, pen-based
  interface, etc.
• This is the latest trend in communications devices

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Multimedia Systems

• Personal computers with a variety of media
  devices
• Allow for more robust displays, music, voice
  recognition and synthesis
• More expensive than a traditional machine, but
  much more useful and capable

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Network computers

• Designed primarily for work situations where
  users access an Intranet (network using Internet
  technologies
• These machines usually have little or no disk
  storage space
• Main benefits are low cost, ease of upgrades,
  manageable

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Computer terminals

• Dumb terminal - No processing occurs at the
  terminal level. Usually associated with a
  mainframe or client/server system
• Intelligent terminals - Have the capability to
  process at the local level (includes transaction
  terminals in grocery store, banks, department
  stores, etc)

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Midrange Systems

• Multi user systems that manage network traffic,
  file access, device management
• More powerful than a personal computer
• Less powerful than a mainframe
• Less costly to purchase, operate, maintain
• Most efficient when scope of use is narrow but
  processing needs are high

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Midrange (cont)

• Used largely in scientific research, process
  control situations, engineering (CAD, CAM, CAO)
• Sometimes used as front end processors to aid a
  mainframe system
• Good devices for telecommunications and network
  control (network servers)

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Midrange (cont)

• Can be used to host an Intranet, Extranet,
  Internet, or client/server system
• Can be configured and programmed to operate
  virtually unaided
• Do not require special climate controlled areas

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Mainframe Systems

• Physically larger than midrange, microcomputers,
  file servers
• Can process more data and faster
• Processing measured in MIPS (millions of
  instructions per second)
• High storage capacity
• Require climate controlled operating areas

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Mainframe Applications

• Support the information and processing needs of
  large corporations, government offices, military
• Can handle vast computational tasks
• Super-server for communications need of large
  client/server networks
• Data warehousing

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Supercomputer Applications

• Used by major universities, multinational
  corporations, largest government divisions
• Cooperative applications between countries
• Use multiple processors (any of which could
  constitute as a mainframe)
• 5million to 50 million cost

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Components of a Computer System

• It is important to understand the components of a
  computer as a system
• Input gt Processing gt Output gt Storage gt Control

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Input

• Input devices allow for the feeding of data to
  the computer system
• Keyboard/keypad
• Touch screen
• Light pens
• Mouse
• OCR
• Voice activation

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Processing

• Central processing unit (microprocessor in a
  personal computer)
• Performs three functions
• Control unit
• Arithmetic-Logic unit
• Primary storage unit

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Output

• Processed data in the form designated by the user
• Devices include
• video display (monitors)
• Audio response
• Printers

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Storage

• Used to store programs (computer instructions),
  data, processed information
• Two types
• Primary storage (main memory)
• Secondary storage (magnetic disk, compact disc,
  magnetic tape)

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Control

• The control unit manages and interprets programs,
  transmission to other components of the system
• Is part of the CPU
• other part is ALU
• CPU contains cache memory

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Primary Storage

• Main memory - microelectronic semiconductors
• Commonly known as RAM (random access memory)
• Sometimes main memory can use ROM (read only
  memory)
• Loss of data if power loss

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Secondary storage

• Commonly known as permanent storage
• Physical storage versus electronic storage
• Support for primary storage

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Multiple Processor Systems

• Some systems use more than one processor unit
• Several configurations
• Usually splits the control unit and the logic unit

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Multi ProcessorConfigurations

• Support Processor - Free up the main processor to
  execute program instructions (can be a math
  co-processor, video display controller or
  magnetic disk controller)
• Coupled Processor - Used mostly to provide for
  fault tolerance
• Parallel Processors - Execute instructions in
  sequence

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cont

• Massively Parallel Processors - Many processors
  aligned to execute hundreds or thousands of
  instructions at the same time
• RISC - Reduced Instruction Set Computer
• Uses less instructions

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• Conclude chapter 2 next week
• Complete coverage of chapter 3 next week