Computer Hardware

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Computer Hardware
Orasa T.
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Learning Objectives

• Identify the major types and uses of
  microcomputer, midrange, and mainframe computer
  systems.
• Outline the major technologies and uses of
  computer peripherals for input, output, and
  storage.

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Learning Objectives (continued)

• Identify the components and functions of a
  computer system.
• Identify the computer system and peripherals you
  would acquire or recommend for a business of your
  choice.

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Section I

• Computer Systems End User and Enterprise
  Computing

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Types of Computer Systems

• All computers are systems of input, processing,
  output, storage, and control components.
• Three basic categories
• Mainframe
• Midrange computers
• Microcomputers

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Types of Computer Systems (continued)

• Mainframe
• Enterprise systems
• Superservers
• Transaction processors
• Supercomputers

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Types of Computer Systems (continued)

• Midrange
• Network servers
• Minicomputers
• Web servers
• Multi-user systems

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Types of Computer Systems (continued)

• Microcomputers
• Personal computers
• Network computers
• Technical workstations
• PDAs
• Information appliances

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Microcomputer Systems

• The most important category of computers
• Desktop
• Laptop
• Workstation computers
• Network servers

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Microcomputer Systems (continued)

• Selection criteria
• Solid performance at a reasonable price
• Operating system ready
• Connectivity

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Microcomputer Systems (continued)

• Network computers
• Designed primarily for use with the Internet and
  corporate intranets
• For specialized or limited computing applications
• Lower cost of purchase, upgrades, maintenance,
  and support

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Microcomputer Systems (continued)

• Network computers (continued)
• Other benefits
• Ease of software distribution and licensing
• Computing platform standardization
• Reduced end user requirements
• Improved manageability

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Microcomputer Systems (continued)

• Information appliances
• PDAs
• Set-top boxes and video-game consoles
• Wireless PDAs
• Cellular and PCS phones

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Microcomputer Systems (continued)

• Computer terminals
• Dumb terminals
• Intelligent terminals
• Network terminals
• Transaction terminals

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Midrange Computer Systems

• Multi-user systems that can manage networks of
  PCs and terminals
• Less costly to buy, operate, and maintain than
  mainframes
• Popular as network servers
• Minicomputers

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Mainframe Computer Systems

• Large, fast, powerful
• Handle high transaction processing volumes or
  complex computational problems
• Super servers for large client/server networks
  and high-volume Internet websites
• Popular for data mining and warehousing

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Mainframe Computer Systems (continued)

• Supercomputers
• Extremely powerful systems specifically designed
  for scientific, engineering, and business
  applications requiring extremely high speeds for
  massive numeric computations
• Use parallel processing architectures
• Process at speeds measured in gigaflops and
  teraflops

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The Computer System Concept

• Computers are organized according to the
  following system functions
• Input
• Keyboards
• Touch screens
• Pens
• Electronic mice
• Optical scanners
• Convert data into electronic form

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The Computer System Concept (continued)

• Processing
• Central Processing Unit (CPU)
• Two subunits
• Arithmetic-Logic Unit (ALU)
• Control Unit

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The Computer System Concept (continued)

• Output
• Video display units
• Printers
• Audio response units
• Convert electronic information into
  human-intelligible form

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The Computer System Concept (continued)

• Storage
• Store data and software instructions
• May also include cache memory
• Primary storage unit (hard drive)
• Secondary storage
• Magnetic disks
• Optical disk drives

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The Computer System Concept (continued)

• Control
• The registers and other circuits of the control
  unit interpret software instructions and transmit
  directions to the other components of the
  computer system

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The Computer System Concept (continued)

• Computer processing speeds
• Milliseconds (thousandths of a second)
• Microseconds (millionths of a second)
• Nanoseconds (billionths of a second)
• Picoseconds (trillionths of a second)

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The Computer System Concept (continued)

• Clock speeds
• Megahertz (MHz)
• Millions of cycles per second
• Gigahertz (GHz)
• Billions of cycles per second

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Section II

• Computer Peripherals Input, Output, and Storage
  Technologies

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Peripherals

• Generic name given to all input, output, and
  secondary storage devices
• Depend on direct connections or
  telecommunications links to the CPU
• All peripherals are online devices

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Input Technologies
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• Natural user interface
• Enter data and commands directly into a computer
• Electronic mice and touch pads
• Optical scanning, handwriting recognition, voice
  recognition

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Pointing Devices

• Used for entering data and text
• Work with your operating systems graphical user
  interface (GUI)
• Electronic mouse
• Trackball
• Pointing stick
• Touch pad
• Touch screen

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Pen-Based Computing

• Used in many hand-held computers and PDAs
• Digitizer pen
• Graphics tablet

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Speech Recognition Systems

• Digitize, analyze, and classify your speech and
  its sound patterns
• Allow operators to perform data entry without
  using their hands to key in data or instructions
• Speaker-independent
• Voice-messaging computers

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Optical Scanning

• Read text or graphics and convert them into
  digital input
• Employ photoelectric devices to scan the
  characters being read

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Optical Scanning (continued)

• Optical character recognition (OCR)
• Reads OCR characters codes
• Merchandise tags
• Product labels
• Sort mail, score tests
• Hand-held optical scanning wands
• Reads bar coding
• Universal Product Code (UPC)

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Other Input Technologies

• Magnetic stripe technology
• Credit cards
• Smart cards
• Embedded microprocessor chip
• Debit, credit, and other cards
• Digital cameras
• Still cameras
• Digital camcorders

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Other Input Technologies (continued)

• Magnetic ink character recognition (MICR)
  technology
• Used by banks to sort and post checks and deposit
  slips
• 14 characters of a standardized design
• Reader-sorters
• Video
• Print
• Storage

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Video Output

• Video monitors
• Cathode ray tube (CRT)
• Liquid crystal displays (LCDs)

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Printed Output

• Inkjet
• Spray ink onto the page one line at a time
• Laser
• Use an electrostatic process similar to a copier

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Storage Trade-Offs
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Storage Trade-Offs (continued)

• Computer storage fundamentals
• Information is stored through the presence or
  absence of electronic or magnetic signals
• Binary representation
• 1 ON
• 0 OFF

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Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)
• Bit
• The smallest element of data
• May have a value of either one or zero
• Byte
• Basic grouping of bits
• Typically, a byte consists of 8 bits and
  represents one character of data

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Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)
• Storage capacities
• Kilobytes (KB)
• 1,000 bytes
• Megabytes (MB)
• 1 million bytes

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Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)
• Gigabytes (GB)
• 1 billion bytes
• Terabytes (TB)
• 1 trillion bytes
• Petabyte (PB)
• 1 quadrillion bytes

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Storage Trade-Offs (continued)

• Direct and sequential access
• Terms direct access and random access describe
  the same concept
• An element of data or instructions can be
  directly stored and retrieved by selecting and
  using any of the locations on the storage media
• Each storage position
• Has a unique address
• Can be individually accessed in approximately the
  same time

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Storage Trade-Offs (continued)

• Direct and sequential access (continued)
• Sequential access
• Does not have unique storage addresses
• Serial process
• Data are recorded one after another in a
  predetermined sequence.
• Locating an individual item requires searching
  all of the data until the desired item is located

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Storage Trade-Offs (continued)
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Semiconductor Memory

• Primary storage of your computer
• Advantages
• Small size
• Great speed
• Shock and temperature resistant
• Disadvantage
• Volatility

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Semiconductor Memory (continued)

• Two basic types of semiconductor memory
• RAM random access memory
• Volatile memory
• Read/write memory
• working memory

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Semiconductor Memory (continued)

• ROM read only memory
• Nonvolatile
• Used for permanent storage
• Can be read but not erased or overwritten
• Variations of ROM
• PROM
• Programmable read only memory
• EPROM
• Erasable programmable read only memory

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Magnetic Disk Storage

• Most common form of secondary storage
• Data is recorded on tracks in the form of tiny
  magnetized spots
• Thousands of bytes recorded on each track

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Magnetic Disk Storage (continued)

• Types of Magnetic Disks
• Floppy disks
• Zip disks
• Hard disk drives

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Magnetic Disk Storage (continued)

• Redundant arrays of independent disks (RAID)
• Provides large capacities with high access speeds
• Data are accessed in parallel over multiple paths
  from many disks
• Fault tolerant
• Storage area networks (SANs)
• Fiber channel LANs that connect many RAID units

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Magnetic Tape Storage

• Used as secondary storage
• Also used in robotic automated drive assemblies
• Lower-cost storage
• Archival storage

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Optical Disk Storage

• CD-ROM
• CD-R
• CD-RW
• DVD
• DVD-ROM
• DVD-RAM

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Optical Disk Storage (continued)

• Business applications
• Image processing
• Provide access to reference materials in a
  convenient, compact form
• videos

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Discussion Questions

• Do you agree with the statement The network is
  the computer?
• What trends are occurring in the development and
  use of the major types of computer systems?

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Discussion Questions (continued)

• Do you think that network computers (NCs) will
  replace personal computers (PCs) in business
  applications?
• Are networks of PCs and servers making mainframe
  computers obsolete?

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Discussion Questions (continued)

• What trends are occurring in the development and
  use of peripheral devices? Why are those trends
  occurring?
• When would you recommend the use of each of the
  following
• Network computers
• NetPCs
• Network terminals
• Information appliances in business applications

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Discussion Questions (continued)

• What processor, memory, magnetic disk storage,
  and video display capabilities would you require
  for a personal computer that you would use for
  business purposes?
• What other peripheral devices and capabilities
  would you want to have for your business PC?

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Real World Case 1 City of Richmond Tim Beaty
Builders
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• The Business Value of PDAs
• What are the business benefits of PDAs for
  business applications?
• What are the limitations of PDAs for business
  use?

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References
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• James A. O'Brien George M. Marakas.
  Management Information Systems Managing
  Information Technology in the Business Enterprise
  6th Ed., Boston McGraw-Hill/ Irwin,2004