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					Hardware
                  Hardware



The physical parts of a
 computer system
             Hardware
The physical parts of a computer system
                      Hardware
               Computers based on:
1.   Vacuum tube based - c1940s
2.   Transistor based - late 50s; low cost and reliable
     transistors available
3.   Integrated Circuit (IC) based - mid 60s
4.   Large Scale Integrated (LSI) circuit based - c80s; These
     have up to 100,000 transistors on a single chip
5.   Very Large Scale Integrated (VLSI) circuit based - c90s;
     These have >100,000 transistors on a single chip.
           Types of Computers
Small (Microcomputers or Personal computers)
           $500 - $7,000

   Desktop Computers and Workstations

   Laptop Computers
   Notebook Computers
   Palmtop Computers
       Personal Digital Assistant
•   Known as handheld computers
•   PDAs are portable computers taken further
•   Pocket sized designed for use on the move
•   Use a pen as input (write directly to screen)
•   Software 'attempts' to translate handwriting by
    reference to stored prototypes
      Types of Computers (contd.)
   Medium-sized computers (minicomputers)

    - $50,000 - $200,000
    - 3 - 25 times faster than a PC
    - Scaled down mainframe
    - Designed to meet the computing needs of a
    department or small company. Typically 4-100
    concurrent users.
    - Can support a number of concurrent applications and
     often uses a time-sharing operation system that aims
     to keep the users busy.
     Types of Computers (contd.)
   Large or Mainframe Computers
    - $100,000 - $2,000,000
    - 10 - 100 times faster than a PC
- A multi-user computer designed to meet the computing needs of
  a large organization
- Generally refers to computers of the 50s and 60s
- Large number of dumb terminals were used for input/output and
  it had a large number of peripherals attached
- Can process a number of applications concurrently. This is
  known as multi-processing which aims to keep the CPU as
  busy as possible
- Usually housed in special rooms.
      Types of Computers (contd.)
   Superlarge or Supercomputers

-$2 million - $20 million
  -50 - 50,000 times faster than a PC
    - A large number of processors interconnected by a network.
    - Break up gigantic scientific problems into manageable parallel
    tasks
    - Used to simulate nuclear explosions, ocean flow, to track the
    trajectories of astronomic bodies.
          Computer Operations
   Input – entering data into the computer;
   Processing – performing operations on the
    data;
   Output – presenting results;
   Storage – saving data, programs, or output for
    future use;
   Communications – sending or retrieving data
    via the Internet, etc.
Hardware Devices
                        Data
• Data consists of raw unprocessed facts.
• The applications and users handle them to turn into
  Information.
• Information is structured, ordered and analyzed data
  useful for decision making. Data is stored in files of
  different types (documents, spreadsheets, databases,
  pictures,…)
Data Representation
         Digital data - is a
          discrete representation,
          breaking the
          information up into
          separate elements
          (digits, that is 0 and 1)



                        Bit
         How Information Is Stored
   Bit is the smallest unit of data, which denotes
    the binary value of 1 or 0, On/Off, Magnetic/Not
   Byte is the ordered collection of bits
      (eight bits grouped together)
- EBCDIC - Extended Binary Coded Decimal Interchange
  Code (8 bits per byte)
- ASCII - American Standard Code for Information Exchange
  (7 or 8 bits per byte)
Parity bit is the extra bit added to each byte to
 help detect errors
Example: "HI" = 0100100001001001
         (using binary code)
     The Computing Systems
Store, Present, and Help Us Modify:
   Text
   Audio
   Images & graphics
   Video
                  System Unit
   Houses the processing hardware for computer


   Contains:
    - CPU
    - Memory (several types)
    - Interfaces to connect external peripheral
     devices ( such as printer, etc.)
Computer Components
              CPU



 INPUT                  SECONDARY
DEVICES                  STORAGE


          BUSES
OUTPUT                 COMMUNICATIONS
DEVICES                   DEVICES




             PRIMARY
             STORAGE
               Motherboard
• The main circuit board, containing computer
  chips and other electronic components, inside
  the system unit to which all computer system
  components connect
  CPU – Central Processing Unit
• The chip located on the motherboard of a
  computer that performs the processing for a
  computer
            Multi-core CPUs
• Contain the processing components or cores of
  multiple independent processors on a single
  CPU (allow computers to work simultaneously
  on more tha one task at a time)
              Types of CPU
• Desktop c. – Intel Core i7
            - AMD PhenomII (2-4 cores)
• Workstation, server
             – Intel Xeon
             - AMD Opteron (2,4,6 cores)
• Notebook, Tablet PC
             - Intel Core 2
             - AMD Turion X2 (1, 2,4 cores)
               Computer Time

                                        # PER     COMPARED
      NAME           LENGTH          SECOND     TO 1 SECOND

     Millisecond   .001 second       thousand   15min 40 sec

     Microsecond .001 millisecond    million    11.6 days
     Nanosecond .001microsecond      billion    31.7 years

     Picosecond    .001 nanosecond   trillion   31,700 years
                              *


Computer Frequency inversely proportional to computer
time
         Processing Speed
• CPU clock speed – measurement of the
  processing speed, which is rated in megahertz
  (MHz) or gigahertz (GHz)
• Highter CPU clock speed more instractions can
  be processed per second
• Example: Core i7 3.2 Ghz
            faster than
           Core i7 2.66 GHz
                 Memory
• Chip-based storage
  - primary - amount of the computer's main
  memory (random access memory or RAM)
  - secondary - amount of long-term storage
  available to a computer (computer's hard drive
  or removable storage media)
           Types of Memory
• Cache memory and register – volatite, means
  that their content is rased when power to the
  memory ceases (like RAM)

• Read-only memory (ROM) and flash memory
  - nonvolatite
                 MEMORY SIZE
•   KILOBYTE (K): 210 bytes... 1024 bytes
•   MEGABYTE (MB): 210 KB... “million” bytes
•   GIGABYTE (GB): 210 MB... “billion” bytes
•   TERABYTE (TB): 210 GB... “trillion” bytes
                         *
 RAM (Random Access Memory)
• Temporary storage for data, programs and the
  operating system while you are using the PC
• It is volatile, meaning that the contents of memory are
  lost forever when the computer is shut off.
              RAM (contd.)
• Capacity measured in bytes
• Type of RAM that can be installed depends on
- CPU (32-bit CPU – up to 3 GB of RAM,
        64-bit – more than 3 GB)
- Operating system (64-bit version of Windows
  Vista – up to 8 GB, up to 16 or more than 128
  GB, depending on the edition)
     ROM (Read-Only Memory)
• Consists of non-erasable hardware modules that
  store program instructions
• It is non-volatile (that is „read only“)
        Ports and Connectors
• Connectors located on the exterior of the
  system unit that are used to connect external
  hardware devicrs
• Each port attached to the appropriate bus on
  the motherboard
            Storage System
• Storage medium is the hardware where data is
  actually stored (CD, flash memory card)
• Storage device is the type of drive by which
  storage media is read
   - internal (inside the CPU)
   - external (plugged into external port)
  - remote (located on another computer)
            Access Methods
• Random (direct) access, means that data can
  be retrieved directly from any location on the
  storage medium, in any order

• Sequential access, means that the data can be
  retrieved in the order in which it is physically
  stored on the medium
               Hard Drive
• Primary storage system used to store most
  programs and data used with a computer
         Types of Hard Drives
- Magnetic hard drive – a hard drive, consisting of
  one or more metal magnetic disks permanently
  sealed with an access mechanism and
  read/write heads, inside its drive
         Types of Hard Drives
• Solid-state drive (SSD) – a hard drive that uses
  flash memory instead of metal magnetic hard
  disks.
            Disc Access Time
• The total time that it takes for a hard drive to
  read/write data
• Include three steps:
   - seek time
   - rotational delay
   - data movement time
• Typically it is around 8.5.milliseconds
              Optical Disks
• A type of storage medium read from and written
  to using a laser beam (Example: CD, DVD)
• Advantages:      - large capacity
                   - durability
• Disadvantages: - fragile
                 Optical Drive
• A drive used with optical discs (CD disc, DVD disc)
            Optical Discs
• Read-Only optical disc (CD-ROM, DVD-ROM,
  BD-ROM)
• Recordable optical disc (CD-R, DVD-R,
  DVD+R, BD-R)
• Rewritable optical disc (CD-RW, DVD-RW,
  DVD+RW, BD-Re)
          Optical Disks (contd.)
1) CD-ROM - 700 MB (0.7 GB), single layer, red laser,
  cheap, outdated. For delivering music, software,
  storing data.
2) DVD+-R/RW (Digital Vesatile Disk), 4.7 GB (DVD-5)
  (single-layer), 8.5 GB (DVD-9) (dual-layer), 9.4 GB
  (double-sided disk), red laser, current, cheap. For
  software, movies, data.
3) Blu-Ray, 25 GB (single layer), 50 GB (double-layer),
  may support up to 6-8 layers in the future, blue laser,
  quite expensive. For high-definition movies, HDTV,
  data.
4) HVD (Holographic Vesatile Disk) - 3.9 TB, 2 lasers,
  very expensive, emerging.
 Other Types of Storage System
• Flash memory – a chip-based storage medium
  that store data using electrons
• Flash memory card – a small , rectangular flash
  memory medium (such as CompactFlash)
 Other Types of Storage System
            (contd.)
• Holographic storage – the type of three
  dimension (3D) storage system that uses
  multiple blue laser beams to store data in three
  dimensions
• Advantages: - speed
              - capability
              - convenient for rarely changed data
 Other Types of Storage System
            (contd.)
• Magnetic tape – storage media consisting of
  plastic tape with a magnetizable surface that
  store data as a series of magnetic spot
• Advantages: - low cost per megabyte
 Other Types of Storage System
            (contd.)
• RAID (redundant arrays of independent disks)
a storage method that uses several hard rives
  working together
• Purpose: - to increase perfomance
          - to protect critical data on storage
  server (to increase fault tolerance)
• Techniques: - disc stripping
               - disc mirroring
RAID




• RAID
                     Bus
• Electronic path over which data can travel
• Bus width is the number of wires in the bus
  over which data can travel, affects the number
  of bits being transmitted at one time
• Throughput or bandwidth is the amount of
  data that can be transferred via the bus in a
  given time period
Input Devices
                Keyboards
• An input device containing numerous keys that
  can be used to input letters, numbers, and
  other symbols
    Pointing and Touch Devices
• An input device that moves an on-screen
  pointer to allow the user to select objects on
  the screen
• Types: - mouse
        - pen/styluses
        - touch screens
                 Scanners
• An input device that reads printed text and
  graphics and transfers them to a computer in
  digital form
   Speech Recognition System

• Speech recognition systems
• Music input systems
         Music Input System
• Used to input music into a computer
Output Devices
                   Printers
• Quality mesured by dots per inch (dpi)
Speed measured in pages per minute (ppm)
• Types: - laser printers (use toner powder)
          - ink-jet printers (use liquid ink)
          - special purposes printers
  (photoprinter, 3D printer)
3D Printing
       Display Devices (Monitor,
            Display Screen)
• CRT monitors
• Flat-panel displays: - liquid crystal displays (LCD)
                    - plasma displays
• Organic light emmiting diode (OLED) displays
      Display Devices (contd.)
• Pixels – the smallest colorable area in an
  electronic image
• Screen resolution affects the amount of
  information (in pixels) displayed on the screen
                Video Card
• Installed inside computer or directly into the
  motherboard (in graphic processing unit GPU)
• Detrmins the graphic capabilities of the
  computer
Audio Output

				
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