1.1.3 Input Output And Storage (SLR03)

• **INPUT DEVICES**

  An input device is one which can be used to put data and information into a computer.

  Examples of input devices include:

  • Keyboard: Used to enter text into a computer
  • Webcam: A camera used by a computer to take photos and record videos
  • Magnetic: stripe reader Used to read data from magnetic stripes on cards like credit and debit cards
  • Barcode: reader Used in supermarket checkouts and access control systems to read information from printed labels and cards
• **Output Devices**

  an output device is one which can be used to send information from the computer

  Examples

  • Speaker
  • Printers
  • Monitor
• TYPES OF STORAGE DEVICES

  • OPTICAL
  • Magnetic
  • Flash(Solid State)
• The most common optical storage medium is CD/DVD, but Blu-ray discs are also available.
• Optical storage devices use laser technology to store and retrieve data.
• A disadvantage of optical storage media is that they have limited capacity compared with other types of storage.
• Types of optical disks in order of increasing capacity

  • CD’s. are small thin and light. However they are easily damaged limited storage capacity slow transfer speeds
  • DVDs. Better for video as more storage space
  • Blu ray 5x more space than dvd‘s good for storing high resolution files
• Magnetic storage uses magnetic fields to read or write data onto a disk. The two main forms of this type of storage are hard drives and floppy disks.
• Hard Drives - Hard drives are made up of many platters coated with a material called magnetically sensitive material. Each platter has a read/write head on both sides. Data is written by changing the polarity of the magnetic field at specific points on the surface of the platter. This changes the orientation of the particles within the magnetic layer so that it represents either a 0 or a 1. To read the data, the heads move over the platter and detect the change in magnetic field strength caused by the different orientations of the particles. These signals are then converted into binary code.
• Examples of Magnetic Storage

  • Hard Disk Drive
  • Magnetic Tape
  • Floppy Disks
• FLASH STORAGE

  • Fast and Compact
  • uses silicon semiconductors to form NAND and NOR gates to store electrical Charge
  • information is stored in block which are combined to form pages
  • erased an reprogrammed electronicaly and is non volatile makes
  • more expensive per gigabyte
• Examples of flash storage

  • Solid State
  • SD cards
• RAM vs ROM

  • RAM Is a type of fast main memory
  • IS Volitile
  • Rom is Read only
  • good for storing bootstrap and bios
• Virtual Storage

  • Storing information remotely
  • often an abstraction of multiple drives acting as one
  • Information can be stored on 100s of drives, often with redundancy factored in

  Examples of virtual storage

  • Cloud drives such as google drive or oneDrive
  • Networked storage used on Offices And Schools

  Evaluation of Virtual Storage

  • Convenient to access and share
  • Limited by Users Network speed
  • For Certain users High Costs can arise