OCR AS ICT Unit 1 Chapter 2

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  • Created by: Sqd3
  • Created on: 16-04-14 15:15

Chapter 2 - Hardware & Software

Hardware: The physical components that make up a computer. (e.g. mouse)

Software: The programming code that makes the computer work. (e.g. applications)

  • System software: Control the working of the computer. (e.g. OS)
  • Application software: Help complete a certain task. (e.g. word processor)



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Chapter 2 - Standardisation

StandardisationThe imposition, by a third party, of a set of standards on manufacturers.

Advantages of standardisation:

  • Allows hardware from one manufacturer to work with that from another. (e.g. USB)

.

A lack of standardisation is when hardware/software made from one company isn't compatible with others made from another company.

Disadvantages of a lack of standardisation:

  • No communication between systems.
  • Purchasing a computer that isn't part of a global standard > all upgrades and parts have to come from specific sources > very expensive.
  • New equipment is needed to bridge gap > very expensive.
  • Limited technical support on the systems > very expensive.
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Chapter 2 - Input Devices

Input Device: Device that gets external information into a system.

  • Keyboard - QWERTY, alphabetical, dvorak, concept.
  • Mouse - joystick, tracker ball, touch pad.
  • Scanner:
    • Barcode - tills - convert barcode to numbers
    • Optical Mark Reader - lottery - checks for present marks
    • Magnetic ***** Reader - credit cards - reads data on magnetic strip
    • Flatbed Scanner - takes image and converts to digial information.
  • Graphics Tablet - flat working areas that has a stylus that can write on it.
  • Digitiser - an item that converts analogue into digital.
  • Microphone
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Chapter 2 - Output and Storage Devices

Output Device: A device that displays the result of processing to the user.

  • Monitor - Displays signals from a computer from a computer.
  • Printer - Print hard copies of information from a computer.
    • Laser Printer - High resolution non-impact, colour and black & white, high costs.
    • Inkjet Printer - Spray ink on paper, quiet, colour and black & white, low costs.
    • Dot Matrix Printer - Impact printer, noisy, colour and black & white.
  • Speakers
  • LED

.

Storage DeviceA device that stores data.

  • Hard Disk Drive
  • CD-ROM   = Portable (stores 700mb)
  • DVD   = Portable (stores > 4.7GB)
  • USB Memory Sticks   = Portable (large storage capacity)
  • External Hard Drives = Portable
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Chapter 2 - Specialist Hardware Devices

Visually Impaired: People who have a loss of vision - it may be total loss of vision in one or both eyes or partial loss.

  • Braille Keyboard - a keyboard with Braille dots on the keys
  • Microphone - an input device for voice recognition.
  • Loudspeaker - an output device for hearing signals and text read out.
  • Screen magnifier - a magnifying glass that fits on top of the screen and enlarges parts of it.
  • Braille printer - an impact printer that can create Braille on a page.
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Chapter 2 - Specialist Hardware Devices

Motor Impaired: People who have a loss or limitation of function in muscle control or movement.

  • Mouth stick - a stick for controlling input with the mouth.
  • Puff-Suck switch - a tube placed in the mouth and blown/sucked through.
  • Eye typer - a device that fits onto the muscles around the eye and when the eye is moved a pointer on the screen moves.
  • Foot mouse - a mouse that is controlled by the foot.
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Chapter 2 - Specialist Software

Specialist software for the physically impaired:

  • Text-to-speech system - Takes written text and outputs it using a speech synthesiser.
  • Speech-to-text system - Takes spoken words and inputs them into a computer.
  • Screen Magnifier - Zooms in on areas of the screen.
  • Predictive Text - Suggests the required word as the letters are typed.
  • Sticky Keys - Allows keys to be pressed once and the system acts as if been held down.
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Chapter 2 - Types of Software

4 Main Types of Software:

  • Operating Systems:
    • Controls the allocation and use of hardware resources (e.g. memory, CPU time and hard disk space)
    • Performs basic data management tasks (e.g. recognising input from the keyboard).
  • User Interfaces:
    • The means by which the user interacts with an application or operating system.
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Chapter 2 - User Interfaces

Styles of User Interfaces:

  • Command Line - User types instructions with a command prompt to control what the computer does.
    • Many commands have switches > Adds functionality.
    • Useful for running commands which can't be accessed from a menu or form.
    • Good for experienced users.
    • Low memory overheads than a GUI > Run commands faster.
    • Need to know the commands.
    • Lots of typing so errors are common.
  • Forms - Provides prompts to fill in information.
    • Guide inexperience users by entering the relevant information in a structured manner.
    • Data entry boxes can be validated.
    • Limited options are presented > not flexible.
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Chapter 2 - User Interfaces

  • Menus - A series of related items that can be selected. (either pop-up or drop-down)
    • Can be cascaded (one menu leads to another)
    • Experienced users can't jump through screens.
  • Natural Language - Allows the users to use their own language to communicate with the computer.
    • Two Types of Natural Language:
      • Spoken - Typified by voice recognition software in word processors.
      • Written - Questions are types in natural language.
  • WIMP - Windows, Icons, Menus and Pointer. (A type of GUI)
    • Easy to use for beginners.
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Chapter 2 - Types of Software (Continued)

  • Utilities:
    • Programs that assist in the monitoring and maintaining of the computer system. (e.g. Virus checkers, file compression software and printer monitorying software).
  • Applications Software:
    • Allows the computer to be used to solve problems and perform tasks for the user (e.g. word processors, databases and spreadsheets)
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