Chapter 2

Chapter 2

1. Hardware

   • The physical components of the computer that you can touch
     • Peripherals; Keyboard, monitor
     • Inside the base unit; motherboard, RAM
   • Input devices
     • Keyboard to input text.
     • Mouse: allows objects to be selected and manipulated on the screen
     • Scanner, optical mark reader
   • Storage devices
     • Hard disk
     • Flash memory
     • Optical memory
   • Output devices
     • Monitor
     • Speaker
     • Printer
       • Laser
       • Inkjet
       • Impact

2. Software

   • Consists of a code which has been written to run programs on the hardware.
   • Word processor, DTP, spread sheet

3. Standardisation

   • A set of rules that both hardware and software have to adhere to in order to be recognised.
     • Software applications are written by many different companies.
   • A lack of standardisation can cause costs, compatibility problems and restrictions to increase.
   • There are many standards that are not all compatible.
     • If you don't buy a computer of global standards then all upgrades and parts will have to come from a specific source and are likely to be expensive.

4. Specialist software

   • Sticky Keys
     • Enables users to hold down keys by just pressing them once and letting them go.
     • For users that have little use of their hands.
   • Predictive text
     • Suggests the required word when you are typing the letters.
     • For the physically disabled and for people that are dyslexic
   • Voice recognition
     • Recognised words can be used to control the interface or enter text.
     • For quadriplegics
   • Zoom
     • Makes part of the screen larger so that the user can see what's on the screen.
     • For the visually impaired

5. Specialist hardware

   • Puff and suck switch
     • A puff or a suck allows the user to select something.
   • Keyboards
     • Braille
       • Keyboard with braille writing for the visually impaired
     • Coloured
       • For dyslexic people
     • Split keyboard
       • Goes either side of your body, for physically disabled
   • Microphones
     • To control the computer or to enter text into the document (speech to text)
     • For quadriplegics
   • Footmouse
     • Control the mouse with your foot, for people with little or no use of their hands.
   • Eye typer
     • A camera follows the movement of the eye and blinking allows the user to select something
   • Braille Printer
     • Impact printer that creates braille on a page

6. Operating systems

   • A piece of software that is used to manage the hardware within a computer system.
   • Manages all communications between applications and hardware
   • Microsoft windows, google chrome
   • Typical operations
     • Responding to input devices
     • Allocating memory to applications
     • Managing security e.g. log on
   • User interfaces
     • The communication that takes place between the user and the computer.
   • Utilities software
     • File compression- makes file sizers smaller in size so that more can be fitted onto a storage medium or to make data transmission quicker.
     • Anti spam- reduces the amount of unwanted email received by an email client
     • De-fragmentation- reorganises data so that large files and programs are kept together instead of fragmented across the disk.

7. User interfaces

   • WIMP interface
   • Command based
   • Natural language
   • Forms dialogue