Hardware Revision

Hardware Revision

1. Input/output devices

   • Definition
     • Input
       • A device that allows the user to put data into the computer
     • Output
       • A device that displays the data that has been processed from an input
   • Devices
     • Input
       • Keyboard
         • They are used for inputting text into the computer
       • Mouse
         • They are used for selecting things on the screen and moving things around
       • Microphone
         • They are used for inputting sound into the computer
     • Output
       • Speakers
         • They are used for playing sound so the user can hear it
       • Monitor
         • They are used for displaying graphics so the user can see them
       • Printer
         • They are used for giving a high quality hard copy of digital images

2. Specialised Devices

   • Types
     • Foot Mouse
       • It works by allowing the user to move their foot to control the mouse
       • It can be used for controlling the mouse
     • Braille Keyboard
       • It is used for typing like a regular keyboard
       • It works by having different patterns of bumps so blind people know which key they are pressing
     • Eye Tracker
       • It can be used for lots of different things like typing or moving the mouse
       • It works by doing different things depending on how the eye moves
     • Voice Synthesiser
       • It can be used for reading things out loud
       • It works by using text-to-speech so it can say text
     • Screen reader
       • It works by using text-to-speech
       • It can be used by blind people for reading
     • Puff-Suck Switch
       • It can do various things like the eye tracker can
       • It works by doing different things depending on how the user breaths into it
     • Voice Control
       • It can be used for doing anything
       • It works by recognising voice commands

3. Secondary storage

   • Definition
     • A piece of hardware that stores non-volatile data
   • Devices
     • Magnetic
       • Harddrive
       • Strengths
         • Fast
         • Large amount of data
         • Cheap
       • Weaknesses
         • Not easily transported
     • Flash
       • USB stick
       • Weaknesses
         • High price
         • Low storage space
       • Strengths
         • Very fast
         • More Durable
     • Optical
       • DVD
       • Weaknesses
         • Low storage space
         • Need a different device to change contents
       • Strengths
         • Good durability
         • Very transportable

4. Primary Storage

   • Definition
     • A piece of hardware that can store volatile data
   • RAM
     • Purpose
       • What it stores
         • Programs that are currently running
     • Benefits of increasing RAM
       • The computer can run more programs at once
       • The virtual memory will need to be used less
   • ROM
     • Purpose
       • What it stores
         • Bootstrap Loader
   • Virtual Memory
     • Why needed
       • If the RAM runs out of space
     • Where is it found
       • Harddrive
     • Definition
       • It is used when the RAM runs out of space

5. CPU

   • Purpose
     • The CPU is responsible for executing a sequence of stored instructions called a program
   • Cache
     • A memory from which high-speed retrieval is possible
   • Clock speed
     • The amount of hertz that can be processed per second
   • Cores
     • The more cores a CPU has, the more simultaneous programs it can run