Unit 2- Computer Science

Unit 2- Computer Science

1. Input and Output Devices

   • Input devices
     • Without input devices, you wouldn't be able to access anything on your computer
     • The most suitable input devices for a range of computer controlled situations include : keyboards,mice,touch screens and a barcode reader
   • Output devices
     • Without output devices, you wouldn't be able to see what you are doing, and you wouldn't have fans or any other external components
     • The most suitable output devices for a wide range of computer controlled situations include : monitors,laser printers,ink-jet printers and speakers

2. C.P.U

   • what a C.P.U looks like
     • Storage
       • Processor
         • Output Devices
         • Input devices
         • Cache
           • main memory (Central processing unit)
   • Clock speed
     • The rate of which the C.P.U is running
     • Measured in hertz
   • C.P.U Cache
     • Reduces the average time to access information from the main memory
   • Central Processing Unit
   • Purpose of a C.P.U
     • The Fetch, Decode, Execute cycle

3. Memory

   • Stores and 'remembers' things
   • Different types of memory- some slower but cheaper, and vice versa
   • R.O.M
     • Non-Volatile
     • Stands for Read Only Memory
   • R.A.M
     • Stands for Random Access Memory
     • R.A.M is Volatile
   • Flash Memory
     • Non-Volatile
     • Commonly used storage system
   • Virtual Memory
     • A portion of the hard drive that helps R.A.M
     • Compensates for R.A.M

4. Binary

   • The computer code which represents the computers 'language'
     • Consists of 0's and 1's
       • Code makes up 'bit strings' which enables values to correspond to different letters, numbers, and symbols
   • How to convert denary numbers into binary
   • How to work out hexadecimal numbers

Imágenes y archivos del mapa