Topic 2 Hardware Revision

Topic 2 Hardware Revision

1. Input and Output Devices

   • Input
     • Keyboard
     • Microphone
     • Joystick
     • Mouse
     • Eye Scanner
   • Both
     • Headset
   • Output
     • Speakers
     • Headphones
     • Printer
     • Monitor

2. Storage

   • ROM and RAM
     • RAM
       • RAM is Volatile, RAM can store up to 4 Gigabytes and the contents can be changed. The contents are where the instructions and data is stored in RAM when it is being used. It is accessed when the computer is turned on.
     • ROM
       • ROM is Non-Volatile can store up to to 1200MB. The contents cant be changed because it is fixed. ROM is accessed when the computer is turned on. Contents are the BIOS.
   • Secondary Storage
     • Optical Disk
       • A Optical storage device which can store around 650MB of data. Often used to store music but you can use it to back up files and data. You have to be careful with it though as it can snap or get scratched.
     • Magnetic Tape
       • A Magnetic storage device that is often used to back up systems overnight. It has a large storage capacity - up to a terrabyte. The main problem is that it is a serial access so finding specific files can take time.
     • Flash Memory
       • Flash memory is a solid state storage device. It is small portable and very reliable. it can store upwards of 2GB of data. It can be plugged into a USB port in your computer.

3. Logic Gates

   • NOT Gate
     • The NOT gate is a very simple gate. IF 0 is the input then the outputs 1 and if 1 is the input then the outputs 0.
   • AND Gate
     • An AND gate needs two inputs. The AND gate tells us that if both the inputs are 1, a 1 will be output, otherwise it outputs 0
   • OR Gate
     • AN OR gate needs two inputs. The OR gate tells us if one OR both of the two inputs are 1, a 1 will be output otherwise it outputs 0