Computer Hardware (topic two)

Computer Hardware (topic two)

1. Memory

   • Any non cache storage
     • e.g memory stick
     • e.g hard drive
     • e.g optical disk

2. Input and output devices

   • input devices are used to input instructions to the computer
   • Output devices output the processed results of the instructions, e.g a monitor

3. The cpu

   • The CPU has three seperate units
     • The registers
       • AKA cache, they are small banks of extremely fast temprorary memory
         • there are 3 levels of cache, level 1, level 2, and level 3 cache.
     • the control unit (CU)
       • This controls the computer, and decides which data must be acted upon
     • The arithmetic logic unit (ALU)
       • Performs all mathematical operations on data

4. Binary logic

   • There are 3 different binary gates
     • AND gates
       • the AND gate tells us if both inputs are 1, by outputting 1, otherwise it will output 0
     • NOT gates
       • The not gate will output the opposite of its input, for example if the input is 1, the output will be 0
     • OR gates
       • the OR gate tells us if one or both inputs are 0, by outputting 0, otherwise it will output 1

5. ROM, and RAM

   • ROM, aka read only memory
     • Non rewriteable memory, used by the cpu during the boot up sequence
   • RAM, aka, random access memory
     • Temprorary memory used to store files that you have open t one time