computer systems

computer systems

1. computer systems consist of a central processing unit (cpu)

   • The cpu consists of...
     • the arithmetic logic unit carries out calculations
       • the controller which is responsible for retrieving data and information
         • registers store small pieces of information
           • • the rhythm of the cpu goes according to the fetch execute cycle
               • clock of cpu measured in hertz (hz)
   • a bus is a number of wires used to connect computer components together to enable communication
   • dual core = two processors
   • fetch execute cycle: an instruction is fetched from memory to CPU, the instruction is decoded, then the instruction is carried out

2. RAM = random access memory

   • is volatile meaning that when switched off, all memory is lost
   • is faster than a hard disk

3. ROM= read only memory

   • content cannot be edited or deleted
     • is not volatile
     • the main memory of a computer is volatile so secondary storage is needed
       • examples of optical storage:cds, dvds, blu-ray disks
       • secondary storage also include,: external hard disk, usb flash memory and cloud storage

4. input

   • an input device is a device that allows you to introduce data into the computer
   • output
     • an output device is a device that allows data to leave the computer
     • e.g speakers
   • e.g keyboard

5. human computer interface

   • the HCI of a computer interface is the means by which the machine and the user interact with each other

6. hexadecimals are used as a shorthand of binary

   • binary/logic gates
     • Computing - created from Mind Map