Computing - OCR - GCSE - Key Points

Computing - OCR - GCSE - Key Points

1. Computer system

   • Software and hardware working together to create a coded solution
   • Input
   • Process
   • Output
   • Importance of
     • Contact
     • Bionic limbs
       • Quality of life
     • Data security
     • Save lives - emergency teams

2. Reliability

   • How dependable it is to trust a computer system to do the job you entrust it with

3. Professional standards

   • Manufacturers set standards to ensure quality control in manufacturing and repair

4. Other considerations

   • User privacy
   • Public safety
   • Environmental issues
     • Adhere to energy regulations/recycling
   • Legality issues

5. CPU - Central processing unit

   • Running programs
   • Operating system
   • Hardware in a computer system that processes data
     • Running programs
       • Operating system
   • Like a brain
   • Fetching - Searching and retrieving instructions from memory
     • Decoding - Sorting the instructions into parts for specific parts of the CPU to handle
       • Executing - Running the combination of the decoded parts
     • CPU interacts with the memory
   • Not necessarily containing the only processor in the computer system

6. HTML

   • HyperText Markup Language

7. Clock speed

   • CPU needs a certain amount of cycles to execute instructions
     • The faster cycles can be completed, the faster instructions can be execute per second. This is the clock speed.
       • Usually measure in GHz
       • Higher clock speed means increased performance

8. Number of cores

   • A CPU can have multiple processors (cores)
     • Allows multiple instructions to be executed simultaneously
       • Higher number of cores means increased performance
     • Not all programs can handle parallel computation
       • Sometimes only one core will be used when executing programs
         • In this case, clock speed would be the more important factor

9. CPU Cache

   • A type of RAM that stores frequently accessed instructions and data so it can be accessed quicker than data on the RAM
   • Web browser cache
     • For example, commonly accessed websites (like Google) will have details stored so it can be accessed quicker next time and load fast.
   • More cache means increased performance
     • More data can be accessed quickly through cache memory, so the load times will be faster
       • This helps long term performance

10. Denary

    • Base-10
      • Only uses ten digits, 0 1 2 3 4 5 6 7 8 9

11. Hexadecimal

    • Base-16
      • 0 1 2 3 4 5 6 7 8 9 A B C D E F

12. Binary

    • Base-2
      • 0 1
        • 1 on, 0 off
          • A bit is either 1 or 0
            • A single binary digit
          • A byte is 8 bits
            • 0110 1001