1.6 Computer Science

1.6 Computer Science

1. EEPROM-Electronically Erasable Programmable Read Only Memory

2. HDD-Hard Disk Drive(moving parts)

   • SDD- Solid State Drive(no moving parts)

3. I/O- Input/Output

4. System Buses

   • Address Bus- Uni-directional
     • Data Bus- Bi-directional
       • Control Bus
   • A bus is a set of parallel wires connecting two or more independent components of a computer system.

5. Processor-Cores

   • Each processor has a 'core' in which instructions are executed
     • Processors can be multi-core
       • Dual core
         • Quad core
           • 8 Core
     • Each core executes instructions independently
     • Cores
       • Quadrupling the number of cores may quadruple the number of instructions executed per second

6. RAM- Random Access Memory

   • Holds data and instructions that are currently in use by the processor
   • ROM- Read Only Memory

7. Key Words

   • Hertz- Number of cycles per second and measures processor speed
     • MHz- 1 million instructions per second
       • GHz- 1 billion instructions per second
   • Execute- carry out an instruction or program
   • Embedded system- A computer system within another device, examples; washing machines, microwaves, tumble dryers etc.
   • Clock Speed- The operating speed of a computer
   • Cache- Very fast, usually a very small amount of memory

8. Processor Speed

   • Measured Hertz(Hz)
     • Typical speeds have spanned across MHz and GHz
       • 1 GHz processor executes 1 billion instructions per second
         • 2 GHz processor executes 2 billion instructions per second

9. CPU- Central Processing Unit

   • The purpose of CPU is to carry out program instructions
     • Fetch
       • Decode
         • Execute
           • Memory stores the program

10. I/O Controllers

    • These are used to allow an interface between a hardware device external to the motherboard and the processor itself
    • I/O Ports
      • Allow communication from an I/O device and the motherboard

11. Peripherals

    • Are any devices that are not directly connected to the CPU