1.1,1.2,1.3 Mind Map

1.1,1.2,1.3 Mind Map

1. Virtual memory

   • What is virtual memory?
     • Virtual memory is when RAM is full then it simulates the memory onto the hard drive
   • Why is virtual memory needed?
     • Virtual memory is needed to run applications on the computer more than what RAM can support and it lets more meory to be used in the system
   • How is virtual memory implemented?
     • VMM- Virtual memory manager
       • VMM creates a file on the hard disk
         • OS can then address the memory

2. Solid State Media

   • No moving part
     • Uses flash memory

3. What can be store in RAM?

   • The thing that gets stored in RAM is programs that are currently used and data

4. What are the three types of secondary storage?

   • The three types are optical, magnetic and solid state

5. What is the main difference between RAM and ROM?

   • The main difference between RAM and ROM is that ROM is a form of non-volatile memory and RAM is volatile memory

6. What is the purpose of a processor?

   • the purpose of a processor is that is processes data and carries out he instructions

7. processors also have 'cache'. this is very fast, and usually a very small amount of memory on the processors chip

   • the cache acts as and intermediary between the processor and the main memory
     • as programs are executing- the cache hols commonly used instructions

8. what affects performance

   • clock speed- doubling the clock speed will double the number of instructions per second
   • cores- quadrupling the number of cores may quadruple the number of instructions executed per second
   • cache size- increasing the cache size will reduce the number of memory to disk transfers and this may speed up the processing of these instuctions

9. embedded system

   • a computer system that is made up of both hardware and software
     • usually for very specialised tasks

10. MAIN MEMORY

    • ROM- Read Only Memory
      • instructions are permanently attached onto the ROM chip
      • when power is turned off- instructions still remain on the ROM chip
      • bootstrap loader is held in ROM
        • it gives instructions to start up the operating system
    • EEPROM- electronically erasable programmable read only memory
      • instructions/data can be erased electronically and replaced

11. I/O controllers

    • these are used to allow an interface between a hardware device external to the motherboard and the processor itself
    • I/O controllers are used for: keyboard, mouse, disk drive and VDU

12. system buses- a bus is a set of parallel wires connecting two or more independent components of a computer system in order to pass signals between them

    • the system is split into three separate busses: the data bus, the address bus and the control bus
      • the data bus- is a system within a computer or device, consisting of a connector or set of wires, that provides transportation for data.
        • the address bus- is a computer bus architecture used to transfer data between devices that are identified by the hardware address of the physical memory
          • the control bus- used by CPUs for communicating with other devices within the computer.