Memory

Memory

1. Volatile memory (Loses memory when power is disconected)

2. Read / Write

3. Main Memory in the computer

4. Used a main memory in the computer – store files, data and programs when they are being used

5. Operating system is copied from secondary storage to RAM when computer is turned on

6. When software application and files are open they are copied from secondary storage to RAM. They stay there till the files or applications are closed.

7. Slower than cache but faster than secondary storage

8. MEMORY

   • ROM
     • Non – volatile
     • Read only
     • Chip built onto the motherboard
     • Contains all the instructions a computer needs to boot up . This is called the BIOS
     • Computer turns on – CPU reads instructions from the ROM – performs self checks and sets up the computer e.g. checks memory is working, what hardware devices are attached and copies the operating system to the RAM
   • Virtual Memory
     • When RAM is full it moves data that has not been recently used to secondary storage called virtual memory
     • Used if too many applications are open at one time
     • If the CPU wants o read data on the virtual memory it must move it back to the RAM
   • Computer Science
     • Networks
       • Lan
         • Data transmitting device that transmits to various devices over a short distance
         • Local area network
         • Connect multiple devices using either wifi or wires
         • Used often by small companies or schools to transmit diles
         • Uses phones, headphones, PDAs, Printers
       • Pan
         • Private area netowrk
         • Used for personal use to connect local devices together
         • Transmits data over a short distance of about 10 meters
       • Wan
         • Wide area network
         • Used over a wide geographical distance , such as over continents
         • Often used by international companies to communicate with each other
         • Uses phones, headphones, PDAs, Printers
       • Peer to Peer
         • When 2 or more computers are connected together
         • Shares the workload of the each computers
         • It shares the workload of each computer, cheaper than a server
         • All computers have the same amount of access as each other, If one gets infected with a virus or malware, all get infected, Harder to manage with no server
       • Client Server
         • Uses a powerful computer as the main computer with less powerful computers as its less