1.2 primary and secondary data Flashcards
(22 cards)
Where is secondary storage memory located
Attached to mother board via wires
Where is primary storage memory located
Directly on motherboard
What is ROM
Stores permanent data and instructions which are needed when the computer is powered up
What is RAM
Stores temporary, currently running data which is wiped when computer is turned off
Is RAM volatile or non - volatile
Volatile
Is ROM volatile or non volatile
Non volatile
What is virtual memory
Section of temporary data on secondary storage e.g. the hard drive for when the RAM gets full. When this data is needed it sends it to the RAM and any unused data is sent back to the hard disk drive
What are the two types of primary data
RAM and ROM
Pros and cons of primary data
Quick to access as it is on motherboard
Limited space
Cons of virtual memory
It is slower as it is secondary storage
Is secondary data volatile
No, all contents are kept
What are the three common types of secondary data
Magnetic, optical and solid state
Example of magnetic storage device
Hard disk drive
Examples of optical storage devices
CD, DVD and Blu-ray
Examples of solid state storage devices
Solid state drive, USB memory stick
How do magnetic devices work
Use magnetic fields to magnetise tiny individual sections of a metal disk. A magnetised section represents binary 1 and demagnetised represents 0. To write data, the head magnetises/ demagnetises sections and to read it, it makes a note on if it’s magnetised or not
Magnetic devices characteristics
Fairly cheap, high in capacity, durable, susceptible to damage, vulnerable to magnetic fields
How do optical devices work
Use a laser scanner to scan the surface of a spinning disc. Disc surface has different tracks which have flat areas (lands) which reflects the light back and hollows (pits) which scatter the laser. Reflected light (flats) represents a binary 1 and no reflection (pits) represents 0
Three types of optical media
ROM (pre-written), R media (blank so can be written to once), and RW (similar to R but can be written on many times)
How do solid state drives work
Use non - volatile RAM to store data indefinitely
Solid state device characteristics
Expensive, smaller in capacity, require little power, durable, portable,
Optical device characteristics
Portable, cheap, easily damaged, portable
