Memory and Storage (Revised) Flashcards
Which type of primary memory is volatile? What does this mean?
RAM-It means that data will be lost when the power is switched off
Why is the fact that ROM is “read only” beneficial for the computer
It makes it ideal for storing instructions and data,these are usually programmed by the computers manufacturer and cannot be overwritten
What does memory do in a computer
it holds data programs and instructions that are currently in use
why does RAM stand for “random access”?
because data and instructions can be fetched from any place within the memory
What is virtual memory
the use of secondary storage as additional primary memory
What does virtual memory do?
enables data that is in RAM (that is not in use) to be transferred to the hard disk. This frees up room in RAM for other programs and data. When that data is needed again, it is transferred again to RAM
Give 2 disadvantages of virtual memory
- it makes a computer run slower-because the processor has to wait when data is being swapped
- RAM can be increases to increase processing time instead
What is secondary storage?
Secondary storage is long term , non volatile storage. It’s used to keep data and programs indefinetely
list a pro and a con of a USB stick
pro-it is useful for transporting files between computers as it is extremely fast and portable
con-it is small in capacity (in comparison to a hdd)
Give 3 details on how magnetic devices work
- magnetic devices use magnetic fields to magnetise tiny individual sections of of a metal spinning disk
- magnetic devices are written to by the head moving across its surface and magnetising or demagnetising a section of the disk
- to read data, the head makes a note of which data is magnetised or not
Give 2 advantages and 2 disadvantages of magnetic disks
- magnetic disks are fairly cheap
- magnetic disks have a very high capacity
- they are easily damaged if dropped
- they are vulnerable to magnetic fields
What are pits and lands
the flat and hollow areas of the track on an optical storage device
pits = 0
lands = 1
Explain 3 examples of optical storage
rom media- has data pre=written to it often found in games, films and music. The data on these cannot be overwritten.
R - come as blank. data can only be written once, but can be read many times
RW- similar to R but can be written to multiple times
Give 3 details about solid state drives
- they are durable as they have no moving parts
- they are typically expensive, therefor they come in smaller sizes
- they use non volatile ram to store data indefinitely
which 2 forms of secondary storage are fast
solid state drives and USB sticks
