Secondary Storage Flashcards
What non - volatile storage options are there?
Hard drive, optical drive (CD), solid state drive, (SSD), USB stick
What is secondary storage used for? (HD, USB, SD cards)
Hard drives can store programs and data, memory - sticks can transfer data from one place to another, SD cards can be used for aditional storage on cameras and smartphones
What are the three main non - volatile storage methods?
Magnetic (hard drives with a magnetic strip or large moving magnet). Optical (lasers read and write data with light). Solid state (data is stored onto solid memory chips with no moving parts).
What are the basic features of a magnetic disk?
A disk will contain concentric circles called tracks that go around the disk. The disk (and tracks) are devided into sectors. Disks also gave a mechanical arm with a magnet to read and write data. A ‘hard’ drive has a solid disk. Drives with plastic disks are known as floppy disk because they are floppy.
What are the main parts of a hard drive?
Magnetic platter containing data (the disk). The drive head that reads and writes data. The actuator that moves the arm. A drive spindle that rotates the disk.
What are the advantages of magnetic storage?
Cheap, large capacity, realatively fast write speed.
What are the disadvantages of magnetic storage?
Lots of mechanical parts, not too durable, not very portable unless small.
What is the typical storage capacity of a hard drive?
500GB - 12TB or greater
What are the basic features of optical storage?
An optical drive contains pits and lands that are burnt or pressed into the drive that spiral out from the middle. A laser measures the pits and lands and converts the signal into 1s and 0s
How do CDs work ?
See showbie. Unit 1: Lesson 4, page 14.
What are the advantages of optical storage?
Cheap, very easily portable, takes up lottle pysical space.
What are the disadvantages of optical storage?
Lower storage capacity than other types, Easily damaged and scratched. Requires a CD reader. Slow write speeds.
What is the capacity of the different types of optical drives?
CD - ROM – up to 720MB. DVD - up to 8.4 GB (dual layered disk). Blu - Ray – up to 50GB (dual layered disk)
Why is the capacity of CDs, DVDs and BluRay different, given that they are the same size?
A CD uses red light to read and write data, which has a larger wavelength to blue light which BluRay uses to allow it to store more data because the indents in the disk are much smaller.
What are the basic feature of a Solid State Drive (SSD)?
SSDs use non volatile flash memory to store data. They have very fast read and write speeds as they dont need to wait for a disk to spin up to the correct location and for an arm to move. They also have no moving parts.
