3.3 data storage and compression Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is primary storage

A

directly accessed by CPU. RAM and ROM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is ROM

A
  • small piece of memory located on motherboard
  • contains startup instructions for computer
  • non volatile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is RAM

A
  • primary storage directly connected to CPU, hold data/instructions currently in use
  • volatile
  • very fast
  • data can be read from/written to
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why do you need primary storage

A
  • access time faster than secondary
  • quicker FDE cycle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is ROM

A
  • small memory chip located on computers motherboard
  • primary storage that holds first instructions computer needs to start up (bootstrap)
  • contains BIOS
  • non-volatile
  • read-only
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is secondary storage

A

not directly accessed by CPU, necessary for more permanent storage of data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how does magnetic storage work

A
  • use platters divided into tracks and sectors
  • data read/written using electromagnets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

example of magnetic storage

A

hard disk drive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

advantages of magnetic storage

A
  • cheap
  • fast
  • hold large amounts of data
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does optical storage work

A
  • use lasers to create and read pits (low) and lands (high)
  • land reflect, pits scatter. detected by light sensor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

examples of optical storage

A
  • compact disks (CDs)
  • digital versatile disks (DVDs)
  • blu-ray disks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

features of optical storage

A
  • low storage
  • slow access to data
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does solid-state storage work

A

use NAND or NOR technology. transistors used as control gates and floating gates. state of transistors represent binary (hold charge?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

types of solid state storage

A
  • solid state drives (SSDs)
  • memory cards
  • USB flash drives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

features of solid-state storage

A

no moving parts: more durable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when is virtual memory used

A

computer doesn’t have enough RAM to store all data & programs currently in use

17
Q

how does virtual memory work

A

pages of data transferred between RAM and virtual memory. (paging in/out) when data needed again, must first be copied back into RAM. v slow

18
Q

what is cloud storage

A

data stored remotely on servers, requires internet connection to access data

19
Q

cloud vs local storage

A
  • cloud can access from any computer, but require internet
  • local fully under users control
  • local always faster to access
  • cloud can have unauthorised access
  • cloud greater ability to increase capacity