T1 - Memory/ Secondary storage

Question 1

Types of Primary storage:

Answer 1

RAM
ROM

Question 2

RAM:

Answer 2

Can be read from and written to
Access to RAM is much faster than a hard drive

Question 3

RAM Stores:

Answer 3

OS first, then Software + Data
RAM holds copies of running programs from hard drive, when your computer is turned on

Question 4

Volatile memory

Answer 4

When your computer is turned off, data stored is lost

Question 5

Virtual memory:

Answer 5

Opened when there is not enough free space in RAM
is part of the hard drive used as an extension to RAM

Question 6

VM Advantages:

Answer 6

Uses cheap secondary storage on the hard drive
Prevents error messages saying ‘out of memory’

Question 7

VM Disadvantages:

Answer 7

very slow to access

Question 8

Read-only memory (ROM)

Answer 8

Stores data even when a computer has no power
Data is read from ROM, but cannot be written to it
- non-volatile

Question 9

non volatile memory

Answer 9

ROM = as the data isn’t lost if the power is off

Question 10

ROM Stores:

Answer 10

• bootsrap
  -bios

Question 11

Bootstrap

Answer 11

• The initial program that is run when the computer is turned on + tells computer where OS is on hard drive

Question 12

Basic Input/Output System (BIOS)

Answer 12

• It controls basic technical configuration of the computer

Question 13

Secondary storage:

Answer 13

not directly accessible to CPU
non-volatile

Question 14

Secondary storage: Uses: hard drive

Answer 14

Programs/data stored on hard drive

Question 15

Secondary storage: Uses: Blu-rays

Answer 15

used to distribute films

Question 16

Secondary storage: Uses: Memory sticks

Answer 16

used to transport data

Question 17

Secondary storage: Uses: Magnetic tape or external hard drives

Answer 17

may be used for backup

Question 18

Secondary storage: Uses: SD cards

Answer 18

can be used for additional storage on cameras and smartphones

Question 19

Secondary storage: Types:

Answer 19

Hard Disk Drive (HDD)
Solid State Drive (SSD)

Question 20

Offline secondary storage:

Answer 20

Compact Disc (CD), Digital Versatile Disc (DVD) or BluRay
Flash memory, SD cards
Removable HDD or SSD
Magnetic tape

Question 21

Magnetic storage description

Answer 21

: Mechanical parts move over the disks surface to read and write data magnetically, or a drive head reads a magnetic tape

Question 22

Magnetic storage Features:

Answer 22

Disk contains concentric circles called tracks
Each track is divided into sectors
Disk heads mounted on mechanical arms read and write the data

Question 23

Magnetic storage used in

Answer 23

hard disks used PCs and laptops.

Question 24

Magnetic storage Advantages:

Answer 24

large storage capacity, up to 6TB or more
relatively fast write speed
very cheap compared to SSD
USB can back up data

Question 25

Magnetic storage Disadvantages:

Answer 25

Lots of mechanical parts,
durability an issue,
Not very portable

Question 26

Optical storage description

Answer 26

: Lasers read and write data using light - uses songs, videos, films.

Question 27

Optical storage Features:

Answer 27

Data is stored as pits and lands pressed into a spiral track
A laser beam passes over the pits and lands the level of reflection is measured
From this signal, 0s and 1s can be derived

Question 28

Optical storage Advantages:

Answer 28

Cheap,
very easily portable,
takes up little space physically

Question 29

Optical storage Disadvantages:

Answer 29

Less storage capacity compared to other types
Easily damaged / scratched, requires a CD reader
Slow write speeds

Question 30

Pit size and wavelength: CD + Blu-ray

Answer 30

A CD has bigger pits and lands as red light has a
larger wavelength
The smaller Blu-ray pits and lands allow it to store more data

Question 31

Solid State: description

Answer 31

Data is recorded onto solid memory chips without any moving parts

Question 32

SSD Features;

Answer 32

non-volatile flash memory to store information

Question 33

Flash memory:

Answer 33

Large electric current used to force electrons through a barrier and trap them on the other side
They remain on the other side until ‘flashed’ with a new current,
Low cost, portable, no moving parts, durable

Question 34

Flash memory: Advantages:

Answer 34

Highly durable
very fast read/write speeds,
no noisy fan or drive arm,
faster start up times

Question 35

Flash memory: Disadvantages:

Answer 35

More expensive
similar storage capacity as magnetic disks

Question 36

How to access VM from hard drive

Answer 36

the existing data in RAM needs to be copied to the virtual memory, then data in virtual memory needs to be copied to RAM