Memory and Storage - may need completion. most info on other deckset

Question 1

3 types of storage

Answer 1

primary
secondary
tertiary (not covered in gcse spec)

Question 2

primary storage types

Answer 2

ram
rom
cache
registers

Question 3

secondary storage types

Answer 3

hard drives
optical
solid state drives
etc

Question 4

wat is secondary storgae

Answer 4

any device able to hold OS, programs + data not currently in use

Question 5

diffferences - primary vs secondary

Answer 5

primary:
all primary, except rom - volatile
smaller storage capacity vs secondary (RAM - GB, Hard disks - TB)
faster acces spedd than 2ndry

secondary:
all non volatile
larger storgae capacity
slower access speed thn primary

Question 6

ROM

Answer 6

small piece of read only memory on motherboard
non volatile
contains 1st instructions 4 coputer (bootstrap)
software stored on ROM - firmware

Question 7

RAM

Answer 7

temprary storage of instrctions and data
holds info being xecuted by processor
volatile
much faster than hard disk

Question 8

beyond the spec
POST

Answer 8

power on self test
sends signals to all oher connected components
wakes up all connected components, makes cpu know they exist

Question 9

virual mem

Answer 9

needed when not enough ram to store open programs
held on hard disk
programs transferred out to virtual mem from ram when not currently being executed
transferred ack to ram from virtual mem when needed

Question 10

why is 2ndry storage needed

Answer 10

because rom read only and ram is volatile
needed for:
storage of programs + data when pwr turned off
semi permanent storage of data that can change
backup of data files
archive of data files

Question 11

what is a drive and media

Answer 11

drive: the device that reads and writes data from 2ndry storage

media: what the data is actually stored on

Question 12

features of optical

Answer 12

low capacity compared to other storage
slow 2 access data
thin, lightweight, portable

Question 13

features of magnetic

Answer 13

high strgae capacity
quick to access data
moving parts which eventually fail
hard disks perform better if theyre defragmented

Question 14

features solid state

Answer 14

medium storage capacity
very quick data access time
no moving parts, very reliable
no noise
low pwr
no need 2 defragment
limited num of read/write cycles
expensive

Question 15

when choosig a storage type, what must you consider

Answer 15

capacity - how much it stores
speed - how quick data read/transferred
protability - how portable is stroage device
durability - how robust is it? will be damaged by shocks and extreme conditios?
relaibiltiy - can it be used repeatedly without failing
cost - how expensive per byte

Question 16

what is optical storage suitable for

Answer 16

read only data distribution on a large scale
small capcity situations

Question 17

what is magnetic sutiable for

Answer 17

when very high data capaivty required
fast access 2 data
low cost situations
cloud storage on server farms

Question 18

what is ssd sutiable 4

Answer 18

low power small embedded systems
rugged applications: portable devices
small to medium data capaity requirements
silent operation
very fast access 2 data
situations where devices has to be small and lightweight

Question 19

optical storage types

Answer 19

cd-r
cr-rw
dvd-r
dvd-rw
blu-ray

Question 20

magnetic sotrage types

Answer 20

hard disk drive
magnetic tape
(flopy disks?)

Question 21

soldi state sotrgae types

Answer 21

ssd
memory stick
flash mem cards

Question 22

units of data capcity

Answer 22

bit - 1 or 0
nibble - 4 bits
byte - 8 bits
kilobyte - 1024 bytes (k)
megabyte - 1000000 bytes (m)
gigabyte - 1000000000 bytes (bn)
terabyte - 1 trilion bytes
petabyte - 1 quadrillion bytes

Question 23

convering between units

Answer 23

if decreasing in size:
from pb - kb -> divide by 1000 per unit type
from byte to bit - divide by 8

if increasing in size:
bit - byte -> x8
kilobyte to petabyte - x1000 per unit type

e.g
1kb x 1000 = 1mb

Question 24

difference between the units

Answer 24

MB/Mb

MB - the capital b means bytes
Mb - lower case b means bits

MB = Megabytes
Mb = Megabits

1MB = 8Mb

capaicty of drives and file sizes measured in bytes
data transfer speeds over networks mesasured in bits

Question 25

in ram how is data represented

Answer 25

by capcitors
if they hold charge - 1 bit
if not - 0 bit

Question 26

how data represented on optical

Answer 26

pit - 0
land - 1

Question 27

how data represented on hard dsk

Answer 27

north magnet pole - 1
south magnet pole - 0

Question 28

what does left binary shift adn right binary hsift do

Answer 28

left shift = multiaply og num by 2
right shift = divide og num by 2

Question 28

how data repsresnted on solid state mem

Answer 28

trapped elec - - 0
free elec - 1

Question 28

how calcualte size fle of image file

Answer 28

colour depth (num of bits needed to store each pixle) * image height (in pixels) * image width (in pixels)

Question 29

how calculate file sizeof sound file

Answer 29

sample rate (num of samples per sec) * duration (in sec)*bit depth (num of bits needed to store each sample)

Question 29

how to calculate file size of text file

Answer 29

bits per charachter (based on standard ascii char set) * num of character (inc. spaces)

Question 29

what affects quality of digitally converted sound wave

Answer 29

sample rate + bit depth

Question 30

why unicode and extended ascii released

Answer 30

not enough chars could be represented by ascii so extended ascii came out

needed representation of all international charachters for all langs so unicode came out

Question 30

two ways of storing images?

Answer 30

bitmap
vector

Question 30

how to add two 8 bit binary integers

Answer 30

1 + 0 = 1
0 + 0 = 0
1 + 1 = 0 (carry 1 across)
1 + 1 + 1(from being carried) = 1 (carry 1 acrsos as well)

Question 31

what is vector used 4

Answer 31

technical drawinfs, logos and clipart

Question 31

the character sets

Answer 31

ASCII - 7 bit (128 chars)
Extended ASCII - 8 bit (256 chars)
Unicode - 16 bit char set (2^16 chars)

Question 31

wha is metadata of bitmap image

Answer 31

additional data stored w/ image to define width, height, bits per pixel (colour depth) and colour palette

Question 31

bitmap

Answer 31

made up of diff colour ssquares
each square has binary value

Question 32

lossy comp

Answer 32

sacrificing the quality to reduce file size
JPEG and GIF use lossy comp

Question 32

vector

Answer 32

mathematics to store the image are stored
e.g
circle drawn by storing details of X and Y coords from middle
radius
width
colour

Question 33

what is bitmap used 4

Answer 33

photogrpahs not made up of simple shapes

Question 33

what r photographs storded in

Answer 33

24bit colour dpeth

Question 34

how does image file size of bitmap image inrease

Answer 34

when colour depth and resolutinon increase

Question 34

def sample rate

Answer 34

how often you record amplitude of sound wave. the more often, the smoother the playback will sound

measured in Hz
higher num smaples, higher quality and increase file size

Question 35

what is bandwidth

Answer 35

range of frequencies a system can transmit or record

Question 35

bit depth def

Answer 35

num of bits stored per sample
the more bit dpeth, better soun quality + increased file size

measured in bits

bit depth = resolution

Question 35

rasons for compresiion

Answer 35

reduces file size to increase amount you can store
smaller files are transferred quicker over the internet - compresion helps quicken transfer spds

Question 36

lossless comp

Answer 36

encodes data and looks for patterns - removes patterns and replaces w/ a code that represnets it
can be used on all types of data
can be turned back into og form
usually less effective than lossy comp at reducing file size
works well w/ image w/ lots of repeating coliur
not well w/ full colour photrpahs

Question 36

suitability of lossy and lssless

Answer 36

text files and executable code cant be compressed and lose data - lossless must be used

for images sound and vids lossy is suitable

Question 36

two types of compression

Answer 36

lossy
lossless