computer

what numbers does denary have

base 10 (1-9)

how many digits does hexadecimal have and how are they represented

base 16

1-9 is normal

10 11 12 13 14 15 is a b c d e f

why is hexadecimal used

easy to read/write

uses fewer characters

less likely to make mistakes

how much binary digits is 1 hexadecimal digit worth

4

when adding binary numbers

0+0=

0+1=

1+0=

1+1=

1+1+1=

0+0=0

0+1=1

1+0=1

1+1=0 carry 1

1+1+1=1 carry 1

overflow error

the maximum denary of an 8 bit binary number is 255, a 9th bit is a clear indication that the sum exceeded this value.

in other words, the sum is too big to be stored using 8 bits

what do you do when asked to binary shift to the left or to the right

left=multiply

right=divide

what needs to happen for a cpu to multiply a binary number

the number needs to be shifted to the left

what happens during the multiplication shifting process

bits can be lost from one end of the register while zeros are added to the opposite end

whats a character set

a list of characters defined by computer hardware and software enabling the computer to understand human characters

What are some examples of a character set

ASCII(american standard code for international interchange)

Extended ASCII

unicode

how much binary bits does ASCII use and how much characters does its character set provide

it uses 7 and this provides a character set that has 128 different characters

How much characters does extended ASCII allow and what are some of its benefits

256 characters and 8 bits

it gives another 128 codes for characters in non-english alphabets and some graphical characters to be included

how much bits does unicode use and how much characters does it enable

it used 16 bits and enables over 65000 characters

how can sound be processed by a computer and whats the digital recording called

The analog signal must be converted into a digital format, a microphone captures the sound and software converts the analog signal to digital, this digital recording is called a sample

how is sampling used to record a sound clip

the amplitude of the sound wave is measured on specific time intervals, each sample is then encoded as a series of binary digits

What’s a pixel

an identifiable dot on an image

what does a bitmap represent

a collection of bits that form a specific image when displayed on a monitor

In a black and white image, each image requires only one bit per pixel and each pixel can be one of two colors, so how many colors does 1 2 3 4 and 5 bits represent

1=2

2=4

3=8

4=16

5-32

what is color depth

the number of bits used to represent each color

what is image resolution

the number of pixels that make up an image

1 byte = ? bits

1 nibble = ? bits

1 byte=8 bits

1 nibble = 4 bits

what is a bit

the basic unit of all computing memory

order bytes KIB MIB GIB from smallest to biggest

Bytes

x1024= KIB

x1024=MIB

x1024=GIB

what is the equation for file size and file size for sound

file size= pixels x bits

file size for sound= sample rate x sample resolution x length of sample

What are the effects of reducing file size on lossy and lossless

lossy : File compression algorithm eliminates unnecessary data from the file and the original file cannot be reconstructed once it has been compressed

lossless: All the data from the original uncompressed file can be reconstructed, this is important for files where loss of data would be disastrous

what’s a mac address

it is a unique static address that is used to identify a device and set by the manufacturer

Differences and characteristics of lossy and lossless compression

lossless

no data is permenantly lost

best when accuracy is essential

usually gives a smaller reduction in file size than lossy

E.G text programs, important documents

lossy

some data is permenantly removed

decompressed file is not identical to the original

the more compression used, the smaller the file but generally lower quality

best when a small file size is more important than perfect quality

E.g JPEG images, MP3 audios, videos

3 benefits of reducing file size

Saving storage space

reducing cost

reduce streaming time

give 5 examples for hexadecimal to be used

URL

ip address

Ascii

Unicode

Assembly language

how is a mac address represented

in hexadecimal