# Component 1.4 - Organisation And Structure Of Data (Finished) Flashcards

What is the denary counting system also known as?

The denary counting system is also known as the Base 10 or decimal counting system

How does the denary counting system represent data?

The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are used to represent numbers, e.g. 138 1 ‘hundred’ 3 ‘tens’ 8 ‘units’

What is the binary counting system also known as?

Binary counting systems is also known as the Base 2 counting system

Why must data be converted to binary format in order for it to be processed by a computer system?

Computer systems can only store and process binary digits, BITs, which are either a 1 or a 0

A binary number is ___ bits

A string of

What is the hexidecimal counting system also known as?

The hexadecimal counting system is also known as the Base 16 counting system.

How are numbers represented in the hexadecimal system?

In the hexadecimal counting system,

the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are used to represent 1–9 and then the characters A, B, C,

D, E and F are used torepresent 10 –15.

Why are hexadecimal numbers widely used rather than binary?

Hexadecimal is widely used as binary numbers can be quickly converted into hexadecimal numbers that are more convenient for humans to use.

What are shifts and what do they involve?

Shifts are manipulations of bit patterns. A shift involves moving the bits in a specified direction, either left or right, by a specified number of places

What can arithmetic shifts be used for?

Doing division and multiplication

What does logical shift right do?

Logical shift right divides a number by 2 with every shift

How does logical shift right work?

76543210

00110100

- What was in bit position 0 (the right most bit) falls off the end and is lost forever.

- What was in bit position 1 moves to bit position 0.

- What was in bit position 2 moves to bit position 1.

- etc…

- A 0 is moved into bit position 7.

What is the sign bit?

One way to represent negative numbers is through sign and magnitude. In this method, the bit at the far left of the bit pattern - the sign bit - indicates whether the number is positive or negative. The rest of the bits in the pattern store the size of the number (called its magnitude).

For example, with an 8-bit pattern, the first bit would be used to indicate positive or negative.0 can indicate a positive number and a 1 can indicate a negative number. The other seven bits would be used to store the actual size of the number.

For example, 10001001 could represent -9:

What does arithmetic shift left do?

Arithmetic shift left multiplies an integer (binary number) by two

What happens when the sign bit is eventually changed in arithmetic shift left?

An overflow occurs

How does arithmetic shift left work?

76543210

00111010

- What was in bit position 0 moves to bit position 1.
- What was in bit position 1 moves to bit position 2.
- etc…
- What was in bit position 7 (the left most bit) falls off the end and is lost forever.
- A 0 is moved into bit position 0.

What does arithmetic shift right do?

Arithmetic shift right will divide a binary number by 2 with every shift and preserve the sign of the number

How does arithmetic shift right work?

The normal shift takes place, but the sign bit stays the same as the data shifts. So if the sign bit was 0, it will be filled in with a 0, if it was 1 it will be filled in with a 1

How long can arithmetic shift left last for?

Arithmetic shift left works until the sign bit is changed, then an overflow occurs

What is the process that converts sound into a digital signal called?

Sampling

What happens in sampling?

Hardware measures the level of sound many times per second and records it as binary digits

What is the sampling frequency?

The sampling frequency is the number of times that sound level is sampled per second

The higher the ___ the ___ the quality of sound

Sampling frequency, higher

What is bit rate (sound)?

The number of bits used per second of audio

What is bit depth (sound)?

Bit depth is the number of bits available for each clip of sound

How are bitmap images stored?

Botmap images are stored as an array of pixels

How will a black and white bitmap image be stored?

It will be stored as an array with a 1 representing black pixel and 0 a white pixel

How is a colour bitmap image stored?

It is stored in an array where each pixel is represented by a number that represents how much red, green and blue is required in the colour of it

What is colour depth (of an image)?

It is how many colours are available for each pixel and is measured in bits

What values would a 1 bot colour depth, 2 bit colour depth allow for?

1 - 1 or 0

2 - 00 01 10 11

How do you calculate the number of colours available for each pixel (colour depth)

2^colour depth

So 5 bit colour depth 2^5 allows for 32 colours

How many bits colour depth is needed for RGB?

24 bits will be needed, each pixel stores 24 bits, the first 8 e.g. 11111111 give red value, next 8 green etc. Each can store a number from 0-255

What is the general file format for vector images?

SVG - scalable vector graphics

What are some common bitmap file types?

JPEG, GIF, PNG