NEXT PAGE >
1.1.1 WHY COMPUTERS USE BINARY |
DATA REPRESENTATION
DESIGNED FOR CIE GCSE EXAMINATIONS
In this section, you’ll dive into how computers handle different types of data. By the end of this topic, you’ll understand the essential building blocks that allow computers to store, process, and display everything from numbers and text to images and sounds.
You’ll start by learning about number systems like binary, denary, and hexadecimal, and how to convert between them. You’ll also discover how computers add binary numbers and how overflow errors happen when there’s more data than an 8-bit system can handle.
Next, we’ll explore how computers represent text, sound, and images in binary. You’ll see how things like character sets, sample rate, and resolution play a role in file size and quality.
Finally, you’ll learn about data storage units and compression techniques, which help make files smaller for easier storage and faster transmission.
By mastering these basics, you’ll be well-prepared to understand more complex computer science concepts later on.
You’ll start by learning about number systems like binary, denary, and hexadecimal, and how to convert between them. You’ll also discover how computers add binary numbers and how overflow errors happen when there’s more data than an 8-bit system can handle.
Next, we’ll explore how computers represent text, sound, and images in binary. You’ll see how things like character sets, sample rate, and resolution play a role in file size and quality.
Finally, you’ll learn about data storage units and compression techniques, which help make files smaller for easier storage and faster transmission.
By mastering these basics, you’ll be well-prepared to understand more complex computer science concepts later on.
TOPIC 1 | DATA REPRESENTATION
1.1 NUMBER SYSTEMS
☐ 1.1.1 WHY COMPUTERS USE BINARY
☐ 1.1.2 BINARY, HEX AND CONVERTIG BETWEEN NUMBER SYSTEMS
☐ 1.1.3 BENEFITS OF HEX
☐ 1.1.4 BINARY ADDITION AND OVERFLOW
☐ 1.1.5 BINARY SHIFTS
☐ 1.1.6 NEGATIVE NUMBER REPRESENTATION, TWO'S COMPLEMENT
1.2 TEXT, SOUND AND IMAGES
☐ 1.2.1 HOW COMPUTERS REPRESENT TEX
☐ 1.2.2 HOW COMPUTERS REPRESENT SOUND
☐ 1.2.3 HOW COMPUTERS REPRESENT IMAGES
1.3 DATA STORAGE AND COMPRESSION
☐ 1.3.1 HOW STORAGE IS MEASURED
☐ 1.3.2 CALCULATING IMAGE AND SOUND FILE SIZE
☐ 1.3.3 PURPOSE OF COMPRESSION
☐ 1.3.4 LOSSY AND LOSSLESS COMPRESSION
EXTRAS
☐ END OF TOPIC REVIEW | COMING SOON
☐ TOPIC 1 KEY TERMINOLOGY
☐ REVISION FLIP CARDS
☐ TOPIC 1 ANSWERS
☐ TOPIC 1 TEACHER RESOURCES (CIE)
1.1 NUMBER SYSTEMS
☐ 1.1.1 WHY COMPUTERS USE BINARY
☐ 1.1.2 BINARY, HEX AND CONVERTIG BETWEEN NUMBER SYSTEMS
☐ 1.1.3 BENEFITS OF HEX
☐ 1.1.4 BINARY ADDITION AND OVERFLOW
☐ 1.1.5 BINARY SHIFTS
☐ 1.1.6 NEGATIVE NUMBER REPRESENTATION, TWO'S COMPLEMENT
1.2 TEXT, SOUND AND IMAGES
☐ 1.2.1 HOW COMPUTERS REPRESENT TEX
☐ 1.2.2 HOW COMPUTERS REPRESENT SOUND
☐ 1.2.3 HOW COMPUTERS REPRESENT IMAGES
1.3 DATA STORAGE AND COMPRESSION
☐ 1.3.1 HOW STORAGE IS MEASURED
☐ 1.3.2 CALCULATING IMAGE AND SOUND FILE SIZE
☐ 1.3.3 PURPOSE OF COMPRESSION
☐ 1.3.4 LOSSY AND LOSSLESS COMPRESSION
EXTRAS
☐ END OF TOPIC REVIEW | COMING SOON
☐ TOPIC 1 KEY TERMINOLOGY
☐ REVISION FLIP CARDS
☐ TOPIC 1 ANSWERS
☐ TOPIC 1 TEACHER RESOURCES (CIE)
SECTION 1 | 1.1 NUMBER SYSTEMS
Binary System
Number Conversions
Denary (base 10), binary (base 2), and hexadecimal (base 16) systems are key. You need to convert:
Hexadecimal
Binary Addition & Overflow
Logical Binary Shifts
Two’s Complement
SECTION 2 | 1.2 TEXT SOUND AND IMAGES
Text Representation
Sound Representation
Image Representation
SECTION 3 | 1.3 DATA STORAGE AND COMPRESSION
Data Storage Units
File Size Calculation
Data Compression
Binary System
- Computers use binary (base 2) to process all data.
- Data is stored in registers and manipulated using logic gates.
Number Conversions
Denary (base 10), binary (base 2), and hexadecimal (base 16) systems are key. You need to convert:
- Denary to Binary and Binary to Denary.
- Denary to Hexadecimal and Hexadecimal to Denary.
- Binary to Hexadecimal and Hexadecimal to Binary.
Hexadecimal
- Useful for simplifying binary data, as it’s more readable for humans.
- Used in areas like memory addresses and colour codes.
Binary Addition & Overflow
- Practice adding two 8-bit binary numbers.
- Overflow occurs if the result exceeds 8 bits, typically if it surpasses the value 255.
Logical Binary Shifts
- Left Shift multiplies, Right Shift divides.
- Only 0s are shifted in, and bits shifted out are lost.
Two’s Complement
- Allows representation of both positive and negative integers.
- Understand conversion between binary and denary using two’s complement.
SECTION 2 | 1.2 TEXT SOUND AND IMAGES
Text Representation
- Text is represented in binary using character sets like ASCII and Unicode.
- Unicode supports more symbols and languages than ASCII, but requires more storage.
Sound Representation
- Sound is converted to binary by sampling the sound wave.
- Sample Rate: Number of samples per second; higher rates mean better quality and larger files.
- Sample Resolution: Bits per sample; higher resolution increases accuracy and file size.
Image Representation
- Images are a grid of pixels each represented in binary.
- Resolution: Total pixels in an image. Higher resolution means better quality and larger files.
- Colour Depth: Bits per pixel to represent colour. Higher depth improves quality but increases the file size.
SECTION 3 | 1.3 DATA STORAGE AND COMPRESSION
Data Storage Units
- Common units: bit, byte, kibibyte (KiB), mebibyte (MiB), gibibyte (GiB), etc.
- Practice converting between units (e.g., 8 bits in a byte, 1024 MiB in 1 GiB).
File Size Calculation
- Use resolution and color depth (for images) or sample rate, resolution, and length (for audio) to calculate file sizes.
Data Compression
- Reduces file sizes for less storage space and faster transmission.
- Lossy Compression: Permanently removes data (e.g., reduces image resolution, and sound quality).
- Lossless Compression: Compresses without data loss (e.g., Run-Length Encoding).
COMING SOON