3.2.2
ASCII
American Standard Code for Information Interchange
American Standard Code for Information Interchange
The American Standard Code for Information Interchange (ASCII) character set is the most common character set.


ASCII
ASCII
- Each character in ASCII is represented by a seven-bit binary code.
- That means there is a maximum of 128 characters.
- ASCII includes all commonly used letters and symbols in the English language.


7-bit letters?
7-bit letters?
- Each letter is represented by seven bits.
- This is useful because when used in an 8-bit system, the extra bit can be used as a check digit.


Limitations of ASCII
Limitations of ASCII
- 128 characters is perfectly fine for the English language. But it does not leave space for characters from other languages.
- An extended ASCII set was released which used all eight bits, but it was still not enough.
- This led to the release of Unicode.
1Problem Solving
1.1Algorithms
1.2Decomposition & Abstraction
2Programming
2.1Develop Code
2.2Constructs
2.3Data Types & Structures
2.6Subprograms
3Data
3.2Data Representation
3.3Data Storage & Compression
3.4Encryption
4Computers
4.1Machines & Computational Modelling
4.2Hardware
4.2.1Elements of Computer Systems
4.2.2Types of Computer Systems
4.2.3Memory - RAM
4.2.4Memory - ROM
4.2.5Memory - Cache
4.2.6Running Out of Memory
4.2.7Virtual Memory
4.2.8Magnetic Storage
4.2.9Properties of Magnetic Media
4.2.10Examples of Magnetic Storage
4.2.11Solid State Storage
4.2.12Properties of Solid State Media
4.2.13Optical Storage
4.2.14Properties of Optical Storage
4.2.15Examples of Optical Storage
4.2.16Types of Optical Disk
4.2.17Von Neumann Architecture
4.2.18Registers of the Central Processing Unit (CPU)
4.2.19Fetch-Decode-Execute Cycle
4.2.20Factors Affecting CPU Performance
4.2.21The Cloud
4.2.22How the Cloud Works
4.2.23The Cloud - Pros
4.2.24The Cloud - Cons
4.2.25End of Topic Test - Hardware
4.4Software
5Communication & The Internet
5.1Networks
5.1.1Benefits of Networks
5.1.2Network Performance
5.1.3Types of Network
5.1.4Client-Server Model
5.1.5Pros of Client-Server Model
5.1.6Cons of Client-Server Model
5.1.7Peer-to-Peer Model
5.1.8Pros of Peer-to-Peer Model
5.1.9Cons of Peer-to-Peer Model
5.1.10Network Hardware
5.1.11Transmission Media
5.1.12WiFi
5.1.13WiFi Frequency and Channels
5.1.14WiFi Encryption
5.1.15Network Protocols
5.1.16Transmission Protocols
5.1.17Web Protocols
5.1.18Email Protocols
5.1.19Layers
5.1.20TCP and OSI Models
5.1.21Advantages of Layering
5.1.22Topology - Star
5.1.23Topology - Mesh
5.1.24Topology - Ring
5.1.25Topology - Bus
5.1.26End of Topic Test - Networks
5.2Network Security
6The Bigger Picture
6.1Emerging Trends, Issues & Impact
6.1.1E-Waste
6.1.2Energy Consumption
6.1.3Positive Environmental Impact
6.1.4Ethical Issues - The Digital Divide
6.1.5Ethical Issues - Net Neutrality
6.1.6Ethical Issues - Working Conditions
6.1.7Ethical Issues - Censorship
6.1.8Online Activity Tracking
6.1.9The Internet of Things
6.1.10Positive Cultural Impacts
6.1.11Negative Cultural Impacts
6.1.12Data Protection Act
6.1.13Computer Misuse Act
6.1.14Copyright Designs and Parents Act
6.1.15Creative Commons Licensing
6.1.16Freedom of Information Act
6.1.17Open Source Software
6.1.18Proprietary Software
6.1.19Licensing Issues
6.1.20End of Topic Test - Software & Issues
Jump to other topics
1Problem Solving
1.1Algorithms
1.2Decomposition & Abstraction
2Programming
2.1Develop Code
2.2Constructs
2.3Data Types & Structures
2.6Subprograms
3Data
3.2Data Representation
3.3Data Storage & Compression
3.4Encryption
4Computers
4.1Machines & Computational Modelling
4.2Hardware
4.2.1Elements of Computer Systems
4.2.2Types of Computer Systems
4.2.3Memory - RAM
4.2.4Memory - ROM
4.2.5Memory - Cache
4.2.6Running Out of Memory
4.2.7Virtual Memory
4.2.8Magnetic Storage
4.2.9Properties of Magnetic Media
4.2.10Examples of Magnetic Storage
4.2.11Solid State Storage
4.2.12Properties of Solid State Media
4.2.13Optical Storage
4.2.14Properties of Optical Storage
4.2.15Examples of Optical Storage
4.2.16Types of Optical Disk
4.2.17Von Neumann Architecture
4.2.18Registers of the Central Processing Unit (CPU)
4.2.19Fetch-Decode-Execute Cycle
4.2.20Factors Affecting CPU Performance
4.2.21The Cloud
4.2.22How the Cloud Works
4.2.23The Cloud - Pros
4.2.24The Cloud - Cons
4.2.25End of Topic Test - Hardware
4.4Software
5Communication & The Internet
5.1Networks
5.1.1Benefits of Networks
5.1.2Network Performance
5.1.3Types of Network
5.1.4Client-Server Model
5.1.5Pros of Client-Server Model
5.1.6Cons of Client-Server Model
5.1.7Peer-to-Peer Model
5.1.8Pros of Peer-to-Peer Model
5.1.9Cons of Peer-to-Peer Model
5.1.10Network Hardware
5.1.11Transmission Media
5.1.12WiFi
5.1.13WiFi Frequency and Channels
5.1.14WiFi Encryption
5.1.15Network Protocols
5.1.16Transmission Protocols
5.1.17Web Protocols
5.1.18Email Protocols
5.1.19Layers
5.1.20TCP and OSI Models
5.1.21Advantages of Layering
5.1.22Topology - Star
5.1.23Topology - Mesh
5.1.24Topology - Ring
5.1.25Topology - Bus
5.1.26End of Topic Test - Networks
5.2Network Security
6The Bigger Picture
6.1Emerging Trends, Issues & Impact
6.1.1E-Waste
6.1.2Energy Consumption
6.1.3Positive Environmental Impact
6.1.4Ethical Issues - The Digital Divide
6.1.5Ethical Issues - Net Neutrality
6.1.6Ethical Issues - Working Conditions
6.1.7Ethical Issues - Censorship
6.1.8Online Activity Tracking
6.1.9The Internet of Things
6.1.10Positive Cultural Impacts
6.1.11Negative Cultural Impacts
6.1.12Data Protection Act
6.1.13Computer Misuse Act
6.1.14Copyright Designs and Parents Act
6.1.15Creative Commons Licensing
6.1.16Freedom of Information Act
6.1.17Open Source Software
6.1.18Proprietary Software
6.1.19Licensing Issues
6.1.20End of Topic Test - Software & Issues
Unlock your full potential with Seneca Premium
Unlimited access to 10,000+ open-ended exam questions
Mini-mock exams based on your study history
Unlock 800+ premium courses & e-books