High-Level vs Low-Level Languages

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High-Level Languages

Most computer languages are written in high-level programming languages.

High-Level Languages

High-level languages (HLLs) include most programming languages such as Python, C++ and Java.
High-level languages are made of human-readable statements that make it easier for us to program.
High-level languages are portable, which means that they can be run on many different types of hardware.

What does a HLL look like?

Commands in a high-level language look very like English. For example:
- print()
- SELECT * FROM users;

Why don't we always use HLLs?

Computers can only process instructions in the form of binary numbers.
We use special software called a translator to convert our HLL source code into an executable binary file.

Advantages

HLLs are quicker to create software because one line of code can perform multiple actions on the CPU.
A programmer does not have to think about how a program interacts with hardware. They can focus on creative problem-solving.

Low-Level Languages

Low-level programming languages are languages which are much closer to computer-understandable binary.

Low-Level Languages

Low-level languages (LLLs) are much closer to executable machine code than high-level languages.
LLLs are harder to read by humans, but are easier to read for the computer.

What does a LLL look like?

LLL commands are not easy to read, and might include commands such as:
- MOV ax, bx
- CMP ch, dh
- CLI

Why do we use LLLs?

LLLs provide exact control over the central processing unit.
LLLs need less translation, and often lead to faster code which is useful for computers with low specifications such as embedded systems.

Comparison

How would you write a simple addition program using values stored in two variables?
High-level language
num1 = 17
num2 = 4
print(num1+num2)
Low-level language (Little Man Code)
INP // Input first number
STA A // Store it in mailbox A
INP // Input second number
ADD A // Add the stored first number to the second
OUT // Output the sum
HLT // Stop
A DAT

1Computer Systems

1.1Systems Architecture

1.1.1Fetch-Execute Cycle

1.1.2Common CPU Components & Their Function

1.1.3Von Neumann Architecture

1.1.4Factors Affecting CPU Performance

1.1.5Embedded Systems

1.1.6Exam-Style Questions - Von Neumann Architecture

1.1.7Diagnostic Misconceptions - Embedded vs General

1.2Memory & Storage

1.2.1Types of Memory

1.2.2Flash Memory

1.2.3Properties of Flash Memory

1.2.4Running Out of Memory

1.2.5Virtual Memory

1.2.6Units of Capacity

1.2.7Calculating Capacity Requirements

1.2.8Solid State Storage

1.2.9Properties of Solid State Media

1.2.10Magnetic Storage

1.2.11Properties of Magnetic Media

1.2.12Examples of Magnetic Storage

1.2.13Optical Storage

1.2.14Properties of Optical Media

1.2.15Examples of Optical Storage

1.2.16Types of Optical Disk

1.2.17Number Bases

1.2.18Converting Number Bases

1.2.19Hexadecimal

1.2.20Using Hexadecimal

1.2.21Converting Denary & Hexadecimal

1.2.22Binary Addition

1.2.23Binary Shifts

1.2.24Representing Text

1.2.25ASCII & Unicode

1.2.26Representing Images

1.2.27Converting Binary & Images

1.2.28Representing Sound

1.2.29Data Compression

1.2.30Grade 9 - Storage

1.2.31Exam-Style Questions - Primary Memory

1.2.32Exam-Style Questions - Storage

1.2.33Exam-Style Questions - Data Conversions

1.2.34Diagnostic Misconceptions - RAM vs ROM

1.2.35Diagnostic Misconceptions - Bits, Nibbles & Bytes

1.2.36Diagnostic Misconceptions - Bits Required to Store

1.2.37End of Topic Test - Computer Systems

1.2.38End of Topic Test - Representation

1.3Computer Networks, Connections & Protocols

1.4Network Security

1.4.1Forms of Attack

1.4.2Penetration Testing

1.4.3Malware

1.4.4How Malware Spreads

1.4.5Social Engineering

1.4.6Phishing

1.4.7Cracking Passwords

1.4.8Denial of Service Attacks

1.4.9Data Interception

1.4.10Methods of Data Interception

1.4.11SQL Injection

1.4.12Network Administration

1.4.13Network Forensics

1.4.14Protecting Against Malware

1.4.15Firewalls

1.4.16User Access Levels

1.4.17Passwords

1.4.18Encryption

1.4.19End of Topic Test - Networks

1.5Systems Software

1.5.1System Software

1.5.2Utility Software

1.5.3Operating Systems

1.5.4User Interfaces

1.5.5Memory & Process Management

1.5.6File Management

1.5.7Device Management

1.5.8User Management

1.5.9Encryption Software

1.5.10Defragmentation Software

1.5.11Data Compression Software

1.5.12Backup Software

1.6Ethical, Legal, Cultural & Environmental Concern

2Computational Thinking, Algorithms & Programming

2.1Algorithms

2.1.1Computational Thinking - Abstraction

2.1.2Computational Thinking - Decomposition

2.1.3Algorithmic Thinking

2.1.4Pseudocode

2.1.5Flowchart Diagrams

2.1.6Interpreting Algorithms

2.1.7Correcting Algorithms

2.1.8Completing Algorithms

2.1.9Search Algorithms

2.1.10Binary Search

2.1.11Linear Search

2.1.12Overview of Sort Algorithms

2.1.13Bubble Sort

2.1.14Merge Sort

2.1.15Insertion Sort

2.1.16Exam-Style Questions - Sorting Algorithms

2.2Programming Fundamentals

2.3Producing Robust Programs

2.3.1Defensive Design

2.3.2Validation & Sanitisation

2.3.3Authentication & Contingencies

2.3.4Maintainability

2.3.5Purpose of Testing

2.3.6Types of Testing

2.3.7Test Plans

2.3.8Types of Errors

2.3.9End of Topic Test - Programming

2.3.10Exam-Style Questions - Testing

2.4Boolean Logic

2.4.1Binary Systems

2.4.2Logic Circuits

2.4.3Boolean Logic

2.4.4Boolean Operators

2.4.5Grade 9 - Logic

2.5Programming Languages & IDEs

2.5.1High-Level vs Low-Level Languages

2.5.2Translation - Compliers & Interpreter

2.5.3Translation - Assemblers

2.5.4Integrated Development Environments

2.5.5Exam-Style Questions - Translation

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