Computing Test Term 1 PDF

Computing Notes Hardware Components Storage (Secondary Memory) → Memory (RAM) → Processor (CPU) Storage The storage (secondary memory) is the set of components that stores programs and data. Storage is persistent: it retains its contents when the power is off. A few common sto...

Computing Notes Hardware Components Storage (Secondary Memory) → Memory (RAM) → Processor (CPU) Storage The storage (secondary memory) is the set of components that stores programs and data. Storage is persistent: it retains its contents when the power is off. A few common storage devices: - Hard disk drives (HDD) - Solid-state drives (SSD) - USB flash drives or USB sticks - SD cards Memory The main memory is the component that stores the programs and data currently in use. Memory is volatile: its contents are lost when the power is off. The main memory is commonly referred to as RAM (random-access memory). When a program must be executed, it is loaded from storage in memory, along with the data required. Any new or modified data must be saved from memory to storage. Processor The processor is the component that executes program instructions. The processor is commonly referred to as the CPU (central processing unit). Instructions are fetched one by one from memory into the processor, along with any required data. The processor decodes and executes each instruction. Any resulting data is moved into memory. An instruction may: - Perform arithmetic or logic operations on data - Perform input/output of data - Control program flow Hard and Software Communication  Computing systems exchange information and form networks using communication components. Programs and data are transferred between computing systems, when required. This allows: - Input to be obtained remotely - Data to be stored on remote systems - Programs to be executed remotely Input and Output Computing systems interact with the user and their surroundings through devices for input and output. - Input: data received by a system - Output: data transmitted from a system Boolean Logic AI Define ‘artificial’. - Created by humans, usually as a copy of or substitute for something natural. What is artificial intelligence? - Any machine that performs tasks that typically require intelligence in humans. But… - There is no single, agreed definition for artificial intelligence. - Because words like ‘intelligence’ and ‘thought’ are very difficult to pin down. - Because a machine considered ‘intelligent’ now will probably be commonplace in a few years. Vector Graphics Bitmap images: Bitmap images (raster graphics) are made up of small individual squares of colour called pixels. Vector images:  Vector graphics are images such as illustrations, icons, and logos. They do not use many colours because they have large areas of solid colour. Bitmap vs. Vector - Bitmap: Made of pixels; gets blurry when scaled. - Vector: Made of paths; scalable without losing quality. Bitmap scalability: Bitmap graphics lose image quality when scaled up or down because they are based on pixels only. The size and colour of the pixels is not recalculated when the graphic is resized. This makes the edges blurred. Inside a vector graphic file: The markup language shown above produces this vector image. The text is from a type of vector graphic file called a SVG (scalable vector graphic). Machine Learning ‘Supervised Learning’ - Like teaching a computer to do a task by showing it examples of how it’s done. - Where a computer learns to make predictions or classify data by being trained on examples that include both inputs and their correct outputs. Provide the machine with examples. Program the machine to learn from examples. ‘Reinforcement Learning’ - When a computer learns by trial and error, earning rewards for good actions and penalties for bad ones. Provide the machine with feedback. Program the machine to learn from feedback. What might not be on the test but study if I have time: Computing systems How many programs can be executed at the same time? - Just one. - At any given time, the processor executes one instruction that is part of one program. - Modern processors have multiple cores. - Each core can execute instructions from a different program. In the building analogy, this is like having multiple workers. - This speeds things up considerably, but alternation between programs is still necessary. The processor can be made to alternate between executing the instructions of different programs. This creates the impression of simultaneous program execution. Operating system Determines how the processor time is allocated. Determines where the programs and data are stored in the main memory. Determines how the programs and data are organised in storage. The operating system is a set of programs that controls the operation of a computing system: - Program execution - Memory management - File system organisation - Input and output - Communication - Graphical user interface