Archives: Theory

Logic Statements

Logic gate circuits can be expressed as a circuit diagram, or as a written logic statement. e.g. Z = ((NOT A) AND (A OR B)) OR (A OR B) Each exam board will have their…

What is Hexadecimal

Hexadecimal is a base 16 number system used in computing. In comparison, the counting we learnt at primary school is actually a base 10 number system (often called decimal or denary), and binary is base…

User Interface Design

A user interface is the boundary between the user and a computer system.  It allows us to communicate with the computer, and vice versa. There are many types of user interfaces, each with their own…

Flowcharts

Flowcharts are a graphical way of representing an algorithm design. A flowchart must have a clear start and finish (unless looping). Flowchart Symbols Name Symbol Explanation Start / Finish Used to indicate the start and…

MP4 Video Compression

MP4s are video files (with audio) compressed using lossy compression. The lossy compression gives huge savings in file size, needed to: Make video streaming services practical (e.g. YouTube, Vimeo, NowTV, on demand TV) Let us record…

Pseudocode

Pseudocode is a method of expressing an algorithm design. Pseudocode is lines of instructions written in a language close to English but with common programming terms used where possible (selection and iteration etc). People with…

Algorithms

An algorithm is a set of instructions/steps/rules that are followed to solve a problem. We follow algorithms every day, maybe without even realising we are doing so: You have a routine for cleaning your teeth…

Library Routine

A library routine is a debugged block of code (subroutine, procedure, function etc), often designed to handle commonly occurring problems or tasks. Library routines are stored in a program library and given names.   This allows…

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