1.1 Data representation

• All data needs to be converted to binary to be processed by a computer.
• Binary is a numbering system that uses only 0s (off) and 1s (on).
• The 0’s and 1’s in binary are referred to as bits.
• By using binary, computers can process and store data using electronic transistors that can be either on or off.
• Millions or billions of transistors can fit onto a microchip.
• Any form of data, including text, images, and sound, needs to be converted to binary before it can be processed by a computer.
• The conversion process involves assigning a binary code to each character, pixel, or sample in the data.
• The resulting binary code can then be processed using logic gates and stored in registers.
• Logic gates are electronic devices that perform logical operations on binary data.
• Logic gates are used to process binary data by applying Boolean logic to the input values and producing a binary output.
• Registers are temporary storage areas in a computer's CPU (central processing unit) that hold binary data during processing.
• Registers are used to store data that needs to be accessed quickly, such as variables in a program or data being manipulated by logic gates.
• The size of a register determines the maximum amount of binary data that can be stored in it at one time.
• Hexadecimal is base 16
• we can represent negative numbers in binary using Two's Complement
• Text is a collection of characters that can be represented in binary, which is the language that computers use to process information.
• To represent text in binary, a computer uses a character set, which is a collection of characters and the corresponding binary codes that represent them.
• ASCII assigns a unique 7-bit binary code to each character, including uppercase and lowercase letters, digits, punctuation marks, and control characters.
• Unicode uses a variable-length encoding scheme that assigns a unique code to each character, which can be represented in binary form using multiple bytes.
• As Unicode requires more bits per character than ASCII, it can result in larger file sizes and slower processing times when working with text-based data.
• Sound is a type of analog signal that is captured and converted into digital form to be processed by a computer.
• To convert sound into digital form, a process called sampling is used.
• Sampling involves taking measurements of the sound wave at regular intervals and converting these measurements into binary data.
• The quality of the digital sound depends on the sample rate, which is the number of samples taken per second.
• To convert sound into digital form, a process called sampling is used.
• Sampling involves taking measurements of the sound wave at regular intervals and converting these measurements into binary data.
• The quality of the digital sound depends on the sample rate, which is the number of samples taken per second.
• A higher sample rate results in a more accurate representation of the original sound wave, but also increases the file size of the digital sound.
• The sample resolution is another factor that affects the quality of the digital sound.
• The sample resolution refers to the number of bits per sample, which determines the level of detail and accuracy of each sample.
• A higher sample resolution results in a more accurate representation of the sound wave, but also increases the file size of the digital sound.
• A high-quality music recording may require a higher sample rate and resolution than something like a voice message.
• A bitmap image is made up of a series of pixels, which are small dots of colour that are arranged in a grid.
• Each pixel in a bitmap image can be represented by a binary code, which is processed by a computer.
• The resolution of an image refers to the number of pixels in the image.
• The colour depth of an image refers to the number of bits used to represent each colour.