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11 Cards in this Set
- Front
- Back
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Why do computers use binary? |
Computers use binary as it only used two states 0 and 1. These can be represented using electricity, off and on. |
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Binary numbers |
In a binary number system each digit is worth 2* the digit before it. |
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Binary addition |
0 + 0 = 0, 0 + 1 = 1, 1 + 0 = 1, 1 + 1 = 10, 1 + 1+ 1 = 11 |
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Converting into hexadecimal |
Step one: Convert the denary number to binary. Step two: Split the binary numbers into 4 bit sections. Step three: Convert each 4 bit section back to denary. Step four: Convert two denary numbers to hex. |
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Character sets |
The character set is the collection of all the characters (Letters, Numbers and Symbols) that the computer can represent. UNICODE uses 16 bits for each symbol, so it has a much larger character set. ASCII uses 7 bits do it can represent fewer characters. |
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Bitmap images |
Binary can be used to create bitmap images. Bitmap images are made up of a grid (or map) of pixels. Each pixel is assigned a binary code to represent it's colour. |
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Resolution |
The concentration of pixels is a bitmap is called its resolution. The higher the resolution (the more pixels it has) the more detailed an image is but the more space it takes up on the disk. |
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Meta data |
As well as the binary value if each pixel a bitmap image holds: - The height of the image in pixels - The width of the image in pixels - The number of bits used for each pixel This helps the computer structure the image, otherwise it just has a string of bits. |
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Converting sound waves to binary |
You can represent these waves as binary by sampling the wave at different places and recoding the amplitude using binary. |
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Sampling |
The more samples you make the higher the sound quality but the larger the file size. |
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Representing instructions in binary |
High level instructions are converted in to operations and operands eg ADD 12. Each operator and operand is represented using a unique binary code. The computer can't tell the difference between operators and operands in binary, it guesses which is which based on their position in the code. The instruction set of a computer is all the operators it can used. |
