Memory & Storage

• The order of data goes:

  Bit, Nibble, Byte, Kilobyte, Megabyte, Gigabyte, Terabyte, Petabyte
• Binary is a computer language that uses only two digits, 0 and 1, to represent data.
• Binary Table.

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• Binary Addition Rules

  • 0 + 0 = 0
  • 0 + 1 = 1
  • 1 + 0 = 1
  • 1 + 1 = 0 (carry 1)
  • 1 + 1 + (carry 1) = 1 (carry 1)
• Hexadecimal is used because it's easier to convert than binary and is more user friendly.
• Hexadecimal conversion table.

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  F)

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  H)

  I)

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• The difference between standard ASCII and extended ASCII is that standard ASCII has 128 characters whereas extended ASCII has 256 characters including symbols such as copyright and trademark.
• The difference between Unicode and ASCII is that ASCII is only for the English language whereas Unicode is universal and has code for other languages and characters.
• A pixel is the smallest unit of a digital image or graphic that can be displayed and represented on a digital display device. 
• Colour depth is the maximum number of colours an image can contain. 
• Resolution is the number of pixels that are displayed per inch for an image. 
• Metadata is an underlying definition or description. 
• Bitmap is a memory organisation or image file format used to store digital images. It is an array of binary data representing the values of pixels in an image or display. 
• This is a bitmap, showing the image an the binary used to create it.

  
• Some examples of metadata are file size and date created.
• A channel is different sound waves for different speakers. 
• Bit depth is how many bits per sample. 
• Bitrate is the number of bits per second. 
• Formula for calculating file size of an image


  File Size = Resolution * Colour Depth
• Formula for calculating file size of sound


  File Size = Sample Rate * Bit Depth * Seconds
• Resolution per image: pixels high * pixels wide