ry. For example : The original 
      IBM PC VGA screen base address is B800:0000 followed by 4000 more bytes.</td>
  </tr>
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    <td><strong>Binary</strong></td>
    <td>Base two numbers used by digital systems. Count with two symbols [ 0 1 
      ] Binary numbers are composed of noughts and ones. Electronically this is 
      achieved by circuits that are switched off or on.</td>
  </tr>
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    <td><strong>Bit Masks </strong></td>
    <td>Patterns of noughts