title: Are the platforms covered by the C standard still in use?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/8007825/rephrased-list-of-platforms-supported-by-the-c-standard">Rephrased: list of platforms supported by the C standard</a>  </p>
  </blockquote>
  
  
  
  <p>The C standard is very loosely defined:
  - it covers two's complement, ones' complement, signed magnitude
  - integers can be of various width, with padding bits
  - certain bit patterns may not represent valid values.</p>
  
  <p>There is a obvious downside to this: it make portable code harder to write. Does anyone know of platforms for which there are still active development work, but which are</p>
  
  <ul>
  <li>not 2's complement or</li>
  <li>the integer width is not 32 bits or 64 bits or</li>
  <li>some integer types have padding bits or</li>
  <li>if you worked on a 2's complement machine, the bit pattern with sign
  bit 1 and all value bits zero is not a valid negative number or</li>
  <li>integer conversion from signed to unsigned (and vice versa) is not via verbatim
  copying of bit patterns or</li>
  <li>right shift of integer is not arithmetic shift or</li>
  <li>the number of value bits in an unsigned type is not the number of
  value bits in the corresponding signed type + 1 or</li>
  <li>conversion from a wider int type to a smaller type is not by
  truncation of the left most bits which would not fit</li>
  </ul>