title: MIL-STD-1750A to Decimal Conversion Examples
body: <p>I am looking at some examples in the <a href="http://www.xgc.com/manuals/m1750-ada/m1750/c189.html#AEN322" rel="nofollow noreferrer">1750A format webpage</a> and some of the examples do not really make sense. I have included the 1750A format specification at the bottom of this post in case anyone isn't familiar with it.</p>
  
  <p>Take this example from Table 3 of the 1750A format webpage:</p>
  
  <p><code>.625x2^4 = 5000 00 04</code></p>
  
  <p>In binary <code>5000 00 04</code> is <code>0101 0000 0000 0000 0000 0000 0000 0100</code></p>
  
  <p>If you convert this to decimal, it does not equal 10, which is .625x2^4. Maybe I am converting it incorrectly.</p>
  
  <p>Take the mantissa, <code>101 0000 0000 0000 0000 0000</code> and subtract 1 giving <code>100 1111 1111 1111 1111 1111</code>. Then flip the bits, giving <code>011 0000 0000 0000 0000 0000</code>. Move the decimal 4 places (since our exponent, <code>0100</code> is 4), giving us <code>0110.0000 0000 0000 0000 000</code>. This equals 6.0, which is not .625x2^4.</p>
  
  <p>I believe the actual value, should be <code>0011 0000 0000 0000 0000 0000 0000 01000</code> or <code>30000004</code> in hex.</p>
  
  <p>Can anyone else confirm my suspicions that this value is labeled incorrectly in Table 3 of the 1750A format page above?</p>
  
  <p>Thank you</p>
  
  <p><img src="https://i.stack.imgur.com/fcUNH.png" alt="1750A"></p>