+-+
        | |
  +-----+ +-----+
  |             |
  +-------------+
  1.2.3.4.5.6.7.8

       Pins


  Normal mod change

  Pins  Pair  Value     Color

   1     2    TD+       white/orange
   2     1    TD-       orange or orange/white
   3     6    RD+       white/green 
   4     5    Notused   white/blue
   5     4    Notused   blue or blue/white
   6     3    RD-       green or green/white
   7     8    Notused   white/brown
   8     7    Notused   brown or brown/white


  Crossover cable

  1 to 3
  2 to 6
  3 to 1
  6 to 2