anchor.diff:      let meltHBNeighbour = 60.0<C>
       let maxOligoLen = dp.pp.maxLength
   
  -    let upRev = revComp up
  +    let upRev = up.RevComp()
       // TODO - if we are near the 5' end of the gene we should use non rare
       // codons.  Can't currently figure out position from params
       // Also need to ensure we don't chew back past 5' start codon
  
positive.code:                             minLength = max 10 (54 - primer1.Length)}
                      let task2 =
                          {tag ="CFwd";
                           temp = down.[primer1.Length..primer1.Length+penC.maxLength];
                           align = ANCHOR.LEFT;
                           strand = STRAND.TOP; 
                           offset = 0;
  
negative.code:         (targetAALen:int option)
          (dp:DesignParams)
          (fwd:bool)
          (up: Dna)
          (prefix: Dna)
          (down: Dna) =
      // Parameters
      // Want ~10 amino acids changed
      // 
  