anchor.diff:  
   header s,
   : s,
  -    dup c,
  +    dup tc,
       bounds
       begin
           2dupxor
       while
  -        count c,
  +        count tc,
       repeat
       2drop
   ;
  
positive.code: meta
      $3f80 org 
  target
  
  $1000 constant UART-D
  $2000 constant UART-STATUS
  
  
  : b.key
      begin
          UART-STATUS io@
          d# 4 and
      until
      UART-D io@
  ;
  
  : b.32
      b.key
      b.key d# 8 lshift or
      b.key d# 16 lshift or
      b.key d# 24 lshift or
  ;
  
  : section
      b.32 b.32
      begin
          2dupxor
      while
          b.32 over !
          d# 4 +
      repeat
      drop drop
  ;
  
  : bootloader
      begin
          b.key d# 27 =
      until
  
      section section
  ;
  
  meta
      4 org 
  
negative.code: ;
  
  header c,
  : tc,
      here c!
      d# 1 tallot
  ;
  