anchor.diff:  
   (defun vram-string (string)
     "Translate a string from ASCII and write it to the PPU IO port."
  -  (let ((*context* (make-instance 'asm6502::local-context :parent *context*)))
  +  (let ((*context* (make-instance 'asm6502:local-context :parent *context*)))
       (jmp (mem :skip))
       (set-label :data)
       (context-emit *context* (reverse (translate-string string)))
       (set-label :skip)
       (ldx (imm (length string)))
       (set-label :copy)
  -    (lda (abx (label :data -1)))
  +    (lda (abx (label :data :offset -1)))
       (sta (mem +vram-io+))
       (dex)
       (bne :copy)))
  
positive.code:         (poke 0 (mem +ppu-cr2+))
          (ldx (imm 255))
          (jsr (mem (label 'fill-nametable-x)))
          (pokeword (label :ram-test-string -1) addr)
          (lda (mem +ppu-status+))
          (ppuaddr (- #x2070 (ceiling (length message) 2)))
          (ldy (imm (length message)))
  
negative.code:     (ldx (mem 'menu-bypass))          ; Check if menu-bypass != #xFFFF
      (inx)
      (asif :zero
        (ldx (mem (label 'menu-bypass :offset 1)))
        (inx)
        (asif :not-zero (jmp (indirect 'menu-bypass)))
        :else
  