anchor.diff:      (jsr 'update-sprites)
   
       ;; Switch pattern tables mid-frame:
  -    (emit-delay (+ (* 114 107) 30))
  +    (emit-delay (+ (* 114 107) 22))
       (lda top-ntaddr)
       (eor (imm #b10010000))            ; Invert pattern bank.
       (sta (mem +ppu-cr1+))
  
positive.code:     (pokeword (label 'music-start) mptr) ; Set initial playback pointer.
      (rts))
  
    (procedure reset
      (sei)
      (cld)
      (poke #b00010000 +ppu-cr1+)         ; NMI off during init.
  
negative.code:     ;; the sprite tables, and if I didn't shut it off, you'd notice
      ;; the background stopped waving.
      (loop repeat 10 do (nop))           ; Realign with hblank.. again.
      ;; Actually, leave the sprites on, otherwise they'll be disabled
      ;; during the DMA transfer, which is unwise.
      (poke #x10 +ppu-cr2+)
  
      (rts))
  
  