anchor.diff:  
   (let* ((global (make-instance 'basic-context :address #x8000))
          (*context* global)
  +       (num-wavy-lines (* 3 26))        ; Must be multiple of 3 !
  +       (log2-wavy-period 6)
          ;; Music:
          (music (binary-file (merge-pathnames "noisejam.nsf" *path*)))
          (music-init (mem #x8080))        ; Hardcoding these..
  
positive.code:       (dex))                            ; Decrememnt sprite index
      (rts))
  
    (procedure wait-for-vblank
      (as/until :not-zero (lda vblank-flag))
      (lda (imm 0))
      (sta vblank-flag)
      (rts))
  
    (procedure brk-handler (rti))
  
    (procedure vblank-handler
      (inc vblank-flag)
      (rti))
  
    (align 256)
    (with-label sine-table
      (loop for i from 0 below 256
            do (db (round (+ 124 (* 99 (sin (* 2 pi i 1/256))))))))
  
  
    ;; Interrupt vectors:
    (advance-to +nmi-vector+)
  
negative.code:     (sta scroll-x)
      (lda (imm 0))
      (sta ntaddr)
      (sta wave)
      (lda (imm 160))
      (sta phase)
  
      (jsr 'initialize-sprites)
  
      (jsr 'update-sprites)
  
      (align 256 #xEA)                    ; Pad with NOPs to next page
      (poke #b10001000 +ppu-cr1+)         ; Enable NMI
  