anchor.diff:  
       (setf *origin* #x8000)
   
  -    (emit-fixed-cycle-player *context* #x80)
  +    (emit-fixed-cycle-player *context* #x80 :break-at-end break-at-end)
   
       (procedure init
         (cld)
  
positive.code:       (pushword (label :seq-end))
        (pushword (label :seq-start))
        (jsr 'player-load)
        
        (rts))
  
      (write-song-data-for-reg-player (funcall continuation) :seq-start :seq-end)
  
negative.code:       (defun ,(intern "NSF-OUTPUT-FILE" package) (filename)
          (generate-nsf-preview ,name #',asm-fn-name :filename filename)))))
  
  (defun emit-fixed-cycle-player (context var-base &key break-at-end)
    "Emit fixed-cycle player routine. Requires VAR-BASE specifies 8 bytes of adjacent zeropage storage."
    (check-type var-base (integer 0 250))
    (let* ((*context* context)
  