anchor.diff:  
   (defvar *run-time-advance*)
   (defvar *run-time*)
  +
  +(defvar *cpu-speed*)
   
   ;; http://wiki.osdev.org/Programmable_Interval_Timer
   (defun configure-pit-tick-rate (hz)
  
positive.code:     (setf (system:io-port/8 #x40) (ldb (byte 8 0) divisor)
            (system:io-port/8 #x40) (ldb (byte 8 8) divisor))))
  
  (defun initialize-time ()
    (when (not (boundp '*heartbeat-wait-queue*))
      (setf *heartbeat-wait-queue* (make-wait-queue :name "Heartbeat wait queue"))
  
negative.code:   (setf *run-time* 0)
    (configure-pit-tick-rate 100)
    (i8259-hook-irq +pit-irq+ 'pit-irq-handler)
    (i8259-unmask-irq +pit-irq+)
    (calibrate-tsc))
  
  (defun pit-irq-handler (interrupt-frame irq)
    (declare (ignore interrupt-frame irq))
  