anchor.diff:           (incf mem-addr 2))
          ;; HPIOO2: INTRQ_Wait
          (ata-intrq-wait device)
  -       (when (ata-controller-hotunplug controller)
  -         (debug-write-line "Pending PIO read aborted due to device hot-unplug.")
  -         (return-from ata-pio-data-out nil))
          ;; Return to HPIOO0.
          (decf count))))
   
  
positive.code:     (loop
         ;; HPIOI0: INTRQ_wait
         (ata-intrq-wait device)
         (when (ata-controller-hotunplug controller)
           (debug-write-line "Pending PIO read aborted due to device hot-unplug.")
           (return-from ata-pio-data-in nil))
         ;; HPIOI1: Check_Status
         (multiple-value-bind (drq timed-out)
             (ata-check-status device)
  
negative.code:   current-channel
    (irq-cvar (make-condition-variable "ATA IRQ Notifier"))
    irq-delivered
    bounce-buffer)
  
  (defstruct (ata-device
  