anchor.diff:        (dotimes (i data-length)
           (setf (aref buf (+ offset i)) (aref data-buf i)))
   
  -      (sync:semaphore-down (mass-storage-semaphore mass-storage))
  +      (when (eq (timed-wait event 1.0) :timeout)
  +        ;; TODO need better error message here
  +        (error "Mass storage read sector status timeout"))
   
         (with-trace-level (4)
           (sup:debug-print-line "%read-sector status buffer:")
  
positive.code:       (dotimes (i data-length)
          (setf (aref data-buf i) (aref buf (+ offset i))))
  
        (sync:semaphore-down (mass-storage-semaphore mass-storage))
  
        (with-trace-level (4)
          (sup:debug-print-line "%write-sector command status "
                                (mass-storage-status mass-storage)))
  
        (bulk-enqueue-buf usbd
                          device
                          (mass-storage-bulk-out-endpt-num mass-storage)
  
negative.code:         (sup:debug-print-line "%read-sector command buffer:")
          (print-buffer sys.int::*cold-stream* cmd-buf :indent "  "))
  
        (when (eq (timed-wait event 1.0) :timeout)
          ;; TODO need better error message here
          (error "Mass storage read sector command timeout"))
  
        (with-trace-level (4)
          (sup:debug-print-line "%read-sector command status "
                                (mass-storage-status mass-storage)))
  
        (setf (sup:event-state event) nil)
        (bulk-enqueue-buf usbd
                          device
                          (mass-storage-bulk-in-endpt-num mass-storage)
                          data-buf
                          data-length)
  
        (when (eq (timed-wait event 1.0) :timeout)
          ;; TODO need better error message here
          (error "Mass storage read sector data timeout"))
  
        (with-trace-level (3)
          (sup:debug-print-line "read sector data buffer:")
  