anchor.diff:                                      (read-first-cluster file-data start)
                                       (fat host))
                     read-buffer-position (read-first-cluster file-data start)
  -                  read-buffer-size (read-size file-data start))
  +                  read-buffer-size (read-file-size file-data start))
               (ecase if-does-not-exist
                 (:error (error 'simple-file-error
                                :pathname pathname
  
positive.code:       (replace result temp-buf :start1 (* n-cluster spc sector-size)))))
  
  ;; TODO Add posibility to resize file
  (defun write-file (fat32 disk start-cluster fat array)
    (let* ((spc (fat32-sectors-per-cluster fat32))
           (sector-size (mezzano.supervisor:disk-sector-size disk))
  
negative.code:         :when (zerop m)
          :return (ash i -2)))
  
  (defun get-fat32-time ()
    "Return time and date in fat32 format"
    (multiple-value-bind (second minute hour date month year) (get-decoded-time)
      (values (logior (ash second -1)
                      (ash minute 5)
                      (ash hour 11))
              (logior date
                      (ash month 5)
                      (ash (- year 1980) 9)))))
  
  (defun read-sector (disk start-sector n-sectors)
    "Read n sectors from disk"
    (let* ((sector-size (mezzano.supervisor:disk-sector-size disk))
  