(defun write-table (table filename)
  (with-open-file (f filename :direction ':output
                              :if-exists :supersede
                              :if-does-not-exist :create
                              :element-type '(unsigned-byte 8))
    (dotimes (i (length table))
      (let* ((val (aref table i))
             (b0 (logand (ash val -24) #xf))
             (b1 (logand (ash val -16) #xf))
             (b2 (logand (ash val -8) #xf))
             (b3 (logand val #xf)))
        (write-byte b0 f)
        (write-byte b1 f)
        (write-byte b2 f)
        (write-byte b3 f)))))

(defun combine-bytes (byte-0 byte-1 byte-2 byte-3)
  (declare ((unsigned-byte 8) byte-0 byte-1 byte-2 byte-3))
  (+ (ash byte-0 24)
     (ash byte-1 16)
     (ash byte-2 8)
     byte-3))

(defun read-table (table table-size filename)
  (with-open-file (f filename :direction ':input
                              :if-exists :supersede
                              :if-does-not-exist :create
                              :element-type '(unsigned-byte 8))
    (dotimes (i table-size)
      (setf (aref table i) (combine-bytes (read-byte f)
                                          (read-byte f)
                                          (read-byte f)
                                          (read-byte f))))))