Log personal file (FCB)  (INT 21h, CAh - Novell NetWare 4.0)

        Entry:
          AH = CAh
          DS:DX -> FCB
            if function C6h lock mode 01h:
               AL = log and lock flag
                    00h  Log file only
                    01h  Lock as well as log file
               BP = timeout in timer ticks (1/18 sec)
        Return:
          AL = error code