NOTIFICATION OF ACCEPTANCE OF DELAYED PAYMENT OF MAINTENANCE FEE
                        (35 U.S.C. 41(c); 37 CFR 1.378)

   The patent(s) listed below are considered as not having expired but are
subject to the conditions set forth in 35 U.S.C. 41(c)(2), in view of the
Petition to Accept Late Payment of the maintenance fees which has been GRANTED
BY THE COMMISSIONER OF PATENTS AND TRADEMARKS, as provided for under 35 U.S.C.
41(c)(1) and 37 CFR 1.378.

                                                Application     Delayed Payment
Patent No.       Serial No.     Patent Date     Filing Date     Acceptance Date

4,640,589        06/836,713        02/03/87        03/03/86        05/03/95
4,813,979        07/151,383        03/21/89        02/02/88        03/29/95
4,865,324        07/152,410        09/12/89        02/04/88        03/15/95
4,928,603        07/203,006        05/29/90        06/06/88        04/24/95