Patents Reinstated Due to the Acceptance of a Late
                         Maintenance Fee From 4/11/97

Patent           Serial            Filing          Issue           Granted
Number           Number            Date            Date            Date

Re. 34,006       07/640,264        01/11/91        07/28/92        04/14/97
4,740,238        07/030,334        03/26/87        04/26/88        04/15/97
4,982,958        07/419,796        10/10/89        01/08/91        04/14/97
5,072,843        07/578,048        09/05/90        12/17/91        04/14/97
5,097,901        07/561,894        08/02/90        03/24/92        04/15/97
5,158,164        07/759,235        09/13/91        10/27/92        04/14/97
5,174,631        07/771,500        10/04/91        12/29/92        04/15/97


              Patents Reinstated Due to the Acceptance of a Late
                         Maintenance Fee From 4/18/97

Patent           Serial            Filing          Issue           Granted
Number           Number            Date            Date            Date

Re. 32,608       06/913,719        09/30/86        02/23/88        04/23/97
Re. 32,631       06/884,728        07/10/86        03/29/88        04/18/97
4,408,147        06/358,697        03/16/82        10/04/83        04/18/97
4,413,859        06/289,783        08/03/81        11/08/83        04/21/97
4,531,692        06/358,014        03/15/82        07/30/85        04/24/97
4,549,739        06/466,502        02/15/83        10/29/85        04/24/97
4,587,123        06/625,623        06/28/84        05/06/86        04/23/97
4,651,069        06/703,731        02/21/85        03/17/87        04/23/97
4,691,948        06/802,533        11/27/85        09/08/87        04/21/97
4,726,362        06/913,934        10/01/86        02/23/88        04/23/97
4,783,967        07/062,218        06/12/87        11/15/88        04/22/97
4,784,400        07/012,327        02/09/87        11/15/88        04/24/97
4,788,838        07/019,518        02/26/87        12/06/88        04/23/97
4,977,775        07/456,725        12/26/89        12/18/90        04/18/97
4,986,320        07/335,035        04/07/89        01/22/91        04/21/97
4,997,932        07/434,324        11/13/89        03/05/91        04/21/97
5,113,315        07/563,491        08/07/90        05/12/92        04/22/97
5,114,673        07/406,918        09/12/89        05/19/92        04/21/97
5,150,349        07/599,035        10/17/90        09/22/92        04/23/97
5,168,989        07/688,975        04/22/91        12/08/92        04/22/97