Patents Reinstated Due to the Acceptance of a
                      Late Maintenance Fee From 03/20/98
   
Patent           Serial            Filing          Issue          Granted 
Number           Number            Date            Date           Date

4,543,630        06/601,808        04/19/84        09/24/85       03/20/98
4,714,245        06/761,895        08/02/85        12/22/87       03/26/98
4,734,769        06/745,441        06/17/85        03/29/88       03/25/98
4,835,047        07/050,705        05/14/87        05/30/89       03/24/98
4,885,495        07/220,739        07/18/88        12/05/89       03/23/98
5,188,095        07/710,252        06/03/91        02/23/93       03/23/98
5,228,823        07/696,195        05/06/91        07/20/93       03/26/98
5,234,028        07/761,341        09/06/91        08/10/93       03/25/98
5,257,253        07/994,077        12/17/92        10/26/93       03/23/98
5,269,501        07/985,195        12/03/92        12/14/93       03/26/98
5,271,793        07/990,671        12/14/92        12/21/93       03/25/98