Waltham - Mr. John A. DeMarco of Waltham died Sunday February 20, 2005 in his home. He was 80. Born and raised in Waltham, a son of the late Giuseppe and Giovannina (DiPietro) DeMarco, he was a graduate of Waltham High School and received a certificate in accounting from Bentley College in Boston. During World War II he served with the U.S. Navy and participated in the battle for Okinawa, the final campaign of the Pacific war. Until his retirement, Mr. DeMarco worked for 33 years as manager of the accounting department for Fenwal, Inc. of Ashland. Studying genealogy was a favorite pastime of his. Mr. DeMarco was the husband of the late Doris E. (Cormier), and brother of the late Palma DAngio, Julia Demeo, Salvatore DeMarco, Victoria Caruso, Benedetto DeMarco, Philomena Barravecchio, Rocco DeMarco, and Virginia Scafidi. He is survived by his children, Diane D. Egidio and her husband Carmine A. of Billerica, John M. DeMarco and his wife Kathleen of Malden and David P. DeMarco of Waltham; one sister, Josephine Perilli of Waltham; one brother, Frank DeMarco of Chelmsford; his grandchildren, Robyn, Lauren, Kerry and Erin DeMarco; his longtime companion, Maryann Mula of Dudley and many nieces and nephews. Relatives and friends are invited to attend the Funeral at 9 a.m. Thursday from The Joyce Funeral Home, 245 Main Street (Rte.20), Waltham followed by a Funeral Mass in Sacred Heart Church, 311 River Street, Waltham at 10 a.m. Burial will be in Mount Feake Cemetery, Waltham. Visiting hours are Wednesday from 4 to 8 p.m. Memorial donations may be made to Newton-Wellesley Hospital Infusion Center, 2014 Washington Street, Newton, MA 02462.