621.381952 LEA\D LEACH, Donald P.        Digital principles and applications / Donald P.Leach, Albert Paul Malvino and Goutam Saha. – 6th ed.. – New Delhi : Tata mcgraw-hill pub., 2006.        xix, 683 p.        Includes appendix and index        ISBN 0-07-060175-5 : Rs. 275.00        1. Computer science        1. Mathematics I. Malvino, Albert Paul I. Saha, Goutam