Computing essentials, 1997-1998 / Timothy J. O'Leary, Linda I. O'Leary. Multimedia edition 1997-1998 O'Leary, Timothy J., 1947- O'Leary, Linda I. Computers. Electronic data processing. QA76.5 .O443 2002 004.1 21 OLC Includes index. New York : McGraw-Hill, c1997. c1997. 1997 Text xvii, 199p. (various pagings) : eng