Donald J. Horsfall, 72, Rydal, Pa., co-wrote nine books about computing.

inquirer.com/obituaries/cor…

Adam Schlesinger, 52, Poughkeepsie, N.Y., songwriter for rock, film, and the stage.

youtu.be/TVoFq7zc5po

John Horton Conway, 82, New Brunswick, N.J., mathematician known as the "magical genius".