There are slides devoted to this topic: Lecture 2, pp. 35-36

Websites

Learn about Schickard and his Calculating Clock – and see pictures of his machine, reconstructed – at the Computing History Museum page.

Visit the History of Computers’ page, “The Calculating Clock of Wilhelm Schickard,” to read about Schickard’s important intellectual correspondence with Keppler and the surviving evidence for his mechanical calculator. To read more about Schickard’s life, check out “The Biography of Wilhelm Schickard” on the same site.

For another, shorter biography on Schickard, read the entry written for the University of St. Andrew’s History of Mathematics archive. 

To read an even shorter description of Schickard’s contribution to computing history, read the Schickard Museum of Computer History’s biography. The Wilhelm Schickard Museum of Computing History is Concordia University Wisconsin’s collection of computers and calculators (unfortunately, it does not contain any copies of Schickard’s clock).

Books

The Universal History of Computing, Georges Ifrah, pp. 121