An updated version of the white paper, now 66 pages, is available at the
www.srvhsrobotics.org web site in the Technical page. The new version is dated Nov 26, 2004.
In addition to revisions throughout, more material covering interrupts and state machines has been added. Of particular note is a demonstration of the hazards associated with access to variables updated by interrupt handlers. This is something that must be carefully attended to if your program employing interrupts is to be kept robust.