Since I didn't see a message to this effect and because I'm very slow on catching up with my reading, there's an interesting article in the November, 2012 issue of IEEE "Computer" titled "Debugging on the Shoulders of Giants: Von Neumann's Programs 65 Years Later" by Barry Fagin and Dale Skrein. Briefly, the two took von Newumann's programming problems described in the 1947 "Planning and Coding Problems for an Electronic Instrument" by Goldstine and von Neumann and ran them on an IAS emulator. Not surprisingly, they discovered a few errors. I say, "not surprisingly" because at the time, the IAS computer wasn't operational. It makes a nice read for a rainy afternoon. --Chuck