Implementation Detail or Invariant?; or, The Hardware Interlock Fallacy

If you are the kind of person who enjoys reading accident reports for fun (hi), you may have heard of the Therac-25, a medical radiation device. Some of us learned about it in school, including yours truly, by reading this paper by Leveson Turner describing how it had some software bugs and ultimately killed Continue reading "Implementation Detail or Invariant?; or, The Hardware Interlock Fallacy"