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1. a complete failure of epic proportions, especially in medical and programming situations. 2. The Therac-25 was a machine made by the Atomic Energy of Canada Limited to treat cancer patients with radiation. 6 people were reported to have received massive overdoses of radiation due in large part to bad software design and poor testing. People died because of it. It is used as an example of why a programmer needs to thoroughly test a program before releasing it for use.
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