Modern high-end processors have a lot of undocumented features. This is rather widely known, though of course not universally known. These have existed for a l

Modern high-end processors have a lot of undocumented features. This is rather widely known, though of course not universally known. These have existed for a long time - https://en.wikipedia.org/wiki/Illegal_opcode https://en.wikipedia.org/wiki/Illegal_opcode . And ... you know this. Checking your comment history https://hn.algolia.com/?dateRange=all&page=0&prefix=true&query=userbinator%20undocumented&sort=byPopularity&type=comment https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... I easily found https://news.ycombinator.com/item?id=8834863 https://news.ycombinator.com/item?id=8834863 > Intel CPUs have had undocumented features since their introduction; it's not hard to imagine their chipsets do too. Before I did the search I thought you were one of the 10,000 (https://xkcd.com/1053/ https://xkcd.com/1053/ ), surprised that others didn't share your enthusiasm. Now I don't understand your surprise. You must surely know your comment about "the hacker spirit is not welcome here" comes across like snobbish gatekeeping, yes? At the very least, the implied lack of knowledge about undocumented features makes it seem that you aren't one to judge what the hacker spirit might be. ... which cannot be correct given your posting history.