An old programming meme is the "Halt-and-Catch-Fire" bug. Entire lists[0] of would-be instruction sets were circulated; HCF was a common one. [0] https://www.

An old programming meme is the "Halt-and-Catch-Fire" bug. Entire lists[0] of would-be instruction sets were circulated; HCF was a common one. [0] https://www.computerhope.com/forum/index.php?topic=36570.0 https://www.computerhope.com/forum/index.php?topic=36570.0