Mnemonic for `Halt and Catch Fire', any of several undocumented and
semi-mythical machine instructions with destructive side-effects,
supposedly included for test purposes on several well-known
architectures going as far back as the IBM 360. The MC6800
microprocessor was the first for which an HCF opcode became widely
known. This instruction caused the processor to {toggle} a subset of
the bus lines as rapidly as it could; in some configurations this
could actually cause lines to burn up. Compare {killer poke}.
[glossary]
[Reference(s) to this entry by made by: {killer poke}]