hcf

Free On-line Dictionary of Computing

1.<operating system> Host Command Facility.

2.<architecture> Halt and Catch Fire. [Jargon File]

(1999-01-24)

The Jargon File

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.