Fossil
1. In software, a misfeature that becomes understandable only in historical context, as a remnant of times past retained so as not to break compatibility.
Example: the retention of
octal as default base for string escapes in
C, in spite of the better match of
hexadecimal to ASCII and modern byte-addressable architectures.
See
dusty deck.
2. More restrictively, a feature with past but no present utility.
Example: the force-all-caps (LCASE) bits in the V7 and
BSD Unix tty driver, designed for use with monocase terminals.
(In a perversion of the usual backward-compatibility goal, this functionality has actually been expanded and renamed in some later
USG Unix releases as the IUCLC and OLCUC bits.)
3. The FOSSIL (Fido/Opus/Seadog Standard Interface Level) driver specification for serial-port access to replace the
brain-dead routines in the IBM PC ROMs.
Fossils are used by most
MS-DOS BBS software in preference to the "supported" ROM routines, which do not support interrupt-driven operation or setting speeds above 9600; the use of a semistandard FOSSIL library is preferable to the
bare metal serial port programming otherwise required.
Since the FOSSIL specification allows additional functionality to be hooked in, drivers that use the
hook but do not provide serial-port access themselves are named with a modifier, as in "video fossil".
[
Jargon File]
