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}]