fossil
a relic, remnant, or representation of an organism that existed in a past geological age, or of the activity of such an organism, occurring in the form of mineralized bones, shells, etc., as casts, impressions, and moulds, and as frozen perfectly preserved organisms
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
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.
fossil
(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.)
fossil
(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".
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)