= D =
=====

D. C. Power Lab: n. The former site of {{SAIL}}.  Hackers thought
   this was very funny because the obvious connection to electrical
   engineering was nonexistent --- the lab was named for a Donald C.
   Power.  Compare {Marginal Hacks}.

daemon: /day'mn/ or /dee'mn/ [from the mythological meaning,
   later rationalized as the acronym `Disk And Execution MONitor'] n.
   A program that is not invoked explicitly, but lies dormant waiting
   for some condition(s) to occur.  The idea is that the perpetrator
   of the condition need not be aware that a daemon is lurking (though
   often a program will commit an action only because it knows that it
   will implicitly invoke a daemon).  For example, under {{ITS}}
   writing a file on the {LPT} spooler's directory would invoke the
   spooling daemon, which would then print the file.  The advantage is
   that programs wanting (in this example) files printed need not
   compete for access to the {LPT}.  They simply enter their
   implicit requests and let the daemon decide what to do with them.
   Daemons are usually spawned automatically by the system, and may
   either live forever or be regenerated at intervals.  Daemon and
   {demon} are often used interchangeably, but seem to have
   distinct connotations.  The term `daemon' was introduced to
   computing by {CTSS} people (who pronounced it /dee'mon/) and
   used it to refer to what ITS called a {dragon}.  Although the
   meaning and the pronunciation have drifted, we think this glossary
   reflects current (1991) usage.

dangling pointer: n. A reference that doesn't actually lead
   anywhere (in C and some other languages, a pointer that doesn't
   actually point at anything valid).  Usually this is because it
   formerly pointed to something that has moved or disappeared.  Used
   as jargon in a generalization of its techspeak meaning; for
   example, a local phone number for a person who has since moved to the
   other coast is a dangling pointer.

Datamation: /day`t*-may'sh*n/ n. A magazine that many hackers
   assume all {suit}s read.  Used to question an unbelieved quote,
   as in "Did you read that in `Datamation?'" It used to
   publish something hackishly funny every once in a while, like the
   original paper on {COME FROM} in 1973, but it has since become much
   more exclusively {suit}-oriented and boring.

day mode: n. See {phase} (sense 1).  Used of people only.

dd: /dee-dee/ [UNIX: from IBM {JCL}] vt. Equivalent to {cat}
   or {BLT}.  This was originally the name of a UNIX copy command
   with special options suitable for block-oriented devices.  Often
   used in heavy-handed system maintenance, as in "Let's dd the root
   partition onto a tape, then use the boot PROM to load it back on to
   a new disk".  The UNIX `dd(1)' was designed with a weird,
   distinctly non-UNIXy keyword option syntax reminiscent of IBM
   System/360 JCL (which had a similar DD command); though the command
   filled a need, the interface design was clearly a prank.  The
   jargon usage is now very rare outside UNIX sites and now nearly
   obsolete even there, as `dd(1)' has been {deprecated} for a
   long time (though it has no exact replacement).  Replaced by
   {BLT} or simple English `copy'.

DDT: /D-D-T/ n. 1. Generic term for a program that assists in
   debugging other programs by showing individual machine instructions
   in a readable symbolic form and letting the user change them.  In
   this sense the term DDT is now archaic, having been widely
   displaced by `debugger' or names of individual programs like
   `dbx', `adb', `gdb', or `sdb'.  2. [ITS] Under
   MIT's fabled {{ITS}} operating system, DDT (running under the alias
   HACTRN) was also used as the {shell} or top level command
   language used to execute other programs.  3. Any one of several
   specific DDTs (sense 1) supported on early DEC hardware.  The DEC
   PDP-10 Reference Handbook (1969) contained a footnote on the first
   page of the documentation for DDT which illuminates the origin of
   the term:

     Historical footnote: DDT was developed at MIT for the PDP-1
     computer in 1961.  At that time DDT stood for "DEC Debugging Tape".
     Since then, the idea of an on-line debugging program has propagated
     throughout the computer industry.  DDT programs are now available
     for all DEC computers.  Since media other than tape are now
     frequently used, the more descriptive name "Dynamic Debugging
     Technique" has been adopted, retaining the DDT acronym.  Confusion
     between DDT-10 and another well known pesticide,
     dichloro-diphenyl-trichloroethane (C14-H9-Cl5) should be minimal
     since each attacks a different, and apparently mutually exclusive,
     class of bugs.

   Sadly, this quotation was removed from later editions of the
   handbook after the {suit}s took over and DEC became much more
   `businesslike'.

de-rezz: /dee-rez'/ [from `de-resolve' via the movie "Tron"]
   (also `derez') 1. vi. To disappear or dissolve; the image that goes
   with it is of an object breaking up into raster lines and static
   and then dissolving.  Occasionally used of a person who seems to
   have suddenly `fuzzed out' mentally rather than physically.
   Usage: extremely silly, also rare.  This verb was actually invented
   as *fictional* hacker jargon, and adopted in a spirit of irony
   by real hackers years after the fact.  2. vt. On a Macintosh, many
   program structures (including the code itself) are managed in small
   segments of the program file known as `resources'. The standard
   resource compiler is Rez.  The standard resource decompiler is
   DeRez.  Thus, decompiling a resource is `derezzing'.  Usage: very
   common.

dead code: n. Routines that can never be accessed because all calls
   to them have been removed, or code that cannot be reached because
   it is guarded by a control structure that provably must always
   transfer control somewhere else.  The presence of dead code may
   reveal either logical errors due to alterations in the program or
   significant changes in the assumptions and environment of the
   program (see also {software rot}); a good compiler should report
   dead code so a maintainer can think about what it means.  Syn.
   {grunge}.

DEADBEEF: /ded-beef/ n. The hexadecimal word-fill pattern for
   freshly allocated memory (decimal -21524111) under a number of
   IBM environments, including the RS/6000.  As in "Your program is
   DEADBEEF" (meaning gone, aborted, flushed from memory); if you
   start from an odd half-word boundary, of course, you have
   BEEFDEAD.

deadlock: n. 1. [techspeak] A situation wherein two or more
   processes are unable to proceed because each is waiting for one of
   the others to do something.  A common example is a program
   communicating to a server, which may find itself waiting for output
   from the server before sending anything more to it, while the
   server is similarly waiting for more input from the controlling
   program before outputting anything.  (It is reported that this
   particular flavor of deadlock is sometimes called a `starvation
   deadlock', though the term `starvation' is more properly used for
   situations where a program can never run simply because it never
   gets high enough priority.  Another common flavor is
   `constipation', where each process is trying to send stuff to
   the other but all buffers are full because nobody is reading
   anything.)  See {deadly embrace}.  2. Also used of
   deadlock-like interactions between humans, as when two people meet
   in a narrow corridor, and each tries to be polite by moving aside
   to let the other pass, but they end up swaying from side to side
   without making any progress because they always both move the same
   way at the same time.

deadly embrace: n. Same as {deadlock}, though usually used only when
   exactly 2 processes are involved.  This is the more popular term in
   Europe, while {deadlock} predominates in the United States.

Death Star: [from the movie "Star Wars"] 1. The AT&T corporate
   logo, which appears on computers sold by AT&T and bears an uncanny
   resemblance to the `Death Star' in the movie.  This usage is
   particularly common among partisans of {BSD} UNIX, who tend to
   regard the AT&T versions as inferior and AT&T as a bad guy.  Copies
   still circulate of a poster printed by Mt. Xinu showing a starscape
   with a space fighter labeled 4.2 BSD streaking away from a broken
   AT&T logo wreathed in flames.  2. AT&T's internal magazine,
   `Focus', uses `death star' for an incorrectly done AT&T logo
   in which the inner circle in the top left is dark instead of light
   --- a frequent result of dark-on-light logo images.

DEC Wars: n. A 1983 {USENET} posting by Alan Hastings and Steve Tarr
   spoofing the "Star Wars" movies in hackish terms.  Some years
   later, ESR (disappointed by Hastings and Tarr's failure to exploit a
   great premise more thoroughly) posted a 3-times-longer complete
   rewrite called "UNIX WARS"; the two are often confused.

DEChead: /dek'hed/ n. 1. A DEC {field servoid}.  Not flattering.
   2. [from `deadhead'] A Grateful Dead fan working at DEC.

deckle: /dek'l/ [from dec- and {nickle}] n. Two {nickle}s;
   10 bits.  Reported among developers for Mattel's GI 1600 (the
   Intellivision games processor), a chip with 16-bit-wide RAM but
   10-bit-wide ROM.

deep hack mode: n. See {hack mode}.

deep magic: [poss. from C. S. Lewis's "Narnia" books] n. An
   awesomely arcane technique central to a program or system, esp. one
   not generally published and available to hackers at large (compare
   {black art}); one that could only have been composed by a true
   {wizard}.  Compiler optimization techniques and many aspects of
   {OS} design used to be {deep magic}; many techniques in
   cryptography, signal processing, graphics, and AI still are.
   Compare {heavy wizardry}.  Esp. found in comments of the form
   "Deep magic begins here...".  Compare {voodoo programming}.

deep space: n. 1. Describes the notional location of any program
   that has gone {off the trolley}.  Esp. used of programs that
   just sit there silently grinding long after either failure or some
   output is expected.  "Uh oh.  I should have gotten a prompt ten
   seconds ago.  The program's in deep space somewhere." Compare
   {buzz}, {catatonic}, {hyperspace}.  2. The metaphorical
   location of a human so dazed and/or confused or caught up in some
   esoteric form of {bogosity} that he or she no longer responds
   coherently to normal communication.  Compare {page out}.

defenestration: [from the traditional Czechoslovak method of
   assassinating prime ministers, via SF fandom] n. 1. Proper karmic
   retribution for an incorrigible punster.  "Oh, ghod, that was
   *awful*!"  "Quick! Defenestrate him!"  2. The act of
   exiting a window system in order to get better response time from a
   full-screen program.  This comes from the dictionary meaning of
   `defenestrate', which is to throw something out a window.  3. The
   act of discarding something under the assumption that it will
   improve matters.  "I don't have any disk space left."  "Well,
   why don't you defenestrate that 100 megs worth of old core dumps?"
   4. [proposed] The requirement to support a command-line interface.
   "It has to run on a VT100."  "Curses!  I've been
   defenestrated!"

defined as: adj. In the role of, usually in an organization-chart
   sense.  "Pete is currently defined as bug prioritizer."  Compare
   {logical}.

dehose: /dee-hohz/ vt. To clear a {hosed} condition.

delint: /dee-lint/ v. To modify code to remove problems detected
   when {lint}ing.

delta: n. 1. [techspeak] A quantitative change, especially a small
   or incremental one (this use is general in physics and
   engineering).  "I just doubled the speed of my program!"  "What
   was the delta on program size?"  "About 30 percent."  (He
   doubled the speed of his program, but increased its size by only 30
   percent.)  2. [UNIX] A {diff}, especially a {diff} stored
   under the set of version-control tools called SCCS (Source Code
   Control System) or RCS (Revision Control System).  3. n. A small
   quantity, but not as small as {epsilon}.  The jargon usage of
   {delta} and {epsilon} stems from the traditional use of these
   letters in mathematics for very small numerical quantities,
   particularly in `epsilon-delta' proofs in limit theory (as in the
   differential calculus).  The term {delta} is often used, once
   {epsilon} has been mentioned, to mean a quantity that is
   slightly bigger than {epsilon} but still very small.  "The cost
   isn't epsilon, but it's delta" means that the cost isn't totally
   negligible, but it is nevertheless very small.  Common
   constructions include `within delta of ---', `within epsilon of
   ---': that is, close to and even closer to.

demented: adj. Yet another term of disgust used to describe a
   program.  The connotation in this case is that the program works as
   designed, but the design is bad.  Said, for example, of a program
   that generates large numbers of meaningless error messages,
   implying that it is on the brink of imminent collapse.  Compare
   {wonky}, {bozotic}.

demigod: n. A hacker with years of experience, a national reputation,
   and a major role in the development of at least one design, tool,
   or game used by or known to more than half of the hacker community.
   To qualify as a genuine demigod, the person must recognizably
   identify with the hacker community and have helped shape it.  Major
   demigods include Ken Thompson and Dennis Ritchie (co-inventors of
   {{UNIX}} and {C}) and Richard M. Stallman (inventor of
   {EMACS}).  In their hearts of hearts, most hackers dream of
   someday becoming demigods themselves, and more than one major
   software project has been driven to completion by the author's
   veiled hopes of apotheosis.  See also {net.god}, {true-hacker}.

demo: /de'moh/ [short for `demonstration'] 1. v. To demonstrate a
   product or prototype.  A far more effective way of inducing bugs to
   manifest than any number of {test} runs, especially when
   important people are watching.  2. n. The act of demoing.

demo mode: [Sun] n. 1. The state of being {heads down} in order
   to finish code in time for a {demo}, usually due yesterday.
   2. A mode in which video games sit there by themselves running
   through a portion of the game, also known as `attract mode'.
   Some serious {app}s have a demo mode they use as a screen saver,
   or may go through a demo mode on startup (for example, the
   Microsoft Windows opening screen --- which lets you impress your
   neighbors without actually having to put up with {Microsloth
   Windows}).

demon: n. 1. [MIT] A portion of a program that is not invoked
   explicitly, but that lies dormant waiting for some condition(s) to
   occur.  See {daemon}.  The distinction is that demons are
   usually processes within a program, while daemons are usually
   programs running on an operating system.  Demons are particularly
   common in AI programs.  For example, a knowledge-manipulation
   program might implement inference rules as demons.  Whenever a new
   piece of knowledge was added, various demons would activate (which
   demons depends on the particular piece of data) and would create
   additional pieces of knowledge by applying their respective
   inference rules to the original piece.  These new pieces could in
   turn activate more demons as the inferences filtered down through
   chains of logic.  Meanwhile, the main program could continue with
   whatever its primary task was.  2. [outside MIT] Often used
   equivalently to {daemon} --- especially in the {{UNIX}} world,
   where the latter spelling and pronunciation is considered mildly
   archaic.

depeditate: /dee-ped'*-tayt/ [by (faulty) analogy with
   `decapitate'] vt.  Humorously, to cut off the feet of.  When one is
   using some computer-aided typesetting tools, careless placement of
   text blocks within a page or above a rule can result in chopped-off
   letter descenders.  Such letters are said to have been depeditated.

deprecated: adj. Said of a program or feature that is considered
   obsolescent and in the process of being phased out, usually in
   favor of a specified replacement.  Deprecated features can,
   unfortunately, linger on for many years.

deserves to lose: adj. Said of someone who willfully does the
   {Wrong Thing}; humorously, if one uses a feature known to be
   {marginal}.  What is meant is that one deserves the consequences
   of one's {losing} actions.  "Boy, anyone who tries to use
   {mess-dos} deserves to {lose}!" ({{ITS}} fans used to say this
   of {{UNIX}}; many still do.)  See also {screw}, {chomp},
   {bagbiter}.

desk check: n.,v. To {grovel} over hardcopy of source code,
   mentally simulating the control flow; a method of catching bugs.
   No longer common practice in this age of on-screen editing, fast
   compiles, and sophisticated debuggers --- though some maintain
   stoutly that it ought to be.  Compare {eyeball search},
   {vdiff}, {vgrep}.

Devil Book: n. `The Design and Implementation of the 4.3BSD
   UNIX Operating System', by Samuel J. Leffler, Marshall Kirk
   McKusick, Michael J. Karels, and John S. Quarterman (Addison-Wesley
   Publishers, 1989) --- the standard reference book on the internals
   of {BSD} UNIX.  So called because the cover has a picture
   depicting a little devil (a visual play on {daemon}) in
   sneakers, holding a pitchfork (referring to one of the
   characteristic features of UNIX, the {fork(2)} system call).

devo: /dee'voh/ [orig. in-house jargon at Symbolics] n. A person in a
   development group.  See also {doco} and {mango}.

dickless workstation: n. Extremely pejorative hackerism for
   `diskless workstation', a class of botches including the Sun 3/50
   and other machines designed exclusively to network with an
   expensive central disk server.  These combine all the disadvantages
   of time-sharing with all the disadvantages of distributed personal
   computers.

dictionary flame: [USENET] n. An attempt to sidetrack a debate
   away from issues by insisting on meanings for key terms that
   presuppose a desired conclusion or smuggle in an implicit premise.
   A common tactic of people who prefer argument over definitions to
   disputes about reality.

diddle: 1. vt. To work with or modify in a not particularly
   serious manner.  "I diddled a copy of {ADVENT} so it didn't
   double-space all the time."  "Let's diddle this piece of code and
   see if the problem goes away."  See {tweak} and {twiddle}.
   2. n. The action or result of diddling.  See also {tweak},
   {twiddle}, {frob}.

diff: /dif/ n. 1. A change listing, especially giving differences
   between (and additions to) source code or documents (the term is
   often used in the plural `diffs').  "Send me your diffs for the
   Jargon File!"  Compare {vdiff}.  2. Specifically, such a listing
   produced by the `diff(1)' command, esp. when used as
   specification input to the `patch(1)' utility (which can
   actually perform the modifications; see {patch}).  This is a
   common method of distributing patches and source updates in the
   UNIX/C world.  See also {vdiff}, {mod}.

digit: n. An employee of Digital Equipment Corporation.  See also
   {VAX}, {VMS}, {PDP-10}, {{TOPS-10}}, {DEChead}, {double
   DECkers}, {field circus}.

dike: vt. To remove or disable a portion of something, as a wire
   from a computer or a subroutine from a program.  A standard slogan
   is "When in doubt, dike it out".  (The implication is that it is
   usually more effective to attack software problems by reducing
   complexity than by increasing it.)  The word `dikes' is widely
   used among mechanics and engineers to mean `diagonal cutters',
   esp.  a heavy-duty metal-cutting device, but may also refer to a
   kind of wire-cutters used by electronics techs.  To `dike
   something out' means to use such cutters to remove something.
   Indeed, the TMRC Dictionary defined dike as "to attack with
   dikes".  Among hackers this term has been metaphorically extended
   to informational objects such as sections of code.

ding: n.,vi. 1. Synonym for {feep}.  Usage: rare among hackers,
   but commoner in the {Real World}.  2. `dinged': What happens
   when someone in authority gives you a minor bitching about
   something, esp. something trivial.  "I was dinged for having a
   messy desk."

dink: /dink/ n. Said of a machine that has the {bitty box}
   nature; a machine too small to be worth bothering with --- sometimes
   the system you're currently forced to work on.  First heard from an
   MIT hacker (BADOB) working on a CP/M system with 64K, in reference
   to any 6502 system, then from fans of 32-bit architectures about
   16-bit machines.  "GNUMACS will never work on that dink machine."
   Probably derived from mainstream `dinky', which isn't sufficiently
   pejorative.

dinosaur: n. 1. Any hardware requiring raised flooring and special
   power.  Used especially of old minis and mainframes, in contrast
   with newer microprocessor-based machines.  In a famous quote from
   the 1988 UNIX EXPO, Bill Joy compared the mainframe in the massive
   IBM display with a grazing dinosaur "with a truck outside pumping
   its bodily fluids through it".  IBM was not amused.  Compare
   {big iron}; see also {mainframe}.  2. [IBM] A very conservative
   user; a {zipperhead}.

dinosaur pen: n. A traditional {mainframe} computer room complete with
   raised flooring, special power, its own ultra-heavy-duty air
   conditioning, and a side order of Halon fire extinguishers.  See
   {boa}.

dinosaurs mating: n. Said to occur when yet another {big iron}
   merger or buyout occurs; reflects a perception by hackers that
   these signal another stage in the long, slow dying of the
   {mainframe} industry.  In its glory days of the 1960s, it was
   `IBM and the Seven Dwarves': Burroughs, Control Data, General
   Electric, Honeywell, NCR, RCA, and Univac.  RCA and GE sold out
   early, and it was `IBM and the Bunch' (Burroughs, Univac, NCR,
   Control Data, and Honeywell) for a while.  Honeywell was bought out
   by Bull; Burroughs merged with Univac to form Unisys (in 1984 --- this
   was when the phrase `dinosaurs mating' was coined); and as this is
   written AT&T is attempting to recover from a disastrously bad first
   6 years in the hardware industry by absorbing NCR.  More such
   earth-shaking unions of doomed giants seem inevitable.

dirty power: n. Electrical mains voltage that is unfriendly to
   the delicate innards of computers.  Spikes, {drop-outs}, average
   voltage significantly higher or lower than nominal, or just plain
   noise can all cause problems of varying subtlety and severity.

Discordianism: /dis-kor'di-*n-ism/ n. The veneration of
   {Eris}, a.k.a. Discordia; widely popular among hackers.
   Discordianism was popularized by Robert Anton Wilson's
   `Illuminatus!' trilogy as a sort of self-subverting Dada-Zen
   for Westerners --- it should on no account be taken seriously but
   is far more serious than most jokes.  Consider, for example, the
   Fifth Commandment of the Pentabarf, from `Principia
   Discordia': "A Discordian is Prohibited of Believing What he
   Reads."  Discordianism is usually connected with an elaborate
   conspiracy theory/joke involving millennia-long warfare between the
   anarcho-surrealist partisans of Eris and a malevolent,
   authoritarian secret society called the Illuminati.  See
   appendix B, {Church of the SubGenius}, and {ha ha only
   serious}.

disk farm: n. (also {laundromat}) A large room or rooms filled
   with disk drives (esp. {washing machine}s).

display hack: n. A program with the same approximate purpose as a
   kaleidoscope: to make pretty pictures.  Famous display hacks
   include {munching squares}, {smoking clover}, the BSD UNIX
   `rain(6)' program, `worms(6)' on miscellaneous UNIXes,
   and the {X} `kaleid(1)' program.  Display hacks can also be
   implemented without programming by creating text files containing
   numerous escape sequences for interpretation by a video terminal;
   one notable example displayed, on any VT100, a Christmas tree with
   twinkling lights and a toy train circling its base.  The {hack
   value} of a display hack is proportional to the esthetic value of
   the images times the cleverness of the algorithm divided by the
   size of the code.  Syn. {psychedelicware}.

Dissociated Press: [play on `Associated Press'; perhaps inspired
   by a reference in the 1949 Bugs Bunny cartoon "What's Up,
   Doc?"] n.  An algorithm for transforming any text into potentially
   humorous garbage even more efficiently than by passing it through a
   {marketroid}.  You start by printing any N consecutive
   words (or letters) in the text.  Then at every step you search for
   any random occurrence in the original text of the last N
   words (or letters) already printed and then print the next word or
   letter.  {EMACS} has a handy command for this.  Here is a short
   example of word-based Dissociated Press applied to an earlier
   version of this Jargon File:

     wart: n. A small, crocky {feature} that sticks out of
     an array (C has no checks for this).  This is relatively
     benign and easy to spot if the phrase is bent so as to be
     not worth paying attention to the medium in question.

   Here is a short example of letter-based Dissociated Press applied
   to the same source:

     window sysIWYG: n. A bit was named aften /bee't*/ prefer
     to use the other guy's re, especially in every cast a
     chuckle on neithout getting into useful informash speech
     makes removing a featuring a move or usage actual
     abstractionsidered interj. Indeed spectace logic or problem!

   A hackish idle pastime is to apply letter-based Dissociated Press
   to a random body of text and {vgrep} the output in hopes of finding
   an interesting new word.  (In the preceding example, `window
   sysIWYG' and `informash' show some promise.)  Iterated applications
   of Dissociated Press usually yield better results.  Similar
   techniques called `travesty generators' have been employed with
   considerable satirical effect to the utterances of USENET flamers;
   see {pseudo}.

distribution: n. 1. A software source tree packaged for
   distribution; but see {kit}.  2. A vague term encompassing
   mailing lists and USENET newsgroups (but not {BBS} {fora}); any
   topic-oriented message channel with multiple recipients.  3. An
   information-space domain (usually loosely correlated with
   geography) to which propagation of a USENET message is restricted;
   a much-underutilized feature.

do protocol: [from network protocol programming] vi. To perform an
   interaction with somebody or something that follows a clearly
   defined procedure.  For example, "Let's do protocol with the
   check" at a restaurant means to ask for the check, calculate the
   tip and everybody's share, collect money from everybody, generate
   change as necessary, and pay the bill.  See {protocol}.

doc: /dok/ n. Common spoken and written shorthand for
   `documentation'.  Often used in the plural `docs' and in the
   construction `doc file' (documentation available on-line).

doco: /do'koh/ [orig. in-house jargon at Symbolics] n. A
   documentation writer.  See also {devo} and {mango}.

documentation:: n. The multiple kilograms of macerated, pounded,
   steamed, bleached, and pressed trees that accompany most modern
   software or hardware products (see also {tree-killer}).  Hackers
   seldom read paper documentation and (too) often resist writing it;
   they prefer theirs to be terse and on-line.  A common comment on
   this is "You can't {grep} dead trees".  See {drool-proof
   paper}, {verbiage}.

dodgy: adj. Syn. with {flaky}.  Preferred outside the U.S.

dogcow: /dog'kow/ n. See {Moof}.

dogwash: /dog'wosh/ [From a quip in the `urgency' field of a very
   optional software change request, ca. 1982.  It was something like
   "Urgency: Wash your dog first".] 1. n. A project of minimal
   priority, undertaken as an escape from more serious work.  2. v.
   To engage in such a project.  Many games and much {freeware} get
   written this way.

domainist: /doh-mayn'ist/ adj. 1. Said of an {{Internet
   address}} (as opposed to a {bang path}) because the part to the
   right of the `@' specifies a nested series of `domains';
   for example, eric@snark.thyrsus.com specifies the machine
   called snark in the subdomain called thyrsus within the
   top-level domain called com.  See also {big-endian}, sense 2.
   2. Said of a site, mailer, or routing program which knows how to
   handle domainist addresses.  3. Said of a person (esp. a site
   admin) who prefers domain addressing, supports a domainist mailer,
   or prosyletizes for domainist addressing and disdains {bang
   path}s.  This is now (1991) semi-obsolete, as most sites have
   converted.

Don't do that, then!: [from an old doctor's office joke about a
   patient with a trivial complaint] Stock response to a user
   complaint.  "When I type control-S, the whole system comes to a
   halt for thirty seconds."  "Don't do that, then!" (or "So don't
   do that!").  Compare {RTFM}.

dongle: /dong'gl/ n. 1. A security or {copy-protection} device
   for commercial microcomputer programs consisting of a serialized
   EPROM and some drivers in a D-25 connector shell, which must be
   connected to an I/O port of the computer while the program is run.
   Programs that use a dongle query the port at startup and at
   programmed intervals thereafter, and terminate if it does not
   respond with the dongle's programmed validation code.  Thus, users
   can make as many copies of the program as they want but must pay
   for each dongle.  The idea was clever, but it was initially a failure, as
   users disliked tying up a serial port this way.  Most dongles on
   the market today (1991) will pass data through the port and monitor
   for {magic} codes (and combinations of status lines) with minimal
   if any interference with devices further down the line --- this
   innovation was necessary to allow daisy-chained dongles for
   multiple pieces of software.  The devices are still not widely
   used, as the industry has moved away from copy-protection schemes
   in general.  2. By extension, any physical electronic key or
   transferrable ID required for a program to function.  See
   {dongle-disk}.

dongle-disk: /don'gl disk/ n. See {dongle}; a `dongle-disk'
   is a floppy disk with some coding that allows an application to
   identify it uniquely.  It can therefore be used as a {dongle}.
   Also called a `key disk'.

donuts: n.obs. A collective noun for any set of memory bits.  This is
   extremely archaic and may no longer be live jargon; it dates from the
   days of ferrite-{core} memories in which each bit was implemented by
   a doughnut-shaped magnetic flip-flop.

doorstop: n. Used to describe equipment that is non-functional and
   halfway expected to remain so, especially obsolete equipment kept
   around for political reasons or ostensibly as a backup.  "When we
   get another Wyse-50 in here, that ADM 3 will turn into a doorstop."
   Compare {boat anchor}.

dot file: [UNIX] n. A file which is not visible to normal
   directory-browsing tools (on UNIX, files named with a leading dot
   are, by convention, not normally presented in directory listings).
   Many programs define one or more dot files in which startup or
   configuration information may be optionally recorded; a user can
   customize the program's behavior by creating the appropriate file in
   the current or home directory.  See also {rc file}.

double bucky: adj. Using both the CTRL and META keys.  "The
   command to burn all LEDs is double bucky F."

   This term originated on the Stanford extended-ASCII keyboard, and
   was later taken up by users of the {space-cadet keyboard} at
   MIT.  A typical MIT comment was that the Stanford {bucky bits}
   (control and meta shifting keys) were nice, but there weren't
   enough of them; you could type only 512 different characters on a
   Stanford keyboard.  An obvious way to address this was simply to
   add more shifting keys, and this was eventually done; but a
   keyboard with that many shifting keys is hard on touch-typists, who
   don't like to move their hands away from the home position on the
   keyboard.  It was half-seriously suggested that the extra shifting
   keys be implemented as pedals; typing on such a keyboard would be
   very much like playing a full pipe organ.  This idea is mentioned
   in a parody of a very fine song by Jeffrey Moss called
   "Rubber Duckie", which was published in `The Sesame
   Street Songbook' (Simon and Schuster 1971, ISBN 671-21036-X).
   These lyrics were written on May 27, 1978, in celebration of the
   Stanford keyboard:

     			Double Bucky

     	Double bucky, you're the one!
     	You make my keyboard lots of fun.
     	    Double bucky, an additional bit or two:
     	(Vo-vo-de-o!)
     	Control and meta, side by side,
     	Augmented ASCII, nine bits wide!
     	    Double bucky!  Half a thousand glyphs, plus a few!
     		Oh,
     		I sure wish that I
     		Had a couple of
     		    Bits more!
     		Perhaps a
     		Set of pedals to
     		Make the number of
     		    Bits four:
     		Double double bucky!
     	Double bucky, left and right
     	OR'd together, outta sight!
     	    Double bucky, I'd like a whole word of
     	    Double bucky, I'm happy I heard of
     	    Double bucky, I'd like a whole word of you!

     	--- The Great Quux (with apologies to Jeffrey Moss)

   [This, by the way, is an excellent example of computer {filk} --- ESR]

   See also {meta bit}, {cokebottle}, and {quadruple bucky}.

double DECkers: n. Used to describe married couples in which both
   partners work for Digital Equipment Corporation.

doubled sig: [USENET] n. A {sig block} that has been included
   twice in a {USENET} article or, less commonly, in an electronic
   mail message.  An article or message with a doubled sig can be
   caused by improperly configured software.  More often, however, it
   reveals the author's lack of experience in electronic
   communication.  See {BIFF}, {pseudo}.

down: 1. adj. Not operating.  "The up escalator is down" is
   considered a humorous thing to say, and "The elevator is down"
   always means "The elevator isn't working" and never refers to
   what floor the elevator is on.  With respect to computers, this
   usage has passed into the mainstream; the extension to other kinds
   of machine is still hackish.  2. `go down' vi. To stop
   functioning; usually said of the {system}.  The message from the
   {console} that every hacker hates to hear from the operator is
   "The system will go down in 5 minutes".  3. `take down',
   `bring down' vt. To deactivate purposely, usually for repair work
   or {PM}.  "I'm taking the system down to work on that bug in the
   tape drive."  Occasionally one hears the word `down' by itself
   used as a verb in this vt. sense.  See {crash}; oppose {up}.

download: vt. To transfer data or (esp.) code from a larger `host'
   system (esp. a {mainframe}) over a digital comm link to a smaller
   `client' system, esp. a microcomputer or specialized peripheral.
   Oppose {upload}.

   However, note that ground-to-space communications has its own usage
   rule for this term.  Space-to-earth transmission is always download
   and the reverse upload regardless of the relative size of the
   computers involved.  So far the in-space machines have invariably
   been smaller; thus the upload/download distinction has been
   reversed from its usual sense.

DP: /D-P/ n. 1. Data Processing.  Listed here because,
   according to hackers, use of the term marks one immediately as a
   {suit}.  See {DPer}.  2. Common abbrev for {Dissociated
   Press}.

DPB: /d*-pib'/ [from the PDP-10 instruction set] vt. To plop
   something down in the middle.  Usage: silly.  "DPB
   yourself into that couch there."  The connotation would be that
   the couch is full except for one slot just big enough for you to
   sit in.  DPB means `DePosit Byte', and was the name of a PDP-10
   instruction that inserts some bits into the middle of some other
   bits.  This usage has been kept alive by the Common LISP function
   of the same name.

DPer: /dee-pee-er/ n. Data Processor.  Hackers are absolutely
   amazed that {suit}s use this term self-referentially.
   "*Computers* process data, not people!"  See {DP}.

dragon: n. [MIT] A program similar to a {daemon}, except that it
   is not invoked at all, but is instead used by the system to perform
   various secondary tasks.  A typical example would be an accounting
   program, which keeps track of who is logged in, accumulates
   load-average statistics, etc.  Under ITS, many terminals displayed
   a list of people logged in, where they were, what they were
   running, etc., along with some random picture (such as a unicorn,
   Snoopy, or the Enterprise), which was generated by the `name
   dragon'.  Usage: rare outside MIT --- under UNIX and most other OSes
   this would be called a `background demon' or {daemon}.  The
   best-known UNIX example of a dragon is `cron(1)'.  At SAIL,
   they called this sort of thing a `phantom'.

Dragon Book: n. The classic text `Compilers: Principles,
   Techniques and Tools', by Alfred V. Aho, Ravi Sethi, and Jeffrey D.
   Ullman (Addison-Wesley 1986; ISBN 0-201-10088-6), so called because
   of the cover design featuring a dragon labeled `complexity of
   compiler design' and a knight bearing the lance `LALR parser
   generator' among his other trappings.  This one is more
   specifically known as the `Red Dragon Book' (1986); an earlier
   edition, sans Sethi and titled `Principles Of Compiler Design'
   (Alfred V. Aho and Jeffrey D. Ullman; Addison-Wesley, 1977; ISBN
   0-201-00022-9), was the `Green Dragon Book' (1977).  (Also `New
   Dragon Book', `Old Dragon Book'.)  The horsed knight and the
   Green Dragon were warily eying each other at a distance; now the
   knight is typing (wearing gauntlets!) at a terminal showing a
   video-game representation of the Red Dragon's head while the rest
   of the beast extends back in normal space.  See also {{book
   titles}}.

drain: [IBM] v. Syn. for {flush} (sense 2).  Has a connotation
   of finality about it; one speaks of draining a device before taking
   it offline.

dread high-bit disease: n. A condition endemic to PRIME (a.k.a.
   PR1ME) minicomputers that results in all the characters having
   their high (0x80) bit ON rather than OFF.  This of course makes
   transporting files to other systems much more difficult, not to
   mention talking to true 8-bit devices.  It is reported that
   PRIME adopted the reversed-8-bit convention in order to save
   25 cents per serial line per machine.  This probably qualifies as one
   of the most {cretinous} design tradeoffs ever made.  See {meta
   bit}.   A few other machines (including the Atari 800) have exhibited
   similar brain damage.

DRECNET: /drek'net/ [from Yiddish/German `dreck', meaning
   dirt] n. Deliberate distortion of DECNET, a networking protocol
   used in the {VMS} community.  So called because DEC helped write
   the Ethernet specification and then (either stupidly or as a
   malignant customer-control tactic) violated that spec in the design
   of DRECNET in a way that made it incompatible.  See also
   {connector conspiracy}.

driver: n. 1. The {main loop} of an event-processing program;
   the code that gets commands and dispatches them for execution.
   2. [techspeak] In `device driver', code designed to handle a
   particular peripheral device such as a magnetic disk or tape unit.
   3. In the TeX   general, `driver' also means a program that translates some
   device-independent or other common format to something a real
   device can actually understand.

droid: n. A person (esp. a low-level bureaucrat or
   service-business employee) exhibiting most of the following
   characteristics: (a) na"ive trust in the wisdom of the parent
   organization or `the system'; (b) a propensity to believe
   obvious nonsense emitted by authority figures (or computers!);
   blind faith; (c) a rule-governed mentality, one unwilling or unable
   to look beyond the `letter of the law' in exceptional
   situations; and (d) no interest in fixing that which is broken; an
   "It's not my job, man" attitude.

   Typical droid positions include supermarket checkout assistant and
   bank clerk; the syndrome is also endemic in low-level government
   employees.  The implication is that the rules and official
   procedures constitute software that the droid is executing.  This
   becomes a problem when the software has not been properly debugged.
   The term `droid mentality' is also used to describe the mindset
   behind this behavior. Compare {suit}, {marketroid}; see
   {-oid}.

drool-proof paper: n. Documentation that has been obsessively {dumbed
   down}, to the point where only a {cretin} could bear to read it, is
   said to have succumbed to the `drool-proof paper syndrome' or to
   have been `written on drool-proof paper'.  For example, this is
   an actual quote from Apple's LaserWriter manual: "Do not expose
   your LaserWriter to open fire or flame."

drop on the floor: vt. To react to an error condition by silently
   discarding messages or other valuable data.  "The gateway
   ran out of memory, so it just started dropping packets on the
   floor."  Also frequently used of faulty mail and netnews relay
   sites that lose messages.  See also {black hole}, {bit bucket}.

drop-ins: [prob. by analogy with {drop-outs}] n. Spurious
   characters appearing on a terminal or console as a result of line noise or
   a system malfunction of some sort.  Esp. used when these are
   interspersed with one's own typed input.  Compare {drop-outs}.

drop-outs: n. 1. A variety of `power glitch' (see {glitch});
   momentary 0 voltage on the electrical mains.  2. Missing characters
   in typed input due to software malfunction or system saturation
   (this can happen under UNIX when a bad connection to a modem swamps
   the processor with spurious character interrupts).  3. Mental
   glitches; used as a way of describing those occasions when the mind
   just seems to shut down for a couple of beats.  See {glitch},
   {fried}.

drugged: adj. (also `on drugs') 1. Conspicuously stupid,
   heading toward {brain-damaged}.  Often accompanied by a
   pantomime of toking a joint (but see appendix B).  2. Of hardware,
   very slow relative to normal performance.

drunk mouse syndrome: n. A malady exhibited by the mouse pointing
   device of some computers.  The typical symptom is for the mouse
   cursor on the screen to move in random directions and not in sync
   with the motion of the actual mouse.  Can usually be corrected by
   unplugging the mouse and plugging it back again.  Another
   recommended fix for optical mice is to rotate your mouse pad
   90 degrees.

   At Xerox PARC in the 1970s, most people kept a can of copier
   cleaner (isopropyl alcohol) at their desks.  When the steel ball on
   the mouse had picked up enough {cruft} to be unreliable, the mouse
   was doused in cleaner, which restored it for a while.  However,
   this operation left a fine residue that accelerated the accumulation
   of cruft, so the dousings became more and more frequent.  Finally,
   the mouse was declared `alcoholic' and sent to the clinic to be
   dried out in a CFC ultrasonic bath.

dumbass attack: /duhm'as *-tak'/ [Purdue] n. Notional cause of a
   novice's mistake made by the experienced, especially one made while
   running as root under UNIX, e.g., typing `rm -r *' or
   `mkfs' on a mounted file system.  Compare {adger}.

dumbed down: adj. Simplified, with a strong connotation of
   *over*simplified.  Often, a {marketroid} will insist that the
   interfaces and documentation of software be dumbed down after the
   designer has burned untold gallons of midnight oil making it
   smart.  This creates friction.  See {user-friendly}.

dump: n. 1. An undigested and voluminous mass of information about a
   problem or the state of a system, especially one routed to the
   slowest available output device (compare {core dump}), and most
   especially one consisting of hex or octal {runes} describing the
   byte-by-byte state of memory, mass storage, or some file.  In {elder
   days}, debugging was generally done by `groveling over' a dump
   (see {grovel}); increasing use of high-level languages and
   interactive debuggers has made this uncommon, and the term `dump'
   now has a faintly archaic flavor.  2. A backup.  This usage is
   typical only at large timesharing installations.

dup killer: /d[y]oop kill'r/ [FidoNet] n. Software that is
   supposed to detect and delete duplicates of a message that may
   have reached the FidoNet system via different routes.

dup loop: /d[y]oop loop/ (also `dupe loop') [FidoNet] n. An
   incorrectly configured system or network gateway may propagate
   duplicate messages on one or more {echo}es, with different
   identification information that renders {dup killer}s
   ineffective.  If such a duplicate message eventually reaches a
   system through which it has already passed (with the original
   identification information), all systems passed on the way back to
   that system are said to be involved in a {dup loop}.

dusty deck: n. Old software (especially applications) which one is
   obliged to remain compatible with (or to maintain).  The term
   implies that the software in question is a holdover from card-punch
   days.  Used esp. when referring to old scientific and
   {number-crunching} software, much of which was written in FORTRAN
   and very poorly documented but is believed to be too expensive to
   replace.  See {fossil}.

DWIM: /dwim/ [acronym, `Do What I Mean'] 1. adj. Able to guess, sometimes
   even correctly, the result intended when bogus input was provided.
   2. n.,obs. The BBNLISP/INTERLISP function that attempted to
   accomplish this feat by correcting many of the more common errors.
   See {hairy}.  3. Occasionally, an interjection hurled at a
   balky computer, esp. when one senses one might be tripping over
   legalisms (see {legalese}).

   Warren Teitelman originally wrote DWIM to fix his typos and
   spelling errors, so it was somewhat idiosyncratic to his style, and
   would often make hash of anyone else's typos if they were
   stylistically different.  This led a number of victims of DWIM to
   claim the acronym stood for `Damn Warren's Infernal Machine!'.

   In one notorious incident, Warren added a DWIM feature to the
   command interpreter used at Xerox PARC.  One day another hacker
   there typed `delete *$' to free up some disk space.  (The editor
   there named backup files by appending `$' to the original file
   name, so he was trying to delete any backup files left over from
   old editing sessions.)  It happened that there weren't any editor
   backup files, so DWIM helpfully reported `*$ not found, assuming
   you meant 'delete *'.'  It then started to delete all the files on
   the disk!  The hacker managed to stop it with a {Vulcan nerve
   pinch} after only a half dozen or so files were lost.
   
   The hacker later said he had been sorely tempted to go to Warren's
   office, tie Warren down in his chair in front of his workstation,
   and then type `delete *$' twice.

   DWIM is often suggested in jest as a desired feature for a complex
   program; it is also occasionally described as the single
   instruction the ideal computer would have.  Back when proofs of
   program correctness were in vogue, there were also jokes about
   `DWIMC' (Do What I Mean, Correctly).  A related term, more often
   seen as a verb, is DTRT (Do The Right Thing); see {Right Thing}.

dynner: /din'r/ 32 bits, by analogy with {nybble} and
   {{byte}}.  Usage: rare and extremely silly.  See also {playte},
   {tayste}, {crumb}.