The Jargon File


The Jargon File
Introduction
How Jargon Works
How to Use the Lexicon

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [^a-zA-Z]

Appendix A --- Appendix B --- Appendix C

T

 /T/  1. [from LISP terminology for `true'] Yes.  Used
   in reply to a question (particularly one asked using The_`-P'_convention
   ).  In LISP, the constant T means `true', among other
   things.  Some hackers use `T' and `NIL' instead of `Yes' and `No'
   almost reflexively.  This sometimes causes misunderstandings.  When
   a waiter or flight attendant asks whether a hacker wants coffee, he
   may well respond `T', meaning that he wants coffee; but of course
   he will be brought a cup of tea instead.  As it happens, most
   hackers (particularly those who frequent Chinese restaurants) like
   tea at least as well as coffee -- so it is not that big a problem.
   2. See time_T (also since_time_T_equals_minus_infinity).
   3. [techspeak] In transaction-processing circles, an abbreviation
   for the noun `transaction'.  4. [Purdue] Alternate spelling of
   tee.  5. A dialect of LISP developed at Yale.

tail recursion

 n.  If you aren't sick of it already, see
   tail_recursion.

talk mode

 n.  A feature supported by UNIX, ITS, and some
   other OSes that allows two or more logged-in users to set up a
   real-time on-line conversation.  It combines the immediacy of
   talking with all the precision (and verbosity) that written
   language entails.  It is difficult to communicate inflection,
   though conventions have arisen for some of these (see the section
   on writing style in the Prependices for details).

   Talk mode has a special set of jargon words, used to save typing,
   which are not used orally.  Some of these are identical to (and
   probably derived from) Morse-code jargon used by ham-radio amateurs
   since the 1920s.

     AFAIK
          as far as I know
     BCNU
          be seeing you
     BTW
          by the way
     BYE?
          are you ready to unlink?  (this is the standard way to end a
          talk-mode conversation; the other person types `BYE' to
          confirm, or else continues the conversation)
     CUL
          see you later
     ENQ?
          are you busy?  (expects `ACK' or `NAK' in return)
     FOO?
          are you there? (often used on unexpected links, meaning also
          "Sorry if I butted in ..." (linker) or "What's up?"
          (linkee))
     FWIW
          for what it's worth
     FYI
          for your information
     FYA
          for your amusement
     GA
          go ahead (used when two people have tried to type
          simultaneously; this cedes the right to type to the other)
     GRMBL
          grumble (expresses disquiet or disagreement)
     HELLOP
          hello? (an instance of the `-P' convention)
     JAM
          just a minute (equivalent to `SEC....')
     MIN
          same as `JAM'
     NIL
          no (see NIL)
     O
          over to you
     OO
          over and out
     /
          another form of "over to you" (from x/y as "x over y")
     \
          lambda (used in discussing LISPy things)
     OBTW
          oh, by the way
     OTOH
          on the other hand
     R U THERE?
          are you there?
     SEC
          wait a second (sometimes written `SEC...')
     T
          yes (see the main entry for T)
     TNX
          thanks
     TNX 1.0E6
          thanks a million (humorous)
     TNXE6
          another form of "thanks a million"
     WRT
          with regard to, or with respect to.
     WTF
          the universal interrogative particle; WTF knows what it
          means?
     WTH
          what the hell?
     <double newline>
          When the typing party has finished, he/she types two
          newlines to signal that he/she is done; this leaves a blank
          line between `speeches' in the conversation, making it
          easier to reread the preceding text.
     <name>:
          When three or more terminals are linked, it is conventional
          for each typist to prepend his/her login name or handle
          and a colon (or a hyphen) to each line to indicate who is
          typing (some conferencing facilities do this automatically).
          The login name is often shortened to a unique prefix
          (possibly a single letter) during a very long conversation.
     /\/\/\
          A giggle or chuckle.  On a MUD, this usually means
          `earthquake fault'.

   Most of the above sub-jargon is used at both Stanford and MIT.
   Several of these expressions are also common in email, esp.
   FYI, FYA, BTW, BCNU, WTF, and CUL.  A few other abbreviations have
   been reported from commercial networks, such as GEnie and
   CompuServe, where on-line `live' chat including more than two
   people is common and usually involves a more `social' context,
   notably the following:

     <g>
          grin
     <gr&d>
          grinning, running, and ducking
     BBL
          be back later
     BRB
          be right back
     HHOJ
          ha ha only joking
     HHOK
          ha ha only kidding
     HHOS
          ha_ha_only_serious
     IMHO
          in my humble opinion (see IMHO)
     LOL
          laughing out loud
     NHOH
          Never Heard of Him/Her (often used in initgame)
     ROTF
          rolling on the floor
     ROTFL
          rolling on the floor laughing
     AFK
          away from keyboard
     b4
          before
     CU l8tr
          see you later
     MORF
          male or female?
     TTFN
          ta-ta for now
     TTYL
          talk to you later
     OIC
          oh, I see
     rehi
          hello again

   Most of these are not used at universities or in the UNIX world,
   though ROTF and TTFN have gained some currency there and IMHO is
   common; conversely, most of the people who know these are
   unfamiliar with FOO?, BCNU, HELLOP, NIL, and T.

   The MUD community uses a mixture of Usenet/Internet emoticons,
   a few of the more natural of the old-style talk-mode abbrevs, and
   some of the `social' list above; specifically, MUD respondents
   report use of BBL, BRB, LOL, b4, BTW, WTF, TTFN, and WTH.  The use
   of `rehi' is also common; in fact, mudders are fond of re-
   compounds and will frequently `rehug' or `rebonk' (see
   bonk/oif) people.  The word `re' by itself is taken as
   `regreet'.  In general, though, MUDders express a preference for
   typing things out in full rather than using abbreviations; this may
   be due to the relative youth of the MUD cultures, which tend to
   include many touch typists and to assume high-speed links.  The
   following uses specific to MUDs are reported:

     CU l8er
          see you later (mutant of `CU l8tr')
     FOAD
          fuck off and die (use of this is generally OTT)
     OTT
          over the top (excessive, uncalled for)
     ppl
          abbrev for "people"
     THX
          thanks (mutant of `TNX'; clearly this comes in batches of
          1138 (the Lucasian K)).
     UOK?
          are you OK?

   Some B1FFisms (notably the variant spelling `d00d')
   appear to be passing into wider use among some subgroups of
   MUDders.

   One final note on talk mode style: neophytes, when in talk mode,
   often seem to think they must produce letter-perfect prose because
   they are typing rather than speaking.  This is not the best
   approach.  It can be very frustrating to wait while your partner
   pauses to think of a word, or repeatedly makes the same spelling
   error and backs up to fix it.  It is usually best just to leave
   typographical errors behind and plunge forward, unless severe
   confusion may result; in that case it is often fastest just to type
   "xxx" and start over from before the mistake.

   See also hakspek, emoticon.

talker system

 n.  British hackerism for software that
   enables real-time chat or talk_mode.

tall card

 n.  A PC/AT-size expansion card (these can be
   larger than IBM PC or XT cards because the AT case is bigger).  See
   also short_card.  When IBM introduced the PS/2 model 30 (its
   last gasp at supporting the ISA) they made the case lower and many
   industry-standard tall cards wouldn't fit; this was felt to be a
   reincarnation of the connector_conspiracy, done with less
   style.

tanked

 adj.  Same as down, used primarily by UNIX
   hackers.  See also hosed.  Popularized as a synonym for
   `drunk' by Steve Dallas in the late lamented "Bloom County"
   comic strip.

TANSTAAFL

 /tan'stah-fl/  [acronym, from Robert Heinlein's
   classic "The Moon is a Harsh Mistress".]  "There Ain't No
   Such Thing As A Free Lunch", often invoked when someone is balking
   at the prospect of using an unpleasantly heavyweight
   technique, or at the poor quality of some piece of free software,
   or at the signal-to-noise_ratio of unmoderated Usenet
   newsgroups.  "What? Don't tell me I have to implement a database
   back end to get my address book program to work!"  "Well,
   TANSTAAFL you know."  This phrase owes some of its popularity to
   the high concentration of science-fiction fans and political
   libertarians in hackerdom (see A_Portrait_of_J._Random_Hacker
    in Appendix B).

tar and feather

 vi.  [from UNIX `tar(1)'] To create a
   transportable archive from a group of files by first sticking them
   together with `tar(1)' (the Tape ARchiver) and then
   compressing the result (see compress).  The latter action is
   dubbed `feathering' partly for euphony and (if only for contrived
   effect) by analogy to what you do with an airplane propeller to
   decrease wind resistance, or with an oar to reduce water
   resistance; smaller files, after all, slip through comm links more
   easily.

taste

 [primarily MIT] n.  1. The quality in a program that
   tends to be inversely proportional to the number of features,
   hacks, and kluges programmed into it.  Also `tasty',
   `tasteful', `tastefulness'.  "This feature comes in N
   tasty flavors."  Although `tasty' and `flavorful' are
   essentially synonyms, `taste' and flavor are not.  Taste
   refers to sound judgment on the part of the creator; a program or
   feature can *exhibit* taste but cannot *have* taste.  On
   the other hand, a feature can have flavor.  Also, flavor
   has the additional meaning of `kind' or `variety' not shared by
   `taste'.  The marked sense of flavor is more popular than
   `taste', though both are widely used.  See also elegant.
   2. Alt. sp. of tayste.

tayste

 /tayst/  n. Two bits; also as taste.
   Syn. crumb, quarter.  See nybble.

TCB

 /T-C-B/  n.  [IBM] 1. Trouble Came Back.  An
   intermittent or difficult-to-reproduce problem that has failed to
   respond to neglect or shotgun_debugging.  Compare
   heisenbug.  Not to be confused with: 2. Trusted Computing
   Base, an `official' jargon term from the Orange_Book.

TCP/IP

 n.  1. [Transmission Control Protocol/Internet Protocol]
   The wide-area-networking protocol that makes the Internet work, and
   the only one most hackers can speak the name of without laughing or
   retching.  Unlike such allegedly `standard' competitors such as
   X.25, DECnet, and the ISO 7-layer stack, TCP/IP evolved primarily
by
   actually being *used*, rather than being handed down from on
   high by a vendor or a heavily-politicized standards committee.
   Consequently, it (a) works, (b) actually promotes cheap
   cross-platform connectivity, and (c) annoys the hell out of
   corporate and governmental empire-builders everywhere.  Hackers
   value all three of these properties. See creationism.  2.
   [Amateur Packet Redio] Sometimes expanded as "The Crap Phil Is
   Pushing".  The reference is to Phil Karn, KA9NQ, and the context
   is an ongoing technical/political war between the majority of sites
   still running AX.25 and a growing minority of TCP/IP relays.

tea, ISO standard cup of

 n.  [South Africa] A cup of tea
   with milk and one teaspoon of sugar, where the milk is poured into
   the cup before the tea.  Variations are ISO 0, with no sugar; ISO
   2, with two spoons of sugar; and so on.

   Like many ISO standards, this one has a faintly alien ring in North
   America, where hackers generally shun the decadent British practice
   of adulterating perfectly good tea with dairy products and
   prefer instead to add a wedge of lemon, if anything.  If one were
   feeling extremely silly, one might hypothesize an analogous `ANSI
   standard cup of tea' and wind up with a political situation
   distressingly similar to several that arise in much more serious
   technical contexts.  Milk and lemon don't mix very well.

TechRef

 /tek'ref/ n.  [MS-DOS] The original "IBM PC
   Technical Reference Manual", including the BIOS listing and
   complete schematics for the PC.  The only PC documentation in the
   issue package that's considered serious by real hackers.

TECO

 /tee'koh/ n.,v.,obs.  1. [originally an acronym for
   `[paper] Tape Editor and COrrector'; later, `Text Editor and
   COrrector'] n. A text editor developed at MIT and modified by just
   about everybody.  With all the dialects included, TECO may have
   been the most prolific editor in use before EMACS, to which it
   was directly ancestral.  Noted for its powerful
   programming-language-like features and its unspeakably hairy
   syntax.  It is literally the case that every string of characters
   is a valid TECO program (though probably not a useful one); one
   common game used to be mentally working out what the TECO commands
   corresponding to human names did.  2. vt. Originally, to edit using
   the TECO editor in one of its infinite variations (see below).
   3. vt.,obs.  To edit even when TECO is *not* the editor being
   used!  This usage is rare and now primarily historical.

   As an example of TECO's obscurity, here is a TECO program that
   takes a list of names such as:

     Loser, J. Random
     Quux, The Great
     Dick, Moby

   sorts them alphabetically according to surname, and then puts the
   surname last, removing the comma, to produce the following:

     Moby Dick
     J. Random Loser
     The Great Quux

   The program is

     [1 J^P$L$$
     J <.-Z; .,(S,$ -D .)FX1 @F^B $K :L I $ G1 L>$$

   (where ^B means `Control-B' (ASCII 0000010) and $ is actually
   an alt or escape (ASCII 0011011) character).

   In fact, this very program was used to produce the second, sorted
   list from the first list.  The first hack at it had a bug: GLS
   (the author) had accidentally omitted the `@' in front
   of `F^B', which as anyone can see is clearly the Wrong_Thing.  It
   worked fine the second time.  There is no space to describe all the
   features of TECO, but it may be of interest that `^P' means
   `sort' and `J<.-Z; ... L>' is an idiomatic series of commands
   for `do once for every line'.

   In mid-1991, TECO is pretty much one with the dust of history,
   having been replaced in the affections of hackerdom by EMACS.
   Descendants of an early (and somewhat lobotomized) version adopted
   by DEC can still be found lurking on VMS and a couple of crufty
   PDP-11 operating systems, however, and ports of the more advanced
   MIT versions remain the focus of some antiquarian interest.  See
   also retrocomputing, write-only_language.


tee

 n.,vt.  [Purdue] A carbon copy of an electronic
   transmission.  "Oh, you're sending him the bits to that?
   Slap on a tee for me."  From the UNIX command `tee(1)',
   itself named after a pipe fitting (see plumbing).  Can also
   mean `save one for me', as in "Tee a slice for me!"  Also
   spelled `T'.

teledildonics

 /tel`*-dil-do'-niks/ n.  Sex in a computer
   simulated virtual reality, esp. computer-mediated sexual
   interaction between the VR presences of two humans.  This
   practice is not yet possible except in the rather limited form of
   erotic conversation on MUDs and the like.  The term, however,
   is widely recognized in the VR community as a ha_ha_only_serious
    projection of things to come.  "When we can sustain a
   multi-sensory surround good enough for teledildonics, *then*
   we'll know we're getting somewhere." See also hot_chat.

Telerat

 /tel'*-rat/ n.  Unflattering hackerism for
   `Teleray', a line of extremely losing terminals.  Compare
   AIDX, Macintrash Nominal_Semidestructor, Open_DeathTrap
   , ScumOS, sun-stools, HP-SUX.

TELNET

 /tel'net/ vt.  (also commonly lowercased as
   `telnet') To communicate with another Internet host using the
   TELNET (RFC 854) protocol (usually using a program of the same
   name).  TOPS-10 people used the word IMPCOM, since that was the
   program name for them.  Sometimes abbreviated to TN /T-N/.  "I
   usually TN over to SAIL just to read the AP News."

ten-finger interface

 n.  The interface between two networks
   that cannot be directly connected for security reasons; refers to
   the practice of placing two terminals side by side and having an
   operator read from one and type into the other.

tense

 adj.  Of programs, very clever and efficient.  A tense
   piece of code often got that way because it was highly bummed,
   but sometimes it was just based on a great idea.  A comment in a
   clever routine by Mike Kazar, once a grad-student hacker at CMU:
   "This routine is so tense it will bring tears to your eyes."  A
   tense programmer is one who produces tense code.

tentacle

 n.  A covert pseudo, sense 1.  An artificial
   identity created in cyberspace for nefarious and deceptive
   purposes.  The implication is that single person may have multiple
   tentacles.  This term was originally floated in some paranoid
   ravings on the cypherpunks list (see cypherpunk, and adopted
   in a spirit of irony by other members. It has since shown up, used
   seriously, in the documentation for some remailer software, and is
   now (1994) widely recognized on the net.

tenured graduate student

 n.  One who has been in graduate
   school for 10 years (the usual maximum is 5 or 6): a `ten-yeared'
   student (get it?).  Actually, this term may be used of any grad
   student beginning in his seventh year.  Students don't really get
   tenure, of course, the way professors do, but a tenth-year graduate
   student has probably been around the university longer than any
   untenured professor.

tera-

 /te'r*/ pref.  [SI] See quantifiers.

teraflop club

 /te'r*-flop kluhb/ n.  [FLOP = Floating
   Point Operation] A mythical association of people who consume
   outrageous amounts of computer time in order to produce a few
   simple pictures of glass balls with intricate ray-tracing
   techniques.  Caltech professor James Kajiya is said to have been
   the founder.  Compare Knights_of_the_Lambda_Calculus.

terminak

 /ter'mi-nak`/ n.  [Caltech, ca. 1979] Any
   malfunctioning computer terminal.  A common failure mode of
   Lear-Siegler ADM 3a terminals caused the `L' key to produce the `K'
   code instead; complaints about this tended to look like "Terminak
   #3 has a bad keyboard.  Pkease fix."  See AIDX, Nominal_Semidestructor
   , Open_DeathTrap, ScumOS, sun-stools,
   Telerat, HP-SUX.

terminal brain death

 n.  The extreme form of terminal_illness
    (sense 1).  What someone who has obviously been hacking
   continuously for far too long is said to be suffering from.

terminal illness

 n.  1. Syn. raster_burn.  2. The
   `burn-in' condition your CRT tends to get if you don't have a
   screen saver.

terminal junkie

 n.  [UK] A wannabee or early larval_stage
    hacker who spends most of his or her time wandering the
   directory tree and writing noddy programs just to get a fix of
   computer time.  Variants include `terminal jockey', `console
   junkie', and console_jockey.  The term `console jockey'
   seems to imply more expertise than the other three (possibly
   because of the exalted status of the console relative to an
   ordinary terminal).  See also twink, read-only_user
   .

terpri

 /ter'pree/ vi.  [from LISP 1.5 (and later,
   MacLISP)] To output a newline.  Now rare as jargon, though
   still used as techspeak in Common LISP.  It is a contraction of
   `TERminate PRInt line', named for the fact that, on some early OSes
   and hardware, no characters would be printed until a complete line
   was formed, so this operation terminated the line and emitted the
   output.

test

 n.  1. Real users bashing on a prototype long enough to
   get thoroughly acquainted with it, with careful monitoring and
   followup of the results.  2. Some bored random user trying a couple
   of the simpler features with a developer looking over his or her
   shoulder, ready to pounce on mistakes.  Judging by the quality of
   most software, the second definition is far more prevalent.  See
   also demo.

TeX

: /tekh/ n.  X An extremely powerful macro-based text formatter
written by
   Donald E. Knuth, very popular in the computer-science
   community (it is good enough to have displaced UNIX troff, the
   other favored formatter, even at many UNIX installations).  TeX
   fans insist on the correct (guttural) pronunciation, and the
   correct spelling (all caps, squished together, with the E depressed
   below the baseline; the mixed-case `TeX' is considered an
   acceptable kluge on ASCII-only devices).  Fans like to proliferate
   names from the word `TeX' -- such as TeXnician (TeX
   user), TeXhacker (TeX programmer), TeXmaster (competent
   TeX programmer), TeXhax, and TeXnique.  See also
   CrApTeX.

   Knuth began TeX because he had become annoyed at the declining
   quality of the typesetting in volumes I--III of his monumental
   "Art of Computer Programming" (see Knuth, also
   bible).  In a manifestation of the typical hackish urge to
   solve the problem at hand once and for all, he began to design his
   own typesetting language.  He thought he would finish it on his
   sabbatical in 1978; he was wrong by only about 8 years.  The
   language was finally frozen around 1985, but volume IV of "The
   Art of Computer Programming" has yet to appear as of mid-1993.  The
   impact and influence of TeX's design has been such that nobody
   minds this very much.  Many grand hackish projects have started as
   a bit of toolsmithing on the way to something else; Knuth's
   diversion was simply on a grander scale than most.

   TeX has also been a noteworthy example of free, shared, but
   high-quality software.  Knuth used to offer monetary awards to
   people who found and reported bugs in it; as the years wore on and
   the few remaining bugs were fixed (and new ones even harder to
   find), the bribe went up.  Though well-written, TeX is so large
   (and so full of cutting edge technique) that it is said to have
   unearthed at least one bug in every Pascal system it has been
   compiled with.

text

 n.  1. [techspeak] Executable code, esp. a `pure
   code' portion shared between multiple instances of a program
   running in a multitasking OS.  Compare English.  2. Textual
   material in the mainstream sense; data in ordinary ASCII or
   EBCDIC representation (see flat-ASCII).  "Those are
   text files; you can review them using the editor."  These two
   contradictory senses confuse hackers, too.

thanks in advance

  [Usenet] Conventional net.politeness
   ending a posted request for information or assistance.  Sometimes
   written `advTHANKSance' or `aTdHvAaNnKcSe' or abbreviated `TIA'.
   See net.-, netiquette.

That's not a bug, that's a feature!

  The canonical
   first parry in a debate about a purported bug.  The complainant, if
   unconvinced, is likely to retort that the bug is then at best a
   misfeature.  See also feature.

the X that can be Y is not the true X

  Yet another instance
   of hackerdom's peculiar attraction to mystical references -- a
   common humorous way of making exclusive statements about a class of
   things.  The template is from the "Tao te Ching": "The Tao
   which can be spoken of is not the true Tao."  The implication is
   often that the X is a mystery accessible only to the enlightened.
   See the trampoline entry for an example, and compare has_the_X_nature
   .

theology

 n.  1. Ironically or humorously used to refer to
   religious_issues.  2. Technical fine points of an abstruse
   nature, esp. those where the resolution is of theoretical
   interest but is relatively marginal with respect to actual use
   of a design or system.  Used esp. around software issues with a
   heavy AI or language-design component, such as the smart-data vs.
   smart-programs dispute in AI.

theory

 n.  The consensus, idea, plan, story, or set of rules
   that is currently being used to inform a behavior.  This usage is a
   generalization and (deliberate) abuse of the technical meaning.
   "What's the theory on fixing this TECO loss?"  "What's the
   theory on dinner tonight?"  ("Chinatown, I guess.")  "What's
   the current theory on letting lusers on during the day?"  "The
   theory behind this change is to fix the following well-known
   screw...."

thinko

 /thing'koh/ n.  [by analogy with `typo'] A
   momentary, correctable glitch in mental processing, especially one
   involving recall of information learned by rote; a bubble in the
   stream of consciousness.  Syn. braino; see also brain_fart
   .  Compare mouso.

This can't happen

  Less clipped variant of can't_happen
   .

This time, for sure!

 excl.  Ritual affirmation frequently
   uttered during protracted debugging sessions involving numerous
   small obstacles (e.g., attempts to bring up a UUCP connection).
   For the proper effect, this must be uttered in a fruity imitation
   of Bullwinkle J. Moose.  Also heard: "Hey, Rocky!  Watch me pull a
   rabbit out of my hat!"  The canonical response is, of course,
   "But that trick *never* works!"  See Humor,_Hacker.

thrash

 vi.  To move wildly or violently, without
   accomplishing anything useful.  Paging or swapping systems that are
   overloaded waste most of their time moving data into and out of
   core (rather than performing useful computation) and are therefore
   said to thrash.  Someone who keeps changing his mind (esp. about
   what to work on next) is said to be thrashing.  A person
   frantically trying to execute too many tasks at once (and not
   spending enough time on any single task) may also be described as
   thrashing.  Compare multitask.

thread

 n.  [Usenet, GEnie, CompuServe] Common abbreviation
   of `topic thread', a more or less continuous chain of postings on
   a single topic.  To `follow a thread' is to read a series of
   Usenet postings sharing a common subject or (more correctly) which
   are connected by Reference headers.  The better newsreaders can
   present news in thread order automatically.

   Interestingly, this is far from a neologism.  The OED says:
   "That which connects the successive points in anything, esp. a
   narrative, train of thought, or the like; the sequence of events
   or ideas continuing throughout the whole course of anything;"
   Citations are given going back to 1642!

three-finger salute

 n.  Syn. Vulcan_nerve_pinch.

thud

 n.  1. Yet another metasyntactic_variable (see
   foo).  It is reported that at CMU from the mid-1970s the
   canonical series of these was `foo', `bar', `thud', `blat'.
   2. Rare term for the hash character, `#' (ASCII 0100011).  See
   ASCII for other synonyms.

thumb

 n.  The slider on a window-system scrollbar.  So
   called because moving it allows you to browse through the contents
   of a text window in a way analogous to thumbing through a book.

thunk

 /thuhnk/ n.  1. "A piece of coding which provides
   an address", according to P. Z. Ingerman, who invented thunks in
   1961 as a way of binding actual parameters to their formal
   definitions in Algol-60 procedure calls.  If a procedure is called
   with an expression in the place of a formal parameter, the compiler
   generates a thunk which computes the expression and leaves the
   address of the result in some standard location.  2. Later
   generalized into: an expression, frozen together with its
   environment, for later evaluation if and when needed (similar to
   what in techspeak is called a `closure').  The process of
   unfreezing these thunks is called `forcing'.  3. A
   stubroutine, in an overlay programming environment, that loads
   and jumps to the correct overlay.  Compare trampoline.
   4. People and activities scheduled in a thunklike manner.  "It
   occurred to me the other day that I am rather accurately modeled by
   a thunk -- I frequently need to be forced to completion." ---
   paraphrased from a plan_file.

   Historical note: There are a couple of onomatopoeic myths
   circulating about the origin of this term.  The most common is that
   it is the sound made by data hitting the stack; another holds that
   the sound is that of the data hitting an accumulator.  Yet another
   suggests that it is the sound of the expression being unfrozen at
   argument-evaluation time.  In fact, according to the inventors, it
   was coined after they realized (in the wee hours after hours of
   discussion) that the type of an argument in Algol-60 could be
   figured out in advance with a little compile-time thought,
   simplifying the evaluation machinery.  In other words, it had
   `already been thought of'; thus it was christened a `thunk',
   which is "the past tense of `think' at two in the morning".

tick

 n.  1. A jiffy (sense 1).  2. In simulations, the
   discrete unit of time that passes between iterations of the
   simulation mechanism.  In AI applications, this amount of time is
   often left unspecified, since the only constraint of interest is
   the ordering of events.  This sort of AI simulation is often
   pejoratively referred to as `tick-tick-tick' simulation,
   especially when the issue of simultaneity of events with long,
   independent chains of causes is handwaved.  3. In the FORTH
   language, a single quote character.

tick-list features

 n.  [Acorn Computers] Features in
   software or hardware that customers insist on but never use
   (calculators in desktop TSRs and that sort of thing).  The American
   equivalent would be `checklist features', but this jargon sense
   of the phrase has not been reported.

tickle a bug

 vt.  To cause a normally hidden bug to manifest
   itself through some known series of inputs or operations.  "You
   can tickle the bug in the Paradise VGA card's highlight handling by
   trying to set bright yellow reverse video."

tiger team

 n.  [U.S. military jargon] 1. Originally, a team
   (of sneakers) whose purpose is to penetrate security, and thus
   test security measures.  These people are paid professionals who do
   hacker-type tricks, e.g., leave cardboard signs saying "bomb" in
   critical defense installations, hand-lettered notes saying "Your
   codebooks have been stolen" (they usually haven't been) inside
   safes, etc.  After a successful penetration, some high-ranking
   security type shows up the next morning for a `security review'
   and finds the sign, note, etc., and all hell breaks loose.  Serious
   successes of tiger teams sometimes lead to early retirement for
   base commanders and security officers (see the patch entry for
   an example).  2. Recently, and more generally, any official
   inspection team or special firefighting group called in to
   look at a problem.

   A subset of tiger teams are professional crackers, testing the
   security of military computer installations by attempting remote
   attacks via networks or supposedly `secure' comm channels.  Some of
   their escapades, if declassified, would probably rank among the
   greatest hacks of all times.  The term has been adopted in
   commercial computer-security circles in this more specific sense.

time bomb

 n.  A subspecies of logic_bomb that is
   triggered by reaching some preset time, either once or
   periodically.  There are numerous legends about time bombs set up
   by programmers in their employers' machines, to go off if the
   programmer is fired or laid off and is not present to perform the
   appropriate suppressing action periodically.

   Interestingly, the only such incident for which we have been
   pointed to documentary evidence took place in the Soviet Union in
   1986!  A disgruntled programmer at the Volga Automobile Plant
   (where the Fiat clones called Ladas were manufactured) planted a
   time bomb which, a week after he'd left on vacation, stopped the
   entire main assembly line for a day.  The case attracted lots of
   attention in the Soviet Union because it was the first cracking
   case to make it to court there.  The perpetrator got a suspended
   sentence of 3 years in jail and was barred from future work as a
   programmer.

time sink

 n.  [poss. by analogy with `heat sink' or
   `current sink'] A project that consumes unbounded amounts of
   time.

time T

 /ti:m T/ n.  1. An unspecified but usually
   well-understood time, often used in conjunction with a later time
   T+1.  "We'll meet on campus at time T or at Louie's
   at time T+1" means, in the context of going out for dinner:
   "We can meet on campus and go to Louie's, or we can meet at
   Louie's itself a bit later."  (Louie's was a Chinese restaurant in
   Palo Alto that was a favorite with hackers.)  Had the number 30
   been used instead of the number 1, it would have implied that the
   travel time from campus to Louie's is 30 minutes; whatever time
   T is (and that hasn't been decided on yet), you can meet
   half an hour later at Louie's than you could on campus and end up
   eating at the same time.  See also since_time_T_equals_minus_infinity
   .

times-or-divided-by

 quant.  [by analogy with
   `plus-or-minus'] Term occasionally used when describing the
   uncertainty associated with a scheduling estimate, for either
   humorous or brutally honest effect.  For a software project, the
   scheduling uncertainty factor is usually at least 2.

Tinkerbell program

 n.  A monitoring program used to scan
   incoming network calls and generate alerts when calls are received
   from particular sites, or when logins are attempted using certain
   IDs.  Named after `Project Tinkerbell', an experimental
   phone-tapping program developed by British Telecom in the early
   1980s.

tip of the ice-cube

 n.   [IBM] The visible part of
   something small and insignificant.  Used as an ironic comment in
   situations where `tip of the iceberg' might be appropriate if the
   subject were at all important.

tired iron

 n.  [IBM] Hardware that is perfectly functional but far
   enough behind the state of the art to have been superseded by new
   products, presumably with sufficient improvement in bang-per-buck
   that the old stuff is starting to look a bit like a dinosaur.

tits on a keyboard

 n.  Small bumps on certain keycaps to
   keep touch-typists registered (usually on the `5' of a numeric
   keypad, and on the `F' and `J' of a QWERTY keyboard;
   but the Mac, perverse as usual, has them on the `D' and
   `K' keys).

TLA

 /T-L-A/ n.  [Three-Letter Acronym] 1. Self-describing
   abbreviation for a species with which computing terminology is
   infested.  2. Any confusing acronym.  Examples include MCA, FTP,
   SNA, CPU, MMU, SCCS, DMU, FPU, NNTP, TLA.  People who like this
   looser usage argue that not all TLAs have three letters, just as
   not all four-letter words have four letters.  One also hears of
   `ETLA' (Extended Three-Letter Acronym, pronounced /ee tee el
   ay/) being used to describe four-letter acronyms.  The term
   `SFLA' (Stupid Four-Letter Acronym) has also been reported.  See
   also YABA.

   The self-effacing phrase "TDM TLA" (Too Damn Many...) is
   often used to bemoan the plethora of TLAs in use.  In 1989, a
   random of the journalistic persuasion asked hacker Paul Boutin
   "What do you think will be the biggest problem in computing in
   the 90s?"  Paul's straight-faced response: "There are only
   17,000 three-letter acronyms." (To be exact, there are 26^3
   = 17,576.)

TMRC

 /tmerk'/ n.  The Tech Model Railroad Club at MIT, one
   of the wellsprings of hacker culture.  The 1959 "Dictionary of
   the TMRC Language" compiled by Peter Samson included several terms
   that became basics of the hackish vocabulary (see esp. foo,
   mung, and frob).

   By 1962, TMRC's legendary layout was already a marvel of complexity
   (and has grown in the thirty years since; all the features
   described here are still present).  The control system alone
   featured about 1200 relays.  There were scram_switches located
   at numerous places around the room that could be thwacked if
   something undesirable was about to occur, such as a train going
   full-bore at an obstruction.  Another feature of the system was a
   digital clock on the dispatch board, which was itself something of
   a wonder in those bygone days before cheap LEDS and seven-segment
   displays.  When someone hit a scram switch the clock stopped and
   the display was replaced with the word `FOO'; at TMRC the scram
   switches are therefore called `foo switches'.

   Steven Levy, in his book "Hackers" (see the
   Bibliography in Appendix C), gives a stimulating account of
   those early years.  TMRC's Power and Signals group included most of
   the early PDP-1 hackers and the people who later bacame the core of
   the MIT AI Lab staff.  Thirty years later that connection is still
   very much alive, and this lexicon accordingly includes a number of
   entries from a recent revision of the TMRC dictionary.

TMRCie

 /tmerk'ee/, n.  [MIT] A denizen of TMRC.

to a first approximation

  1. [techspeak] When one is doing
   certain numerical computations, an approximate solution may be
   computed by any of several heuristic methods, then refined to a
   final value.  By using the starting point of a first approximation
   of the answer, one can write an algorithm that converges more
   quickly to the correct result.  2. In jargon, a preface to any
   comment that indicates that the comment is only approximately true.
   The remark "To a first approximation, I feel good" might indicate
   that deeper questioning would reveal that not all is perfect (e.g.,
   a nagging cough still remains after an illness).

to a zeroth approximation

  [from `to a first
   approximation'] A *really* sloppy approximation; a wild
   guess.  Compare social_science_number.

toad

 vt. [MUD]  1. Notionally, to change a MUD player into
   a toad.  2. To permanently and totally exile a player from the MUD.
   A very serious action, which can only be done by a MUD wizard;
   often involves a lot of debate among the other characters first.
   See also frog, FOD.

toast

 1. n.  Any completely inoperable system or component,
   esp. one that has just crashed and burned: "Uh, oh ... I
   think the serial board is toast."  2. vt. To cause a system to
   crash accidentally, especially in a manner that requires manual
   rebooting.  "Rick just toasted the firewall_machine again."
   Compare fried.

toaster

 n.  1. The archetypal really stupid application for
   an embedded microprocessor controller; often used in comments that
   imply that a scheme is inappropriate technology (but see
   elevator_controller).  "DWIM for an assembler?  That'd
   be as silly as running UNIX on your toaster!"  2. A very, very
   dumb computer. "You could run this program on any dumb toaster."
   See bitty_box, Get_a_real_computer!, toy, beige_toaster
   .  3. A Macintosh, esp. the Classic Mac.  Some hold that
   this is implied by sense 2.  4. A peripheral device.  "I bought my
   box without toasters, but since then I've added two boards and a
   second disk drive."

toeprint

 n.  A footprint of especially small size.

toggle

 vt.  To change a bit from whatever state it is
   in to the other state; to change from 1 to 0 or from 0 to 1.  This
   comes from `toggle switches', such as standard light switches,
   though the word `toggle' actually refers to the mechanism that
   keeps the switch in the position to which it is flipped rather than
   to the fact that the switch has two positions.  There are four
   things you can do to a bit: set it (force it to be 1), clear (or
   zero) it, leave it alone, or toggle it.  (Mathematically, one would
   say that there are four distinct boolean-valued functions of one
   boolean argument, but saying that is much less fun than talking
   about toggling bits.)

tool

 1. n.  A program used primarily to create, manipulate,
   modify, or analyze other programs, such as a compiler or an editor
   or a cross-referencing program.  Oppose app, operating_system
   .  2. [UNIX] An application program with a simple,
   `transparent' (typically text-stream) interface designed
   specifically to be used in programmed combination with other tools
   (see filter, plumbing).  3. [MIT: general to students
   there] vi. To work; to study (connotes tedium).  The TMRC
   Dictionary defined this as "to set one's brain to the
   grindstone".  See hack.  4. n. [MIT] A student who studies
   too much and hacks too little.  (MIT's student humor magazine
   rejoices in the name "Tool and Die".)

toolsmith

 n.  The software equivalent of a tool-and-die
   specialist; one who specializes in making the tools with which
   other programmers create applications.  Many hackers consider this
   more fun than applications per se; to understand why, see
   uninteresting.  Jon Bentley, in the "Bumper-Sticker Computer
   Science" chapter of his book "More Programming Pearls",
   quotes Dick Sites from DEC as saying "I'd rather write programs to
   write programs than write programs".

topic drift

 n.  Term used on GEnie, Usenet and other
   electronic fora to describe the tendency of a thread to drift
   away from the original subject of discussion (and thus, from the
   Subject header of the originating message), or the results of that
   tendency.  Often used in gentle reminders that the discussion has
   strayed off any useful track.  "I think we started with a question
   about Niven's last book, but we've ended up discussing the sexual
   habits of the common marmoset.  Now *that's* topic drift!"

topic group

 n.  Syn. forum.

TOPS-10

: /tops-ten/ n.  DEC's proprietary OS for the
   fabled PDP-10 machines, long a favorite of hackers but now
   effectively extinct.  A fountain of hacker folklore; see Appendix
   A.  See also ITS, TOPS-20, TWENEX, VMS,
   operating_system.  TOPS-10 was sometimes called BOTS-10 (from
   `bottoms-ten') as a comment on the inappropriateness of describing
   it as the top of anything.

TOPS-20

: /tops-twen'tee/ n.  See TWENEX.

tourist

 n.  [ITS] A guest on the system, especially one who
   generally logs in over a network from a remote location for
   comm_mode, email, games, and other trivial purposes.  One step
   below luser.  Hackers often spell this turist, perhaps by
   some sort of tenuous analogy with luser (this also expresses
   the ITS culture's penchant for six-letterisms).  Compare
   twink, read-only_user.

tourist information

 n.  Information in an on-line display
   that is not immediately useful, but contributes to a viewer's
   gestalt of what's going on with the software or hardware behind it.
   Whether a given piece of info falls in this category depends partly
   on what the user is looking for at any given time.  The `bytes
   free' information at the bottom of an MS-DOS `dir' display is
   tourist information; so (most of the time) is the TIME information
   in a UNIX `ps(1)' display.

touristic

 adj.  Having the quality of a tourist.  Often
   used as a pejorative, as in `losing touristic scum'.  Often
   spelled `turistic' or `turistik', so that phrase might be more
   properly rendered `lusing turistic scum'.

toy

 n.  A computer system; always used with qualifiers.
   1. `nice toy': One that supports the speaker's hacking style
   adequately.  2. `just a toy': A machine that yields insufficient
   computrons for the speaker's preferred uses.  This is not
   condemnatory, as is bitty_box; toys can at least be fun.  It
   is also strongly conditioned by one's expectations; Cray XMP users
   sometimes consider the Cray-1 a `toy', and certainly all RISC
   boxes and mainframes are toys by their standards.  See also Get_a_real_computer!
   .

toy language

 n.  A language useful for instructional
   purposes or as a proof-of-concept for some aspect of
   computer-science theory, but inadequate for general-purpose
   programming.  Bad_Things can result when a toy language is
   promoted as a general purpose solution for programming (see
   bondage-and-discipline_language); the classic example is
   Pascal.  Several moderately well-known formalisms for
   conceptual tasks such as programming Turing machines also qualify
   as toy languages in a less negative sense.  See also MFTL.

toy problem

 n.  [AI] A deliberately oversimplified case of a
   challenging problem used to investigate, prototype, or test
   algorithms for a real problem.  Sometimes used pejoratively.  See
   also gedanken, toy_program.

toy program

 n.  1. One that can be readily comprehended;
   hence, a trivial program (compare noddy).  2. One for which
   the effort of initial coding dominates the costs through its life
   cycle.  See also noddy.

trampoline

 n.  An incredibly hairy technique, found in
   some HLL and program-overlay implementations (e.g., on the
   Macintosh), that involves on-the-fly generation of small executable
   (and, likely as not, self-modifying) code objects to do indirection
   between code sections.  These pieces of live_data are called
   `trampolines'.  Trampolines are notoriously difficult to
   understand in action; in fact, it is said by those who use this
   term that the trampoline that doesn't bend your brain is not the
   true trampoline.  See also snap.

trap

  1. n. A program interrupt, usually an interrupt caused
   by some exceptional situation in the user program.  In most cases,
   the OS performs some action, then returns control to the program.
   2. vi. To cause a trap.  "These instructions trap to the
   monitor."  Also used transitively to indicate the cause of the
   trap.  "The monitor traps all input/output instructions."

   This term is associated with assembler programming (`interrupt'
   or `exception' is more common among HLL programmers) and
   appears to be fading into history among programmers as the role of
   assembler continues to shrink.  However, it is still important to
   computer architects and systems hackers (see system,
   sense 1), who use it to distinguish deterministically repeatable
   exceptions from timing-dependent ones (such as I/O interrupts).

trap door

 n.  (alt. `trapdoor') 1. Syn. back_door
   -- a Bad_Thing.  2. [techspeak] A `trap-door function' is
   one which is easy to compute but very difficult to compute the
   inverse of.  Such functions are Good_Things with important
   applications in cryptography, specifically in the construction of
   public-key cryptosystems.

trash

 vt.  To destroy the contents of (said of a data
   structure).  The most common of the family of near-synonyms
   including mung, mangle, and scribble.

trawl

 v.  To sift through large volumes of data (e.g.,
   Usenet postings, FTP archives, or the Jargon File) looking for
   something of interest.

tree-killer

 n.  [Sun] 1. A printer.  2. A person who wastes
   paper.  This epithet should be interpreted in a broad sense;
   `wasting paper' includes the production of spiffy but
   content-free documents.  Thus, most suits are
   tree-killers.  The negative loading of this term may reflect the
   epithet `tree-killer' applied by Treebeard the Ent to the Orcs
   in J.R.R. Tolkien's "Lord of the Rings" (see also
   elvish, elder_days).

treeware

 /tree'weir/ n.  Printouts, books, and other
   information media made from pulped dead trees.  Compare
   tree-killer, see documentation.

trit

 /trit/ n.  [by analogy with `bit'] One base-3
   digit; the amount of information conveyed by a selection among one
   of three equally likely outcomes (see also bit).  Trits arise,
   for example, in the context of a flag that should actually be
   able to assume *three* values -- such as yes, no, or unknown.
   Trits are sometimes jokingly called `3-state bits'.  A trit may
   be semi-seriously referred to as `a bit and a half', although it
   is linearly equivalent to 1.5849625 bits (that is,
   log2(3)
   bits).

trivial

 adj.  1. Too simple to bother detailing.  2. Not
   worth the speaker's time.  3. Complex, but solvable by methods so
   well known that anyone not utterly cretinous would have
   thought of them already.  4. Any problem one has already solved
   (some claim that hackish `trivial' usually evaluates to `I've
   seen it before').  Hackers' notions of triviality may be quite at
   variance with those of non-hackers.  See nontrivial,
   uninteresting.

troff

: /T'rof/ or /trof/ n.   [UNIX] The gray
   eminence of UNIX text processing; a formatting and phototypesetting
   program, written originally in PDP-11 assembler and then in
   barely-structured early C by the late Joseph Ossanna, modeled after
   the earlier ROFF which was in turn modeled after Multics' RUNOFF by
   Jerome Saltzer (*that* name came from the expression "to run
   off a copy").  A companion program, nroff, formats output for
   terminals and line printers.

   In 1979, Brian Kernighan modified `troff' so that it could
   drive phototypesetters other than the Graphic Systems CAT.  His
   paper describing that work ("A Typesetter-independent troff,"
   AT&T CSTR #97) explains troff's durability.  After discussing the
   program's "obvious deficiencies -- a rebarbative input syntax,
   mysterious and undocumented properties in some areas, and a
   voracious appetite for computer resources" and noting the ugliness
   and extreme hairiness of the code and internals, Kernighan
   concludes:

     None of these remarks should be taken as denigrating Ossanna's
     accomplishment with TROFF.  It has proven a remarkably robust
     tool, taking unbelievable abuse from a variety of preprocessors
     and being forced into uses that were never conceived of in the
     original design, all with considerable grace under fire.

   The success of TeX and desktop publishing systems have
   reduced `troff''s relative importance, but this tribute
   perfectly captures the strengths that secured `troff' a place
   in hacker folklore; indeed, it could be taken more generally as an
   indication of those qualities of good programs that, in the long
   run, hackers most admire.

troglodyte

 n.  [Commodore] 1. A hacker who never leaves his
   cubicle.  The term `Gnoll' (from Dungeons & Dragons) is also
   reported.  2. A curmudgeon attached to an obsolescent computing
   environment.  The combination `ITS troglodyte' was flung around
   some during the Usenet and email wringle-wrangle attending the
   2.x.x revision of the Jargon File; at least one of the people it
   was intended to describe adopted it with pride.

troglodyte mode

 n.  [Rice University] Programming with the
   lights turned off, sunglasses on, and the terminal inverted (black
   on white) because you've been up for so many days straight that
   your eyes hurt (see raster_burn).  Loud music blaring from a
   stereo stacked in the corner is optional but recommended.  See
   larval_stage, hack_mode.

Trojan horse

 n.  [coined by MIT-hacker-turned-NSA-spook Dan
   Edwards] A malicious, security-breaking program that is disguised
   as something benign, such as a directory lister, archiver, game, or
   (in one notorious 1990 case on the Mac) a program to find and
   destroy viruses!  See back_door, virus, worm,
   phage, mockingbird.

troll

 v.,n.  To utter a posting on Usenet designed to
   attract stupid responses or flames.  May derive from the
   phrase "trolling for newbies" or some similar construction.
   The well-constructed troll is a post that induces lots of newbies
   and flamers to make themselves look even more like idiots than they
   already do, while subtly conveying to the more savvy and
   experienced that it is in fact a deliberate troll.  If you don't
   fall for the joke, you get to be in on it.

   Some people claim that the troll is properly a narrower category
   than flame_bait, that a troll is categorized by containing
   some assertion that is wrong but not overtly controversial.

tron

 v.  [NRL, CMU; prob. fr. the movie "Tron"] To
   become inaccessible except via email or `talk(1)', especially
   when one is normally available via telephone or in person.
   Frequently used in the past tense, as in: "Ran seems to have
   tronned on us this week" or "Gee, Ran, glad you were able to
   un-tron yourself".  One may also speak of `tron mode'; compare
   spod.

true-hacker

 n.  [analogy with `trufan' from SF fandom] One
   who exemplifies the primary values of hacker culture, esp.
   competence and helpfulness to other hackers.  A high compliment.
   "He spent 6 hours helping me bring up UUCP and netnews on my
   FOOBAR 4000 last week -- manifestly the act of a true-hacker."
   Compare demigod, oppose munchkin.

tty

 /T-T-Y/, /tit'ee/ n.  The latter pronunciation was
   primarily ITS, but some UNIX people say it this way as well; this
   pronunciation is *not* considered to have sexual
   undertones. 1. A terminal of the teletype variety, characterized by
   a noisy mechanical printer, a very limited character set, and poor
   print quality.  Usage: antiquated (like the TTYs themselves).  See
   also bit-paired_keyboard.  2. [especially UNIX] Any terminal
   at all; sometimes used to refer to the particular terminal
   controlling a given job.  3. [UNIX] Any serial port, whether or not
   the device connected to it is a terminal; so called because under
   UNIX such devices have names of the form tty*.  Ambiguity between
   senses 2 and 3 is common but seldom bothersome.

tube

  1. n. A CRT terminal.  Never used in the mainstream
   sense of TV; real hackers don't watch TV, except for Loony Toons,
   Rocky & Bullwinkle, Trek Classic, the Simpsons, and the occasional
   cheesy old swashbuckler movie.  2. [IBM] To send a copy of
   something to someone else's terminal.  "Tube me that
   note?"

tube time

 n.  Time spent at a terminal or console.  More
   inclusive than hacking time; commonly used in discussions of what
   parts of one's environment one uses most heavily.  "I find I'm
   spending too much of my tube time reading mail since I started this
   revision."

tunafish

 n.  In hackish lore, refers to the mutated
   punchline of an age-old joke to be found at the bottom of the
   manual pages of `tunefs(8)' in the original BSD 4.2
   distribution.  The joke was removed in later releases once
   commercial sites started using 4.2.  Tunefs relates to the
   `tuning' of file-system parameters for optimum performance, and
   at the bottom of a few pages of wizardly inscriptions was a `BUGS'
   section consisting of the line "You can tune a file system, but
   you can't tunafish".  Variants of this can be seen in other BSD
   versions, though it has been excised from some versions by
   humorless management droids.  The [nt]roff source for SunOS
   4.1.1 contains a comment apparently designed to prevent this:
   "Take this out and a Unix Demon will dog your steps from now until
   the `time_t''s wrap around."

tune

 vt.  [from automotive or musical usage] To optimize a
   program or system for a particular environment, esp. by adjusting
   numerical parameters designed as hooks for tuning, e.g., by
   changing `#define' lines in C.  One may `tune for time'
   (fastest execution), `tune for space' (least memory use), or
   `tune for configuration' (most efficient use of hardware).  See
   bum, hot_spot, hand-hacking.

turbo nerd

 n.  See computer_geek.

Turing tar-pit

 n.  1. A place where anything is possible but
   nothing of interest is practical.  Alan Turing helped lay the
   foundations of computer science by showing that all machines and
   languages capable of expressing a certain very primitive set of
   operations are logically equivalent in the kinds of computations
   they can carry out, and in principle have capabilities that differ
   only in speed from those of the most powerful and elegantly
   designed computers.  However, no machine or language exactly
   matching Turing's primitive set has ever been built (other than
   possibly as a classroom exercise), because it would be horribly
   slow and far too painful to use.  A `Turing tar-pit' is any
   computer language or other tool that shares this property.  That
   is, it's theoretically universal -- but in practice, the harder
   you struggle to get any real work done, the deeper its inadequacies
   suck you in.  Compare bondage-and-discipline_language.  2. The
   perennial holy_wars over whether language A or B is the "most
   powerful".

turist

 /too'rist/ n.  Var. sp. of tourist, q.v.  Also
   in adjectival form, `turistic'.  Poss. influenced by luser
   and `Turing'.

tweak

 vt.  1. To change slightly, usually in reference to a
   value.  Also used synonymously with twiddle.  If a program is
   almost correct, rather than figure out the precise problem you
   might just keep tweaking it until it works.  See frobnicate
   and fudge_factor; also see shotgun_debugging.  2. To
   tune or bum a program; preferred usage in the U.K.

tweeter

 n.  [University of Waterloo] Syn. perf,
   chad (sense 1).  This term (like woofer) has been in use
   at Waterloo since 1972 but is elsewhere unknown.  In audio jargon,
   the word refers to the treble speaker(s) on a hi-fi.

TWENEX

: n.  /twe'neks/ The TOPS-20 operating system by DEC
   -- the second proprietary OS for the PDP-10 -- preferred by most
   PDP-10 hackers over TOPS-10 (that is, by those who were not
   ITS or WAITS partisans).  TOPS-20 began in 1969 as Bolt,
   Beranek & Newman's TENEX operating system using special paging
   hardware.  By the early 1970s, almost all of the systems on the
   ARPANET ran TENEX.  DEC purchased the rights to TENEX from BBN and
   began work to make it their own.  The first in-house code name for
   the operating system was VIROS (VIRtual memory Operating System);
   when customers started asking questions, the name was changed to
   SNARK so DEC could truthfully deny that there was any project
   called VIROS.  When the name SNARK became known, the name was
   briefly reversed to become KRANS; this was quickly abandoned when
   someone objected that `krans' meant `funeral wreath' in Swedish
   (though some Swedish speakers have since said it means simply
   `wreath'; this part of the story may be apocryphal).  Ultimately
   DEC picked TOPS-20 as the name of the operating system, and it was
   as TOPS-20 that it was marketed.  The hacker community, mindful of
   its origins, quickly dubbed it TWENEX (a contraction of `twenty
   TENEX'), even though by this point very little of the original
   TENEX code remained (analogously to the differences between AT&T V6
   UNIX and BSD).  DEC people cringed when they heard "TWENEX", but
   the term caught on nevertheless (the written abbreviation `20x'
   was also used).  TWENEX was successful and very popular; in fact,
   there was a period in the early 1980s when it commanded as fervent
   a culture of partisans as UNIX or ITS -- but DEC's decision to
   scrap all the internal rivals to the VAX architecture and its
   relatively stodgy VMS OS killed the DEC-20 and put a sad end to
   TWENEX's brief day in the sun.  DEC attempted to convince TOPS-20
   users to convert to VMS, but instead, by the late 1980s, most
   of the TOPS-20 hackers had migrated to UNIX.

twiddle

 n.  1. Tilde (ASCII 1111110, `~').  Also called
   `squiggle', `sqiggle' (sic -- pronounced /skig'l/), and
   `twaddle', but twiddle is the most common term.  2. A small and
   insignificant change to a program.  Usually fixes one bug and
   generates several new ones (see also shotgun_debugging).
   3. vt. To change something in a small way.  Bits, for example, are
   often twiddled.  Twiddling a switch or knob implies much less sense
   of purpose than toggling or tweaking it; see frobnicate.  To
   speak of twiddling a bit connotes aimlessness, and at best doesn't
   specify what you're doing to the bit; `toggling a bit' has a more
   specific meaning (see bit_twiddling, toggle).

twilight zone

 n.   [IRC] Notionally, the area of
   cyberspace where IRC operators live.  An op is said to
   have a "connection to the twilight zone".
   

twink

 /twink/ n.  [UCSC] Equivalent to read-only_user
   .  Also reported on the Usenet group soc.motss; may derive
   from gay slang for a cute young thing with nothing upstairs
   (compare mainstream `chick').

twirling baton

 n.  [PLATO] The overstrike sequence -/|\-/|\-
   which produces an animated twirling baton.  If you output it with a
   single backspace between characters, the baton spins in place.  If
   you output the sequence BS SP between characters, the baton spins
   from left to right.  If you output BS SP BS BS between characters,
   the baton spins from right to left.

   The twirling baton was a popular component of animated signature
   files on the pioneering PLATO educational timesharing system.  The
   `archie' Internet service is perhaps the best-known baton
   program today; it uses the twirling baton as an idler indicating
   that the program is working on a query.

two pi

 quant.  The number of years it takes to finish one's
   thesis.  Occurs in stories in the following form: "He started on
   his thesis; 2 pi years later..."

two-to-the-N

 quant.  An amount much larger than N but
   smaller than infinity.  "I have 2-to-the-N things to
   do before I can go out for lunch" means you probably won't show
   up.

twonkie

 /twon'kee/ n.  The software equivalent of a
   Twinkie (a variety of sugar-loaded junk food, or (in gay slang) the
   male equivalent of `chick'); a useless `feature' added to look
   sexy and placate a marketroid (compare Saturday-night_special
   ).  The term may also be related to "The Twonky",
   title menace of a classic SF short story by Lewis Padgett (Henry
   Kuttner and C. L. Moore), first published in the September 1942
   "Astounding Science Fiction" and subsequently much
   anthologized.


The Jargon File
Introduction
How Jargon Works
How to Use the Lexicon

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [^a-zA-Z]

Appendix A --- Appendix B --- Appendix C