: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} to compute the expression and leave 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 holds 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 {handwave}d. 3. In the FORTH language, a single quote character.
:tick-list features: [Acorn Computers] n. 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 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: [U.S. military jargon] n. 1. Originally, a team 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 {cracker}s, 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 sink: [poss. by analogy with `heat sink' or `current sink'] n. 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: [by analogy with `plus-or-minus'] quant. 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.
:tinycrud: /ti:'nee-kruhd/ n. 1. A pejorative used by habitues of older game-oriented {MUD} versions for TinyMUDs and other user-extensible {MUD} variants; esp. common among users of the rather violent and competitive AberMUD and MIST systems. These people justify the slur on the basis of how (allegedly) inconsistent and lacking in genuine atmosphere the scenarios generated in user extensible MUDs can be. Other common knocks on them are that they feature little overall plot, bad game topology, little competitive interaction, etc. —- not to mention the alleged horrors of the TinyMUD code itself. This dispute is one of the MUD world's hardiest perennial {holy wars}. 2. TinyMud-oriented chat on the USENET group rec.games.mud and elsewhere, especially {newbie} questions and flamage.
:tip of the ice-cube: [IBM] n. The visible part of something small andinsignificant. Used as an ironic comment in situations where `tipof the iceberg' might be appropriate if the subject were at allimportant.
:tired iron: [IBM] n. Hardware that is perfectly functional butfar enough behind the state of the art to have been superseded by newproducts, presumably with sufficient improvement in bang-per-buck thatthe 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/ [Three-Letter Acronym] n. 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 which became basics of the hackish vocabulary (see esp. {foo} 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 switch}es 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 (no model railroad can begin to approximate the scale distances between towns and stations, so model railroad timetables assume a fast clock so that it seems to take about the right amount of time for a train to complete its journey). 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/, /tuh-merk'ee/ [MIT] n. 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}.
: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."
: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}). 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. [MIT] n. 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-diespecialist; one who specializes in making the {tool}s with whichother programmers create applications. Many hackers consider thismore fun than applications per se; to understand why, see{uninteresting}. Jon Bentley, in the "Bumper-Sticker ComputerScience" chapter of his book `More Programming Pearls', quotes DickSites from DEC as saying "I'd rather write programs to write programsthan write programs".
:topic drift: n. Term used on GEnie, USENET and other electronicfora to describe the tendency of a {thread} to drift away fromthe original subject of discussion (and thus, from the Subjectheader of the originating message), or the results of thattendency. Often used in gentle reminders that the discussion hasstrayed off any useful track. "I think we started with a questionabout Niven's last book, but we've ended up discussing the sexualhabits 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}}.
:toto: /toh'toh/ n. This is reported to be the default scratch file name among French-speaking programmers —- in other words, a francophone {foo}. It is reported that the phonetic mutations "titi", "tata", and "tutu" canonically follow `toto', analogously to {bar}, {baz} and {quux} in English.
:tourist: [ITS] n. 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 styleadequately. 2. `just a toy': A machine that yieldsinsufficient {computron}s for the speaker's preferred uses. Thisis not condemnatory, as is {bitty box}; toys can at least be fun.It is also strongly conditioned by one's expectations; Cray XMPusers sometimes consider the Cray-1 a `toy', and certainly all RISCboxes and mainframes are toys by their standards. See also {Geta real computer!}.
:toy language: n. A language useful for instructional purposes oras a proof-of-concept for some aspect of computer-science theory,but inadequate for general-purpose programming. {Bad Thing}scan result when a toy language is promoted as a general purposesolution for programming (see {bondage-and-disciplinelanguage}); the classic example is {{Pascal}}. Several moderatelywell-known formalisms for conceptual tasks such as programming Turingmachines also qualify as toy languages in a less negative sense.See also {MFTL}.
:toy problem: [AI] n. A deliberately oversimplified case of achallenging problem used to investigate, prototype, or testalgorithms for a real problem. Sometimes used pejoratively. Seealso {gedanken}, {toy program}.
:toy program: n. 1. One that can be readily comprehended; hence, atrivial program (compare {noddy}). 2. One for which the effortof 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: alt. `trapdoor' n. 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 Thing}s 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 or FTP archives) looking for something of interest.
:tree-killer: [Sun] n. 1. A printer. 2. A person who wastes paper. This should be interpreted in a broad sense; `wasting paper' includes the production of {spiffy} but {content-free} documents. Thus, most {suit}s 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' trilogy (see also {elvish}, {elder days}).
:trit: /trit/ [by analogy with `bit'] n. One base-3 digit; theamount of information conveyed by a selection among one of threeequally likely outcomes (see also {bit}). These arise, forexample, in the context of a {flag} that should actually be ableto assume *three* values —- such as yes, no, or unknown. Trits aresometimes jokingly called `3-state bits'. A trit may besemi-seriously referred to as `a bit and a half', although it islinearly 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: /tee'rof/ or /trof/ [UNIX] n. 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 Ossana, modeled after the earlier ROFF which was in turn modeled after Multics' RUNOFF. 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 Ossana'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 which, in the long run, hackers most admire.
:troglodyte: [Commodore] n. 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: [Rice University] n. Programming with the lightsturned off, sunglasses on, and the terminal inverted (black onwhite) because you've been up for so many days straight that youreyes hurt (see {raster burn}). Loud music blaring from a stereostacked in the corner is optional but recommended. See {larvalstage}, {hack mode}.
:Trojan horse: [coined by MIT-hacker-turned-NSA-spook Dan Edwards]n. A program designed to break security or damage a system that isdisguised as something else benign, such as a directory lister,archiver, a game, or (in one notorious 1990 case on the Mac) aprogram to find and destroy viruses! See {back door}, {virus},{worm}.
:tron: [NRL, CMU; prob. fr. the movie `Tron'] v. To becomeinaccessible except via email or `talk(1)', especially whenone is normally available via telephone or in person. Frequentlyused in the past tense, as in: "Ran seems to have tronned on usthis week" or "Gee, Ran, glad you were able to un-tronyourself". One may also speak of `tron mode'.
:true-hacker: [analogy with `trufan' from SF fandom] n. One whoexemplifies the primary values of hacker culture, esp. competenceand helpfulness to other hackers. A high compliment. "He spent6 hours helping me bring up UUCP and netnews on my FOOBAR 4000last week —- manifestly the act of a true-hacker." Compare{demigod}, oppose {munchkin}.
:tty: /T-T-Y/ [UNIX], /tit'ee/ [ITS, but some UNIX people say it this way as well; this pronunciation is not considered to have sexual undertones] n. 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 (see {appendix B}). 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 {droid}s. 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: [from automotive or musical usage] vt. To optimize a program or system for a particular environment, esp. by adjusting numerical parameters designed as {hook}s 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 which 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: [University of Waterloo] n. 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:: /twe'neks/ n. 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 it was discovered that `krans' meant `funeral wreath' in Swedish. 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 hackers 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. 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: [IRC] n. Notionally, the area of cyberspace where {IRC} operators live. An {op} is said to have a "connection to the twilight zone".
:twink: /twink/ [UCSC] n. 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').
:two pi: quant. The number of years it takes to finish one'sthesis. Occurs in stories in the following form: "He started onhis thesis; 2 pi years later…"
:two-to-the-N: quant. An amount much larger than {N} but smallerthan {infinity}. "I have 2-to-the-N things to do before I cango 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}). This 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.
= U = =====
:UBD: /U-B-D/ [abbreviation for `User Brain Damage'] An abbreviation used to close out trouble reports obviously due to utter cluelessness on the user's part. Compare {pilot error}; oppose {PBD}; see also {brain-damaged}.
:UN*X: n. Used to refer to the UNIX operating system (a trademark ofAT&T) in writing, but avoiding the need for the ugly{(TM)} typography.Also used to refer to any or all varieties of Unixoid operatingsystems. Ironically, lawyers now say (1990) that the requirementfor the TM-postfix has no legal force, but the asterisk usageis entrenched anyhow. It has been suggested that there may be apsychological connection to practice in certain religions(especially Judaism) in which the name of the deity is neverwritten out in full, e.g., `YHWH' or `G—d' is used. See also{glob}.
:undefined external reference: excl. [UNIX] A message from UNIX's linker. Used in speech to flag loose ends or dangling references in an argument or discussion.
:under the hood: prep. [hot-rodder talk] 1. Used to introduce the underlying implementation of a product (hardware, software, or idea). Implies that the implementation is not intuitively obvious from the appearance, but the speaker is about to enable the listener to {grok} it. "Let's now look under the hood to see how …." 2. Can also imply that the implementation is much simpler than the appearance would indicate: "Under the hood, we are just fork/execing the shell." 3. Inside a chassis, as in "Under the hood, this baby has a 40MHz 68030!"
:undocumented feature: n. See {feature}.
:uninteresting: adj. 1. Said of a problem that, although {nontrivial}, can be solved simply by throwing sufficient resources at it. 2. Also said of problems for which a solution would neither advance the state of the art nor be fun to design and code.
Hackers regard uninteresting problems as intolerable wastes of time, to be solved (if at all) by lesser mortals. *Real* hackers (see {toolsmith}) generalize uninteresting problems enough to make them interesting and solve them —- thus solving the original problem as a special case (and, it must be admitted, occasionally turning a molehill into a mountain, or a mountain into a tectonic plate). See {WOMBAT}, {SMOP}; compare {toy problem}, oppose {interesting}.
:UNIX:: /yoo'niks/ [In the authors' words, "A weak pun on Multics"] n. (also `Unix') An interactive time-sharing system originally invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7. Dennis Ritchie, the inventor of C, is considered a co-author of the system. The turning point in UNIX's history came when it was reimplemented almost entirely in C during 1972—1974, making it the first source-portable OS. UNIX subsequently underwent mutations and expansions at the hands of many different people, resulting in a uniquely flexible and developer-friendly environment. In 1991, UNIX is the most widely used multiuser general-purpose operating system in the world. Many people consider this the most important victory yet of hackerdom over industry opposition (but see {UNIX weenie} and {UNIX conspiracy} for an opposing point of view). See {Version 7}, {BSD}, {USG UNIX}.
:UNIX brain damage: n. Something that has to be done to break a network program (typically a mailer) on a non-UNIX system so that it will interoperate with UNIX systems. The hack may qualify as `UNIX brain damage' if the program conforms to published standards and the UNIX program in question does not. UNIX brain damage happens because it is much easier for other (minority) systems to change their ways to match non-conforming behavior than it is to change all the hundreds of thousands of UNIX systems out there.
An example of UNIX brain damage is a {kluge} in a mail server to recognize bare line feed (the UNIX newline) as an equivalent form to the Internet standard newline, which is a carriage return followed by a line feed. Such things can make even a hardened {jock} weep.
:UNIX conspiracy: [ITS] n. According to a conspiracy theory long popular among {{ITS}} and {{TOPS-20}} fans, UNIX's growth is the result of a plot, hatched during the 1970s at Bell Labs, whose intent was to hobble AT&T's competitors by making them dependent upon a system whose future evolution was to be under AT&T's control. This would be accomplished by disseminating an operating system that is apparently inexpensive and easily portable, but also relatively unreliable and insecure (so as to require continuing upgrades from AT&T). This theory was lent a substantial impetus in 1984 by the paper referenced in the {back door} entry.
In this view, UNIX was designed to be one of the first computer viruses (see {virus}) —- but a virus spread to computers indirectly by people and market forces, rather than directly through disks and networks. Adherents of this `UNIX virus' theory like to cite the fact that the well-known quotation "UNIX is snake oil" was uttered by DEC president Kenneth Olsen shortly before DEC began actively promoting its own family of UNIX workstations. (Olsen now claims to have been misquoted.)
:UNIX weenie: [ITS] n. 1. A derogatory play on `UNIX wizard', common among hackers who use UNIX by necessity but would prefer alternatives. The implication is that although the person in question may consider mastery of UNIX arcana to be a wizardly skill, the only real skill involved is the ability to tolerate (and the bad taste to wallow in) the incoherence and needless complexity that is alleged to infest many UNIX programs. "This shell script tries to parse its arguments in 69 bletcherous ways. It must have been written by a real UNIX weenie." 2. A derogatory term for anyone who engages in uncritical praise of UNIX. Often appearing in the context "stupid UNIX weenie". See {Weenix}, {UNIX conspiracy}. See also {weenie}.
:unixism: n. A piece of code or a coding technique that depends on the protected multi-tasking environment with relatively low process-spawn overhead that exists on virtual-memory UNIX systems. Common {unixism}s include: gratuitous use of `fork(2)'; the assumption that certain undocumented but well-known features of UNIX libraries such as `stdio(3)' are supported elsewhere; reliance on {obscure} side-effects of system calls (use of `sleep(2)' with a 0 argument to clue the scheduler that you're willing to give up your time-slice, for example); the assumption that freshly allocated memory is zeroed; and the assumption that fragmentation problems won't arise from never `free()'ing memory. Compare {vaxocentrism}; see also {New Jersey}.
:unleaded: adj. Said of decaffeinated coffee, diet coke, and otherimitation {programming fluid}s. "Do you want regular orunleaded?". Appears to be widespread among programmers associatedwith the oil industry in Texas (and probably elsewhere). Usage:silly, and probably unintelligable to the next generation ofhackers.
:unroll: v. To repeat the body of a loop several times in succession.This optimization technique reduces the number of times theloop-termination test has to be executed. But it only works ifthe number of iterations desired is a multiple of the number ofrepetitions of the body. Something has to be done to take careof any leftover iterations —- such as {Duff's device}.
:unswizzle: v. See {swizzle}.
:unwind the stack: vi. 1. [techspeak] During the execution of a procedural language, one is said to `unwind the stack' from a called procedure up to a caller when one discards the stack frame and any number of frames above it, popping back up to the level of the given caller. In C this is done with `longjmp'/`setjmp', in LISP with `throw/catch'. See also {smash the stack}. 2. People can unwind the stack as well, by quickly dealing with a bunch of problems: "Oh heck, let's do lunch. Just a second while I unwind my stack."
:unwind-protect: [MIT: from the name of a LISP operator] n. A task you must remember to perform before you leave a place or finish a project. "I have an unwind-protect to call my advisor."
:up: adj. 1. Working, in order. "The down escalator is up." Oppose {down}. 2. `bring up': vt. To create a working version and start it. "They brought up a down system." 3. `come up' vi. To become ready for production use.
:upload: /uhp'lohd/ v. 1. [techspeak] To transfer programs or data over a digital communications link from a smaller or peripheral `client' system to a larger or central `host' one. A transfer in the other direction is, of course, called a {download} (but see the note about ground-to-space comm under that entry). 2. [speculatively] To move the essential patterns and algorithms that make up one's mind from one's brain into a computer. Only those who are convinced that such patterns and algorithms capture the complete essence of the self view this prospect with gusto.
:upthread: adv. Earlier in the discussion (see {thread}), i.e., `above'. "As Joe pointed out upthread, …" See also {followup}.
:urchin: n. See {munchkin}.
:USENET: /yoos'net/ or /yooz'net/ [from `Users' Network'] n. A distributed {bboard} (bulletin board) system supported mainly by UNIX machines. Originally implemented in 1979-1980 by Steve Bellovin, Jim Ellis, Tom Truscott, and Steve Daniel at Duke University, it has swiftly grown to become international in scope and is now probably the largest decentralized information utility in existence. As of early 1991, it hosts well over 700 {newsgroup}s and an average of 16 megabytes (the equivalent of several thousand paper pages) of new technical articles, news, discussion, chatter, and {flamage} every day.
:user: n. 1. Someone doing `real work' with the computer, using it as a means rather than an end. Someone who pays to use a computer. See {real user}. 2. A programmer who will believe anything you tell him. One who asks silly questions. [GLS observes: This is slightly unfair. It is true that users ask questions (of necessity). Sometimes they are thoughtful or deep. Very often they are annoying or downright stupid, apparently because the user failed to think for two seconds or look in the documentation before bothering the maintainer.] See {luser}. 3. Someone who uses a program from the outside, however skillfully, without getting into the internals of the program. One who reports bugs instead of just going ahead and fixing them.
The general theory behind this term is that there are two classes of people who work with a program: there are implementors (hackers) and {luser}s. The users are looked down on by hackers to some extent because they don't understand the full ramifications of the system in all its glory. (The few users who do are known as `real winners'.) The term is a relative one: a skilled hacker may be a user with respect to some program he himself does not hack. A LISP hacker might be one who maintains LISP or one who uses LISP (but with the skill of a hacker). A LISP user is one who uses LISP, whether skillfully or not. Thus there is some overlap between the two terms; the subtle distinctions must be resolved by context.
:user-friendly: adj. Programmer-hostile. Generally used by hackers ina critical tone, to describe systems that hold the user's hand soobsessively that they make it painful for the more experienced andknowledgeable to get any work done. See {menuitis}, {drool-proofpaper}, {Macintrash}, {user-obsequious}.
:user-obsequious: adj. Emphatic form of {user-friendly}. Connotesa system so verbose, inflexible, and determinedly simple-mindedthat it is nearly unusable. "Design a system any fool can use andonly a fool will want to use it." See {WIMP environment},{Macintrash}.
:USG UNIX: /U-S-G yoo'niks/ n. Refers to AT&T UNIXcommercial versions after {Version 7}, especially System III andSystem V releases 1, 2, and 3. So called because during most ofthe life-span of those versions AT&T's support crew was called the`UNIX Support Group'. See {BSD}, {{UNIX}}.
:UTSL: // [UNIX] n. On-line acronym for `Use the Source, Luke' (a pun on Obi-Wan Kenobi's "Use the Force, Luke!" in `Star Wars') —- analogous to {RTFM} but more polite. This is a common way of suggesting that someone would be best off reading the source code that supports whatever feature is causing confusion, rather than making yet another futile pass through the manuals or broadcasting questions that haven't attracted {wizard}s to answer them. In theory, this is appropriately directed only at associates of some outfit with a UNIX source license; in practice, bootlegs of UNIX source code (made precisely for reference purposes) are so ubiquitous that one may utter this at almost anyone on the network without concern. In the near future (this written in 1991) source licenses may become even less important; after the recent release of the Mach 3.0 microkernel, given the continuing efforts of the {GNU} project, and with the 4.4BSD release on the horizon, complete free source code for UNIX-clone toolsets and kernels should soon be widely available.
:UUCPNET: n. The store-and-forward network consisting of all the world's connected UNIX machines (and others running some clone of the UUCP (UNIX-to-UNIX CoPy) software). Any machine reachable only via a {bang path} is on UUCPNET. See {network address}.
= V = =====
:vadding: /vad'ing/ [from VAD, a permutation of ADV (i.e., {ADVENT}), used to avoid a particular {admin}'s continual search-and-destroy sweeps for the game] n. A leisure-time activity of certain hackers involving the covert exploration of the `secret' parts of large buildings —- basements, roofs, freight elevators, maintenance crawlways, steam tunnels, and the like. A few go so far as to learn locksmithing in order to synthesize vadding keys. The verb is `to vad' (compare {phreaking}; see also {hack}, sense 9). This term dates from the late 1970s, before which such activity was simply called `hacking'; the older usage is still prevalent at MIT.
The most extreme and dangerous form of vadding is `elevator rodeo', a.k.a. `elevator surfing', a sport played by wrasslin' down a thousand-pound elevator car with a 3-foot piece of string, and then exploiting this mastery in various stimulating ways (such as elevator hopping, shaft exploration, rat-racing, and the ever-popular drop experiments). Kids, don't try this at home! See also {hobbit} (sense 2).
:vanilla: [from the default flavor of ice cream in the U.S.] adj. Ordinary {flavor}, standard. When used of food, very often does not mean that the food is flavored with vanilla extract! For example, `vanilla wonton soup' means ordinary wonton soup, as opposed to hot-and-sour wonton soup. Applied to hardware and software, as in "Vanilla Version 7 UNIX can't run on a vanilla 11/34." Also used to orthogonalize chip nomenclature; for instance, a 74V00 means what TI calls a 7400, as distinct from a 74LS00, etc. This word differs from {canonical} in that the latter means `default', whereas vanilla simply means `ordinary'. For example, when hackers go on a {great-wall}, hot-and-sour wonton soup is the {canonical} wonton soup to get (because that is what most of them usually order) even though it isn't the vanilla wonton soup.
:vannevar: /van'*-var/ n. A bogus technological prediction or a foredoomed engineering concept, esp. one that fails by implicitly assuming that technologies develop linearly, incrementally, and in isolation from one another when in fact the learning curve tends to be highly nonlinear, revolutions are common, and competition is the rule. The prototype was Vannevar Bush's prediction of `electronic brains' the size of the Empire State Building with a Niagara-Falls-equivalent cooling system for their tubes and relays, made at a time when the semiconductor effect had already been demonstrated. Other famous vannevars have included magnetic-bubble memory, LISP machines, {videotex}, and a paper from the late 1970s that computed a purported ultimate limit on areal density for ICs that was in fact less than the routine densities of 5 years later.
:vaporware: /vay'pr-weir/ n. Products announced far in advance ofany release (which may or may not actually take place).
:var: /veir/ or /var/ n. Short for `variable'. Compare {arg},{param}.
:VAX: /vaks/ n. 1. [from Virtual Address eXtension] The most successful minicomputer design in industry history, possibly excepting its immediate ancestor, the PDP-11. Between its release in 1978 and its eclipse by {killer micro}s after about 1986, the VAX was probably the hacker's favorite machine of them all, esp. after the 1982 release of 4.2 BSD UNIX (see {BSD}). Esp. noted for its large, assembler-programmer-friendly instruction set —- an asset that became a liability after the RISC revolution. 2. A major brand of vacuum cleaner in Britain. Cited here because its alleged sales pitch, "Nothing sucks like a VAX!" became a sort of battle-cry of RISC partisans. It is sometimes claimed that this slogan was *not* actually used by the Vax vacuum-cleaner people, but was actually that of a rival brand called Electrolux (as in "Nothing sucks like…"); your editors have not yet been able to verify either version of the legend. It is also claimed that DEC actually entered a cross-licensing deal with the vacuum-Vax people that allowed them to market VAX computers in the U.K. in return for not challenging the vacuum cleaner trademark in the U.S.
:VAXectomy: /vak-sek't*-mee/ [by analogy with `vasectomy'] n. A VAX removal. DEC's Microvaxen, especially, are much slower than newer RISC-based workstations such as the SPARC. Thus, if one knows one has a replacement coming, VAX removal can be cause for celebration.
:VAXen: /vak'sn/ [from `oxen', perhaps influenced by `vixen'] n. (alt. `vaxen') The plural canonically used among hackers for the DEC VAX computers. "Our installation has four PDP-10s and twenty vaxen." See {boxen}.
:vaxherd: n. /vaks'herd/ [from `oxherd'] A VAX operator.
:vaxism: /vak'sizm/ n. A piece of code that exhibits {vaxocentrism} in critical areas. Compare {PC-ism}, {unixism}.
:vaxocentrism: /vak`soh-sen'trizm/ [analogy with `ethnocentrism'] n. A notional disease said to afflict C programmers who persist in coding according to certain assumptions that are valid (esp. under UNIX) on {VAXen} but false elsewhere. Among these are:
1. The assumption that dereferencing a null pointer is safe because it is all bits 0, and location 0 is readable and 0. Problem: this may instead cause an illegal-address trap on non-VAXen, and even on VAXen under OSes other than BSD UNIX. Usually this is an implicit assumption of sloppy code (forgetting to check the pointer before using it), rather than deliberate exploitation of a misfeature.)
2. The assumption that characters are signed.
3. The assumption that a pointer to any one type can freely be cast into a pointer to any other type. A stronger form of this is the assumption that all pointers are the same size and format, which means you don't have to worry about getting the types correct in calls. Problem: this fails on word-oriented machines or others with multiple pointer formats.
4. The assumption that the parameters of a routine are stored in memory, contiguously, and in strictly ascending or descending order. Problem: this fails on many RISC architectures.
5. The assumption that pointer and integer types are the same size, and that pointers can be stuffed into integer variables (and vice-versa) and drawn back out without being truncated or mangled. Problem: this fails on segmented architectures or word-oriented machines with funny pointer formats.
6. The assumption that a data type of any size may begin at any byte address in memory (for example, that you can freely construct and dereference a pointer to a word- or greater-sized object at an odd char address). Problem: this fails on many (esp. RISC) architectures better optimized for {HLL} execution speed, and can cause an illegal address fault or bus error.
7. The (related) assumption that there is no padding at the end of types and that in an array you can thus step right from the last byte of a previous component to the first byte of the next one. This is not only machine- but compiler-dependent.
8. The assumption that memory address space is globally flat and that the array reference `foo[-1]' is necessarily valid. Problem: this fails at 0, or other places on segment-addressed machines like Intel chips (yes, segmentation is universally considered a {brain-damaged} way to design machines (see {moby}), but that is a separate issue).
9. The assumption that objects can be arbitrarily large with no special considerations. Problem: this fails on segmented architectures and under non-virtual-addressing environments.
10. The assumption that the stack can be as large as memory. Problem:this fails on segmented architectures or almost anything elsewithout virtual addressing and a paged stack.
11. The assumption that bits and addressable units within an object areordered in the same way and that this order is a constant ofnature. Problem: this fails on {big-endian} machines.
12. The assumption that it is meaningful to compare pointers to different objects not located within the same array, or to objects of different types. Problem: the former fails on segmented architectures, the latter on word-oriented machines or others with multiple pointer formats.
13. The assumption that an `int' is 32 bits, or (nearly equivalently) the assumption that `sizeof(int) == sizeof(long)'. Problem: this fails on PDP-11s, 286-based systems and even on 386 and 68000 systems under some compilers.
14. The assumption that `argv[]' is writable. Problem: this fails in many embedded-systems C environments and even under a few flavors of UNIX.
Note that a programmer can validly be accused of vaxocentrism even if he or she has never seen a VAX. Some of these assumptions (esp. 2—5) were valid on the PDP-11, the original C machine, and became endemic years before the VAX. The terms `vaxocentricity' and `all-the-world's-a-VAX syndrome' have been used synonymously.
:vdiff: /vee'dif/ v.,n. Visual diff. The operation of finding differences between two files by {eyeball search}. The term `optical diff' has also been reported, and is sometimes more specifically used for the act of superimposing two nearly identical printouts on one another and holding them up to a light to spot differences. Though this method is poor for detecting omissions in the `rear' file, it can also be used with printouts of graphics, a claim few if any diff programs can make. See {diff}.
:veeblefester: /vee'b*l-fes`tr/ [from the "Born Loser" comix via Commodore; prob. originally from `Mad' Magazine's `Veeblefeetzer' parodies ca. 1960] n. Any obnoxious person engaged in the (alleged) professions of marketing or management. Antonym of {hacker}. Compare {suit}, {marketroid}.
:Venus flytrap: [after the insect-eating plant] n. See {firewall machine}.
:verbage: /ver'b*j/ n. A deliberate misspelling and mispronunciation of {verbiage} that assimilates it to the word `garbage'. Compare {content-free}. More pejorative than `verbiage'.
:verbiage: n. When the context involves a software or hardware system, this refers to {{documentation}}. This term borrows the connotations of mainstream `verbiage' to suggest that the documentation is of marginal utility and that the motives behind its production have little to do with the ostensible subject.
:Version 7: alt. V7 /vee' se'vn/ n. The 1978 unsupported release of {{UNIX}} ancestral to all current commercial versions. Before the release of the POSIX/SVID standards, V7's features were often treated as a UNIX portability baseline. See {BSD}, {USG UNIX}, {{UNIX}}. Some old-timers impatient with commercialization and kernel bloat still maintain that V7 was the Last True UNIX.
:vgrep: /vee'grep/ v.,n. Visual grep. The operation of finding patterns in a file optically rather than digitally (also called an `optical grep'). See {grep}; compare {vdiff}.
:vi: /V-I/, *not* /vi:/ and *never* /siks/ [from `Visual Interface'] n. A screen editor crufted together by Bill Joy for an early {BSD} release. Became the de facto standard UNIX editor and a nearly undisputed hacker favorite outside of MIT until the rise of {EMACS} after about 1984. Tends to frustrate new users no end, as it will neither take commands while expecting input text nor vice versa, and the default setup provides no indication of which mode one is in (one correspondent accordingly reports that he has often heard the editor's name pronounced /vi:l/). Nevertheless it is still widely used (about half the respondents in a 1991 USENET poll preferred it), and even EMACS fans often resort to it as a mail editor and for small editing jobs (mainly because it starts up faster than the bulkier versions of EMACS). See {holy wars}.
:videotex: n. obs. An electronic service offering people the privilege of paying to read the weather on their television screens instead of having somebody read it to them for free while they brush their teeth. The idea bombed everywhere it wasn't government-subsidized, because by the time videotex was practical the installed base of personal computers could hook up to timesharing services and do the things for which videotex might have been worthwhile better and cheaper. Videotex planners badly overestimated both the appeal of getting information from a computer and the cost of local intelligence at the user's end. Like the {gorilla arm} effect, this has been a cautionary tale to hackers ever since. See also {vannevar}.
:virgin: adj. Unused; pristine; in a known initial state. "Let's bring up a virgin system and see if it crashes again." (Esp. useful after contracting a {virus} through {SEX}.) Also, by extension, buffers and the like within a program that have not yet been used.
:virtual: [via the technical term `virtual memory', prob. from the term `virtual image' in optics] adj. 1. Common alternative to {logical}; often used to refer to the artificial objects created by a computer system to help the system control access to shared resources. 2. Simulated; performing the functions of something that isn't really there. An imaginative child's doll may be a virtual playmate. Oppose {real}.
:virtual Friday: n. The last day before an extended weekend, if that day is not a `real' Friday. For example, the U.S. holiday Thanksgiving is always on a Thursday. The next day is often also a holiday or taken as an extra day off, in which case Wednesday of that week is a virtual Friday (and Thursday is a virtual Saturday, as is Friday). There are also `virtual Mondays' that are actually Tuesdays, after the three-day weekends associated with many national holidays in the U.S.
:virtual reality: n. 1. Computer simulations that use 3-D graphics and devices such as the Dataglove to allow the user to interact with the simulation. See {cyberspace}. 2. A form of network interaction incorporating aspects of role-playing games, interactive theater, improvisational comedy, and `true confessions' magazines. In a virtual reality forum (such as USENET's alt.callahans newsgroup or the {MUD} experiments on Internet), interaction between the participants is written like a shared novel complete with scenery, `foreground characters' that may be personae utterly unlike the people who write them, and common `background characters' manipulable by all parties. The one iron law is that you may not write irreversible changes to a character without the consent of the person who `owns' it. Otherwise anything goes. See {bamf}, {cyberspace}.
:virus: [from the obvious analogy with biological viruses, via SF] n. A cracker program that searches out other programs and `infects' them by embedding a copy of itself in them, so that they become {Trojan Horse}s. When these programs are executed, the embedded virus is executed too, thus propagating the `infection'. This normally happens invisibly to the user. Unlike a {worm}, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends (see {SEX}). The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently for a while, it starts doing things like writing cute messages on the terminal or playing strange tricks with your display (some viruses include nice {display hack}s). Many nasty viruses, written by particularly perversely minded {cracker}s, do irreversible damage, like nuking all the user's files.
In the 1990s, viruses have become a serious problem, especially among IBM PC and Macintosh users (the lack of security on these machines enables viruses to spread easily, even infecting the operating system). The production of special anti-virus software has become an industry, and a number of exaggerated media reports have caused outbreaks of near hysteria among users; many {luser}s tend to blame *everything* that doesn't work as they had expected on virus attacks. Accordingly, this sense of `virus' has passed not only into techspeak but into also popular usage (where it is often incorrectly used to denote a {worm} or even a {Trojan horse}). Compare {back door}; see also {UNIX conspiracy}.
:visionary: n. 1. One who hacks vision, in the sense of an Artificial Intelligence researcher working on the problem of getting computers to `see' things using TV cameras. (There isn't any problem in sending information from a TV camera to a computer. The problem is, how can the computer be programmed to make use of the camera information? See {SMOP}, {AI-complete}.) 2. [IBM] One who reads the outside literature. At IBM, apparently, such a penchant is viewed with awe and wonder.
:VMS: /V-M-S/ n. DEC's proprietary operating system for its VAX minicomputer; one of the seven or so environments that loom largest in hacker folklore. Many UNIX fans generously concede that VMS would probably be the hacker's favorite commercial OS if UNIX didn't exist; though true, this makes VMS fans furious. One major hacker gripe with VMS concerns its slowness —- thus the following limerick:
There once was a system called VMSOf cycles by no means abstemious.It's chock-full of hacksAnd runs on a VAXAnd makes my poor stomach all squeamious.—- The Great Quux
See also {VAX}, {{TOPS-10}}, {{TOPS-20}}, {{UNIX}}, {runic}.
:voice: vt. To phone someone, as opposed to emailing them or connecting in {talk mode}. "I'm busy now; I'll voice you later."
:voice-net: n. Hackish way of referring to the telephone system, analogizing it to a digital network. USENET {sig block}s not uncommonly include the sender's phone next to a "Voice:" or "Voice-Net:" header; common variants of this are "Voicenet" and "V-Net". Compare {paper-net}, {snail-mail}.
:voodoo programming: [from George Bush's "voodoo economics"] n. The use by guess or cookbook of an {obscure} or {hairy} system, feature, or algorithm that one does not truly understand. The implication is that the technique may not work, and if it doesn't, one will never know why. Almost synonymous with {black magic}, except that black magic typically isn't documented and *nobody* understands it. Compare {magic}, {deep magic}, {heavy wizardry}, {rain dance}, {cargo cult programming}, {wave a dead chicken}.
:VR: // [MUD] n. On-line abbrev for {virtual reality}, as opposed to {RL}.
:Vulcan nerve pinch: n. [from the old "Star Trek" TV series via
Commodore Amiga hackers] The keyboard combination that forces a
soft-boot or jump to ROM monitor (on machines that support such a
feature). On many micros this is Ctrl-Alt-Del; on Suns, L1-A; on
some Macintoshes, it is