Go to the previous, next section.

= B =

back door /n./

A hole in the security of a system deliberately left in place by designers or maintainers. The motivation for such holes is not always sinister; some operating systems, for example, come out of the box with privileged accounts intended for use by field service technicians or the vendor's maintenance programmers. Syn. trap door; may also be called a `wormhole'. See also iron box, cracker, worm, logic bomb.

Historically, back doors have often lurked in systems longer than anyone expected or planned, and a few have become widely known. Ken Thompson's 1983 Turing Award lecture to the ACM admitted the existence of a back door in early Unix versions that may have qualified as the most fiendishly clever security hack of all time. In this scheme, the C compiler contained code that would recognize when the `login' command was being recompiled and insert some code recognizing a password chosen by Thompson, giving him entry to the system whether or not an account had been created for him.

Normally such a back door could be removed by removing it from the source code for the compiler and recompiling the compiler. But to recompile the compiler, you have to use the compiler -- so Thompson also arranged that the compiler would recognize when it was compiling a version of itself, and insert into the recompiled compiler the code to insert into the recompiled `login' the code to allow Thompson entry -- and, of course, the code to recognize itself and do the whole thing again the next time around! And having done this once, he was then able to recompile the compiler from the original sources; the hack perpetuated itself invisibly, leaving the back door in place and active but with no trace in the sources.

The talk that suggested this truly moby hack was published as "Reflections on Trusting Trust", "Communications of the ACM 27", 8 (August 1984), pp. 761--763 (text available at http://www.acm.org/classics). Ken Thompson has since confirmed that this hack was implemented and that the Trojan Horse code did appear in the login binary of a Unix Support group machine. Ken says the crocked compiler was never distributed. Your editor has heard two separate reports that suggest that the crocked login did make it out of Bell Labs, notably to BBN, and that it enabled at least one late-night login across the network by someone using the login name `kt'.

backbone cabal /n./

A group of large-site administrators who pushed through the Great Renaming and reined in the chaos of Usenet during most of the 1980s. The cabal mailing list disbanded in late 1988 after a bitter internal catfight.

backbone site /n./

A key Usenet and email site; one that processes a large amount of third-party traffic, especially if it is the home site of any of the regional coordinators for the Usenet maps. Notable backbone sites as of early 1993, when this sense of the term was beginning to pass out of general use due to wide availability of cheap Internet connections, included uunet and the mail machines at Rutgers University, UC Berkeley, DEC's Western Research Laboratories, Ohio State University, and the University of Texas. Compare rib site, leaf site.

[1996 update: This term is seldom heard any more. The UUCP network world that gave it meaning has nearly disappeared; everyone is on the Internet now and network traffic is distributed in very different patterns. --ESR]


See bignum (sense 3), moby (sense 4), and pseudoprime.

background /n.,adj.,vt./

To do a task `in background' is to do it whenever foreground matters are not claiming your undivided attention, and `to background' something means to relegate it to a lower priority. "For now, we'll just print a list of nodes and links; I'm working on the graph-printing problem in background." Note that this implies ongoing activity but at a reduced level or in spare time, in contrast to mainstream `back burner' (which connotes benign neglect until some future resumption of activity). Some people prefer to use the term for processing that they have queued up for their unconscious minds (a tack that one can often fruitfully take upon encountering an obstacle in creative work). Compare amp off, slopsucker.

Technically, a task running in background is detached from the terminal where it was started (and often running at a lower priority); oppose foreground. Nowadays this term is primarily associated with Unix, but it appears to have been first used in this sense on OS/360.

backspace and overstrike /interj./

Whoa! Back up. Used to suggest that someone just said or did something wrong. Common among APL programmers.

backward combatability /bak'w*rd k*m-bat'*-bil'*-tee/ /n./

[CMU, Tektronix: from `backward compatibility'] A property of hardware or software revisions in which previous protocols, formats, layouts, etc. are irrevocably discarded in favor of `new and improved' protocols, formats, and layouts, leaving the previous ones not merely deprecated but actively defeated. (Too often, the old and new versions cannot definitively be distinguished, such that lingering instances of the previous ones yield crashes or other infelicitous effects, as opposed to a simple "version mismatch" message.) A backwards compatible change, on the other hand, allows old versions to coexist without crashes or error messages, but too many major changes incorporating elaborate backwards compatibility processing can lead to extreme software bloat. See also flag day.

BAD /B-A-D/ /adj./

[IBM: acronym, `Broken As Designed'] Said of a program that is bogus because of bad design and misfeatures rather than because of bugginess. See working as designed.

Bad Thing /n./

[from the 1930 Sellar & Yeatman parody "1066 And All That"] Something that can't possibly result in improvement of the subject. This term is always capitalized, as in "Replacing all of the 9600-baud modems with bicycle couriers would be a Bad Thing". Oppose Good Thing. British correspondents confirm that Bad Thing and Good Thing (and prob. therefore Right Thing and Wrong Thing) come from the book referenced in the etymology, which discusses rulers who were Good Kings but Bad Things. This has apparently created a mainstream idiom on the British side of the pond.

bag on the side /n./

[prob. originally related to a colostomy bag] An extension to an established hack that is supposed to add some functionality to the original. Usually derogatory, implying that the original was being overextended and should have been thrown away, and the new product is ugly, inelegant, or bloated. Also /v./ phrase, `to hang a bag on the side [of]'. "C++? That's just a bag on the side of C ...." "They want me to hang a bag on the side of the accounting system."

bagbiter /bag'bi:t-*r/ /n./

1. Something, such as a program or a computer, that fails to work, or works in a remarkably clumsy manner. "This text editor won't let me make a file with a line longer than 80 characters! What a bagbiter!" 2. A person who has caused you some trouble, inadvertently or otherwise, typically by failing to program the computer properly. Synonyms: loser, cretin, chomper. 3. `bite the bag' /vi./ To fail in some manner. "The computer keeps crashing every five minutes." "Yes, the disk controller is really biting the bag." The original loading of these terms was almost undoubtedly obscene, possibly referring to the scrotum, but in their current usage they have become almost completely sanitized.

ITS's `lexiphage' program was the first and to date only known example of a program intended to be a bagbiter.

bagbiting /adj./

Having the quality of a bagbiter. "This bagbiting system won't let me compute the factorial of a negative number." Compare losing, cretinous, bletcherous, `barfucious' (under barfulous) and `chomping' (under chomp).

balloonian variable /n./

[Commodore users; perh. a deliberate phonetic mangling of `boolean variable'?] Any variable that doesn't actually hold or control state, but must nevertheless be declared, checked, or set. A typical balloonian variable started out as a flag attached to some environment feature that either became obsolete or was planned but never implemented. Compatibility concerns (or politics attached to same) may require that such a flag be treated as though it were live.

bamf /bamf/

1. [from X-Men comics; originally "bampf"] /interj./ Notional sound made by a person or object teleporting in or out of the hearer's vicinity. Often used in virtual reality (esp. MUD) electronic fora when a character wishes to make a dramatic entrance or exit. 2. The sound of magical transformation, used in virtual reality fora like MUDs. 3. In MUD circles, "bamf" is also used to refer to the act by which a MUD server sends a special notification to the MUD client to switch its connection to another server ("I'll set up the old site to just bamf people over to our new location."). 4. Used by MUDders on occasion in a more general sense related to sense 3, to refer to directing someone to another location or resource ("A user was asking about some technobabble so I bamfed them to http://www.ccil.org/jargon/jargon.html.")

banana label /n./

The labels often used on the sides of macrotape reels, so called because they are shaped roughly like blunt-ended bananas. This term, like macrotapes themselves, is still current but visibly headed for obsolescence.

banana problem /n./

[from the story of the little girl who said "I know how to spell `banana', but I don't know when to stop"]. Not knowing where or when to bring a production to a close (compare fencepost error). One may say `there is a banana problem' of an algorithm with poorly defined or incorrect termination conditions, or in discussing the evolution of a design that may be succumbing to featuritis (see also creeping elegance, creeping featuritis). See item 176 under HAKMEM, which describes a banana problem in a Dissociated Press implementation. Also, see one-banana problem for a superficially similar but unrelated usage.

bandwidth /n./

1. Used by hackers (in a generalization of its technical meaning) as the volume of information per unit time that a computer, person, or transmission medium can handle. "Those are amazing graphics, but I missed some of the detail -- not enough bandwidth, I guess." Compare low-bandwidth. 2. Attention span. 3. On Usenet, a measure of network capacity that is often wasted by people complaining about how items posted by others are a waste of bandwidth.


1. /n./ Common spoken name for `!' (ASCII 0100001), especially when used in pronouncing a bang path in spoken hackish. In elder days this was considered a CMUish usage, with MIT and Stanford hackers preferring excl or shriek; but the spread of Unix has carried `bang' with it (esp. via the term bang path) and it is now certainly the most common spoken name for `!'. Note that it is used exclusively for non-emphatic written `!'; one would not say "Congratulations bang" (except possibly for humorous purposes), but if one wanted to specify the exact characters `foo!' one would speak "Eff oh oh bang". See shriek, ASCII. 2. /interj./ An exclamation signifying roughly "I have achieved enlightenment!", or "The dynamite has cleared out my brain!" Often used to acknowledge that one has perpetrated a thinko immediately after one has been called on it.

bang on /vt./

To stress-test a piece of hardware or software: "I banged on the new version of the simulator all day yesterday and it didn't crash once. I guess it is ready for release." The term pound on is synonymous.

bang path /n./

An old-style UUCP electronic-mail address specifying hops to get from some assumed-reachable location to the addressee, so called because each hop is signified by a bang sign. Thus, for example, the path ...!bigsite!foovax!barbox!me directs people to route their mail to machine bigsite (presumably a well-known location accessible to everybody) and from there through the machine foovax to the account of user me on barbox.

In the bad old days of not so long ago, before autorouting mailers became commonplace, people often published compound bang addresses using the { } convention (see glob) to give paths from several big machines, in the hopes that one's correspondent might be able to get mail to one of them reliably (example: ...!{seismo, ut-sally, ihnp4}!rice!beta!gamma!me). Bang paths of 8 to 10 hops were not uncommon in 1981. Late-night dial-up UUCP links would cause week-long transmission times. Bang paths were often selected by both transmission time and reliability, as messages would often get lost. See Internet address, network, the, and sitename.

banner /n./

1. The title page added to printouts by most print spoolers (see spool). Typically includes user or account ID information in very large character-graphics capitals. Also called a `burst page', because it indicates where to burst (tear apart) fanfold paper to separate one user's printout from the next. 2. A similar printout generated (typically on multiple pages of fan-fold paper) from user-specified text, e.g., by a program such as Unix's banner({1,6}). 3. On interactive software, a first screen containing a logo and/or author credits and/or a copyright notice.

bar /bar/ /n./

1. The second metasyntactic variable, after foo and before baz. "Suppose we have two functions: FOO and BAR. FOO calls BAR...." 2. Often appended to foo to produce foobar.

bare metal /n./

1. New computer hardware, unadorned with such snares and delusions as an operating system, an HLL, or even assembler. Commonly used in the phrase `programming on the bare metal', which refers to the arduous work of bit bashing needed to create these basic tools for a new machine. Real bare-metal programming involves things like building boot proms and BIOS chips, implementing basic monitors used to test device drivers, and writing the assemblers that will be used to write the compiler back ends that will give the new machine a real development environment. 2. `Programming on the bare metal' is also used to describe a style of hand-hacking that relies on bit-level peculiarities of a particular hardware design, esp. tricks for speed and space optimization that rely on crocks such as overlapping instructions (or, as in the famous case described in The Story of Mel, a Real Programmer (in Appendix A), interleaving of opcodes on a magnetic drum to minimize fetch delays due to the device's rotational latency). This sort of thing has become less common as the relative costs of programming time and machine resources have changed, but is still found in heavily constrained environments such as industrial embedded systems, and in the code of hackers who just can't let go of that low-level control. See Real Programmer.

In the world of personal computing, bare metal programming (especially in sense 1 but sometimes also in sense 2) is often considered a Good Thing, or at least a necessary evil (because these machines have often been sufficiently slow and poorly designed to make it necessary; see ill-behaved). There, the term usually refers to bypassing the BIOS or OS interface and writing the application to directly access device registers and machine addresses. "To get 19.2 kilobaud on the serial port, you need to get down to the bare metal." People who can do this sort of thing well are held in high regard.

barf /barf/ /n.,v./

[from mainstream slang meaning `vomit'] 1. /interj./ Term of disgust. This is the closest hackish equivalent of the Valspeak "gag me with a spoon". (Like, euwww!) See bletch. 2. /vi./ To say "Barf!" or emit some similar expression of disgust. "I showed him my latest hack and he barfed" means only that he complained about it, not that he literally vomited. 3. /vi./ To fail to work because of unacceptable input, perhaps with a suitable error message, perhaps not. Examples: "The division operation barfs if you try to divide by 0." (That is, the division operation checks for an attempt to divide by zero, and if one is encountered it causes the operation to fail in some unspecified, but generally obvious, manner.) "The text editor barfs if you try to read in a new file before writing out the old one." See choke, gag. In Commonwealth Hackish, `barf' is generally replaced by `puke' or `vom'. barf is sometimes also used as a metasyntactic variable, like foo or bar.

barfmail /n./

Multiple bounce messages accumulating to the level of serious annoyance, or worse. The sort of thing that happens when an inter-network mail gateway goes down or wonky.

barfulation /bar`fyoo-lay'sh*n/ /interj./

Variation of barf used around the Stanford area. An exclamation, expressing disgust. On seeing some particularly bad code one might exclaim, "Barfulation! Who wrote this, Quux?"

barfulous /bar'fyoo-l*s/ /adj./

(alt. `barfucious', /bar-fyoo-sh*s/)

Said of something that would make anyone barf, if only for esthetic reasons.

barney /n./

In Commonwealth hackish, `barney' is to fred (sense #1) as bar is to foo. That is, people who commonly use `fred' as their first metasyntactic variable will often use `barney' second. The reference is, of course, to Fred Flintstone and Barney Rubble in the Flintstones cartoons.

baroque /adj./

Feature-encrusted; complex; gaudy; verging on excessive. Said of hardware or (esp.) software designs, this has many of the connotations of elephantine or monstrosity but is less extreme and not pejorative in itself. "Metafont even has features to introduce random variations to its letterform output. Now that is baroque!" See also rococo.

BASIC /bay'-sic/ /n./

[acronym: Beginner's All-purpose Symbolic Instruction Code] A programming language, originally designed for Dartmouth's experimental timesharing system in the early 1960s, which has since become the leading cause of brain damage in proto-hackers. Edsger W. Dijkstra observed in "Selected Writings on Computing: A Personal Perspective" that "It is practically impossible to teach good programming style to students that have had prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration." This is another case (like Pascal) of the cascading lossage that happens when a language deliberately designed as an educational toy gets taken too seriously. A novice can write short BASIC programs (on the order of 10-20 lines) very easily; writing anything longer (a) is very painful, and (b) encourages bad habits that will make it harder to use more powerful languages well. This wouldn't be so bad if historical accidents hadn't made BASIC so common on low-end micros. As it is, it ruins thousands of potential wizards a year.

[1995: Some languages called `BASIC' aren't quite this nasty any more, having acquired Pascal- and C-like procedures and control structures and shed their line numbers. --ESR]

batch /adj./

1. Non-interactive. Hackers use this somewhat more loosely than the traditional technical definitions justify; in particular, switches on a normally interactive program that prepare it to receive non-interactive command input are often referred to as `batch mode' switches. A `batch file' is a series of instructions written to be handed to an interactive program running in batch mode. 2. Performance of dreary tasks all at one sitting. "I finally sat down in batch mode and wrote out checks for all those bills; I guess they'll turn the electricity back on next week..." 3. `batching up': Accumulation of a number of small tasks that can be lumped together for greater efficiency. "I'm batching up those letters to send sometime" "I'm batching up bottles to take to the recycling center."

bathtub curve /n./

Common term for the curve (resembling an end-to-end section of one of those claw-footed antique bathtubs) that describes the expected failure rate of electronics with time: initially high, dropping to near 0 for most of the system's lifetime, then rising again as it `tires out'. See also burn-in period, infant mortality.

baud /bawd/ /n./

[simplified from its technical meaning] /n./ Bits per second. Hence kilobaud or Kbaud, thousands of bits per second. The technical meaning is `level transitions per second'; this coincides with bps only for two-level modulation with no framing or stop bits. Most hackers are aware of these nuances but blithely ignore them.

Historical note: `baud' was originally a unit of telegraph signalling speed, set at one pulse per second. It was proposed at the International Telegraph Conference of 1927, and named after J.M.E. Baudot (1845--1903), the French engineer who constructed the first successful teleprinter.

baud barf /bawd barf/ /n./

The garbage one gets on the monitor when using a modem connection with some protocol setting (esp. line speed) incorrect, or when someone picks up a voice extension on the same line, or when really bad line noise disrupts the connection. Baud barf is not completely random, by the way; hackers with a lot of serial-line experience can usually tell whether the device at the other end is expecting a higher or lower speed than the terminal is set to. Really experienced ones can identify particular speeds.

baz /baz/ /n./

1. The third metasyntactic variable "Suppose we have three functions: FOO, BAR, and BAZ. FOO calls BAR, which calls BAZ...." (See also fum) 2. /interj./ A term of mild annoyance. In this usage the term is often drawn out for 2 or 3 seconds, producing an effect not unlike the bleating of a sheep; /baaaaaaz/. 3. Occasionally appended to foo to produce `foobaz'.

Earlier versions of this lexicon derived `baz' as a Stanford corruption of bar. However, Pete Samson (compiler of the TMRC lexicon) reports it was already current when he joined TMRC in 1958. He says "It came from "Pogo". Albert the Alligator, when vexed or outraged, would shout `Bazz Fazz!' or `Rowrbazzle!' The club layout was said to model the (mythical) New England counties of Rowrfolk and Bassex (Rowrbazzle mingled with (Norfolk/Suffolk/Middlesex/Essex)."

bboard /bee'bord/ /n./

[contraction of `bulletin board'] 1. Any electronic bulletin board; esp. used of BBS systems running on personal micros, less frequently of a Usenet newsgroup (in fact, use of this term for a newsgroup generally marks one either as a newbie fresh in from the BBS world or as a real old-timer predating Usenet). 2. At CMU and other colleges with similar facilities, refers to campus-wide electronic bulletin boards. 3. The term `physical bboard' is sometimes used to refer to an old-fashioned, non-electronic cork-and-thumbtack memo board. At CMU, it refers to a particular one outside the CS Lounge.

In either of senses 1 or 2, the term is usually prefixed by the name of the intended board (`the Moonlight Casino bboard' or `market bboard'); however, if the context is clear, the better-read bboards may be referred to by name alone, as in (at CMU) "Don't post for-sale ads on general".

BBS /B-B-S/ /n./

[abbreviation, `Bulletin Board System'] An electronic bulletin board system; that is, a message database where people can log in and leave broadcast messages for others grouped (typically) into topic groups. Thousands of local BBS systems are in operation throughout the U.S., typically run by amateurs for fun out of their homes on MS-DOS boxes with a single modem line each. Fans of Usenet and Internet or the big commercial timesharing bboards such as CompuServe and GEnie tend to consider local BBSes the low-rent district of the hacker culture, but they serve a valuable function by knitting together lots of hackers and users in the personal-micro world who would otherwise be unable to exchange code at all. See also bboard.

beam /vt./

[from Star Trek Classic's "Beam me up, Scotty!"] To transfer softcopy of a file electronically; most often in combining forms such as `beam me a copy' or `beam that over to his site'. Compare blast, snarf, BLT.

beanie key /n./

[Mac users] See command key.

beep /n.,v./

Syn. feep. This term is techspeak under MS-DOS and OS/2, and seems to be generally preferred among micro hobbyists.

beige toaster /n./

A Macintosh. See toaster; compare Macintrash, maggotbox.

bells and whistles /n./

[by analogy with the toyboxes on theater organs] Features added to a program or system to make it more flavorful from a hacker's point of view, without necessarily adding to its utility for its primary function. Distinguished from chrome, which is intended to attract users. "Now that we've got the basic program working, let's go back and add some bells and whistles." No one seems to know what distinguishes a bell from a whistle.

bells, whistles, and gongs /n./

A standard elaborated form of bells and whistles; typically said with a pronounced and ironic accent on the `gongs'.

benchmark [techspeak] /n./

An inaccurate measure of computer performance. "In the computer industry, there are three kinds of lies: lies, damn lies, and benchmarks." Well-known ones include Whetstone, Dhrystone, Rhealstone (see h), the Gabriel LISP benchmarks (see gabriel), the SPECmark suite, and LINPACK. See also machoflops, MIPS, smoke and mirrors.

Berkeley Quality Software /adj./

(often abbreviated `BQS') Term used in a pejorative sense to refer to software that was apparently created by rather spaced-out hackers late at night to solve some unique problem. It usually has nonexistent, incomplete, or incorrect documentation, has been tested on at least two examples, and core dumps when anyone else attempts to use it. This term was frequently applied to early versions of the dbx(1) debugger. See also Berzerkeley.

Note to British and Commonwealth readers: that's /berk'lee/, not /bark'lee/ as in British Received Pronunciation.

berklix /berk'liks/ /n.,adj./

[contraction of `Berkeley Unix'] See BSD. Not used at Berkeley itself. May be more common among suits attempting to sound like cognoscenti than among hackers, who usually just say `BSD'.

Berzerkeley /b*r-zer'klee/ /n./

[from `berserk', via the name of a now-deceased record label] Humorous distortion of `Berkeley' used esp. to refer to the practices or products of the BSD Unix hackers. See software bloat, Missed'em-five, Berkeley Quality Software.

Mainstream use of this term in reference to the cultural and political peculiarities of UC Berkeley as a whole has been reported from as far back as the 1960s.

beta /bay't*/, /be't*/ or (Commonwealth) /bee't*/ /n./

1. Mostly working, but still under test; usu. used with `in': `in beta'. In the Real World, systems (hardware or software) software often go through two stages of release testing: Alpha (in-house) and Beta (out-house?). Beta releases are generally made to a group of lucky (or unlucky) trusted customers. 2. Anything that is new and experimental. "His girlfriend is in beta" means that he is still testing for compatibility and reserving judgment. 3. Flaky; dubious; suspect (since beta software is notoriously buggy).

Historical note: More formally, to beta-test is to test a pre-release (potentially unreliable) version of a piece of software by making it available to selected (or self-selected) customers and users. This term derives from early 1960s terminology for product cycle checkpoints, first used at IBM but later standard throughout the industry. `Alpha Test' was the unit, module, or component test phase; `Beta Test' was initial system test. These themselves came from earlier A- and B-tests for hardware. The A-test was a feasibility and manufacturability evaluation done before any commitment to design and development. The B-test was a demonstration that the engineering model functioned as specified. The C-test (corresponding to today's beta) was the B-test performed on early samples of the production design.

BFI /B-F-I/ /n./

See brute force and ignorance. Also encountered in the variants `BFMI', `brute force and massive ignorance' and `BFBI' `brute force and bloody ignorance'.

bible /n./

1. One of a small number of fundamental source books such as Knuth and K&R. 2. The most detailed and authoritative reference for a particular language, operating system, or other complex software system.

BiCapitalization /n./

The act said to have been performed on trademarks (such as PostScript, NeXT, NeWS, VisiCalc, FrameMaker, TK!solver, EasyWriter) that have been raised above the ruck of common coinage by nonstandard capitalization. Too many marketroid types think this sort of thing is really cute, even the 2,317th time they do it. Compare studlycaps.

B1FF /bif/ [Usenet] (alt. `BIFF') /n./

The most famous pseudo, and the prototypical newbie. Articles from B1FF feature all uppercase letters sprinkled liberally with bangs, typos, `cute' misspellings (EVRY BUDY LUVS GOOD OLD BIFF CUZ LIKE THIS!!!), use (and often misuse) of fragments of talk mode abbreviations, a long sig block (sometimes even a doubled sig), and unbounded naivete. B1FF posts articles using his elder brother's VIC-20. B1FF's location is a mystery, as his articles appear to come from a variety of sites. However, BITNET seems to be the most frequent origin. The theory that B1FF is a denizen of BITNET is supported by B1FF's (unfortunately invalid) electronic mail address: B1FF@BIT.NET.

[1993: Now It Can Be Told! My spies inform me that B1FF was originally created by Joe Talmadge <jat@cup.hp.com>, also the author of the infamous and much-plagiarized "Flamer's Bible". The BIFF filter he wrote was later passed to Richard Sexton, who posted BIFFisms much more widely. Versions have since been posted for the amusement of the net at large. --ESR]

biff /bif/ /vt./

To notify someone of incoming mail. From the BSD utility biff(1), which was in turn named after a friendly golden Labrador who used to chase frisbees in the halls at UCB while 4.2BSD was in development. There was a legend that it had a habit of barking whenever the mailman came, but the author of biff says this is not true. No relation to B1FF.

Big Gray Wall /n./

What faces a VMS user searching for documentation. A full VMS kit comes on a pallet, the documentation taking up around 15 feet of shelf space before the addition of layered products such as compilers, databases, multivendor networking, and programming tools. Recent (since VMS version 5) DEC documentation comes with gray binders; under VMS version 4 the binders were orange (`big orange wall'), and under version 3 they were blue. See VMS. Often contracted to `Gray Wall'.

big iron /n./

Large, expensive, ultra-fast computers. Used generally of number-crunching supercomputers such as Crays, but can include more conventional big commercial IBMish mainframes. Term of approval; compare heavy metal, oppose dinosaur.

Big Red Switch /n./

[IBM] The power switch on a computer, esp. the `Emergency Pull' switch on an IBM mainframe or the power switch on an IBM PC where it really is large and red. "This !@%$% bitty box is hung again; time to hit the Big Red Switch." Sources at IBM report that, in tune with the company's passion for TLAs, this is often abbreviated as `BRS' (this has also become established on FidoNet and in the PC clone world). It is alleged that the emergency pull switch on an IBM 360/91 actually fired a non-conducting bolt into the main power feed; the BRSes on more recent mainframes physically drop a block into place so that they can't be pushed back in. People get fired for pulling them, especially inappropriately (see also molly-guard). Compare power cycle, three-finger salute, 120 reset; see also scram switch.

Big Room, the /n./

The extremely large room with the blue ceiling and intensely bright light (during the day) or black ceiling with lots of tiny night-lights (during the night) found outside all computer installations. "He can't come to the phone right now, he's somewhere out in the Big Room."

big win /n./

Serendipity. "Yes, those two physicists discovered high-temperature superconductivity in a batch of ceramic that had been prepared incorrectly according to their experimental schedule. Small mistake; big win!" See win big.

big-endian /adj./

[From Swift's "Gulliver's Travels" via the famous paper "On Holy Wars and a Plea for Peace" by Danny Cohen, USC/ISI IEN 137, dated April 1, 1980] 1. Describes a computer architecture in which, within a given multi-byte numeric representation, the most significant byte has the lowest address (the word is stored `big-end-first'). Most processors, including the IBM 370 family, the PDP-10, the Motorola microprocessor families, and most of the various RISC designs current in late 1995, are big-endian. Big-endian byte order is also sometimes called `network order'. See little-endian, middle-endian, NUXI problem, swab. 2. An Internet address the wrong way round. Most of the world follows the Internet standard and writes email addresses starting with the name of the computer and ending up with the name of the country. In the U.K. the Joint Networking Team had decided to do it the other way round before the Internet domain standard was established. Most gateway sites have ad-hockery in their mailers to handle this, but can still be confused. In particular, the address me@uk.ac.bris.pys.as could be interpreted in JANET's big-endian way as one in the U.K. (domain uk) or in the standard little-endian way as one in the domain as (American Samoa) on the opposite side of the world.

bignum /big'nuhm/ /n./

[orig. from MIT MacLISP] 1. [techspeak] A multiple-precision computer representation for very large integers. 2. More generally, any very large number. "Have you ever looked at the United States Budget? There's bignums for you!" 3. [Stanford] In backgammon, large numbers on the dice especially a roll of double fives or double sixes (compare moby, sense 4). See also El Camino Bignum.

Sense 1 may require some explanation. Most computer languages provide a kind of data called `integer', but such computer integers are usually very limited in size; usually they must be smaller than than @Math{2^(31)} (2,147,483,648) or (on a bitty box) @Math{2^(15)} (32,768). If you want to work with numbers larger than that, you have to use floating-point numbers, which are usually accurate to only six or seven decimal places. Computer languages that provide bignums can perform exact calculations on very large numbers, such as 1000! (the factorial of 1000, which is 1000 times 999 times 998 times ... times 2 times 1). For example, this value for 1000! was computed by the MacLISP system using bignums:


bigot /n./

A person who is religiously attached to a particular computer, language, operating system, editor, or other tool (see religious issues). Usually found with a specifier; thus, `cray bigot', `ITS bigot', `APL bigot', `VMS bigot', `Berkeley bigot'. Real bigots can be distinguished from mere partisans or zealots by the fact that they refuse to learn alternatives even when the march of time and/or technology is threatening to obsolete the favored tool. It is truly said "You can tell a bigot, but you can't tell him much." Compare weenie.

bit /n./

[from the mainstream meaning and `Binary digIT'] 1. [techspeak] The unit of information; the amount of information obtained by asking a yes-or-no question for which the two outcomes are equally probable. 2. [techspeak] A computational quantity that can take on one of two values, such as true and false or 0 and 1. 3. A mental flag: a reminder that something should be done eventually. "I have a bit set for you." (I haven't seen you for a while, and I'm supposed to tell or ask you something.) 4. More generally, a (possibly incorrect) mental state of belief. "I have a bit set that says that you were the last guy to hack on EMACS." (Meaning "I think you were the last guy to hack on EMACS, and what I am about to say is predicated on this, so please stop me if this isn't true.")

"I just need one bit from you" is a polite way of indicating that you intend only a short interruption for a question that can presumably be answered yes or no.

A bit is said to be `set' if its value is true or 1, and `reset' or `clear' if its value is false or 0. One speaks of setting and clearing bits. To toggle or `invert' a bit is to change it, either from 0 to 1 or from 1 to 0. See also flag, trit, mode bit.

The term `bit' first appeared in print in the computer-science sense in 1949, and seems to have been coined by early computer scientist John Tukey. Tukey records that it evolved over a lunch table as a handier alternative to `bigit' or `binit'.

bit bang /n./

Transmission of data on a serial line, when accomplished by rapidly tweaking a single output bit, in software, at the appropriate times. The technique is a simple loop with eight OUT and SHIFT instruction pairs for each byte. Input is more interesting. And full duplex (doing input and output at the same time) is one way to separate the real hackers from the wannabees.

Bit bang was used on certain early models of Prime computers, presumably when UARTs were too expensive, and on archaic Z80 micros with a Zilog PIO but no SIO. In an interesting instance of the cycle of reincarnation, this technique returned to use in the early 1990s on some RISC architectures because it consumes such an infinitesimal part of the processor that it actually makes sense not to have a UART. Compare cycle of reincarnation.

bit bashing /n./

(alt. `bit diddling' or bit twiddling) Term used to describe any of several kinds of low-level programming characterized by manipulation of bit, flag, nybble, and other smaller-than-character-sized pieces of data; these include low-level device control, encryption algorithms, checksum and error-correcting codes, hash functions, some flavors of graphics programming (see bitblt), and assembler/compiler code generation. May connote either tedium or a real technical challenge (more usually the former). "The command decoding for the new tape driver looks pretty solid but the bit-bashing for the control registers still has bugs." See also bit bang, mode bit.

bit bucket /n./

1. The universal data sink (originally, the mythical receptacle used to catch bits when they fall off the end of a register during a shift instruction). Discarded, lost, or destroyed data is said to have `gone to the bit bucket'. On Unix, often used for /dev/null. Sometimes amplified as `the Great Bit Bucket in the Sky'. 2. The place where all lost mail and news messages eventually go. The selection is performed according to Finagle's Law; important mail is much more likely to end up in the bit bucket than junk mail, which has an almost 100% probability of getting delivered. Routing to the bit bucket is automatically performed by mail-transfer agents, news systems, and the lower layers of the network. 3. The ideal location for all unwanted mail responses: "Flames about this article to the bit bucket." Such a request is guaranteed to overflow one's mailbox with flames. 4. Excuse for all mail that has not been sent. "I mailed you those figures last week; they must have landed in the bit bucket." Compare black hole.

This term is used purely in jest. It is based on the fanciful notion that bits are objects that are not destroyed but only misplaced. This appears to have been a mutation of an earlier term `bit box', about which the same legend was current; old-time hackers also report that trainees used to be told that when the CPU stored bits into memory it was actually pulling them `out of the bit box'. See also chad box.

Another variant of this legend has it that, as a consequence of the `parity preservation law', the number of 1 bits that go to the bit bucket must equal the number of 0 bits. Any imbalance results in bits filling up the bit bucket. A qualified computer technician can empty a full bit bucket as part of scheduled maintenance.

bit decay /n./

See bit rot. People with a physics background tend to prefer this variant for the analogy with particle decay. See also computron, quantum bogodynamics.

bit rot /n./

Also bit decay. Hypothetical disease the existence of which has been deduced from the observation that unused programs or features will often stop working after sufficient time has passed, even if `nothing has changed'. The theory explains that bits decay as if they were radioactive. As time passes, the contents of a file or the code in a program will become increasingly garbled.

There actually are physical processes that produce such effects (alpha particles generated by trace radionuclides in ceramic chip packages, for example, can change the contents of a computer memory unpredictably, and various kinds of subtle media failures can corrupt files in mass storage), but they are quite rare (and computers are built with error-detecting circuitry to compensate for them). The notion long favored among hackers that cosmic rays are among the causes of such events turns out to be a myth; see the cosmic rays entry for details.

The term software rot is almost synonymous. Software rot is the effect, bit rot the notional cause.

bit twiddling /n./

1. (pejorative) An exercise in tuning (see tune) in which incredible amounts of time and effort go to produce little noticeable improvement, often with the result that the code becomes incomprehensible. 2. Aimless small modification to a program, esp. for some pointless goal. 3. Approx. syn. for bit bashing; esp. used for the act of frobbing the device control register of a peripheral in an attempt to get it back to a known state.

bit-paired keyboard /n./ obs.

(alt. `bit-shift keyboard') A non-standard keyboard layout that seems to have originated with the Teletype ASR-33 and remained common for several years on early computer equipment. The ASR-33 was a mechanical device (see EOU), so the only way to generate the character codes from keystrokes was by some physical linkage. The design of the ASR-33 assigned each character key a basic pattern that could be modified by flipping bits if the SHIFT or the CTRL key was pressed. In order to avoid making the thing more of a Rube Goldberg kluge than it already was, the design had to group characters that shared the same basic bit pattern on one key.

Looking at the ASCII chart, we find:

high  low bits
bits  0000 0001 0010 0011 0100 0101 0110 0111 1000 1001
 010        !    "    #    $    %    &    '    (    )
 011   0    1    2    3    4    5    6    7    8    9

This is why the characters !"#$%&'() appear where they do on a Teletype (thankfully, they didn't use shift-0 for space). This was not the weirdest variant of the QWERTY layout widely seen, by the way; that prize should probably go to one of several (differing) arrangements on IBM's even clunkier 026 and 029 card punches.

When electronic terminals became popular, in the early 1970s, there was no agreement in the industry over how the keyboards should be laid out. Some vendors opted to emulate the Teletype keyboard, while others used the flexibility of electronic circuitry to make their product look like an office typewriter. These alternatives became known as `bit-paired' and `typewriter-paired' keyboards. To a hacker, the bit-paired keyboard seemed far more logical -- and because most hackers in those days had never learned to touch-type, there was little pressure from the pioneering users to adapt keyboards to the typewriter standard.

The doom of the bit-paired keyboard was the large-scale introduction of the computer terminal into the normal office environment, where out-and-out technophobes were expected to use the equipment. The `typewriter-paired' standard became universal, `bit-paired' hardware was quickly junked or relegated to dusty corners, and both terms passed into disuse.

bitblt /bit'blit/ /n./

[from BLT, q.v.] 1. Any of a family of closely related algorithms for moving and copying rectangles of bits between main and display memory on a bit-mapped device, or between two areas of either main or display memory (the requirement to do the Right Thing in the case of overlapping source and destination rectangles is what makes BitBlt tricky). 2. Synonym for blit or BLT. Both uses are borderline techspeak.

BITNET /bit'net/ /n./

[acronym: Because It's Time NETwork] Everybody's least favorite piece of the network (see network, the). The BITNET hosts are a collection of IBM dinosaurs and VAXen (the latter with lobotomized comm hardware) that communicate using 80-character EBCDIC card images (see eighty-column mind); thus, they tend to mangle the headers and text of third-party traffic from the rest of the ASCII/ RFC-822 world with annoying regularity. BITNET was also notorious as the apparent home of B1FF.

bits /pl.n./

1. Information. Examples: "I need some bits about file formats." ("I need to know about file formats.") Compare core dump, sense 4. 2. Machine-readable representation of a document, specifically as contrasted with paper: "I have only a photocopy of the Jargon File; does anyone know where I can get the bits?". See softcopy, source of all good bits See also bit.

bitty box /bit'ee boks/ /n./

1. A computer sufficiently small, primitive, or incapable as to cause a hacker acute claustrophobia at the thought of developing software on or for it. Especially used of small, obsolescent, single-tasking-only personal machines such as the Atari 800, Osborne, Sinclair, VIC-20, TRS-80, or IBM PC. 2. [Pejorative] More generally, the opposite of `real computer' (see Get a real computer!). See also mess-dos, toaster, and toy.

bixie /bik'see/ /n./

Variant emoticons used on BIX (the Byte Information eXchange). The smiley bixie is <@_@>, apparently intending to represent two cartoon eyes and a mouth. A few others have been reported.

black art /n./

A collection of arcane, unpublished, and (by implication) mostly ad-hoc techniques developed for a particular application or systems area (compare black magic). VLSI design and compiler code optimization were (in their beginnings) considered classic examples of black art; as theory developed they became deep magic, and once standard textbooks had been written, became merely heavy wizardry. The huge proliferation of formal and informal channels for spreading around new computer-related technologies during the last twenty years has made both the term `black art' and what it describes less common than formerly. See also voodoo programming.

black hole /n./

What a piece of email or netnews has fallen into if it disappears mysteriously between its origin and destination sites (that is, without returning a bounce message). "I think there's a black hole at foovax!" conveys suspicion that site foovax has been dropping a lot of stuff on the floor lately (see drop on the floor). The implied metaphor of email as interstellar travel is interesting in itself. Compare bit bucket.

black magic /n./

A technique that works, though nobody really understands why. More obscure than voodoo programming, which may be done by cookbook. Compare also black art, deep magic, and magic number (sense 2).

Black Screen of Death n.

[prob. related to the Floating Head of Death in a famous "Far Side" cartoon.] A failure mode of Microsloth Windows. On an attempt to launch a DOS box, a networked Windows system not uncommonly blanks the screen and locks up the PC so hard that it requires a cold boot to recover. This unhappy phenomenon is known as The Black Screen of Death.

Black Thursday n.

February 8th, 1996 -- the day of the signing into law of the CDA, so called by analogy with the catastrophic "Black Friday" in 1929 that began the Great Depression.

blammo /v./

[Oxford Brookes University and alumni, UK] To forcibly remove someone from any interactive system, especially talker systems. The operators, who may remain hidden, may `blammo' a user who is misbehaving. Very similar to MIT gun; in fact, the `blammo-gun' is a notional device used to `blammo' someone. While in actual fact the only incarnation of the blammo-gun is the command used to forcibly eject a user, operators speak of different levels of blammo-gun fire; e.g., a blammo-gun to `stun' will temporarily remove someone, but a blammo-gun set to `maim' will stop someone coming back on for a while.

blargh /blarg/ /n./

[MIT] The opposite of ping, sense 5; an exclamation indicating that one has absorbed or is emitting a quantum of unhappiness. Less common than ping.

blast 1. /v.,n./

Synonym for BLT, used esp. for large data sends over a network or comm line. Opposite of snarf. Usage: uncommon. The variant `blat' has been reported. 2. vt. [HP/Apollo] Synonymous with nuke (sense 3). Sometimes the message Unable to kill all processes. Blast them (y/n)? would appear in the command window upon logout.

blat /n./

1. Syn. blast, sense 1. 2. See thud.

bletch /blech/ /interj./

[from Yiddish/German `brechen', to vomit, poss. via comic-strip exclamation `blech'] Term of disgust. Often used in "Ugh, bletch". Compare barf.

bletcherous /blech'*-r*s/ /adj./

Disgusting in design or function; esthetically unappealing. This word is seldom used of people. "This keyboard is bletcherous!" (Perhaps the keys don't work very well, or are misplaced.) See losing, cretinous, bagbiting, bogus, and random. The term bletcherous applies to the esthetics of the thing so described; similarly for cretinous. By contrast, something that is `losing' or `bagbiting' may be failing to meet objective criteria. See also bogus and random, which have richer and wider shades of meaning than any of the above.

blink /vi.,n./

To use a navigator or off-line message reader to minimize time spent on-line to a commercial network service. As of late 1994, this term was said to be in wide use in the UK, but is rare or unknown in the US.

blinkenlights /blink'*n-li:tz/ /n./

Front-panel diagnostic lights on a computer, esp. a dinosaur. Derives from the last word of the famous blackletter-Gothic sign in mangled pseudo-German that once graced about half the computer rooms in the English-speaking world. One version ran in its entirety as follows:


Das computermachine ist nicht fuer gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitzensparken. Ist nicht fuer gewerken bei das dumpkopfen. Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das pockets muss; relaxen und watchen das blinkenlichten.

This silliness dates back at least as far as 1959 at Stanford University and had already gone international by the early 1960s, when it was reported at London University's ATLAS computing site. There are several variants of it in circulation, some of which actually do end with the word `blinkenlights'.

In an amusing example of turnabout-is-fair-play, German hackers have developed their own versions of the blinkenlights poster in fractured English, one of which is reproduced here:


This room is fullfilled mit special electronische equippment. Fingergrabbing and pressing the cnoeppkes from the computers is allowed for die experts only! So all the "lefthanders" stay away and do not disturben the brainstorming von here working intelligencies. Otherwise you will be out thrown and kicked anderswhere! Also: please keep still and only watchen astaunished the blinkenlights.

See also geef.

Old-time hackers sometimes get nostalgic for blinkenlights because they were so much more fun to look at than a blank panel. Sadly, very few computers still have them (the three LEDs on a PC keyboard certainly don't count). The obvious reasons (cost of wiring, cost of front-panel cutouts, almost nobody needs or wants to interpret machine-register states on the fly anymore) are only part of the story. Another part of it is that radio-frequency leakage from the lamp wiring was beginning to be a problem as far back as transistor machines. But the most fundamental fact is that there are very few signals slow enough to blink an LED these days! With slow CPUs, you could watch the bus register or instruction counter tick, but at 33/66/150MHz it's all a blur.

blit /blit/ /vt./

1. To copy a large array of bits from one part of a computer's memory to another part, particularly when the memory is being used to determine what is shown on a display screen. "The storage allocator picks through the table and copies the good parts up into high memory, and then blits it all back down again." See bitblt, BLT, dd, cat, blast, snarf. More generally, to perform some operation (such as toggling) on a large array of bits while moving them. 2. Sometimes all-capitalized as `BLIT': an early experimental bit-mapped terminal designed by Rob Pike at Bell Labs, later commercialized as the AT&T 5620. (The folk etymology from `Bell Labs Intelligent Terminal' is incorrect. Its creators liked to claim that "Blit" stood for the Bacon, Lettuce, and Interactive Tomato.)

blitter /blit'r/ /n./

A special-purpose chip or hardware system built to perform blit operations, esp. used for fast implementation of bit-mapped graphics. The Commodore Amiga and a few other micros have these, but sine 1990 the trend is away from them (however, see cycle of reincarnation). Syn. raster blaster.

blivet /bliv'*t/ /n./

[allegedly from a World War II military term meaning "ten pounds of manure in a five-pound bag"] 1. An intractable problem. 2. A crucial piece of hardware that can't be fixed or replaced if it breaks. 3. A tool that has been hacked over by so many incompetent programmers that it has become an unmaintainable tissue of hacks. 4. An out-of-control but unkillable development effort. 5. An embarrassing bug that pops up during a customer demo. 6. In the subjargon of computer security specialists, a denial-of-service attack performed by hogging limited resources that have no access controls (for example, shared spool space on a multi-user system).

This term has other meanings in other technical cultures; among experimental physicists and hardware engineers of various kinds it seems to mean any random object of unknown purpose (similar to hackish use of frob). It has also been used to describe an amusing trick-the-eye drawing resembling a three-pronged fork that appears to depict a three-dimensional object until one realizes that the parts fit together in an impossible way.


1. /n./ [acronym: Binary Large OBject] Used by database people to refer to any random large block of bits that needs to be stored in a database, such as a picture or sound file. The essential point about a BLOB is that it's an object that cannot be interpreted within the database itself. 2. /v./ To mailbomb someone by sending a BLOB to him/her; esp. used as a mild threat. "If that program crashes again, I'm going to BLOB the core dump to you."

block /v./

[from process scheduling terminology in OS theory] 1. /vi./ To delay or sit idle while waiting for something. "We're blocking until everyone gets here." Compare busy-wait. 2. `block on' /vt./ To block, waiting for (something). "Lunch is blocked on Phil's arrival."

block transfer computations /n./

[from the television series "Dr. Who"] Computations so fiendishly subtle and complex that they could not be performed by machines. Used to refer to any task that should be expressible as an algorithm in theory, but isn't. (The Z80's LDIR instruction, "Computed Block Transfer with increment", may also be relevant)

Bloggs Family, the /n./

An imaginary family consisting of Fred and Mary Bloggs and their children. Used as a standard example in knowledge representation to show the difference between extensional and intensional objects. For example, every occurrence of "Fred Bloggs" is the same unique person, whereas occurrences of "person" may refer to different people. Members of the Bloggs family have been known to pop up in bizarre places such as the DEC Telephone Directory. Compare Mbogo, Dr. Fred.

blow an EPROM /bloh *n ee'prom/ /v./

(alt. `blast an EPROM', `burn an EPROM') To program a read-only memory, e.g. for use with an embedded system. This term arose because the programming process for the Programmable Read-Only Memories (PROMs) that preceded present-day Erasable Programmable Read-Only Memories (EPROMs) involved intentionally blowing tiny electrical fuses on the chip. The usage lives on (it's too vivid and expressive to discard) even though the write process on EPROMs is nondestructive.

blow away /vt./

To remove (files and directories) from permanent storage, generally by accident. "He reformatted the wrong partition and blew away last night's netnews." Oppose nuke.

blow out /vi./

[prob. from mining and tunneling jargon] Of software, to fail spectacularly; almost as serious as crash and burn. See blow past, blow up, die horribly.

blow past /vt./

To blow out despite a safeguard. "The server blew past the 5K reserve buffer."

blow up /vi./

1. [scientific computation] To become unstable. Suggests that the computation is diverging so rapidly that it will soon overflow or at least go nonlinear. 2. Syn. blow out.

BLT /B-L-T/, /bl*t/ or (rarely) /belt/ /n.,vt./

Synonym for blit. This is the original form of blit and the ancestor of bitblt. It referred to any large bit-field copy or move operation (one resource-intensive memory-shuffling operation done on pre-paged versions of ITS, WAITS, and TOPS-10 was sardonically referred to as `The Big BLT'). The jargon usage has outlasted the PDP-10 BLock Transfer instruction from which BLT derives; nowadays, the assembler mnemonic BLT almost always means `Branch if Less Than zero'.

Blue Book /n./

1. Informal name for one of the three standard references on the page-layout and graphics-control language PostScript ("PostScript Language Tutorial and Cookbook", Adobe Systems, Addison-Wesley 1985, QA76.73.P67P68, ISBN 0-201-10179-3); the other three official guides are known as the Green Book, the Red Book, and the White Book (sense 2). 2. Informal name for one of the three standard references on Smalltalk: "Smalltalk-80: The Language and its Implementation", David Robson, Addison-Wesley 1983, QA76.8.S635G64, ISBN 0-201-11371-63 (this book also has green and red siblings). 3. Any of the 1988 standards issued by the CCITT's ninth plenary assembly. These include, among other things, the X.400 email spec and the Group 1 through 4 fax standards. See also book titles.

blue box

/n./ 1. obs. Once upon a time, before all-digital switches made it possible for the phone companies to move them out of band, one could actually hear the switching tones used to route long-distance calls. Early phreakers built devices called `blue boxes' that could reproduce these tones, which could be used to commandeer portions of the phone network. (This was not as hard as it may sound; one early phreak acquired the sobriquet `Captain Crunch' after he proved that he could generate switching tones with a plastic whistle pulled out of a box of Captain Crunch cereal!) There were other colors of box with more specialized phreaking uses; red boxes, black boxes, silver boxes, etc. 2. /n./ An IBM machine, especially a large (non-PC) one.

Blue Glue /n./

[IBM] IBM's SNA (Systems Network Architecture), an incredibly losing and bletcherous communications protocol widely favored at commercial shops that don't know any better. The official IBM definition is "that which binds blue boxes together." See fear and loathing. It may not be irrelevant that Blue Glue is the trade name of a 3M product that is commonly used to hold down the carpet squares to the removable panel floors common in dinosaur pens. A correspondent at U. Minn. reports that the CS department there has about 80 bottles of the stuff hanging about, so they often refer to any messy work to be done as `using the blue glue'.

blue goo /n./

Term for `police' nanobots intended to prevent gray goo, denature hazardous waste, destroy pollution, put ozone back into the stratosphere, prevent halitosis, and promote truth, justice, and the American way, etc. The term `Blue Goo' can be found in Dr. Seuss's "Fox In Socks" to refer to a substance much like bubblegum. `Would you like to chew blue goo, sir?'. See nanotechnology.

blue wire /n./

[IBM] Patch wires added to circuit boards at the factory to correct design or fabrication problems. These may be necessary if there hasn't been time to design and qualify another board version. Compare purple wire, red wire, yellow wire.

blurgle /bler'gl/ /n./

[UK] Spoken metasyntactic variable, to indicate some text that is obvious from context, or which is already known. If several words are to be replaced, blurgle may well be doubled or tripled. "To look for something in several files use `grep string blurgle blurgle'." In each case, "blurgle blurgle" would be understood to be replaced by the file you wished to search. Compare mumble, sense 7.

BNF /B-N-F/ /n./

1. [techspeak] Acronym for `Backus-Naur Form', a metasyntactic notation used to specify the syntax of programming languages, command sets, and the like. Widely used for language descriptions but seldom documented anywhere, so that it must usually be learned by osmosis from other hackers. Consider this BNF for a U.S. postal address:

 <postal-address> ::= <name-part> <street-address> <zip-part>

 <personal-part> ::= <name> | <initial> "."

 <name-part> ::= <personal-part> <last-name> [<jr-part>] <EOL>
               | <personal-part> <name-part>

 <street-address> ::= [<apt>] <house-num> <street-name> <EOL>

 <zip-part> ::= <town-name> "," <state-code> <ZIP-code> <EOL>

This translates into English as: "A postal-address consists of a name-part, followed by a street-address part, followed by a zip-code part. A personal-part consists of either a first name or an initial followed by a dot. A name-part consists of either: a personal-part followed by a last name followed by an optional `jr-part' (Jr., Sr., or dynastic number) and end-of-line, or a personal part followed by a name part (this rule illustrates the use of recursion in BNFs, covering the case of people who use multiple first and middle names and/or initials). A street address consists of an optional apartment specifier, followed by a street number, followed by a street name. A zip-part consists of a town-name, followed by a comma, followed by a state code, followed by a ZIP-code followed by an end-of-line." Note that many things (such as the format of a personal-part, apartment specifier, or ZIP-code) are left unspecified. These are presumed to be obvious from context or detailed somewhere nearby. See also parse. 2. Any of a number number of variants and extensions of BNF proper, possibly containing some or all of the regexp wildcards such as * or +. In fact the example above isn't the pure form invented for the Algol-60 report; it uses [], which was introduced a few years later in IBM's PL/I definition but is now universally recognized. 3. In science-fiction fandom, a `Big-Name Fan' (someone famous or notorious). Years ago a fan started handing out black-on-green BNF buttons at SF conventions; this confused the hacker contingent terribly.

boa [IBM] /n./

Any one of the fat cables that lurk under the floor in a dinosaur pen. Possibly so called because they display a ferocious life of their own when you try to lay them straight and flat after they have been coiled for some time. It is rumored within IBM that channel cables for the 370 are limited to 200 feet because beyond that length the boas get dangerous -- and it is worth noting that one of the major cable makers uses the trademark `Anaconda'.

board /n./

1. In-context synonym for bboard; sometimes used even for Usenet newsgroups (but see usage note under bboard, sense 1). 2. An electronic circuit board.

boat anchor /n./

1. Like doorstop but more severe; implies that the offending hardware is irreversibly dead or useless. "That was a working motherboard once. One lightning strike later, instant boat anchor!" 2. A person who just takes up space. 3. Obsolete but still working hardware, especially when used of an old S100-bus hobbyist system; originally a term of annoyance, but became more and more affectionate as the hardware became more and more obsolete.

bodysurf code /n./

A program or segment of code written quickly in the heat of inspiration without the benefit of formal design or deep thought. Like its namesake sport, the result is too often a wipeout that leaves the programmer eating sand.

BOF /B-O-F/ or /bof/ /n./

Abbreviation for the phrase "Birds Of a Feather" (flocking together), an informal discussion group and/or bull session scheduled on a conference program. It is not clear where or when this term originated, but it is now associated with the USENIX conferences for Unix techies and was already established there by 1984. It was used earlier than that at DECUS conferences and is reported to have been common at SHARE meetings as far back as the early 1960s.

BOFH // /n./

Acronym, Bastard Operator From Hell. A system administrator with absolutely no tolerance for lusers. "You say you need more filespace? <massive-global-delete> Seems to me you have plenty left..." Many BOFHs (and others who would be BOFHs if they could get away with it) hang out in the newsgroup alt.sysadmin.recovery, although there has also been created a top-level newsgroup hierarchy (bofh.*) of their own.

Several people have written stories about BOFHs. The set usually considered canonical is by Simon Travaglia and may be found at the Bastard Home Page, http://prime-mover.cc.waikato.ac.nz/Bastard.html.

bogo-sort /boh`goh-sort'/ /n./

(var. `stupid-sort') The archetypical perversely awful algorithm (as opposed to bubble sort, which is merely the generic bad algorithm). Bogo-sort is equivalent to repeatedly throwing a deck of cards in the air, picking them up at random, and then testing whether they are in order. It serves as a sort of canonical example of awfulness. Looking at a program and seeing a dumb algorithm, one might say "Oh, I see, this program uses bogo-sort." Compare bogus, brute force, Lasherism.

bogometer /boh-gom'-*t-er/ /n./

A notional instrument for measuring bogosity. Compare the `wankometer' described in the wank entry; see also bogus.

bogon /boh'gon/ /n./

[by analogy with proton/electron/neutron, but doubtless reinforced after 1980 by the similarity to Douglas Adams's `Vogons'; see the Bibliography in Appendix C and note that Arthur Dent actually mispronounces `Vogons' as `Bogons' at one point] 1. The elementary particle of bogosity (see quantum bogodynamics). For instance, "the Ethernet is emitting bogons again" means that it is broken or acting in an erratic or bogus fashion. 2. A query packet sent from a TCP/IP domain resolver to a root server, having the reply bit set instead of the query bit. 3. Any bogus or incorrectly formed packet sent on a network. 4. By synecdoche, used to refer to any bogus thing, as in "I'd like to go to lunch with you but I've got to go to the weekly staff bogon". 5. A person who is bogus or who says bogus things. This was historically the original usage, but has been overtaken by its derivative senses 1--4. See also bogosity, bogus; compare psyton, fat electrons, magic smoke.

The bogon has become the type case for a whole bestiary of nonce particle names, including the `clutron' or `cluon' (indivisible particle of cluefulness, obviously the antiparticle of the bogon) and the futon (elementary particle of randomness, or sometimes of lameness). These are not so much live usages in themselves as examples of a live meta-usage: that is, it has become a standard joke or linguistic maneuver to "explain" otherwise mysterious circumstances by inventing nonce particle names. And these imply nonce particle theories, with all their dignity or lack thereof (we might note parenthetically that this is a generalization from "(bogus particle) theories" to "bogus (particle theories)"!). Perhaps such particles are the modern-day equivalents of trolls and wood-nymphs as standard starting-points around which to construct explanatory myths. Of course, playing on an existing word (as in the `futon') yields additional flavor. Compare magic smoke.

bogon filter /boh'gon fil'tr/ /n./

Any device, software or hardware, that limits or suppresses the flow and/or emission of bogons. "Engineering hacked a bogon filter between the Cray and the VAXen, and now we're getting fewer dropped packets." See also bogosity, bogus.

bogon flux /boh'gon fluhks/ /n./

A measure of a supposed field of bogosity emitted by a speaker, measured by a bogometer; as a speaker starts to wander into increasing bogosity a listener might say "Warning, warning, bogon flux is rising". See quantum bogodynamics.

bogosity /boh-go's*-tee/ /n./

1. The degree to which something is bogus. At CMU, bogosity is measured with a bogometer; in a seminar, when a speaker says something bogus, a listener might raise his hand and say "My bogometer just triggered". More extremely, "You just pinned my bogometer" means you just said or did something so outrageously bogus that it is off the scale, pinning the bogometer needle at the highest possible reading (one might also say "You just redlined my bogometer"). The agreed-upon unit of bogosity is the microLenat. 2. The potential field generated by a bogon flux; see quantum bogodynamics. See also bogon flux, bogon filter, bogus.

bogotify /boh-go't*-fi:/ /vt./

To make or become bogus. A program that has been changed so many times as to become completely disorganized has become bogotified. If you tighten a nut too hard and strip the threads on the bolt, the bolt has become bogotified and you had better not use it any more. This coinage led to the notional `autobogotiphobia' defined as `the fear of becoming bogotified'; but is not clear that the latter has ever been `live' jargon rather than a self-conscious joke in jargon about jargon. See also bogosity, bogus.

bogue out /bohg owt/ /vi./

To become bogus, suddenly and unexpectedly. "His talk was relatively sane until somebody asked him a trick question; then he bogued out and did nothing but flame afterwards." See also bogosity, bogus.

bogus /adj./

1. Non-functional. "Your patches are bogus." 2. Useless. "OPCON is a bogus program." 3. False. "Your arguments are bogus." 4. Incorrect. "That algorithm is bogus." 5. Unbelievable. "You claim to have solved the halting problem for Turing Machines? That's totally bogus." 6. Silly. "Stop writing those bogus sagas."

Astrology is bogus. So is a bolt that is obviously about to break. So is someone who makes blatantly false claims to have solved a scientific problem. (This word seems to have some, but not all, of the connotations of random -- mostly the negative ones.)

It is claimed that `bogus' was originally used in the hackish sense at Princeton in the late 1960s. It was spread to CMU and Yale by Michael Shamos, a migratory Princeton alumnus. A glossary of bogus words was compiled at Yale when the word was first popularized (see autobogotiphobia under bogotify). The word spread into hackerdom from CMU and MIT. By the early 1980s it was also current in something like the hackish sense in West Coast teen slang, and it had gone mainstream by 1985. A correspondent from Cambridge reports, by contrast, that these uses of `bogus' grate on British nerves; in Britain the word means, rather specifically, `counterfeit', as in "a bogus 10-pound note".

Bohr bug /bohr buhg/ /n./

[from quantum physics] A repeatable bug; one that manifests reliably under a possibly unknown but well-defined set of conditions. Antonym of heisenbug; see also mandelbug, schroedinbug.

boink /boynk/

[Usenet: variously ascribed to the TV series "Cheers" "Moonlighting", and "Soap"] 1. /v./ To have sex with; compare bounce, sense 3. (This is mainstream slang.) In Commonwealth hackish the variant `bonk' is more common. 2. /n./ After the original Peter Korn `Boinkon' Usenet parties, used for almost any net social gathering, e.g., Miniboink, a small boink held by Nancy Gillett in 1988; Minniboink, a Boinkcon in Minnesota in 1989; Humpdayboinks, Wednesday get-togethers held in the San Francisco Bay Area. Compare @-party. 3. Var of `bonk'; see bonk/oif.


1. /v./ General synonym for crash (sense 1) except that it is not used as a noun; esp. used of software or OS failures. "Don't run Empire with less than 32K stack, it'll bomb." 2. /n.,v./ Atari ST and Macintosh equivalents of a Unix `panic' or Amiga guru (sense 2), in which icons of little black-powder bombs or mushroom clouds are displayed, indicating that the system has died. On the Mac, this may be accompanied by a decimal (or occasionally hexadecimal) number indicating what went wrong, similar to the Amiga guru meditation number. MS-DOS machines tend to get locked up in this situation.

bondage-and-discipline language /n./

A language (such as Pascal, Ada, APL, or Prolog) that, though ostensibly general-purpose, is designed so as to enforce an author's theory of `right programming' even though said theory is demonstrably inadequate for systems hacking or even vanilla general-purpose programming. Often abbreviated `B&D'; thus, one may speak of things "having the B&D nature". See Pascal; oppose languages of choice.

bonk/oif /bonk/, /oyf/ /interj./

In the MUD community, it has become traditional to express pique or censure by `bonking' the offending person. Convention holds that one should acknowledge a bonk by saying `oif!' and there is a myth to the effect that failing to do so upsets the cosmic bonk/oif balance, causing much trouble in the universe. Some MUDs have implemented special commands for bonking and oifing. See also talk mode.

book titles

There is a tradition in hackerdom of informally tagging important textbooks and standards documents with the dominant color of their covers or with some other conspicuous feature of the cover. Many of these are described in this lexicon under their own entries. See Aluminum Book, Blue Book, Camel Book, Cinderella Book, Devil Book, Dragon Book, Green Book, Orange Book, Pink-Shirt Book, Purple Book, Red Book, Silver Book, White Book, Wizard Book, Yellow Book, and bible; see also rainbow series. Since about 1983 this tradition has gotten a boost from the popular O'Reilly Associates line of technical books, which usually feature some kind of exotic animal on the cover.

boot /v.,n./

[techspeak; from `by one's bootstraps'] To load and initialize the operating system on a machine. This usage is no longer jargon (having passed into techspeak) but has given rise to some derivatives that are still jargon.

The derivative `reboot' implies that the machine hasn't been down for long, or that the boot is a bounce (sense 4) intended to clear some state of wedgitude. This is sometimes used of human thought processes, as in the following exchange: "You've lost me." "OK, reboot. Here's the theory...."

This term is also found in the variants `cold boot' (from power-off condition) and `warm boot' (with the CPU and all devices already powered up, as after a hardware reset or software crash).

Another variant: `soft boot', reinitialization of only part of a system, under control of other software still running: "If you're running the mess-dos emulator, control-alt-insert will cause a soft-boot of the emulator, while leaving the rest of the system running."

Opposed to this there is `hard boot', which connotes hostility towards or frustration with the machine being booted: "I'll have to hard-boot this losing Sun." "I recommend booting it hard." One often hard-boots by performing a power cycle.

Historical note: this term derives from `bootstrap loader', a short program that was read in from cards or paper tape, or toggled in from the front panel switches. This program was always very short (great efforts were expended on making it short in order to minimize the labor and chance of error involved in toggling it in), but was just smart enough to read in a slightly more complex program (usually from a card or paper tape reader), to which it handed control; this program in turn was smart enough to read the application or operating system from a magnetic tape drive or disk drive. Thus, in successive steps, the computer `pulled itself up by its bootstraps' to a useful operating state. Nowadays the bootstrap is usually found in ROM or EPROM, and reads the first stage in from a fixed location on the disk, called the `boot block'. When this program gains control, it is powerful enough to load the actual OS and hand control over to it.

bottom feeder /n./

Syn. for slopsucker, derived from the fishermen's and naturalists' term for finny creatures who subsist on the primordial ooze.

bottom-up implementation /n./

Hackish opposite of the techspeak term `top-down design'. It is now received wisdom in most programming cultures that it is best to design from higher levels of abstraction down to lower, specifying sequences of action in increasing detail until you get to actual code. Hackers often find (especially in exploratory designs that cannot be closely specified in advance) that it works best to build things in the opposite order, by writing and testing a clean set of primitive operations and then knitting them together.

bounce /v./

1. [perhaps by analogy to a bouncing check] An electronic mail message that is undeliverable and returns an error notification to the sender is said to `bounce'. See also bounce message. 2. [Stanford] To play volleyball. The now-demolished D. C. Power Lab building used by the Stanford AI Lab in the 1970s had a volleyball court on the front lawn. From 5 P.M. to 7 P.M. was the scheduled maintenance time for the computer, so every afternoon at 5 would come over the intercom the cry: "Now hear this: bounce, bounce!", followed by Brian McCune loudly bouncing a volleyball on the floor outside the offices of known volleyballers. 3. To engage in sexual intercourse; prob. from the expression `bouncing the mattress', but influenced by Roo's psychosexually loaded "Try bouncing me, Tigger!" from the "Winnie-the-Pooh" books. Compare boink. 4. To casually reboot a system in order to clear up a transient problem. Reported primarily among VMS users. 5. [VM/CMS programmers] Automatic warm-start of a machine after an error. "I logged on this morning and found it had bounced 7 times during the night" 6. [IBM] To power cycle a peripheral in order to reset it.

bounce message /n./

[Unix] Notification message returned to sender by a site unable to relay email to the intended Internet address recipient or the next link in a bang path (see bounce, sense 1). Reasons might include a nonexistent or misspelled username or a down relay site. Bounce messages can themselves fail, with occasionally ugly results; see sorcerer's apprentice mode and software laser. The terms `bounce mail' and `barfmail' are also common.

boustrophedon /n./

[from a Greek word for turning like an ox while plowing] An ancient method of writing using alternate left-to-right and right-to-left lines. This term is actually philologists' techspeak and typesetters' jargon. Erudite hackers use it for an optimization performed by some computer typesetting software and moving-head printers. The adverbial form `boustrophedonically' is also found (hackers purely love constructions like this).

box /n./

1. A computer; esp. in the construction `foo box' where foo is some functional qualifier, like `graphics', or the name of an OS (thus, `Unix box', `MS-DOS box', etc.) "We preprocess the data on Unix boxes before handing it up to the mainframe." 2. [IBM] Without qualification but within an SNA-using site, this refers specifically to an IBM front-end processor or FEP /F-E-P/. An FEP is a small computer necessary to enable an IBM mainframe to communicate beyond the limits of the dinosaur pen. Typically used in expressions like the cry that goes up when an SNA network goes down: "Looks like the box has fallen over." (See fall over.) See also IBM, fear and loathing, fepped out, Blue Glue.

boxed comments /n./

Comments (explanatory notes attached to program instructions) that occupy several lines by themselves; so called because in assembler and C code they are often surrounded by a box in a style something like this:

 * This is a boxed comment in C style

Common variants of this style omit the asterisks in column 2 or add a matching row of asterisks closing the right side of the box. The sparest variant omits all but the comment delimiters themselves; the `box' is implied. Oppose winged comments.

boxen /bok'sn/ /pl.n./

[by analogy with VAXen] Fanciful plural of box often encountered in the phrase `Unix boxen', used to describe commodity Unix hardware. The connotation is that any two Unix boxen are interchangeable.

boxology /bok-sol'*-jee/ /n./

Syn. ASCII art. This term implies a more restricted domain, that of box-and-arrow drawings. "His report has a lot of boxology in it." Compare macrology.

bozotic /boh-zoh'tik/ or /boh-zo'tik/ /adj./

[from the name of a TV clown even more losing than Ronald McDonald] Resembling or having the quality of a bozo; that is, clownish, ludicrously wrong, unintentionally humorous. Compare wonky, demented. Note that the noun `bozo' occurs in slang, but the mainstream adjectival form would be `bozo-like' or (in New England) `bozoish'.

BQS /B-Q-S/ /adj./

Syn. Berkeley Quality Software.

brain dump /n./

The act of telling someone everything one knows about a particular topic or project. Typically used when someone is going to let a new party maintain a piece of code. Conceptually analogous to an operating system core dump in that it saves a lot of useful state before an exit. "You'll have to give me a brain dump on FOOBAR before you start your new job at HackerCorp." See core dump (sense 4). At Sun, this is also known as `TOI' (transfer of information).

brain fart /n./

The actual result of a braino, as opposed to the mental glitch that is the braino itself. E.g., typing dir on a Unix box after a session with DOS.

brain-damaged /adj./

1. [generalization of `Honeywell Brain Damage' (HBD), a theoretical disease invented to explain certain utter cretinisms in Honeywell Multics] /adj./ Obviously wrong; cretinous; demented. There is an implication that the person responsible must have suffered brain damage, because he should have known better. Calling something brain-damaged is really bad; it also implies it is unusable, and that its failure to work is due to poor design rather than some accident. "Only six monocase characters per file name? Now that's brain-damaged!" 2. [esp. in the Mac world] May refer to free demonstration software that has been deliberately crippled in some way so as not to compete with the commercial product it is intended to sell. Syn. crippleware.

brain-dead /adj./

Brain-damaged in the extreme. It tends to imply terminal design failure rather than malfunction or simple stupidity. "This comm program doesn't know how to send a break -- how brain-dead!"

braino /bray'no/ /n./

Syn. for thinko. See also brain fart.

branch to Fishkill /n./

[IBM: from the location of one of the corporation's facilities] Any unexpected jump in a program that produces catastrophic or just plain weird results. See jump off into never-never land, hyperspace.

bread crumbs /n./

Debugging statements inserted into a program that emit output or log indicators of the program's state to a file so you can see where it dies or pin down the cause of surprising behavior. The term is probably a reference to the Hansel and Gretel story from the Brothers Grimm; in several variants, a character leaves a trail of bread crumbs so as not to get lost in the woods.


1. /vt./ To cause to be broken (in any sense). "Your latest patch to the editor broke the paragraph commands." 2. /v./ (of a program) To stop temporarily, so that it may debugged. The place where it stops is a `breakpoint'. 3. [techspeak] /vi./ To send an RS-232 break (two character widths of line high) over a serial comm line. 4. [Unix] /vi./ To strike whatever key currently causes the tty driver to send SIGINT to the current process. Normally, break (sense 3), delete or control-C does this. 5. `break break' may be said to interrupt a conversation (this is an example of verb doubling). This usage comes from radio communications, which in turn probably came from landline telegraph/teleprinter usage, as badly abused in the Citizen's Band craze a few years ago.

break-even point /n./

In the process of implementing a new computer language, the point at which the language is sufficiently effective that one can implement the language in itself. That is, for a new language called, hypothetically, FOOGOL, one has reached break-even when one can write a demonstration compiler for FOOGOL in FOOGOL, discard the original implementation language, and thereafter use working versions of FOOGOL to develop newer ones. This is an important milestone; see MFTL.

Since this entry was first written, several correspondents have reported that there actually was a compiler for a tiny Algol-like language called Foogol floating around on various VAXen in the early and mid-1980s. A FOOGOL implementation is available at the Retrocomputing Museum http://www.ccil.org/retro.

breath-of-life packet /n./

[XEROX PARC] An Ethernet packet that contains bootstrap (see boot) code, periodically sent out from a working computer to infuse the `breath of life' into any computer on the network that has happened to crash. Machines depending on such packets have sufficient hardware or firmware code to wait for (or request) such a packet during the reboot process. See also dickless workstation.

The notional `kiss-of-death packet', with a function complementary to that of a breath-of-life packet, is recommended for dealing with hosts that consume too many network resources. Though `kiss-of-death packet' is usually used in jest, there is at least one documented instance of an Internet subnet with limited address-table slots in a gateway machine in which such packets were routinely used to compete for slots, rather like Christmas shoppers competing for scarce parking spaces.

breedle /n./

See feep.

bring X to its knees /v./

To present a machine, operating system, piece of software, or algorithm with a load so extreme or pathological that it grinds to a halt. "To bring a MicroVAX to its knees, try twenty users running vi -- or four running EMACS." Compare hog.

brittle /adj./

Said of software that is functional but easily broken by changes in operating environment or configuration, or by any minor tweak to the software itself. Also, any system that responds inappropriately and disastrously to abnormal but expected external stimuli; e.g., a file system that is usually totally scrambled by a power failure is said to be brittle. This term is often used to describe the results of a research effort that were never intended to be robust, but it can be applied to commercially developed software, which displays the quality far more often than it ought to. Oppose robust.

broadcast storm /n./

An incorrect packet broadcast on a network that causes most hosts to respond all at once, typically with wrong answers that start the process over again. See network meltdown; compare mail storm.

brochureware /n./

Planned but non-existent product like vaporware, but with the added implication that marketing is actively selling and promoting it (they've printed brochures). Brochureware is often deployed as a strategic weapon; the idea is to con customers into not committing to an existing product of the competition's. It is a safe bet that when a brochureware product finally becomes real, it will be more expensive than and inferior to the alternatives that had been available for years.

broken /adj./

1. Not working properly (of programs). 2. Behaving strangely; especially (when used of people) exhibiting extreme depression.

broken arrow /n./

[IBM] The error code displayed on line 25 of a 3270 terminal (or a PC emulating a 3270) for various kinds of protocol violations and "unexpected" error conditions (including connection to a down computer). On a PC, simulated with `->/_', with the two center characters overstruck.

Note: to appreciate this term fully, it helps to know that `broken arrow' is also military jargon for an accident involving nuclear weapons....

BrokenWindows /n./

Abusive hackerism for the crufty and elephantine X environment on Sun machines; properly called `OpenWindows'.

broket /broh'k*t/ or /broh'ket`/ /n./

[by analogy with `bracket': a `broken bracket'] Either of the characters `<' and `>', when used as paired enclosing delimiters. This word originated as a contraction of the phrase `broken bracket', that is, a bracket that is bent in the middle. (At MIT, and apparently in the Real World as well, these are usually called angle brackets.)

Brooks's Law /prov./

"Adding manpower to a late software project makes it later" -- a result of the fact that the expected advantage from splitting work among @Math{N} programmers is @Math{O(N)} (that is, proportional to @Math{N}), but the complexity and communications cost associated with coordinating and then merging their work is @Math{O(N^2)} (that is, proportional to the square of @Math{N}). The quote is from Fred Brooks, a manager of IBM's OS/360 project and author of "The Mythical Man-Month" (Addison-Wesley, 1975, ISBN 0-201-00650-2), an excellent early book on software engineering. The myth in question has been most tersely expressed as "Programmer time is fungible" and Brooks established conclusively that it is not. Hackers have never forgotten his advice; too often, management still does. See also creationism, second-system effect, optimism.

browser /n./

A program specifically designed to help users view and navigate hypertext, on-line documentation, or a database. While this general sense has been present in jargon for a long time, the proliferation of browsers for the World Wide Web after 1992 has made it much more popular and provided a central or default meaning of the word previously lacking in hacker usage. Nowadays, if someone mentions using a `browser' without qualification, one may assume it is a Web browser.

BRS /B-R-S/ /n./

Syn. Big Red Switch. This abbreviation is fairly common on-line.

brute force /adj./

Describes a primitive programming style, one in which the programmer relies on the computer's processing power instead of using his or her own intelligence to simplify the problem, often ignoring problems of scale and applying naive methods suited to small problems directly to large ones. The term can also be used in reference to programming style: brute-force programs are written in a heavyhanded, tedious way, full of repetition and devoid of any elegance or useful abstraction (see also brute force and ignorance).

The canonical example of a brute-force algorithm is associated with the `traveling salesman problem' (TSP), a classical NP-hard problem: Suppose a person is in, say, Boston, and wishes to drive to @Math{N} other cities. In what order should the cities be visited in order to minimize the distance travelled? The brute-force method is to simply generate all possible routes and compare the distances; while guaranteed to work and simple to implement, this algorithm is clearly very stupid in that it considers even obviously absurd routes (like going from Boston to Houston via San Francisco and New York, in that order). For very small @Math{N} it works well, but it rapidly becomes absurdly inefficient when @Math{N} increases (for @Math{N = 15}, there are already 1,307,674,368,000 possible routes to consider, and for @Math{N = 1000} -- well, see bignum). Sometimes, unfortunately, there is no better general solution than brute force. See also NP-.

A more simple-minded example of brute-force programming is finding the smallest number in a large list by first using an existing program to sort the list in ascending order, and then picking the first number off the front.

Whether brute-force programming should actually be considered stupid or not depends on the context; if the problem is not terribly big, the extra CPU time spent on a brute-force solution may cost less than the programmer time it would take to develop a more `intelligent' algorithm. Additionally, a more intelligent algorithm may imply more long-term complexity cost and bug-chasing than are justified by the speed improvement.

Ken Thompson, co-inventor of Unix, is reported to have uttered the epigram "When in doubt, use brute force". He probably intended this as a ha ha only serious, but the original Unix kernel's preference for simple, robust, and portable algorithms over brittle `smart' ones does seem to have been a significant factor in the success of that OS. Like so many other tradeoffs in software design, the choice between brute force and complex, finely-tuned cleverness is often a difficult one that requires both engineering savvy and delicate esthetic judgment.

brute force and ignorance /n./

A popular design technique at many software houses -- brute force coding unrelieved by any knowledge of how problems have been previously solved in elegant ways. Dogmatic adherence to design methodologies tends to encourage this sort of thing. Characteristic of early larval stage programming; unfortunately, many never outgrow it. Often abbreviated BFI: "Gak, they used a bubble sort! That's strictly from BFI." Compare bogosity.

BSD /B-S-D/ /n./

[abbreviation for `Berkeley Software Distribution'] a family of Unix versions for the DEC VAX and PDP-11 developed by Bill Joy and others at Berzerkeley starting around 1980, incorporating paged virtual memory, TCP/IP networking enhancements, and many other features. The BSD versions (4.1, 4.2, and 4.3) and the commercial versions derived from them (SunOS, ULTRIX, and Mt. Xinu) held the technical lead in the Unix world until AT&T's successful standardization efforts after about 1986, and are still widely popular. Note that BSD versions going back to 2.9 are often referred to by their version numbers, without the BSD prefix. See 4.2, Unix, USG Unix.

BUAF // /n./

[abbreviation, from alt.fan.warlord] Big Ugly ASCII Font -- a special form of ASCII art. Various programs exist for rendering text strings into block, bloob, and pseudo-script fonts in cells between four and six character cells on a side; this is smaller than the letters generated by older banner (sense 2) programs. These are sometimes used to render one's name in a sig block, and are critically referred to as `BUAF's. See warlording.

BUAG // /n./

[abbreviation, from alt.fan.warlord] Big Ugly ASCII Graphic. Pejorative term for ugly ASCII art, especially as found in sig blocks. For some reason, mutations of the head of Bart Simpson are particularly common in the least imaginative sig blocks. See warlording.

bubble sort /n./

Techspeak for a particular sorting technique in which pairs of adjacent values in the list to be sorted are compared and interchanged if they are out of order; thus, list entries `bubble upward' in the list until they bump into one with a lower sort value. Because it is not very good relative to other methods and is the one typically stumbled on by naive and untutored programmers, hackers consider it the canonical example of a naive algorithm. The canonical example of a really bad algorithm is bogo-sort. A bubble sort might be used out of ignorance, but any use of bogo-sort could issue only from brain damage or willful perversity.

bucky bits /buh'kee bits/ /n./

1. obs. The bits produced by the CONTROL and META shift keys on a SAIL keyboard (octal 200 and 400 respectively), resulting in a 9-bit keyboard character set. The MIT AI TV (Knight) keyboards extended this with TOP and separate left and right CONTROL and META keys, resulting in a 12-bit character set; later, LISP Machines added such keys as SUPER, HYPER, and GREEK (see space-cadet keyboard). 2. By extension, bits associated with `extra' shift keys on any keyboard, e.g., the ALT on an IBM PC or command and option keys on a Macintosh.

It has long been rumored that `bucky bits' were named for Buckminster Fuller during a period when he was consulting at Stanford. Actually, bucky bits were invented by Niklaus Wirth when he was at Stanford in 1964--65; he first suggested the idea of an EDIT key to set the 8th bit of an otherwise 7-bit ASCII character). It seems that, unknown to Wirth, certain Stanford hackers had privately nicknamed him `Bucky' after a prominent portion of his dental anatomy, and this nickname transferred to the bit. Bucky-bit commands were used in a number of editors written at Stanford, including most notably TV-EDIT and NLS.

The term spread to MIT and CMU early and is now in general use. Ironically, Wirth himself remained unaware of its derivation for nearly 30 years, until GLS dug up this history in early 1993! See double bucky, quadruple bucky.

buffer chuck /n./

Shorter and ruder syn. for buffer overflow.

buffer overflow /n./

What happens when you try to stuff more data into a buffer (holding area) than it can handle. This may be due to a mismatch in the processing rates of the producing and consuming processes (see overrun and firehose syndrome), or because the buffer is simply too small to hold all the data that must accumulate before a piece of it can be processed. For example, in a text-processing tool that crunches a line at a time, a short line buffer can result in lossage as input from a long line overflows the buffer and trashes data beyond it. Good defensive programming would check for overflow on each character and stop accepting data when the buffer is full up. The term is used of and by humans in a metaphorical sense. "What time did I agree to meet you? My buffer must have overflowed." Or "If I answer that phone my buffer is going to overflow." See also spam, overrun screw.

bug /n./

An unwanted and unintended property of a program or piece of hardware, esp. one that causes it to malfunction. Antonym of feature. Examples: "There's a bug in the editor: it writes things out backwards." "The system crashed because of a hardware bug." "Fred is a winner, but he has a few bugs" (i.e., Fred is a good guy, but he has a few personality problems).

Historical note: Admiral Grace Hopper (an early computing pioneer better known for inventing COBOL) liked to tell a story in which a technician solved a glitch in the Harvard Mark II machine by pulling an actual insect out from between the contacts of one of its relays, and she subsequently promulgated bug in its hackish sense as a joke about the incident (though, as she was careful to admit, she was not there when it happened). For many years the logbook associated with the incident and the actual bug in question (a moth) sat in a display case at the Naval Surface Warfare Center (NSWC). The entire story, with a picture of the logbook and the moth taped into it, is recorded in the "Annals of the History of Computing", Vol. 3, No. 3 (July 1981), pp. 285--286.

The text of the log entry (from September 9, 1947), reads "1545 Relay #70 Panel F (moth) in relay. First actual case of bug being found". This wording establishes that the term was already in use at the time in its current specific sense -- and Hopper herself reports that the term `bug' was regularly applied to problems in radar electronics during WWII.

Indeed, the use of `bug' to mean an industrial defect was already established in Thomas Edison's time, and a more specific and rather modern use can be found in an electrical handbook from 1896 ("Hawkin's New Catechism of Electricity", Theo. Audel & Co.) which says: "The term `bug' is used to a limited extent to designate any fault or trouble in the connections or working of electric apparatus." It further notes that the term is "said to have originated in quadruplex telegraphy and have been transferred to all electric apparatus."

The latter observation may explain a common folk etymology of the term; that it came from telephone company usage, in which "bugs in a telephone cable" were blamed for noisy lines. Though this derivation seems to be mistaken, it may well be a distorted memory of a joke first current among telegraph operators more than a century ago!

Or perhaps not a joke. Historians of the field inform us that the term "bug" was regularly used in the early days of telegraphy to refer to a variety of semi-automatic telegraphy keyers that would send a string of dots if you held them down. In fact, the Vibroplex keyers (which were among the most common of this type) even had a graphic of a beetle on them! While the ability to send repeated dots automatically was very useful for professional morse code operators, these were also significantly trickier to use than the older manual keyers, and it could take some practice to ensure one didn't introduce extraneous dots into the code by holding the key down a fraction too long. In the hands of an inexperienced operator, a Vibroplex "bug" on the line could mean that a lot of garbled Morse would soon be coming your way.

Actually, use of `bug' in the general sense of a disruptive event goes back to Shakespeare! In the first edition of Samuel Johnson's dictionary one meaning of `bug' is "A frightful object; a walking spectre"; this is traced to `bugbear', a Welsh term for a variety of mythological monster which (to complete the circle) has recently been reintroduced into the popular lexicon through fantasy role-playing games.

In any case, in jargon the word almost never refers to insects. Here is a plausible conversation that never actually happened:

"There is a bug in this ant farm!"

"What do you mean? I don't see any ants in it."

"That's the bug."

A careful discussion of the etymological issues can be found in a paper by Fred R. Shapiro, 1987, "Entomology of the Computer Bug: History and Folklore", American Speech 62(4):376-378.

[There has been a widespread myth that the original bug was moved to the Smithsonian, and an earlier version of this entry so asserted. A correspondent who thought to check discovered that the bug was not there. While investigating this in late 1990, your editor discovered that the NSWC still had the bug, but had unsuccessfully tried to get the Smithsonian to accept it -- and that the present curator of their History of American Technology Museum didn't know this and agreed that it would make a worthwhile exhibit. It was moved to the Smithsonian in mid-1991, but due to space and money constraints has not yet been exhibited. Thus, the process of investigating the original-computer-bug bug fixed it in an entirely unexpected way, by making the myth true! --ESR]

bug-compatible /adj./

Said of a design or revision that has been badly compromised by a requirement to be compatible with fossils or misfeatures in other programs or (esp.) previous releases of itself. "MS-DOS 2.0 used \ as a path separator to be bug-compatible with some cretin's choice of / as an option character in 1.0."

bug-for-bug compatible /n./

Same as bug-compatible, with the additional implication that much tedious effort went into ensuring that each (known) bug was replicated.

bug-of-the-month club /n./

[from "book-of-the-month club", a time-honored mail-order-marketing technique in the U.S.] A mythical club which users of `sendmail(1)' (the UNIX mail daemon) belong to; this was coined on the Usenet newsgroup comp.security.unix at a time when sendmail security holes, which allowed outside crackers access to the system, were being uncovered at an alarming rate, forcing sysadmins to update very often. Also, more completely, `fatal security bug-of-the-month club'.

buglix /buhg'liks/ /n./

Pejorative term referring to DEC's ULTRIX operating system in its earlier severely buggy versions. Still used to describe ULTRIX, but without nearly so much venom. Compare AIDX, HP-SUX, Nominal Semidestructor, Telerat, sun-stools.

bulletproof /adj./

Used of an algorithm or implementation considered extremely robust; lossage-resistant; capable of correctly recovering from any imaginable exception condition -- a rare and valued quality. Syn. armor-plated.


1. /vt./ To make highly efficient, either in time or space, often at the expense of clarity. "I managed to bum three more instructions out of that code." "I spent half the night bumming the interrupt code." In 1996, this term and the practice it describes are semi-obsolete. In elder days, John McCarthy (inventor of LISP) used to compare some efficiency-obsessed hackers among his students to "ski bums"; thus, optimization became "program bumming", and eventually just "bumming". 2. To squeeze out excess; to remove something in order to improve whatever it was removed from (without changing function; this distinguishes the process from a featurectomy). 3. /n./ A small change to an algorithm, program, or hardware device to make it more efficient. "This hardware bum makes the jump instruction faster." Usage: now uncommon, largely superseded by /v./ tune (and /n./ tweak, hack), though none of these exactly capture sense 2. All these uses are rare in Commonwealth hackish, because in the parent dialects of English `bum' is a rude synonym for `buttocks'.

bump /vt./

Synonym for increment. Has the same meaning as C's ++ operator. Used esp. of counter variables, pointers, and index dummies in for, while, and do-while loops.

burble /v./

[from Lewis Carroll's "Jabberwocky"] Like flame, but connotes that the source is truly clueless and ineffectual (mere flamers can be competent). A term of deep contempt. "There's some guy on the phone burbling about how he got a DISK FULL error and it's all our comm software's fault." This is mainstream slang in some parts of England.

buried treasure /n./

A surprising piece of code found in some program. While usually not wrong, it tends to vary from crufty to bletcherous, and has lain undiscovered only because it was functionally correct, however horrible it is. Used sarcastically, because what is found is anything but treasure. Buried treasure almost always needs to be dug up and removed. "I just found that the scheduler sorts its queue using bubble sort! Buried treasure!"

burn-in period /n./

1. A factory test designed to catch systems with marginal components before they get out the door; the theory is that burn-in will protect customers by outwaiting the steepest part of the bathtub curve (see infant mortality). 2. A period of indeterminate length in which a person using a computer is so intensely involved in his project that he forgets basic needs such as food, drink, sleep, etc. Warning: Excessive burn-in can lead to burn-out. See hack mode, larval stage.

Historical note: the origin of "burn-in" (sense 1) is apparently the practice of setting a new-model airplane's brakes on fire, then extinguishing the fire, in order to make them hold better. This was done on the first version of the U.S. spy-plane, the U-2.

burst page /n./

Syn. banner, sense 1.

busy-wait /vi./

Used of human behavior, conveys that the subject is busy waiting for someone or something, intends to move instantly as soon as it shows up, and thus cannot do anything else at the moment. "Can't talk now, I'm busy-waiting till Bill gets off the phone."

Technically, `busy-wait' means to wait on an event by spinning through a tight or timed-delay loop that polls for the event on each pass, as opposed to setting up an interrupt handler and continuing execution on another part of the task. This is a wasteful technique, best avoided on time-sharing systems where a busy-waiting program may hog the processor.

buzz /vi./

1. Of a program, to run with no indication of progress and perhaps without guarantee of ever finishing; esp. said of programs thought to be executing tight loops of code. A program that is buzzing appears to be catatonic, but never gets out of catatonia, while a buzzing loop may eventually end of its own accord. "The program buzzes for about 10 seconds trying to sort all the names into order." See spin; see also grovel. 2. [ETA Systems] To test a wire or printed circuit trace for continuity by applying an AC rather than DC signal. Some wire faults will pass DC tests but fail a buzz test. 3. To process an array or list in sequence, doing the same thing to each element. "This loop buzzes through the tz array looking for a terminator type."

BWQ /B-W-Q/ /n./

[IBM: abbreviation, `Buzz Word Quotient'] The percentage of buzzwords in a speech or documents. Usually roughly proportional to bogosity. See TLA.

by hand /adv./

1. Said of an operation (especially a repetitive, trivial, and/or tedious one) that ought to be performed automatically by the computer, but which a hacker instead has to step tediously through. "My mailer doesn't have a command to include the text of the message I'm replying to, so I have to do it by hand." This does not necessarily mean the speaker has to retype a copy of the message; it might refer to, say, dropping into a subshell from the mailer, making a copy of one's mailbox file, reading that into an editor, locating the top and bottom of the message in question, deleting the rest of the file, inserting `>' characters on each line, writing the file, leaving the editor, returning to the mailer, reading the file in, and later remembering to delete the file. Compare eyeball search. 2. By extension, writing code which does something in an explicit or low-level way for which a presupplied library routine ought to have been available. "This cretinous B-tree library doesn't supply a decent iterator, so I'm having to walk the trees by hand."

byte /bi:t/ /n./

[techspeak] A unit of memory or data equal to the amount used to represent one character; on modern architectures this is usually 8 bits, but may be 9 on 36-bit machines. Some older architectures used `byte' for quantities of 6 or 7 bits, and the PDP-10 supported `bytes' that were actually bitfields of 1 to 36 bits! These usages are now obsolete, and even 9-bit bytes have become rare in the general trend toward power-of-2 word sizes.

Historical note: The term was coined by Werner Buchholz in 1956 during the early design phase for the IBM Stretch computer; originally it was described as 1 to 6 bits (typical I/O equipment of the period used 6-bit chunks of information). The move to an 8-bit byte happened in late 1956, and this size was later adopted and promulgated as a standard by the System/360. The word was coined by mutating the word `bite' so it would not be accidentally misspelled as bit. See also nybble.

bytesexual /bi:t`sek'shu-*l/ /adj./

Said of hardware, denotes willingness to compute or pass data in either big-endian or little-endian format (depending, presumably, on a mode bit somewhere). See also NUXI problem.

bzzzt, wrong /bzt rong/ /excl./

[Usenet/Internet] From a Robin Williams routine in the movie "Dead Poets Society" spoofing radio or TV quiz programs, such as Truth or Consequences, where an incorrect answer earns one a blast from the buzzer and condolences from the interlocutor. A way of expressing mock-rude disagreement, usually immediately following an included quote from another poster. The less abbreviated "*Bzzzzt*, wrong, but thank you for playing" is also common; capitalization and emphasis of the buzzer sound varies.

Go to the previous, next section.