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big-endian
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bignum
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big win
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= B =
big-endianadj.
[common; 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, thePDP-10, the Motorola microprocessor families, and most of the various RISC designs are big-endian. Big-endian byte order is also sometimes called `network order'. Seelittle-endian,middle-endian,NUXI problem,swab. 2. AnInternet addressthe 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 havead-hockeryin their mailers to handle this, but can still be confused. In particular, the addressme@uk.ac.bris.pys.ascould be interpreted in JANET's big-endian way as one in the U.K. (domainuk) or in the standard little-endian way as one in the domainas(American Samoa) on the opposite side of the world.
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bignum
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bigot
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big-endian
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bignum/big'nuhm/ n.
[common; 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 (comparemoby, sense 4). See alsoEl 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 2^(31) (2,147,483,648) or (on abitty box) 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:
402387260077093773543702433923003985719374864210714632543799910429938512398629020592044208486969404800479988610197196058631666872994808558901323829669944590997424504087073759918823627727188732519779505950995276120874975462497043601418278094646496291056393887437886487337119181045825783647849977012476632889835955735432513185323958463075557409114262417474349347553428646576611667797396668820291207379143853719588249808126867838374559731746136085379534524221586593201928090878297308431392844403281231558611036976801357304216168747609675871348312025478589320767169132448426236131412508780208000261683151027341827977704784635868170164365024153691398281264810213092761244896359928705114964975419909342221566832572080821333186116811553615836546984046708975602900950537616475847728421889679646244945160765353408198901385442487984959953319101723355556602139450399736280750137837615307127761926849034352625200015888535147331611702103968175921510907788019393178114194545257223865541461062892187960223838971476088506276862967146674697562911234082439208160153780889893964518263243671616762179168909779911903754031274622289988005195444414282012187361745992642956581746628302955570299024324153181617210465832036786906117260158783520751516284225540265170483304226143974286933061690897968482590125458327168226458066526769958652682272807075781391858178889652208164348344825993266043367660176999612831860788386150279465955131156552036093988180612138558600301435694527224206344631797460594682573103790084024432438465657245014402821885252470935190620929023136493273497565513958720559654228749774011413346962715422845862377387538230483865688976461927383814900140767310446640259899490222221765904339901886018566526485061799702356193897017860040811889729918311021171229845901641921068884387121855646124960798722908519296819372388642614839657382291123125024186649353143970137428531926649875337218940694281434118520158014123344828015051399694290153483077644569099073152433278288269864602789864321139083506217095002597389863554277196742822248757586765752344220207573630569498825087968928162753848863396909959826280956121450994871701244516461260379029309120889086942028510640182154399457156805941872748998094254742173582401063677404595741785160829230135358081840096996372524230560855903700624271243416909004153690105933983835777939410970027753472000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.
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bigot
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bit
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bignum
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bigotn.
[common] A person who is religiously attached to a particular computer, language, operating system, editor, or other tool (seereligious 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." Compareweenie,Amiga Persecution Complex.
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bit
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bit bang
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bigot
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bitn.
[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. Totoggleor `invert' a bit is to change it, either from 0 to 1 or from 1 to 0. See alsoflag,trit,mode bit.
The term `bit' first appeared in print in the computer-science sense in a 1948 paper by information theorist Claude Shannon, and was there credited to the early computer scientist John Tukey (who also seems to have coined the term `software'). Tukey records that `bit' evolved over a lunch table as a handier alternative to `bigit' or `binit', at a conference in the winter of 1943-44.
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bit bang
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bit bangn.
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 thewannabees.
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 thecycle 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. Comparecycle of reincarnation.
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bit bashing
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bit bucket
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bit bashingn.
(alt. `bit diddling' orbit twiddling) Term used to describe any of several kinds of low-level programming characterized by manipulation ofbit,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 (seebitblt), 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 alsobit bang,mode bit.
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bit bucket
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bit bucketn.
[very common] 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'. OnUnix, 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 toFinagle'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." Compareblack 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 alsochad 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.
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bit decay
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bit decayn.
Seebit rot. People with a physics background tend to prefer this variant for the analogy with particle decay. See alsocomputron,quantum bogodynamics.
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bit rot
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bit rotn.
[common] Alsobit 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 thecosmic raysentry for details.
The termsoftware rotis almost synonymous. Software rot is the effect, bit rot the notional cause.
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bit twiddling
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bit twiddlingn.
[very common] 1. (pejorative) An exercise in tuning (seetune) 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. forbit 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.
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bit-paired keyboard
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bit-paired keyboardn.,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 (seeEOU), 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 even more of a 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 bitsbits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001010 ! " # $ % & ' ( )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). The Teletype Model 33 was actually designed before ASCII existed, and was originally intended to use a code that contained these two rows:
low bitshigh 0000 0010 0100 0110 1000 1010 1100 1110bits 0001 0011 0101 0111 1001 1011 1101 111110 ) ! bel # $ % wru & * ( " : ? _ , .11 0 1 2 3 4 5 6 7 8 9 ' ; / - esc del
The result would have been something closer to a normal keyboard. But as it happened, Teletype had to use a lot of persuasion just to keep ASCII, and the Model 33 keyboard, from looking like this instead:
! " ? $ ' & - ( ) ; : * / , .0 1 2 3 4 5 6 7 8 9 + ~ < > × |
Teletype's wasnotthe weirdest variant of theQWERTYlayout 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. Either choice was supported by the ANSI computer keyboard standard, X4.14-1971, which referred to the alternatives as `logical bit pairing' and `typewriter pairing'. 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, X4.14 was superseded by X4.23-1982, `bit-paired' hardware was quickly junked or relegated to dusty corners, and both terms passed into disuse.
However, in countries without a long history of touch typing, the argument against the bit-paired keyboard layout was weak or nonexistent. As a result, the standard Japanese keyboard, used on PCs, Unix boxen etc. still has all of the !"#$%&'() characters above the numbers in the ASR-33 layout.
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bitblt
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BITNET
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bitblt/bit'blit/ n.
[fromBLT, q.v.] 1. [common] 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 theRight Thingin the case of overlapping source and destination rectangles is what makes BitBlt tricky). 2. Synonym forblitorBLT. Both uses are borderline techspeak.
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BITNET
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BITNET/bit'net/ n., obs.
[acronym: Because It's Time NETwork] Everybody's least favorite piece of the network (seethe network) - until AOL happened. The BITNET hosts were a collection of IBM dinosaurs and VAXen (the latter with lobotomized comm hardware) that communicate using 80-characterEBCDICcard images (seeeighty-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 ofB1FF. By 1995 it had, much to everyone's relief, been obsolesced and absorbed into the Internet. Unfortunately, around this time we also got AOL.
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bits
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bitspl.n.
1. Information. Examples: "I need some bits about file formats." ("I need to know about file formats.") Comparecore 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?". Seesoftcopy,source of all good bitsSee alsobit.
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bitty box
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bixen
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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' (seeGet a real computer!). See alsomess-dos,toaster, andtoy.
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bixen
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bixie
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bixenpl.n.
Users of BIX (the BIX Information eXchange, formerly the Byte Information eXchange). Parallels other plurals like boxen,VAXen, oxen.
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bixie
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bixie/bik'see/ n.
Variantemoticons used on BIX (the BIX Information eXchange). The most common (smiley) bixie is <@_@>, representing two cartoon eyes and a mouth. These were originally invented in an SF fanzine called APA-L and imported to BIX by one of the earliest users.
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black art
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black hole
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bixie
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black artn.
[common] A collection of arcane, unpublished, and (by implication) mostly ad-hoc techniques developed for a particular application or systems area (compareblack magic). VLSI design and compiler code optimization were (in their beginnings) considered classic examples of black art; as theory developed they becamedeep magic, and once standard textbooks had been written, became merelyheavy 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 alsovoodoo programming.
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black hole
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black magic
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black art
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black holen.,vt.
[common] What data (a piece of email or netnews, or a stream of TCP/IP packets) has fallen into if it disappears mysteriously between its origin and destination sites (that is, without returning abounce message). "I think there's a black hole atfoovax!" conveys suspicion that sitefoovaxhas been dropping a lot of stuff on the floor lately (seedrop on the floor). The implied metaphor of email as interstellar travel is interesting in itself. Readily verbed as `blackhole': "That router is blackholing IDP packets." Comparebit bucketand seeRBL.