= H =
=====

h: [from SF fandom] infix. A method of `marking' common words,
   i.e., calling attention to the fact that they are being used in a
   nonstandard, ironic, or humorous way.  Originated in the fannish
   catchphrase "Bheer is the One True Ghod!" from decades ago.
   H-infix marking of `Ghod' and other words spread into the 1960s
   counterculture via underground comix, and into early hackerdom
   either from the counterculture or from SF fandom (the three overlapped
   heavily at the time).  More recently, the h infix has become an
   expected feature of benchmark names (Dhrystone, Rhealstone,
   etc.); this is prob. patterning on the original Whetstone (the name
   of a laboratory) but influenced by the fannish/counterculture
   h infix.

ha ha only serious: [from SF fandom, orig. as mutation of HHOK,
   `Ha Ha Only Kidding'] A phrase (often seen abbreviated as HHOS)
   that aptly captures the flavor of much hacker discourse.  Applied
   especially to parodies, absurdities, and ironic jokes that are both
   intended and perceived to contain a possibly disquieting amount of
   truth, or truths that are constructed on in-joke and self-parody.
   This lexicon contains many examples of ha-ha-only-serious in both
   form and content.  Indeed, the entirety of hacker culture is often
   perceived as ha-ha-only-serious by hackers themselves; to take it
   either too lightly or too seriously marks a person as an outsider,
   a {wannabee}, or in {larval stage}.  For further
   enlightenment on this subject, consult any Zen master.  See also
   {{Humor, Hacker}}, and {AI koans}.

hack: 1. n. Originally, a quick job that produces what is needed,
   but not well.  2. n. An incredibly good, and perhaps very
   time-consuming, piece of work that produces exactly what is needed.
   3. vt. To bear emotionally or physically.  "I can't hack this
   heat!"  4. vt. To work on something (typically a program).  In an
   immediate sense: "What are you doing?"  "I'm hacking TECO."
   In a general (time-extended) sense: "What do you do around here?"
   "I hack TECO."  More generally, "I hack `foo'" is roughly
   equivalent to "`foo' is my major interest (or project)".  "I
   hack solid-state physics."  5. vt. To pull a prank on.  See
   sense 2 and {hacker} (sense 5).  6. vi. To interact with a
   computer in a playful and exploratory rather than goal-directed
   way.  "Whatcha up to?"  "Oh, just hacking."  7. n. Short for
   {hacker}.  8. See {nethack}.

   Constructions on this term abound.  They include `happy
   hacking' (a farewell), `how's hacking?' (a friendly greeting
   among hackers) and `hack, hack' (a fairly content-free but
   friendly comment, often used as a temporary farewell).  For more on
   the meaning of hack see appendix A.  See also {neat hack},
   {real hack}.

hack attack: [poss. by analogy with `Big Mac Attack' from ads
   for the McDonald's fast-food chain; the variant `big hack attack'
   is reported] n. Nearly synonymous with {hacking run}, though the
   latter more strongly implies an all-nighter.

hack mode: n. 1. What one is in when hacking, of course.  2. More
   specifically, a Zen-like state of total focus on The Problem that
   may be achieved when one is hacking (this is why every good hacker
   is part mystic).  Ability to enter such concentration at will
   correlates strongly with wizardliness; it is one of the most
   important skills learned during {larval stage}.  Sometimes
   amplified as `deep hack mode'.

   Being yanked out of hack mode (see {priority interrupt}) may be
   experienced as a physical shock, and the sensation of being in it
   is more than a little habituating.  The intensity of this
   experience is probably by itself sufficient explanation for the
   existence of hackers, and explains why many resist being promoted
   out of positions where they can code.  See also {cyberspace}
   (sense 2).

   Some aspects of hackish etiquette will appear quite odd to an
   observer unaware of the high value placed on hack mode.  For
   example, if someone appears at your door, it is perfectly okay to
   hold up a hand (without turning one's eyes away from the screen) to
   avoid being interrupted.  One may read, type, and interact with the
   computer for quite some time before further acknowledging the
   other's presence (of course, he or she is reciprocally free to
   leave without a word).  The understanding is that you might be in
   {hack mode} with a lot of delicate {state} (sense 2) in your
   head, and you dare not {swap} that context out until you have
   reached a good point to pause. See also {juggling eggs}.

hack on: vt. To {hack}; implies that the subject is some
   pre-existing hunk of code that one is evolving, as opposed to
   something one might {hack up}.

hack together: vt. To throw something together so it will work.
   Unlike `kluge together' or {cruft together}, this does not
   necessarily have negative connotations.

hack up: vt. To {hack}, but generally implies that the result is
   a hack in sense 1 (a quick hack).  Contrast this with {hack on}.
   To `hack up on' implies a {quick-and-dirty} modification to an
   existing system.  Contrast {hacked up}; compare {kluge up},
   {monkey up}, {cruft together}.

hack value: n. Often adduced as the reason or motivation for
   expending effort toward a seemingly useless goal, the point being
   that the accomplished goal is a hack.  For example, MacLISP had
   features for reading and printing Roman numerals, which were
   installed purely for hack value.  See {display hack} for one
   method of computing hack value, but this cannot really be
   explained.  As a great artist once said of jazz: "If you hafta ask,
   you ain't never goin' to find out."

hack-and-slay: v. (also `hack-and-slash') 1. To play a {MUD}
   or go mudding, especially with the intention of {berserking} for
   pleasure.  2. To undertake an all-night programming/hacking
   session, interspersed with stints of mudding as a change of pace.
   This term arose on the British academic network amongst students
   who worked nights and logged onto Essex University's MUDs during
   public-access hours (2 A.M. to 7 A.M.).  Usually more
   mudding than work was done in these sessions.

hacked off: [analogous to `pissed off'] adj. Said of system
   administrators who have become annoyed, upset, or touchy owing to
   suspicions that their sites have been or are going to be victimized
   by crackers, or used for inappropriate, technically illegal, or
   even overtly criminal activities.  For example, having unreadable
   files in your home directory called `worm', `lockpick', or `goroot'
   would probably be an effective (as well as impressively obvious and
   stupid) way to get your sysadmin hacked off at you.

hacked up: adj. Sufficiently patched, kluged, and tweaked that the
   surgical scars are beginning to crowd out normal tissue (compare
   {critical mass}).  Not all programs that are hacked become
   `hacked up'; if modifications are done with some eye to coherence
   and continued maintainability, the software may emerge better for
   the experience.  Contrast {hack up}.

hacker: [originally, someone who makes furniture with an axe] n.
   1. A person who enjoys exploring the details of programmable
   systems and how to stretch their capabilities, as opposed to most
   users, who prefer to learn only the minimum necessary.  2. One who
   programs enthusiastically (even obsessively) or who enjoys
   programming rather than just theorizing about programming.  3. A
   person capable of appreciating {hack value}.  4. A person who is
   good at programming quickly.  5. An expert at a particular program,
   or one who frequently does work using it or on it; as in `a UNIX
   hacker'.  (Definitions 1 through 5 are correlated, and people who fit
   them congregate.)  6. An expert or enthusiast of any kind.  One
   might be an astronomy hacker, for example.  7. One who enjoys the
   intellectual challenge of creatively overcoming or circumventing
   limitations.  8. [deprecated] A malicious meddler who tries to
   discover sensitive information by poking around.  Hence `password
   hacker', `network hacker'.  See {cracker}.

   It is better to be described as a hacker by others than to describe
   oneself that way.  Hackers consider themselves something of an
   elite (a meritocracy based on ability), though one to which new
   members are gladly welcome.  There is thus a certain ego
   satisfaction to be had in identifying yourself as a hacker (but if
   you claim to be one and are not, you'll quickly be labeled
   {bogus}).

hacking run: [analogy with `bombing run' or `speed run'] n. A
   hack session extended long outside normal working times, especially
   one longer than 12 hours.  May cause you to `change phase the hard
   way' (see {phase}).

Hacking X for Y: [ITS] n. The information ITS made publicly
   available about each user (the INQUIR record) was a sort of form in
   which the user could fill out fields.  On display, two of these
   fields were combined into a project description of the form
   "Hacking X for Y" (e.g., `"Hacking perceptrons for
   Minsky"').  This form of description became traditional and has
   since been carried over to other systems with more general
   facilities for self-advertisement (such as UNIX {plan file}s).

Hackintosh: n. 1. An Apple Lisa that has been hacked into emulating a
   Macintosh (also called a `Mac XL').  2. A Macintosh assembled
   from parts theoretically belonging to different models in the line.

hackish: /hak'ish/ adj. (also {hackishness} n.) 1. Said of
   something that is or involves a hack.  2. Of or pertaining to
   hackers or the hacker subculture.  See also {true-hacker}.

hackishness: n. The quality of being or involving a hack.  This
   term is considered mildly silly.  Syn.  {hackitude}.

hackitude: n. Syn. {hackishness}; this word is considered sillier.

hair: [back-formation from {hairy}] n. The complications that
   make something hairy.  "Decoding {TECO} commands requires a
   certain amount of hair."  Often seen in the phrase `infinite
   hair', which connotes extreme complexity.  Also in `hairiferous'
   (tending to promote hair growth): "GNUMACS Elisp encourages lusers
   to write complex editing modes."  "Yeah, it's pretty hairiferous
   all right." (or just: "Hair squared!")

hairy: adj. 1. Annoyingly complicated.  "{DWIM} is incredibly
   hairy."  2. Incomprehensible.  "{DWIM} is incredibly hairy."
   3. Of people, high-powered, authoritative, rare, expert, and/or
   incomprehensible.  Hard to explain except in context: "He knows
   this hairy lawyer who says there's nothing to worry about."  See
   also {hirsute}.

HAKMEM: /hak'mem/ n. MIT AI Memo 239 (February 1972).  A
   legendary collection of neat mathematical and programming hacks
   contributed by many people at MIT and elsewhere.  (The title of the
   memo really is "HAKMEM", which is a 6-letterism for `hacks
   memo'.)  Some of them are very useful techniques, powerful
   theorems, or interesting unsolved problems, but most fall into the
   category of mathematical and computer trivia.  Here is a sampling
   of the entries (with authors), slightly paraphrased:

   Item 41 (Gene Salamin): There are exactly 23,000 prime numbers less
   than 2^18.

   Item 46 (Rich Schroeppel): The most *probable* suit
   distribution in bridge hands is 4-4-3-2, as compared to 4-3-3-3,
   which is the most *evenly* distributed.  This is because the
   world likes to have unequal numbers: a thermodynamic effect saying
   things will not be in the state of lowest energy, but in the state
   of lowest disordered energy.

   Item 81 (Rich Schroeppel): Count the magic squares of order 5
   (that is, all the 5-by-5 arrangements of the numbers from 1 to 25
   such that all rows, columns, and diagonals add up to the same
   number).  There are about 320 million, not counting those that
   differ only by rotation and reflection.

   Item 154 (Bill Gosper): The myth that any given programming language is
   machine independent is easily exploded by computing the sum of
   powers of 2.  If the result loops with period = 1 with
   sign +, you are on a sign-magnitude machine.  If the result
   loops with period = 1 at -1, you are on a
   twos-complement machine.  If the result loops with period greater
   than 1, including the beginning, you are on a ones-complement
   machine.  If the result loops with period greater than 1, not
   including the beginning, your machine isn't binary --- the pattern
   should tell you the base.  If you run out of memory, you are on a
   string or bignum system.  If arithmetic overflow is a fatal error,
   some fascist pig with a read-only mind is trying to enforce machine
   independence.  But the very ability to trap overflow is machine
   dependent.  By this strategy, consider the universe, or, more
   precisely, algebra: Let X = the sum of many powers of 2 =
   ...111111.  Now add X to itself:
   X + X = ...111110 Thus, 2X = X - 1, so
   X = -1.  Therefore algebra is run on a machine (the
   universe) that is two's-complement.

   Item 174 (Bill Gosper and Stuart Nelson): 21963283741 is the only
   number such that if you represent it on the {PDP-10} as both an
   integer and a floating-point number, the bit patterns of the two
   representations are identical.

   Item 176 (Gosper): The "banana phenomenon" was encountered when
   processing a character string by taking the last 3 letters typed
   out, searching for a random occurrence of that sequence in the
   text, taking the letter following that occurrence, typing it out,
   and iterating.  This ensures that every 4-letter string output
   occurs in the original.  The program typed BANANANANANANANA....  We
   note an ambiguity in the phrase, "the Nth occurrence of."  In one
   sense, there are five 00's in 0000000000; in another, there are
   nine.  The editing program TECO finds five.  Thus it finds only the
   first ANA in BANANA, and is thus obligated to type N next.  By
   Murphy's Law, there is but one NAN, thus forcing A, and thus a
   loop.  An option to find overlapped instances would be useful,
   although it would require backing up N - 1 characters before
   seeking the next N-character string.

   Note: This last item refers to a {Dissociated Press}
   implementation.  See also {banana problem}.

   HAKMEM also contains some rather more complicated mathematical and
   technical items, but these examples show some of its fun flavor.

hakspek: /hak'speek/ n. A shorthand method of spelling found on
   many British academic bulletin boards and {talker system}s.
   Syllables and whole words in a sentence are replaced by single
   ASCII characters the names of which are phonetically similar or
   equivalent, while multiple letters are usually dropped.  Hence,
   `for' becomes `4'; `two', `too', and `to' become `2'; `ck'
   becomes `k'.  "Before I see you tomorrow" becomes "b4 i c u
   2moro".  First appeared in London about 1986, and was probably
   caused by the slowness of available talker systems, which
   operated on archaic machines with outdated operating systems and
   no standard methods of communication.  Has become rarer since.
   See also {talk mode}.

hamster: n. 1. [Fairchild] A particularly slick little piece of code
   that does one thing well; a small, self-contained hack.  The image
   is of a hamster happily spinning its exercise wheel.  2. [UK] Any item
   of hardware made by Amstrad, a company famous for its cheap
   plastic PC-almost-compatibles.

hand-hacking: n. 1. The practice of translating {hot spot}s from
   an {HLL} into hand-tuned assembler, as opposed to trying to
   coerce the compiler into generating better code.  Both the term and
   the practice are becoming uncommon.  See {tune}, {bum}, {by
   hand}; syn.  with v. {cruft}.  2. More generally, manual
   construction or patching of data sets that would normally be
   generated by a translation utility and interpreted by another
   program, and aren't really designed to be read or modified by
   humans.

handshaking: n. Hardware or software activity designed to start or
   keep two machines or programs in synchronization as they {do
   protocol}.  Often applied to human activity; thus, a hacker might
   watch two people in conversation nodding their heads to indicate
   that they have heard each others' points and say "Oh, they're
   handshaking!".  See also {protocol}.

handwave: [poss. from gestures characteristic of stage magicians]
   1. v. To gloss over a complex point; to distract a listener; to
   support a (possibly actually valid) point with blatantly faulty
   logic.  2. n. The act of handwaving.  "Boy, what a handwave!"

   If someone starts a sentence with "Clearly..." or
   "Obviously..." or "It is self-evident that...", it is
   a good bet he is about to handwave (alternatively, use of these
   constructions in a sarcastic tone before a paraphrase of someone
   else's argument suggests that it is a handwave).  The theory behind
   this term is that if you wave your hands at the right moment, the
   listener may be sufficiently distracted to not notice that what you
   have said is {bogus}.  Failing that, if a listener does object,
   you might try to dismiss the objection with a wave of your hand.

   The use of this word is often accompanied by gestures: both hands
   up, palms forward, swinging the hands in a vertical plane pivoting
   at the elbows and/or shoulders (depending on the magnitude of the
   handwave); alternatively, holding the forearms in one position
   while rotating the hands at the wrist to make them flutter.  In
   context, the gestures alone can suffice as a remark; if a speaker
   makes an outrageously unsupported assumption, you might simply wave
   your hands in this way, as an accusation, far more eloquent than
   words could express, that his logic is faulty.

hang: v. 1. To wait for an event that will never occur.  "The
   system is hanging because it can't read from the crashed drive".
   See {wedged}, {hung}.  2. To wait for some event to occur; to
   hang around until something happens.  "The program displays a menu
   and then hangs until you type a character."  Compare {block}.
   3. To attach a peripheral device, esp. in the construction `hang
   off':  "We're going to hang another tape drive off the file
   server."  Implies a device attached with cables, rather than
   something that is strictly inside the machine's chassis.

Hanlon's Razor: prov. A corollary of {Finagle's Law}, similar to
   Occam's Razor, that reads "Never attribute to malice that which can
   be adequately explained by stupidity."  The derivation of the
   common title Hanlon's Razor is unknown; a similar epigram has been
   attributed to William James.  Quoted here because it seems to be a
   particular favorite of hackers, often showing up in {fortune
   cookie} files and the login banners of BBS systems and commercial
   networks.  This probably reflects the hacker's daily experience of
   environments created by well-intentioned but short-sighted people.

happily: adv.  Of software, used to emphasize that a program is
   unaware of some important fact about its environment, either
   because it has been fooled into believing a lie, or because it
   doesn't care.  The sense of `happy' here is not that of elation,
   but rather that of blissful ignorance.  "The program continues to
   run, happily unaware that its output is going to /dev/null."

hard boot: n. See {boot}.

hardcoded: adj. 1. Said of data inserted directly into a program,
   where it cannot be easily modified, as opposed to data in some
   {profile}, resource (see {de-rezz} sense 2), or environment
   variable that a {user} or hacker can easily modify.  2. In C,
   this is esp. applied to use of a literal instead of a
   `#define' macro (see {magic number}).

hardwarily: /hard-weir'*-lee/ adv. In a way pertaining to
   hardware.  "The system is hardwarily unreliable."  The adjective
   `hardwary' is *not* traditionally used, though it has recently
   been reported from the U.K.  See {softwarily}.

hardwired: adj. 1. In software, syn. for {hardcoded}.  2. By
   extension, anything that is not modifiable, especially in the sense
   of customizable to one's particular needs or tastes.

has the X nature: [seems to derive from Zen Buddhist koans of the
   form "Does an X have the Buddha-nature?"] adj. Common hacker
   construction for `is an X', used for humorous emphasis.  "Anyone
   who can't even use a program with on-screen help embedded in it
   truly has the {loser} nature!"  See also {the X that can be Y
   is not the true X}.

hash bucket: n. A notional receptacle into which more than one
   thing accessed by the same key or short code might be dropped.
   When you look up a name in the phone book (for example), you
   typically hash it by extracting its first letter; the hash buckets
   are the alphabetically ordered letter sections.  This is used as
   techspeak with respect to code that uses actual hash functions; in
   jargon, it is used for human associative memory as well.  Thus, two
   things `in the same hash bucket' may be confused with each other.
   "If you hash English words only by length, you get too many common
   grammar words in the first couple of hash buckets." Compare {hash
   collision}.

hash collision: [from the technical usage] n. (var. `hash
   clash') When used of people, signifies a confusion in associative
   memory or imagination, especially a persistent one (see
   {thinko}).  True story: One of us [ESR] was once on the phone
   with a friend about to move out to Berkeley.  When asked what he
   expected Berkeley to be like, the friend replied: "Well, I have
   this mental picture of naked women throwing Molotov cocktails, but
   I think that's just a collision in my hash tables."  Compare
   {hash bucket}.

hat: n. Common (spoken) name for the circumflex (`^', ASCII
   1011110) character.  See {ASCII} for other synonyms.

HCF: /H-C-F/ n. Mnemonic for `Halt and Catch Fire', any of
   several undocumented and semi-mythical machine instructions with
   destructive side-effects, supposedly included for test purposes on
   several well-known architectures going as far back as the IBM 360.
   The MC6800 microprocessor was the first for which the HCF opcode
   became widely known.  This instruction caused the processor to
   {toggle} a subset of the bus lines as rapidly as it could; in
   some configurations this can actually cause lines to burn
   up.

heads down: [Sun] adj. Concentrating, usually so heavily and for so
   long that everything outside the focus area is missed.  See also
   {hack mode} and {larval stage}, although it is not confined to
   fledgling hackers.

heartbeat: n. 1. The signal emitted by a Level 2 Ethernet
   transceiver at the end of every packet to show that the
   collision-detection circuit is still connected.  2. A periodic
   synchronization signal used by software or hardware, such as a bus
   clock or a periodic interrupt.  3. The `natural' oscillation
   frequency of a computer's clock crystal, before frequency division
   down to the machine's clock rate.  4. A signal emitted at regular
   intervals by software to demonstrate that it is still alive.
   Sometimes hardware is designed to reboot the machine if it stops
   hearing a heartbeat.  See also {breath-of-life packet}.

heavy metal: [Cambridge] n. Syn. {big iron}.

heavy wizardry: n. Code or designs that trade on a particularly
   intimate knowledge or experience of a particular operating system
   or language or complex application interface.  Distinguished from
   {deep magic}, which trades more on arcane *theoretical*
   knowledge.  Writing device drivers is heavy wizardry; so is
   interfacing to {X} (sense 2) without a toolkit.  Esp. found in
   comments similar to "Heavy wizardry begins here ...".  Compare
   {voodoo programming}.

heavyweight: adj. High-overhead; {baroque}; code-intensive;
   featureful, but costly.  Esp. used of communication protocols,
   language designs, and any sort of implementation in which maximum
   generality and/or ease of implementation has been pushed at the
   expense of mundane considerations such as speed, memory utilization,
   and startup time.  {EMACS} is a heavyweight editor; {X} is an
   *extremely* heavyweight window system.  This term isn't
   pejorative, but one man's heavyweight is another's {elephantine}
   and a third's {monstrosity}.  Oppose `lightweight'.

heisenbug: /hi:'zen-buhg/ [from Heisenberg's Uncertainty
   Principle in quantum physics] n. A bug that disappears or alters
   its behavior when one attempts to probe or isolate it.  Antonym of
   {Bohr bug}; see also {mandelbug}.  In C, nine out of ten heisenbugs
   result from either {fandango on core} phenomena (esp. lossage
   related to corruption of the malloc {arena}) or errors that
   {smash the stack}.

Helen Keller mode: n. State of a hardware or software system that
   is deaf, dumb, and blind, i.e., accepting no input and generating no
   output, usually due to an infinite loop or some other excursion
   into {deep space}.  (Unfair to the real Helen Keller, whose
   success at learning speech was triumphant.)  See also
   {go flatline}, {catatonic}.

hello, sailor!: interj. Occasional West Coast equivalent of
   {hello, world}; seems to have originated at SAIL, later
   associated with the game {Zork} (which also included "hello,
   aviator" and "hello, implementor").  Originally from the
   traditional hooker's greeting to a swabbie fresh off the boat, of
   course.

hello, wall!: excl. See {wall}.

hello, world: interj. 1. The canonical minimal test message in the
   C/UNIX universe.  2. Any of the minimal programs that emit this
   message.  Traditionally, the first program a C coder is supposed to
   write in a new environment is one that just prints "hello, world"
   to standard output (and indeed it is the first example program
   in {K&R}).  Environments that generate an unreasonably large
   executable for this trivial test or which require a {hairy}
   compiler-linker invocation to generate it are considered to
   {lose} (see {X}).  3. Greeting uttered by a hacker making an
   entrance or requesting information from anyone present.  "Hello,
   world!  Is the {VAX} back up yet?"

hex: n. 1. Short for {{hexadecimal}}, base 16.  2. A 6-pack
   of anything (compare {quad}, sense 2).  Neither usage has
   anything to do with {magic} or {black art}, though the pun is
   appreciated and occasionally used by hackers.  True story: As a
   joke, some hackers once offered some surplus ICs for sale to be
   worn as protective amulets against hostile magic.  The chips were,
   of course, hex inverters.

hexadecimal:: n. Base 16.  Coined in the early 1960s to replace
   earlier `sexadecimal', which was too racy and amusing for stuffy
   IBM, and later adopted by the rest of the industry.

   Actually, neither term is etymologically pure.  If we take `binary'
   to be paradigmatic, the most etymologically correct term for
   base 10, for example, is `denary', which
   comes from `deni' (ten at a time, ten each), a Latin `distributive'
   number; the corresponding term for base-16 would be something like
   `sendenary'.  `Decimal' is from an ordinal number; the
   corresponding prefix for 6 would imply something like
   `sextidecimal'.  The `sexa-' prefix is Latin but incorrect in this
   context, and `hexa-' is Greek.  The word `octal' is similarly
   incorrect; a correct form would be `octaval' (to go with decimal),
   or `octonary' (to go with binary).  If anyone ever implements a
   base-3 computer, computer scientists will be faced with the
   unprecedented dilemma of a choice between two *correct* forms;
   both `ternary' and `trinary' have a claim to this throne.

hexit: /hek'sit/ n. A hexadecimal digit (0--9, and A--F or a--f).
   Used by people who claim that there are only *ten* digits,
   dammit; sixteen-fingered human beings are rather rare, despite what
   some keyboard designs might seem to imply (see {space-cadet
   keyboard}).

hidden flag: [scientific computation] n. An extra option added to a
   routine without changing the calling sequence.  For example,
   instead of adding an explicit input variable to instruct a routine
   to give extra diagnostic output, the programmer might just add a
   test for some otherwise meaningless feature of the existing inputs,
   such as a negative mass.  Liberal use of hidden flags can make a
   program very hard to debug and understand.

high bit: [from `high-order bit'] n. 1. The most significant
   bit in a byte.  2. By extension, the most significant part of
   something other than a data byte: "Spare me the whole {saga},
   just give me the high bit."  See also {meta bit}, {hobbit},
   {dread high-bit disease}, and compare the mainstream slang
   `bottom line'.

high moby: /hi:' mohb'ee/ n. The high half of a 512K {PDP-10}'s
   physical address space; the other half was of course the low moby.  This
   usage has been generalized in a way that has outlasted the
   {PDP-10}; for example, at the 1990 Washington D.C. Area Science
   Fiction Conclave (Disclave), when a miscommunication resulted in two
   separate wakes being held in commemoration of the shutdown of MIT's
   last {{ITS}} machines, the one on the upper floor was dubbed the
   `high moby' and the other the `low moby'.  All parties involved
   {grok}ked this instantly.  See {moby}.

highly: [scientific computation] adv. The preferred modifier for
   overstating an understatement.  As in: `highly nonoptimal', the
   worst possible way to do something; `highly nontrivial', either
   impossible or requiring a major research project; `highly
   nonlinear', completely erratic and unpredictable; `highly
   nontechnical', drivel written for {luser}s, oversimplified to the
   point of being misleading or incorrect (compare {drool-proof
   paper}).  In other computing cultures, postfixing of {in the
   extreme} might be preferred.

hirsute: adj. Occasionally used humorously as a synonym for {hairy}.

HLL: /H-L-L/ n. [High-Level Language (as opposed to assembler)]
   Found primarily in email and news rather than speech.  Rarely, the
   variants `VHLL' and `MLL' are found.  VHLL stands for `Very-High-Level
   Language' and is used to describe a {bondage-and-discipline
   language} that the speaker happens to like; Prolog and Backus's FP
   are often called VHLLs.  `MLL' stands for `Medium-Level Language' and is
   sometimes used half-jokingly to describe {C}, alluding to its
   `structured-assembler' image.  See also {languages of choice}.

hobbit: n. 1. The High Order Bit of a byte; same as the {meta
   bit} or {high bit}.  2. The non-ITS name of vad@ai.mit.edu
   (*Hobbit*), master of lasers.

hog: n.,vt. 1. Favored term to describe programs or hardware that
   seem to eat far more than their share of a system's resources,
   esp. those which noticeably degrade interactive response.
   *Not* used of programs that are simply extremely large or
   complex or that are merely painfully slow themselves (see {pig,
   run like a}).  More often than not encountered in qualified forms,
   e.g., `memory hog', `core hog', `hog the processor', `hog
   the disk'.  "A controller that never gives up the I/O bus
   gets killed after the bus-hog timer expires."   2. Also said
   of *people* who use more than their fair share of resources
   (particularly disk, where it seems that 10% of the people use 90%
   of the disk, no matter how big the disk is or how many people use
   it).  Of course, once disk hogs fill up one filesystem, they
   typically find some other new one to infect, claiming to the
   sysadmin that they have an important new project to complete.

holy wars: [from {USENET}, but may predate it] n. {flame
   war}s over {religious issues}.  The paper by Danny Cohen that
   popularized the terms {big-endian} and {little-endian} in
   connection with the LSB-first/MSB-first controversy was entitled
   "On Holy Wars and a Plea for Peace".  Other perennial Holy
   Wars have included {EMACS} vs. {vi}, my personal computer vs.
   everyone else's personal computer, {{ITS}} vs. {{UNIX}},
   {{UNIX}} vs. {VMS}, {BSD} UNIX vs. {USG UNIX}, {C} vs.
   {{Pascal}}, {C} vs. {LISP}, etc., ad nauseam.  The
   characteristic that distinguishes {holy wars} from normal
   technical disputes is that in a holy wars most of the participants
   spend their time trying to pass off personal value choices and
   cultural attachments as objective technical evaluations. See also
   {theology}.

home box: n. A hacker's personal machine, especially one he or she
   owns.  "Yeah?  Well, *my* home box runs a full 4.2 BSD, so
   there!"

hook: n. A software or hardware feature included in order to
   simplify later additions or changes by a user.  For example,
   a simple program that prints numbers might always print them in
   base 10, but a more flexible version would let a variable
   determine what base to use; setting the variable to 5 would make
   the program print numbers in base 5.  The variable is a simple
   hook.  An even more flexible program might examine the variable
   and treat a value of 16 or less as the base to use, but treat any
   other number as the address of a user-supplied routine for printing
   a number.  This is a {hairy} but powerful hook; one can then write a
   routine to print numbers as Roman numerals, say, or as Hebrew
   characters, and plug it into the program through the hook.  Often
   the difference between a good program and a superb one is that the
   latter has useful hooks in judiciously chosen places.  Both may do
   the original job about equally well, but the one with the hooks is
   much more flexible for future expansion of capabilities ({EMACS},
   for example, is *all* hooks).  The term `user exit' is
   synonymous but much more formal and less hackish.

hop: n. One file transmission in a series required to get a file
   from point A to point B on a store-and-forward network.  On such
   networks (including {UUCPNET} and {FidoNet}), the important
   inter-machine metric is the number of hops in the shortest path
   between them, rather than their geographical separation.  See
   {bang path}.

hose: 1. vt. To make non-functional or greatly degraded in
   performance.  "That big ray-tracing program really hoses the
   system."  See {hosed}.  2. n. A narrow channel through which
   data flows under pressure.  Generally denotes data paths that
   represent performance bottlenecks.  3. n. Cabling, especially
   thick Ethernet cable.  This is sometimes called `bit hose' or
   `hosery' (play on `hosiery') or `etherhose'.  See also
   {washing machine}.

hosed: adj. Same as {down}.  Used primarily by UNIX hackers.
   Humorous: also implies a condition thought to be relatively easy to
   reverse.  Probably derived from the Canadian slang `hoser'
   popularized by the Bob and Doug Mackenzie skits on SCTV.  See
   {hose}.  It is also widely used of people in the mainstream sense
   of `in an extremely unfortunate situation'.

   Once upon a time, a Cray that had been experiencing periodic
   difficulties crashed, and it was announced to have been hosed.
   It was discovered that the crash was due to the disconnection of
   some coolant hoses.  The problem was corrected, and users were then
   assured that everything was OK because the system had been rehosed.
   See also {dehose}.

hot spot: n. 1. [primarily used by C/UNIX programmers, but
   spreading] It is received wisdom that in most programs, less than
   10% of the code eats 90% of the execution time; if one were to
   graph instruction visits versus code addresses, one would typically
   see a few huge spikes amidst a lot of low-level noise.  Such spikes
   are called `hot spots' and are good candidates for heavy
   optimization or {hand-hacking}.  The term is especially used of
   tight loops and recursions in the code's central algorithm, as
   opposed to (say) initial set-up costs or large but infrequent I/O
   operations.  See {tune}, {bum}, {hand-hacking}.  2. The
   active location of a cursor on a bit-map display.  "Put the
   mouse's hot spot on the `ON' widget and click the left button."
   3. In a massively parallel computer with shared memory, the one
   location that all 10,000 processors are trying to read or
   write at once (perhaps because they are all doing a {busy-wait}
   on the same lock).

house wizard: [prob. from ad-agency lingo, `house freak'] n. A
   hacker occupying a technical-specialist, R&D, or systems position
   at a commercial shop.  A really effective house wizard can have
   influence out of all proportion to his/her ostensible rank and
   still not have to wear a suit.  Used esp. of UNIX wizards.  The
   term `house guru' is equivalent.

HP-SUX: /H-P suhks/ n. Unflattering hackerism for HP-UX,
   Hewlett-Packard's UNIX port.  Features some truly unique bogosities
   in the filesystem internals and elsewhere which occasionally create
   portability problems.  HP-UX is often referred to as `hockey-pux'
   inside HP, and one respondent claims that the proper pronunciation
   is /H-P ukkkhhhh/ as though one were about to spit.  Another such
   alternate spelling and pronunciation is "H-PUX" /H-puhks/.
   Hackers at HP/Apollo (the former Apollo Computers which was swallowed
   by HP in 1989) have been heard to complain that Mr. Packard should
   have pushed to have his name first, if for no other reason than the
   greater eloquence of the resulting acronym.  Compare {buglix}.
   See also {Telerat}, {sun-stools}, {terminak}.

huff: v. To compress data using a Huffman code.  Various programs
   that use such methods have been called `HUFF' or some variant
   thereof.  Oppose {puff}.  Compare {crunch}, {compress}.

humma: // excl. A filler word used on various `chat' and
   `talk' programs when you had nothing to say but felt that it was
   important to say something.  The word apparently originated (at
   least with this definition) on the MECC Timeshare System (MTS, a
   now-defunct educational time-sharing system running in Minnesota
   during the 1970s and the early 1980s) but was later sighted on
   early UNIX systems.

Humor, Hacker:: n. A distinctive style of shared intellectual humor
   found among hackers, having the following distinctive
   characteristics:

   1. Fascination with form-vs.-content jokes, paradoxes, and humor
   having to do with confusion of metalevels (see {meta}).  One way
   to make a hacker laugh: hold a red index card in front of him/her
   with "GREEN" written on it, or vice-versa (note, however, that
   this is funny only the first time).

   2. Elaborate deadpan parodies of large intellectual constructs, such
   as specifications (see {write-only memory}), standards documents,
   language descriptions (see {INTERCAL}), and even entire scientific
   theories (see {quantum bogodynamics}, {computron}).

   3. Jokes that involve screwily precise reasoning from bizarre,
   ludicrous, or just grossly counter-intuitive premises.

   4. Fascination with puns and wordplay.

   5. A fondness for apparently mindless humor with subversive
   currents of intelligence in it --- for example, old Warner Brothers
   and Rocky & Bullwinkle cartoons, the Marx brothers, the early
   B-52s, and Monty Python's Flying Circus.  Humor that combines this
   trait with elements of high camp and slapstick is especially
   favored.

   6. References to the symbol-object antinomies and associated ideas
   in Zen Buddhism and (less often) Taoism.  See {has the X nature},
   {Discordianism}, {zen}, {ha ha only serious}, {AI koans}.

   See also {filk}, {retrocomputing}, and appendix B.  If you have an
   itchy feeling that all 6 of these traits are really aspects of
   one thing that is incredibly difficult to talk about exactly, you
   are (a) correct and (b) responding like a hacker.  These traits are
   also recognizable (though in a less marked form) throughout
   {{science-fiction fandom}}.

hung: [from `hung up'] adj. Equivalent to {wedged}, but more
   common at UNIX/C sites.  Not generally used of people.  Syn. with
   {locked up}, {wedged}; compare {hosed}.  See also {hang}.
   A hung state is distinguished from {crash}ed or {down}, where the
   program or system is also unusable but because it is not running
   rather than because it is waiting for something.  However, the
   recovery from both situations is often the same.

hungry puppy: n. Syn. {slopsucker}.

hungus: /huhng'g*s/ [perhaps related to slang `humongous'] adj.
   Large, unwieldy, usually unmanageable.  "TCP is a hungus piece of
   code."  "This is a hungus set of modifications."

hyperspace: /hi:'per-spays/ n. A memory location that is *far*
   away from where the program counter should be pointing, often
   inaccessible because it is not even mapped in.  "Another core
   dump --- looks like the program jumped off to hyperspace
   somehow."  (Compare {jump off into never-never land}.)  This
   usage is from the SF notion of a spaceship jumping `into
   hyperspace', that is, taking a shortcut through higher-dimensional
   space --- in other words, bypassing this universe.  The variant
   `east hyperspace' is recorded among CMU and Bliss hackers.