Part 13

[Outsiders often observe in the PARC culture an institutional arrogance which usage of this term exemplifies. The brilliance and scope of PARC's contributions to computer science have been such that this superior attitude is not much resented. --- ESR]

:dirty power: n. Electrical mains voltage that is unfriendly to the delicate innards of computers. Spikes, {drop-outs}, average voltage significantly higher or lower than nominal, or just plain noise can all cause problems of varying subtlety and severity (these are collectively known as {power hit}s).

:disclaimer: n. [USENET] n. Statement ritually appended to many USENET postings (sometimes automatically, by the posting software) reiterating the fact (which should be obvious, but is easily forgotten) that the article reflects its author's opinions and not necessarily those of the organization running the machine through which the article entered the network.

:Discordianism: /dis-kor'di-*n-ism/ n. The veneration of {Eris}, a.k.a. Discordia; widely popular among hackers. Discordianism was popularized by Robert Shea and Robert Anton Wilson's `{Illuminatus!}' trilogy as a sort of self-subverting Dada-Zen for Westerners --- it should on no account be taken seriously but is far more serious than most jokes. Consider, for example, the Fifth Commandment of the Pentabarf, from `Principia Discordia': "A Discordian is Prohibited of Believing What he Reads." Discordianism is usually connected with an elaborate conspiracy theory/joke involving millennia-long warfare between the anarcho-surrealist partisans of Eris and a malevolent, authoritarian secret society called the Illuminati. See {Religion} under {appendix B}, {Church of the SubGenius}, and {ha ha only serious}.

:disk farm: n. (also {laundromat}) A large room or rooms filled with disk drives (esp. {washing machine}s).

:display hack: n. A program with the same approximate purpose as a kaleidoscope: to make pretty pictures. Famous display hacks include {munching squares}, {smoking clover}, the BSD UNIX `rain(6)' program, `worms(6)' on miscellaneous UNIXes, and the {X} `kaleid(1)' program. Display hacks can also be implemented without programming by creating text files containing numerous escape sequences for interpretation by a video terminal; one notable example displayed, on any VT100, a Christmas tree with twinkling lights and a toy train circling its base. The {hack value} of a display hack is proportional to the esthetic value of the images times the cleverness of the algorithm divided by the size of the code. Syn. {psychedelicware}.

:Dissociated Press: [play on `Associated Press'; perhaps inspired by a reference in the 1949 Bugs Bunny cartoon "What's Up, Doc?"] n. An algorithm for transforming any text into potentially humorous garbage even more efficiently than by passing it through a {marketroid}. You start by printing any N consecutive words (or letters) in the text. Then at every step you search for any random occurrence in the original text of the last N words (or letters) already printed and then print the next word or letter. {EMACS} has a handy command for this. Here is a short example of word-based Dissociated Press applied to an earlier version of this Jargon File:

wart: n. A small, crocky {feature} that sticks out of an array (C has no checks for this). This is relatively benign and easy to spot if the phrase is bent so as to be not worth paying attention to the medium in question.

Here is a short example of letter-based Dissociated Press applied to the same source:

window sysIWYG: n. A bit was named aften /bee't*/ prefer to use the other guy's re, especially in every cast a chuckle on neithout getting into useful informash speech makes removing a featuring a move or usage actual abstractionsidered interj. Indeed spectace logic or problem!

A hackish idle pastime is to apply letter-based Dissociated Press to a random body of text and {vgrep} the output in hopes of finding an interesting new word. (In the preceding example, `window sysIWYG' and `informash' show some promise.) Iterated applications of Dissociated Press usually yield better results. Similar techniques called `travesty generators' have been employed with considerable satirical effect to the utterances of USENET flamers; see {pseudo}.

:distribution: n. 1. A software source tree packaged for distribution; but see {kit}. 2. A vague term encompassing mailing lists and USENET newsgroups (but not {BBS} {fora}); any topic-oriented message channel with multiple recipients. 3. An information-space domain (usually loosely correlated with geography) to which propagation of a USENET message is restricted; a much-underutilized feature.

:do protocol: [from network protocol programming] vi. To perform an interaction with somebody or something that follows a clearly defined procedure. For example, "Let's do protocol with the check" at a restaurant means to ask for the check, calculate the tip and everybody's share, collect money from everybody, generate change as necessary, and pay the bill. See {protocol}.

:doc: /dok/ n. Common spoken and written shorthand for `documentation'. Often used in the plural `docs' and in the construction `doc file' (documentation available on-line).

:doco: /do'koh/ [orig. in-house jargon at Symbolics] n. A documentation writer. See also {devo} and {mango}.

:documentation:: n. The multiple kilograms of macerated, pounded, steamed, bleached, and pressed trees that accompany most modern software or hardware products (see also {tree-killer}). Hackers seldom read paper documentation and (too) often resist writing it; they prefer theirs to be terse and on-line. A common comment on this is "You can't {grep} dead trees". See {drool-proof paper}, {verbiage}.

:dodgy: adj. Syn. with {flaky}. Preferred outside the U.S.

:dogcow: /dog'kow/ n. See {Moof}.

:dogwash: /dog'wosh/ [From a quip in the `urgency' field of a very optional software change request, ca. 1982. It was something like "Urgency: Wash your dog first".] 1. n. A project of minimal priority, undertaken as an escape from more serious work. 2. v. To engage in such a project. Many games and much {freeware} get written this way.

:domainist: /doh-mayn'ist/ adj. 1. Said of an {{Internet address}} (as opposed to a {bang path}) because the part to the right of the `@' specifies a nested series of `domains'; for example, eric@snark.thyrsus.com specifies the machine called snark in the subdomain called thyrsus within the top-level domain called com. See also {big-endian}, sense 2. 2. Said of a site, mailer, or routing program which knows how to handle domainist addresses. 3. Said of a person (esp. a site admin) who prefers domain addressing, supports a domainist mailer, or prosyletizes for domainist addressing and disdains {bang path}s. This is now (1991) semi-obsolete, as most sites have converted.

:Don't do that, then!: [from an old doctor's office joke about a patient with a trivial complaint] Stock response to a user complaint. "When I type control-S, the whole system comes to a halt for thirty seconds." "Don't do that, then!" (or "So don't do that!"). Compare {RTFM}.

:dongle: /dong'gl/ n. 1. A security or {copy protection} device for commercial microcomputer programs consisting of a serialized EPROM and some drivers in a D-25 connector shell, which must be connected to an I/O port of the computer while the program is run. Programs that use a dongle query the port at startup and at programmed intervals thereafter, and terminate if it does not respond with the dongle's programmed validation code. Thus, users can make as many copies of the program as they want but must pay for each dongle. The idea was clever, but it was initially a failure, as users disliked tying up a serial port this way. Most dongles on the market today (1991) will pass data through the port and monitor for {magic} codes (and combinations of status lines) with minimal if any interference with devices further down the line --- this innovation was necessary to allow daisy-chained dongles for multiple pieces of software. The devices are still not widely used, as the industry has moved away from copy-protection schemes in general. 2. By extension, any physical electronic key or transferrable ID required for a program to function. See {dongle-disk}.

[Note: in early 1992, advertising copy from Rainbow Technologies (a manufacturer of dongles) included a claim that the word derived from "Don Gall", allegedly the inventor of the device. The company's receptionist will cheerfully tell you that the story is a myth invented for the ad copy. Nevertheless, I expect it to haunt my life as a lexicographer for at least the next ten years. ---ESR]

:dongle-disk: /don'gl disk/ n. See {dongle}; a `dongle-disk' is a floppy disk which is required in order to perform some task. Some contain special coding that allows an application to identify it uniquely, others *are* special code that does something that normally-resident programs don't or can't. (For example, AT&T's "Unix PC" would only come up in {root mode} with a special boot disk.) Also called a `key disk'.

:donuts: n.obs. A collective noun for any set of memory bits. This is extremely archaic and may no longer be live jargon; it dates from the days of ferrite-{core} memories in which each bit was implemented by a doughnut-shaped magnetic flip-flop.

:doorstop: n. Used to describe equipment that is non-functional and halfway expected to remain so, especially obsolete equipment kept around for political reasons or ostensibly as a backup. "When we get another Wyse-50 in here, that ADM 3 will turn into a doorstop." Compare {boat anchor}.

:dot file: [UNIX] n. A file which is not visible by default to normal directory-browsing tools (on UNIX, files named with a leading dot are, by convention, not normally presented in directory listings). Many programs define one or more dot files in which startup or configuration information may be optionally recorded; a user can customize the program's behavior by creating the appropriate file in the current or home directory. (Therefore, dot files tend to {creep} --- with every nontrivial application program defining at least one, a user's home directory can be filled with scores of dot files, of course without the user's really being aware of it.) See also {rc file}.

:double bucky: adj. Using both the CTRL and META keys. "The command to burn all LEDs is double bucky F."

This term originated on the Stanford extended-ASCII keyboard, and was later taken up by users of the {space-cadet keyboard} at MIT. A typical MIT comment was that the Stanford {bucky bits} (control and meta shifting keys) were nice, but there weren't enough of them; you could type only 512 different characters on a Stanford keyboard. An obvious way to address this was simply to add more shifting keys, and this was eventually done; but a keyboard with that many shifting keys is hard on touch-typists, who don't like to move their hands away from the home position on the keyboard. It was half-seriously suggested that the extra shifting keys be implemented as pedals; typing on such a keyboard would be very much like playing a full pipe organ. This idea is mentioned in a parody of a very fine song by Jeffrey Moss called "Rubber Duckie", which was published in `The Sesame Street Songbook' (Simon and Schuster 1971, ISBN 0-671-21036-X). These lyrics were written on May 27, 1978, in celebration of the Stanford keyboard:

Double Bucky

Double bucky, you're the one! You make my keyboard lots of fun. Double bucky, an additional bit or two: (Vo-vo-de-o!) Control and meta, side by side, Augmented ASCII, nine bits wide! Double bucky! Half a thousand glyphs, plus a few! Oh, I sure wish that I Had a couple of Bits more! Perhaps a Set of pedals to Make the number of Bits four: Double double bucky! Double bucky, left and right OR'd together, outta sight! Double bucky, I'd like a whole word of Double bucky, I'm happy I heard of Double bucky, I'd like a whole word of you!

--- The Great Quux (with apologies to Jeffrey Moss)

[This, by the way, is an excellent example of computer {filk} --- ESR] See also {meta bit}, {cokebottle}, and {quadruple bucky}.

:double DECkers: n. Used to describe married couples in which both partners work for Digital Equipment Corporation.

:doubled sig: [USENET] n. A {sig block} that has been included twice in a {USENET} article or, less commonly, in an electronic mail message. An article or message with a doubled sig can be caused by improperly configured software. More often, however, it reveals the author's lack of experience in electronic communication. See {BIFF}, {pseudo}.

:down: 1. adj. Not operating. "The up escalator is down" is considered a humorous thing to say, and "The elevator is down" always means "The elevator isn't working" and never refers to what floor the elevator is on. With respect to computers, this usage has passed into the mainstream; the extension to other kinds of machine is still hackish. 2. `go down' vi. To stop functioning; usually said of the {system}. The message from the {console} that every hacker hates to hear from the operator is "The system will go down in 5 minutes". 3. `take down', `bring down' vt. To deactivate purposely, usually for repair work or {PM}. "I'm taking the system down to work on that bug in the tape drive." Occasionally one hears the word `down' by itself used as a verb in this vt. sense. See {crash}; oppose {up}.

:download: vt. To transfer data or (esp.) code from a larger `host' system (esp. a {mainframe}) over a digital comm link to a smaller `client' system, esp. a microcomputer or specialized peripheral. Oppose {upload}.

However, note that ground-to-space communications has its own usage rule for this term. Space-to-earth transmission is always download and the reverse upload regardless of the relative size of the computers involved. So far the in-space machines have invariably been smaller; thus the upload/download distinction has been reversed from its usual sense.

:DP: /D-P/ n. 1. Data Processing. Listed here because, according to hackers, use of the term marks one immediately as a {suit}. See {DPer}. 2. Common abbrev for {Dissociated Press}.

:DPB: /d*-pib'/ [from the PDP-10 instruction set] vt. To plop something down in the middle. Usage: silly. "DPB yourself into that couch there." The connotation would be that the couch is full except for one slot just big enough for you to sit in. DPB means `DePosit Byte', and was the name of a PDP-10 instruction that inserts some bits into the middle of some other bits. This usage has been kept alive by the Common LISP function of the same name.

:DPer: /dee-pee-er/ n. Data Processor. Hackers are absolutely amazed that {suit}s use this term self-referentially. "*Computers* process data, not people!" See {DP}.

:dragon: n. [MIT] A program similar to a {daemon}, except that it is not invoked at all, but is instead used by the system to perform various secondary tasks. A typical example would be an accounting program, which keeps track of who is logged in, accumulates load-average statistics, etc. Under ITS, many terminals displayed a list of people logged in, where they were, what they were running, etc., along with some random picture (such as a unicorn, Snoopy, or the Enterprise), which was generated by the `name dragon'. Usage: rare outside MIT --- under UNIX and most other OSes this would be called a `background demon' or {daemon}. The best-known UNIX example of a dragon is `cron(1)'. At SAIL, they called this sort of thing a `phantom'.

:Dragon Book: n. The classic text `Compilers: Principles, Techniques and Tools', by Alfred V. Aho, Ravi Sethi, and Jeffrey D. Ullman (Addison-Wesley 1986; ISBN 0-201-10088-6), so called because of the cover design featuring a dragon labeled `complexity of compiler design' and a knight bearing the lance `LALR parser generator' among his other trappings. This one is more specifically known as the `Red Dragon Book' (1986); an earlier edition, sans Sethi and titled `Principles Of Compiler Design' (Alfred V. Aho and Jeffrey D. Ullman; Addison-Wesley, 1977; ISBN 0-201-00022-9), was the `Green Dragon Book' (1977). (Also `New Dragon Book', `Old Dragon Book'.) The horsed knight and the Green Dragon were warily eying each other at a distance; now the knight is typing (wearing gauntlets!) at a terminal showing a video-game representation of the Red Dragon's head while the rest of the beast extends back in normal space. See also {{book titles}}.

:drain: [IBM] v. Syn. for {flush} (sense 2). Has a connotation of finality about it; one speaks of draining a device before taking it offline.

:dread high-bit disease: n. A condition endemic to PRIME (a.k.a. PR1ME) minicomputers that results in all the characters having their high (0x80) bit ON rather than OFF. This of course makes transporting files to other systems much more difficult, not to mention talking to true 8-bit devices. Folklore had it that PRIME adopted the reversed-8-bit convention in order to save 25 cents per serial line per machine; PRIME old-timers, on the other hand, claim they inherited the disease from Honeywell via customer NASA's compatibility requirements and struggled manfully to cure it. Whoever was responsible, this probably qualifies as one of the most {cretinous} design tradeoffs ever made. See {meta bit}. A few other machines have exhibited similar brain damage.

:DRECNET: /drek'net/ [from Yiddish/German `dreck', meaning dirt] n. Deliberate distortion of DECNET, a networking protocol used in the {VMS} community. So called because DEC helped write the Ethernet specification and then (either stupidly or as a malignant customer-control tactic) violated that spec in the design of DRECNET in a way that made it incompatible. See also {connector conspiracy}.

:driver: n. 1. The {main loop} of an event-processing program; the code that gets commands and dispatches them for execution. 2. [techspeak] In `device driver', code designed to handle a particular peripheral device such as a magnetic disk or tape unit. 3. In the TeX world and the computerized typesetting world in general, `driver' also means a program that translates some device-independent or other common format to something a real device can actually understand.

:droid: n. A person (esp. a low-level bureaucrat or service-business employee) exhibiting most of the following characteristics: (a) na"ive trust in the wisdom of the parent organization or `the system'; (b) a propensity to believe obvious nonsense emitted by authority figures (or computers!); blind faith; (c) a rule-governed mentality, one unwilling or unable to look beyond the `letter of the law' in exceptional situations; and (d) no interest in fixing that which is broken; an "It's not my job, man" attitude.

Typical droid positions include supermarket checkout assistant and bank clerk; the syndrome is also endemic in low-level government employees. The implication is that the rules and official procedures constitute software that the droid is executing. This becomes a problem when the software has not been properly debugged. The term `droid mentality' is also used to describe the mindset behind this behavior. Compare {suit}, {marketroid}; see {-oid}.

:drool-proof paper: n. Documentation that has been obsessively {dumbed down}, to the point where only a {cretin} could bear to read it, is said to have succumbed to the `drool-proof paper syndrome' or to have been `written on drool-proof paper'. For example, this is an actual quote from Apple's LaserWriter manual: "Do not expose your LaserWriter to open fire or flame."

:drop on the floor: vt. To react to an error condition by silently discarding messages or other valuable data. "The gateway ran out of memory, so it just started dropping packets on the floor." Also frequently used of faulty mail and netnews relay sites that lose messages. See also {black hole}, {bit bucket}.

:drop-ins: [prob. by analogy with {drop-outs}] n. Spurious characters appearing on a terminal or console as a result of line noise or a system malfunction of some sort. Esp. used when these are interspersed with one's own typed input. Compare {drop-outs}.

:drop-outs: n. 1. A variety of `power glitch' (see {glitch}); momentary 0 voltage on the electrical mains. 2. Missing characters in typed input due to software malfunction or system saturation (this can happen under UNIX when a bad connection to a modem swamps the processor with spurious character interrupts). 3. Mental glitches; used as a way of describing those occasions when the mind just seems to shut down for a couple of beats. See {glitch}, {fried}.

:drugged: adj. (also `on drugs') 1. Conspicuously stupid, heading toward {brain-damaged}. Often accompanied by a pantomime of toking a joint (but see {appendix B}). 2. Of hardware, very slow relative to normal performance.

:drum: adj,n. Ancient techspeak term referring to slow, cylindrical magnetic media which were once state-of-the-art mass-storage devices. Under BSD UNIX the disk partition used for swapping is still called `/dev/drum'; this has led to considerable humor and not a few straight-faced but utterly bogus `explanations' getting foisted on {newbie}s. See also "{The Story of Mel, a Real Programmer}" in {appendix A}.

:drunk mouse syndrome: (also `mouse on drugs') n. A malady exhibited by the mouse pointing device of some computers. The typical symptom is for the mouse cursor on the screen to move in random directions and not in sync with the motion of the actual mouse. Can usually be corrected by unplugging the mouse and plugging it back again. Another recommended fix for optical mice is to rotate your mouse pad 90 degrees.

At Xerox PARC in the 1970s, most people kept a can of copier cleaner (isopropyl alcohol) at their desks. When the steel ball on the mouse had picked up enough {cruft} to be unreliable, the mouse was doused in cleaner, which restored it for a while. However, this operation left a fine residue that accelerated the accumulation of cruft, so the dousings became more and more frequent. Finally, the mouse was declared `alcoholic' and sent to the clinic to be dried out in a CFC ultrasonic bath.

:Duff's device: n. The most dramatic use yet seen of {fall through} in C, invented by Tom Duff when he was at Lucasfilm. Trying to {bum} all the instructions he could out of an inner loop that copied data serially onto an output port, he decided to {unroll} it. He then realized that the unrolled version could be implemented by *interlacing* the structures of a switch and a loop:

register n = (count + 7) / 8; /* count > 0 assumed */

switch (count % 8) { case 0: do { *to = *from++; case 7: *to = *from++; case 6: *to = *from++; case 5: *to = *from++; case 4: *to = *from++; case 3: *to = *from++; case 2: *to = *from++; case 1: *to = *from++; } while (--n > 0); }

Having verified that the device is valid portable C, Duff announced it. C's default {fall through} in case statements has long been its most controversial single feature; Duff observed that "This code forms some sort of argument in that debate, but I'm not sure whether it's for or against."

:dumb terminal: n. A terminal which is one step above a {glass tty}, having a minimally-addressable cursor but no on-screen editing or other features which are claimed by a {smart terminal}. Once upon a time, when glass ttys were common and addressable cursors were something special, what is now called a dumb terminal could pass for a smart terminal.

:dumbass attack: /duhm'as *-tak'/ [Purdue] n. Notional cause of a novice's mistake made by the experienced, especially one made while running as {root} under UNIX, e.g., typing `rm -r *' or `mkfs' on a mounted file system. Compare {adger}.

:dumbed down: adj. Simplified, with a strong connotation of *over*simplified. Often, a {marketroid} will insist that the interfaces and documentation of software be dumbed down after the designer has burned untold gallons of midnight oil making it smart. This creates friction. See {user-friendly}.

:dump: n. 1. An undigested and voluminous mass of information about a problem or the state of a system, especially one routed to the slowest available output device (compare {core dump}), and most especially one consisting of hex or octal {runes} describing the byte-by-byte state of memory, mass storage, or some file. In {elder days}, debugging was generally done by `groveling over' a dump (see {grovel}); increasing use of high-level languages and interactive debuggers has made this uncommon, and the term `dump' now has a faintly archaic flavor. 2. A backup. This usage is typical only at large timesharing installations.