The Hacker's Dictionary, - [best reads of all time .txt] 📗

can generate ideas and actually emit them in speech. For example, noted computer architect C. Gordon Bell (designer of the PDP-11) is said, with some awe, to think at about 1200 mL but only talk at about 300; he is frequently reduced to fragments of sentences as his mouth tries to keep up with his speeding brain.

:minifloppies: n. 5.25-inch {vanilla} floppy disks, as opposed to 3.5-inch or {microfloppies} and the now-obsolescent 8-inch variety. At one time, this term was a trademark of Shugart Associates for their SA-400 minifloppy drive. Nobody paid any attention. See {stiffy}.

:MIPS: /mips/ [abbreviation] n. 1. A measure of computing speed; formally, `Million Instructions Per Second' (that's 10^6

per second, not 2^(20)!); often rendered by hackers as Meaningless Indication of Processor Speed' or in other unflattering ways. This joke expresses a nearly universal attitude about the value of most {benchmark} claims, said attitude being one of the great cultural divides between hackers and {marketroid}s. The singular is sometimes1 MIP' even though this is clearly etymologically wrong. See also {KIPS} and {GIPS}. 2. Computers, especially large computers, considered abstractly as sources of {computron}s. "This is just a workstation; the heavy MIPS are hidden in the basement." 3. The corporate name of a particular RISC-chip company; among other things, they designed the processor chips used in DEC's 3100

workstation series. 4. Acronym for `Meaningless Information per Second' (a joke, prob. from sense 1).

:misbug: /mis-buhg/ [MIT] n. An unintended property of a program that turns out to be useful; something that should have been a {bug} but turns out to be a {feature}. Usage: rare. Compare {green lightning}. See {miswart}.

:misfeature: /mis-fee'chr/ or /mis'fee`chr/ n. A feature that eventually causes lossage, possibly because it is not adequate for a new situation which has evolved. Since it results from a deliberate and properly-implemented feature, a misfeature is not a bug. Nor is it a simple unforeseen side effect; the term implies that the feature in question was carefully planned, but its long-term consequences were not accurately or adequately predicted (which is quite different from not having thought ahead at all). A misfeature can be a particularly stubborn problem to resolve, because fixing it usually involves a substantial philosophical change to the structure of the system involved.

Many misfeatures (especially in user-interface design) arise because the designers/implementors mistake their personal tastes for laws of nature. Often a former feature becomes a misfeature because a tradeoff was made whose parameters subsequently change (possibly only in the judgment of the implementors). "Well, yeah, it is kind of a misfeature that file names are limited to 6

characters, but the original implementors wanted to save directory space and we're stuck with it for now."

:Missed'em-five: n. Pejorative hackerism for AT&T System V UNIX, generally used by {BSD} partisans in a bigoted mood. (The synonym `SysVile' is also encountered.) See {software bloat}, {Berzerkeley}.

:missile address: n. See {ICBM address}.

:miswart: /mis-wort/ [from {wart} by analogy with {misbug}] n.

A {feature} that superficially appears to be a {wart} but has been determined to be the {Right Thing}. For example, in some versions of the {EMACS} text editor, the `transpose characters' command exchanges the character under the cursor with the one before it on the screen, except when the cursor is at the end of a line, in which case the two characters before the cursor are exchanged.

While this behavior is perhaps surprising, and certainly inconsistent, it has been found through extensive experimentation to be what most users want. This feature is a miswart.

:moby: /moh'bee/ [MIT: seems to have been in use among model railroad fans years ago. Derived from Melville's `Moby Dick'

(some say from `Moby Pickle').] 1. adj. Large, immense, complex, impressive. "A Saturn V rocket is a truly moby frob." "Some MIT undergrads pulled off a moby hack at the Harvard-Yale game."

(See "{The Meaning of Hack'}"). 2. n. obs. The maximum address space of a machine (see below). For a 680[234]0 or VAX or most modern 32-bit architectures, it is 4,294,967,296 8-bit bytes (4 gigabytes). 3. A title of address (never of third-person reference), usually used to show admiration, respect, and/or friendliness to a competent hacker. "Greetings, moby Dave. How's that address-book thing for the Mac going?" 4. adj. In backgammon, doubles on the dice, as inmoby sixes', moby ones', etc. Compare this with {bignum} (sense 2): double sixes are both bignums and moby sixes, but moby ones are not bignums (the use ofmoby' to describe double ones is sarcastic). Standard emphatic forms: Moby foo',moby win', moby loss'.Foby moo': a spoonerism due to Richard Greenblatt.

This term entered hackerdom with the Fabritek 256K memory added to the MIT AI PDP-6 machine, which was considered unimaginably huge when it was installed in the 1960s (at a time when a more typical memory size for a timesharing system was 72 kilobytes). Thus, a moby is classically 256K 36-bit words, the size of a PDP-6 or PDP-10 moby. Back when address registers were narrow the term was more generally useful, because when a computer had virtual memory mapping, it might actually have more physical memory attached to it than any one program could access directly. One could then say "This computer has 6 mobies" meaning that the ratio of physical memory to address space is 6, without having to say specifically how much memory there actually is. That in turn implied that the computer could timeshare six `full-sized' programs without having to swap programs between memory and disk.

Nowadays the low cost of processor logic means that address spaces are usually larger than the most physical memory you can cram onto a machine, so most systems have much less than one theoretical native' moby of {core}. Also, more modern memory-management techniques (esp. paging) make themoby count' less significant.

However, there is one series of popular chips for which the term could stand to be revived --- the Intel 8088 and 80286 with their incredibly {brain-damaged} segmented-memory designs. On these, a `moby' would be the 1-megabyte address span of a segment/offset pair (by coincidence, a PDP-10 moby was exactly 1 megabyte of 9-bit bytes).

:mod: vt.,n. 1. Short for modify' ormodification'. Very commonly used --- in fact the full terms are considered markers that one is being formal. The plural `mods' is used esp. with reference to bug fixes or minor design changes in hardware or software, most esp. with respect to {patch} sets or a {diff}.

Short for {modulo} but used only for its techspeak sense.

:mode: n. A general state, usually used with an adjective describing the state. Use of the word mode' rather thanstate' implies that the state is extended over time, and probably also that some activity characteristic of that state is being carried out. "No time to hack; I'm in thesis mode." In its jargon sense, `mode' is most often attributed to people, though it is sometimes applied to programs and inanimate objects. In particular, see {hack mode}, {day mode}, {night mode}, {demo mode}, {fireworks mode}, and {yoyo mode}; also {talk mode}.

One also often hears the verbs enable' anddisable' used in connection with jargon modes. Thus, for example, a sillier way of saying "I'm going to crash" is "I'm going to enable crash mode now". One might also hear a request to "disable flame mode, please".

In a usage much closer to techspeak, a mode is a special state which certain user interfaces must pass into in order to perform certain functions. For example, in order to insert characters into a document in the UNIX editor `vi', one must type the "i" key, which invokes the "Insert" command. The effect of this command is to put vi into "insert mode", in which typing the "i" key has a quite different effect (to wit, it inserts an "i" into the document). One must then hit another special key, "ESC", in order to leave "insert mode". Nowadays, moded interfaces are generally considered {losing}, but survive in quite a few widely-used tools built in less enlightened times.

:mode bit: n. A {flag}, usually in hardware, that selects between two (usually quite different) modes of operation. The connotations are different from {flag} bit in that mode bits are mainly written during a boot or set-up phase, are seldom explicitly read, and seldom change over the lifetime of an ordinary program. The classic example was the EBCDIC-vs.-ASCII bit (#12) of the Program Status Word of the IBM 360. Another was the bit on a PDP-12 that controlled whether it ran the PDP-8 or the LINC instruction set.

:modulo: /mo'dyu-loh/ prep. Except for. An overgeneralization of mathematical terminology; one can consider saying that 4 = 22 except for the 9s (4 = 22 mod 9). "Well, LISP seems to work okay now, modulo that {GC} bug." "I feel fine today modulo a slight headache."

:molly-guard: /mol'ee-gard/ [University of Illinois] n. A shield to prevent tripping of some {Big Red Switch} by clumsy or ignorant hands. Originally used of some plexiglass covers improvised for the BRS on an IBM 4341 after a programmer's toddler daughter (named Molly) frobbed it twice in one day. Later generalized to covers over stop/reset switches on disk drives and networking equipment.

:Mongolian Hordes technique: n. Development