:Ninety-Ninety Rule: /n./ "The first 90% of the code accounts
for the first 90% of the development time. The remaining 10% of
the code accounts for the other 90% of the development time."
Attributed to Tom Cargill of Bell Labs, and popularized by Jon
Bentley's September 1985 "Bumper-Sticker Computer Science"
column in "Communications of the ACM". It was there called
the "Rule of Credibility", a name which seems not to have stuck.
:NMI: /N-M-I/ /n./ Non-Maskable Interrupt. An IRQ 7 on the
PDP-11 or 680[01234]0; the NMI line on an 80[1234]86. In contrast
with a {priority interrupt} (which might be ignored, although
that is unlikely), an NMI is *never* ignored. Except, that
is, on {clone} boxes, where NMI is often ignored on the
motherboard because flaky hardware can generate many spurious
ones.
:no-op: /noh'op/ /n.,v./ alt. NOP /nop/ [no operation] 1. A machine instruction that does nothing (sometimes used in assembler-level programming as filler for data or patch areas, or to overwrite code to be removed in binaries). See also {JFCL}. 2. A person who contributes nothing to a project, or has nothing going on upstairs, or both. As in "He's a no-op." 3. Any operation or sequence of operations with no effect, such as circling the block without finding a parking space, or putting money into a vending machine and having it fall immediately into the coin-return box, or asking someone for help and being told to go away. "Oh, well, that was a no-op." Hot-and-sour soup (see {great-wall}) that is insufficiently either is `no-op soup'; so is wonton soup if everybody else is having hot-and-sour.
:noddy: /nod'ee/ /adj./ [UK: from the children's books] 1. Small and un-useful, but demonstrating a point. Noddy programs are often written by people learning a new language or system. The archetypal noddy program is {hello, world}. Noddy code may be used to demonstrate a feature or bug of a compiler. May be used of real hardware or software to imply that it isn't worth using. "This editor's a bit noddy." 2. A program that is more or less instant to produce. In this use, the term does not necessarily connote uselessness, but describes a {hack} sufficiently trivial that it can be written and debugged while carrying on (and during the space of) a normal conversation. "I'll just throw together a noddy {awk} script to dump all the first fields." In North America this might be called a {mickey mouse program}. See {toy program}.
:node: /n./ 1. [Internet, UUCP] A host machine on the network. 2. [MS-DOS BBSes] A dial-in line on a BBS. Thus an MS-DOS {sysop} might say that his BBS has 4 nodes even though it has a single machine and no Internet link, confusing an Internet hacker no end.
:NOMEX underwear: /noh'meks uhn'-der-weir/ /n./ [Usenet] Syn. {asbestos longjohns}, used mostly in auto-related mailing lists and newsgroups. NOMEX underwear is an actual product available on the racing equipment market, used as a fire resistance measure and required in some racing series.
:Nominal Semidestructor: /n./ Soundalike slang for `National Semiconductor', found among other places in the Networking/2 networking sources. During the late 1970s to mid-1980s this company marketed a series of microprocessors including the NS16000 and NS32000 and several variants. At one point early in the great microprocessor race, the specs on these chips made them look like serious competition for the rising Intel 80x86 and Motorola 680x0 series. Unfortunately, the actual parts were notoriously flaky and never implemented the full instruction set promised in their literature, apparently because the company couldn't get any of the mask steppings to work as designed. They eventually sank without trace, joining the Zilog Z8000 and a few even more obscure also-rans in the graveyard of forgotten microprocessors. Compare {HP-SUX}, {AIDX}, {buglix}, {Macintrash}, {Telerat}, {Open DeathTrap}, {ScumOS}, {sun-stools}.
:non-optimal solution: /n./ (also `sub-optimal solution') An astoundingly stupid way to do something. This term is generally used in deadpan sarcasm, as its impact is greatest when the person speaking looks completely serious. Compare {stunning}. See also {Bad Thing}.
:nonlinear: /adj./ [scientific computation] 1. Behaving in an erratic and unpredictable fashion; unstable. When used to describe the behavior of a machine or program, it suggests that said machine or program is being forced to run far outside of design specifications. This behavior may be induced by unreasonable inputs, or may be triggered when a more mundane bug sends the computation far off from its expected course. 2. When describing the behavior of a person, suggests a tantrum or a {flame}. "When you talk to Bob, don't mention the drug problem or he'll go nonlinear for hours." In this context, `go nonlinear' connotes `blow up out of proportion' (proportion connotes linearity).
:nontrivial: /adj./ Requiring real thought or significant computing power. Often used as an understated way of saying that a problem is quite difficult or impractical, or even entirely unsolvable ("Proving P=NP is nontrivial"). The preferred emphatic form is `decidedly nontrivial'. See {trivial}, {uninteresting}, {interesting}.