ICD: Installable Client Driver.
IDE: Integrated Drive Electronics. The most popular hard
drive interface, whose controller functions are built into the drive's circuitry.
All motherboards today come standard with two IDE channels that can each control
up to two devices. Hard drives connect to these interfaces via a 40-pin connector.
IEEE 1394: Also known as FireWire in the Macintosh market.
A high-speed bus protocol that transfers data at up to 400Mbits per second.
1394 is a great interface for digital video peripherals and may someday be
used for high-speed modems.
IEEE 802.3: An IEEE standard that describes twisted-pair
Ethernet wiring using baseband signaling. Although IEEE 802.3 generally covers
speeds all the way up to 10Mbps, it is generally now only used in reference
to 10BaseT.
IEEE 802.3u: An IEEE standard that covers 100Mbps Fast
Ethernet.
image size: A particular image resolution.
image map: A web image with multiple associated links instead
of just one. Image maps can be built as both "client side" (the browser supports
the code to define where users can click) or "server side" (the Web server
supports the code to define where users can click). All 3.0 browsers and up
support client-side image maps, which is recommended.
image-to-image transfers: The DirectX transforms between
images. This is similar to a Photoshop filter such as blur, wipe, and fade.
INF: INFormation file. A file that contains installation
information for applications and hardware.
initial reflections: When a sound is made in an enclosed
space, it bounces off all the surfaces repeatedly. Our ears and brains make
use of the first few bounces we hear, called the "initial reflections," to
judge how far we are from nearby walls. However, once sound that has come
via multiple bounces begins to reach our ears, we perceive the effect as reverberation
and can no longer use the information to locate any particular feature of
the space.
Installable Client Driver: see OpenGL ICD
integer: A whole number, such as 1, 2, 3, etc. Computers can manipulate integers
much faster and more accurately than they can manipulate floating-point numbers
(fractions), but integers aren't precise enough for some operations.
integrated circuit: The blanket term for all computer chips--CPUs,
memory modules, core-logic chipsets, 3D accelerators, and even the chips run
$10 calculators. All integrated circuits contain microscopic layers of circuit
paths applied by photolithography.
integrated processors: A processor that, in addition to
the CPU core, offers additional functionality, such as built-in 3D acceleration
or audio. Integrated processors generally offer a cost benefit, but the "everything
but the kitchen sink" approach can sometimes detract from overall performance.
integrated signal processor: see DSP
integration: Adding more functions to a chip. Over time,
advances in manufacturing technology make it possible to squeeze more transistors
onto a silicon chip. Engineers can use those transistors to add more functionality.
Devices that used to be built as separate chips can be combined into a single
chip.
interactive virtual sets: A realistic-looking set that's
been created using 3D software. When the talent are standing in front of a
blue screen, they can be chroma keyed out and their backgrounds and foregrounds
can be replaced with an interactive virtual set.
interchangeable lens: The ability to remove one lens from
a camera and replace with a more appropriate model, usually either wide-angle,
telephoto, or macro.
interface burst speed: The speed that data can be accessed
from the drive's onboard read-ahead memory. This measures the speed of the
drive and controller interface.
interleave: Interleaving, or the staggering of sectors,
gives the hard drive time to read all the sectors it needs to in a single
rotation. By allowing the drive to read sectors #1, #7 and #13 and then picking
up sectors #2 and so on, the drive is able to eliminate wasted rotations.
internal rendering: Refers to the color-depth a 3D accelerator
will render a scene at. Depending on the videocard, this may be 16-bit (64K
colors), 24-bit (16 million colors) or 32-bit (16 million colors plus 8-bit
alpha). The higher the internal-rendering bit depth, the more colorful the
output.
interlaced: When even lines are displayed after odd lines
on a CRT (Cathode Ray Tube) terminal or TV. This method of displaying an image
creates an irritating flutter that is visible when still images such as text
are displayed. Most computer displays are noninterlaced.
interpolation: A mathematical process used to estimate a value that lies between
two known values.
interrupt: A signal informing a program that an event has
occurred. When a program receives an interrupt signal, it takes a specified
action (which can be to ignore the signal). Interrupt signals can cause a
program to suspend itself temporarily to service the interrupt. Interrupt
signals can come from a variety of sources. For example, every keystroke generates
an interrupt signal. Interrupts can also be generated by other devices, such
as a printer, to indicate that some event has occurred. These are called hardware
interrupts. Interrupt signals initiated by programs are called software interrupts.
intranet: An internal corporate network. An intranet web
site looks and acts just like any other web site, but includes a secure firewall
to protect it from unauthorized entry from nonemployees.
inverse kinematics: A system of defining interrelationships
between objects linked in a hierarchy. Each object is moved according to these
relationships relative to the others. The "inverse" designation signifies
that the last object in the chain is moved and the relative movement is computed
from it up through the last or root object (highest in the hierarchy) rather
than from the highest to the lowest in the chain (forward kinematics).
invisible images: Transparent images on web pages with
pixel-level precision. You can make a clear/invisible image in any image-editing
tool that exports transparent GIFs.
I/O connector: Any connector that allows a user to add-on
a device for the computer's use. A serial or parallel port is one example
of an I/O port. An AGP or PCI expansion slot is another example of an I/O
connector, where devices can be connected to a PC.
IP address: A unique number that identifies a PC or some
other device on a network. (IP stands for Internet Protocol.) Every computer
attached to the Internet has an IP address, although it's common for multiple
computers to share a pool of addresses.
IPX: Internetwork Packet Exchange. A networking protocol
developed for Novell NetWare networks that can route messages from one node
to another. It's usually used in conjunction with SPX so that complete delivery
of data packets is guaranteed. IPX data packets include network addresses
which is why it is a routable protocol. IPX resides at layers 3 (Network Layer)
and 4 (Transport Layer) of the OSI model.
IPX/SPX: Internet Packet Exchange/Sequenced Packet Exchange.
Closely linked protocols that help data get from Point A to Point B across
a network. IPX routes data packets to the appropriate network node. Because
data packets can sometimes get lost while traversing a network, SPX ensures
that all the packets belonging to a single file get to the node intact.
IrDA: Infrared data-transfer protocol that allows wireless
connections between conforming hardware.
IRQ: Interrupt Request. Unless coded to cooperate with
each other, no two parts of a computer can access CPU cycles at precisely
the same time. The sundry installed devices must therefore send Interrupt
Requests to the operating system, asking for the processor's undivided attention.
In modern computers, IRQ-dependent devices (e.g., keyboards, mice, soundcards)
vie for interrupt priority among 16 different IRQ slots. If you need to install
a new IRQ-dependent device but have run out of slots, you're out of luck,
Bucky.
ISA: Industry Standard Architecture. Hailing from the early
days of the PC, the ISA bus runs at from 8MHz to 10MHz with a maximum throughput
of 8MB a second. Think slower than a Yugo.
ISDN: Integrated Services Digital Network. An international
digital telecommunications standard that accommodates voice, data, and signaling
over digital telephone lines. Its two common twisted pairs of wires deliver
two 64Kbps bearer signals and one 16Kbps data signal. The two bearer signals
can be used simultaneously, one for voice and one for data, or you can use
both lines for data for data rates of 128Kbps.
isoparm: Isoparameter. Subdivision of a NURBS.
ISO: ISO 9660 is a specification defined by the ISO standards
organization that outlines how a CD-ROM directory format is to be laid out
and read between different computer systems. Using the ISO 9660 standard CD-ROM
file format, virtually any computer can read a CD-ROM disc. ISO is a least-common-denominator
file system 8-dot-3 naming conventions (limited to uppercase letters A to
Z, numerals 0 to 9, and the underscore character), and subdirectories are
limited to eight levels deep. A disc that is written to the ISO 9660 specification
will read on any ISO 9660-compliant drive.
ISP: Internet Service Provider. ISPs are companies that
sell Internet access to businesses and individuals. Local phone companies
and long-distance companies can be ISPs, but most ISPs are independent vendors.
ISV: Independent software vendor. A developer that creates software that is not proprietary to a single manufacturer or platform.