C/C++: Two closely related programming languages often used
by professionals for software development. C came first and is a conventional
procedural-type language. C++ came later and adds object-oriented extensions.
cache: A dedicated or reserved bank of memory that is used
to improve your computer's performance. It provides a temporary storage area
for instructions and data that acts as a fast swap to and from your CPU. The
larger the cache, the greater the performance.
CAD/CAM: Computer-Assisted Design/ Computer-Assisted Manufacturing.
Use of a computer to create schematics and blueprints. These systems must accurately
dimension aspects and calculate dependencies.
Cascading Style Sheets: A language applied to HTML to control
the style of a document: which fonts and colors to use, how much white space
to insert, etc. You specify the style at the top of the document, and it applies
to all the elements on a page.
Category # Cable: The rating placed on UTP cable by the Electronics
Industries Association (EIA) to explain how fast a cable can transmit data.
Cat cabling is broken down as follows:
Cat-1 and -2: Used for voice and low-speed data.
Cat-3: Used for data speeds up to 16Mbps.
Cat-4: Used for data speeds up to 20Mbps.
Cat-5: Used for data speeds up to 100Mbps.
Cat-5 Enhanced: Used for data speeds up to 200Mbps.
Cat-6: Used for data speeds up to 600Mbps.
Cathode Ray Tube: Traditional monitors contain CRTs, which work by passing an
electron beam through a screen filter and onto to a field of phosphorous dots,
which light up and define the image you see.
CAV: see Constant Angular Velocity
CCD: Charged Couple Device. It is a tiny silicon wafer that's
built into many of today's digital cameras and video camcorders. It's a sensor
used to convert light into a video signal, made up of thousands of tiny, light-sensitive
pixels that react to incoming light. Its tiny semiconductors are connected so
that the output of one serves as the input of the next. From there, the light
is converted into an electrical signal that can be recorded onto a videotape.
CD-DA: Compact Disc-Digital Audio. Music CDs, developed by
Sony and Philips in 1982.
CD-R: Compact Disc Recorder. A CD drive device that can not
only read, but also record data and music onto special media.
CD-ROM cache: A storage area in main system memory for frequently
accessed information (it's always faster to pull data off of high-speed memory
rather than slow-speed CD-ROM media).
CDRFS: see Compact Disc-Recordable File System
CD-RW: See Compact Disc-ReWritable
CD Text: An expansion of the CD audio format which adds information
such as artist names, and album and song titles to the table of contents. New
CD Text-enabled players can then take this info and display it during playback.
CF-2: Compact Flash 2. A postage stamp-sized industry-standard
memory module.
CGDC: Computer Game Developers Conference. An annual gathering
of electronic entertainment companies, gaming hardware vendors, and the developers
that love them.
Character Generator (CG): A software application for creating
titles and credits.
charge coupled device: A tiny silicon wafer that's built into
many of today's camcorders. It's used to convert light into a video signal.
It's made up of thousands of tiny, light-sensitive pixels that react to incoming
light. From there, the light is converted into an electrical signal that can
be recorded onto a videotape.
chipset Silicon chips on the motherboard that help direct instructions
from memory and the CPU and the various buses in the PC.
chroma key: Hardware effect that lets you sample out a colored
background, remove it from the picture, and replace it with something else.
chromakey: Replacing a specific color or range of colors, usually
a pure shade of blue or green, from a primary video source with part of a second
video source. It's how they get the weathermap behind the meteorologist, or
Superman to fly over Metropolis.
CHS IDE Mode Type: CHS (Cylinders, Heads, Sectors-per-track)
translations used to bypass the limits imposed by the OS. The parameters used
to determine the capacity of a hard drive. They are the actual number of cylinders,
heads, and sectors per track on the drive platters.
CIS: see Contact Image Sensor.
CISC: (pronounced sisk) Complex Instruction-Set Computing.
An architectural design style for microprocessors that dates back to the 1970s.
CISC processors try to conserve memory and other system resources by encoding
program instructions in a compact format and by using complex instructions that
perform multiple operations. Also see RISC.
class library: A collection of classes (object definitions)
that programmers use to build object-oriented programs. Essentially, it's a
prewritten code library that saves programmers from reinventing the wheel so
they can develop applications more rapidly.
client: A single-user computer attached to a network. Clients
are usually desktop PCs but can also include laptop computers and even hand-held
devices. Clients can access servers and sometimes other clients over the network.
client machine: Also known as an end-user machine. Represents
the performance limits that a game developer must keep in mind when designing
the latest and greatest technology.
clock cycle: One moment in the life of a microprocessor. During
this "tick," electrical signals flow through circuits and turn transistors
on or off, which is how a processor does its work. The number of clock ticks
per second is the clock frequency, typically expressed in megahertz (200MHz
equals 200 million cycles per second).
clock frequency: The rate at which a microprocessor performs
internal operations. This is regulated by a "clock" or oscillator
that synchronizes operations inside the chip. It's expressed in clock cycles,
e.g., 200MHz equals 200 million cycles per second.
clock multiplier: CPU speeds are determined by multiplying
the speed of the system bus by a variable number--the clock multiplier. For
example, a 550MHz CPU running on a 100MHz system bus uses a multiplier of 5.5.
clock speed: The frequency at which a CPU or 3D accelerator
chip operates. Measured in megahertz. The faster the clock speed, the more powerful
the chip.
cluster: Also called "allocation units," a cluster
is the number of sectors that the OS allocates each time disk space is needed.
For example, if the cluster size is 16 (thirty-two, 512B sectors per cluster),
then every file will use 16K even though the actual file size may be less. So
a small file that was only 1K would actually take up 16K.
CLV: see Constant Linear Velocity
CMOS: Complementary Metal Oxide Semiconductor. Sensor used
in digital cameras whose semiconductors use both negative and positive polarity
circuits and require less power than CCDs.
CMYK separations: Process of converting the RGB spectrum based
on the light spectrum to a reflective physics system based on the four colors
used in most printing: Cyan, Magenta, Yellow, and Black (which is represented
as "K").
co-axial S/PDIF: see S/PDIF
COBOL: COmmon Business-Oriented Language. COBOL is a programming
language that dates back to the 1950s and was the standard for many years on
mainframe computers. Some say that most of the code still running on computers
today was written in COBOL, but it has been largely superseded by modern languages.
code base: The foundation or backbone of the code infrastructure.
codec: A tool (either software or hardware) that takes an analog
signal and converts it to a digital signal and compresses it to your hard drive.
collision detection: The ability of a 3D object to physically
react to another 3D object in space and time.
color cast: Tint present across an entire image that does not
reflect the actual light being photographed.
color convergence: Each pixel on a CRT monitor is composed
of a red, green, and blue phosphor dot. The dots must be aligned--or converged--properly
to ensure a sharp display. Some high-end monitors have controls to correct misconvergence.
color shift: See color cast.
colored lighting: The first 3D games used simple white light to illuminate objects
and cast shadows. With the advent of faster CPUs and 3D hardware acceleration,
games now have the raw power to mix different colored lights to achieve more
spectacular ambient effects.
Command Tag Queuing: A feature of the SCSI-2 protocol that
allows device controllers to accept and queue multiple commands from multiple
host processes without waiting for a pending I/O request to be completed, resulting
in a more efficiently utilized SCSI bus. Basically, it allows devices to immediately
accept and execute other commands while data that has already been read or written
is sent back up the bus to the SCSI host adapter. It also allows the device
controller to execute commands in a different order than they may have been
received from the host adapter. Performance improves significantly when a device
is optimized to execute commands in a more intelligent order.
command turnaround: The turnaround time a computer takes between
the commands it issues to the drive. This command turnaround time--during which
the bus remains idle--is essentially overhead and constitutes a very significant
portion of the overall time available on the bus.
Compact Disc-Recordable: A write-once technology that uses
gold recordable discs. Standard 74min CD-R media can hold up to 650MB of data.
Compact Disc-Recordable File System: A file system developed
specifically for CD-R by Sony. It utilizes packet writing and requires a reader
driver that can be imbedded into each disc written that allows other computers
to read it. The disc requires a "link area" between packets on the
disc that links packets together. This creates overhead that reduces the size
of a typical 74min disc from 650MB to 520MB. After recording a session, you
are required to "freeze" the disc, enabling it to be read on a CD-ROM
drive. Each freeze performed consumes an additional 13.5MB of space.
Compact Disc-ReWritable: A rewritable technology whose media
can be written to and erased approximately 1,000 times before failure. Standard
74min CD-RW media can hold up to 500MB when formatted for fixed-length packet
writing.
CompactFlash: Portable memory format that is read, via adapter,
in PC card drives.
compiler: A tool that programmers use to convert their code
into object code (also known as binary code, executable code, or machine code).
Object code is the actual code that runs on a computer. Compilers also check
for errors in source code.
composite: TV A video signal where the red, blue, and green
signals are mixed together. Usually, the output connector will be an RCA cable
type.
compression: A way to shrink file size, to reduce in size or
volume. Compression is important to make large graphics take up less bandwidth.
compression algorithm: Formula that calculates how aggressively
an image processor replaces image data with smaller pattern information. The
end result is smaller files and more artifacting, in direct proportion.
compressors: A routine or program that compresses data.
Connect/Disconnect: Allows multiple connected drives to share
the SCSI bus bandwidth by allowing them to disconnect individually from the
SCSI bus when other drives/devices have information to send.
console game: Your basic "video game." Runs on a
self-contained, non-upgradable box, such as the Nintendo N64 or Sega Saturn,
instead of on a PC, which can be upgraded with new hardware.
Constant Angular Velocity: CAV CD-ROM drives spin the disc
at a constant speed, so the data rate increases as the pickup moves to the outer
edges of the disc. Constant motor speed eliminates the need for settling of
the optical pickup after seeking data, resulting in an improved access rate.
CAV-based drives are simpler to design and produce because the motor doesn't
need to change speed.
Constant Linear Velocity: CLV drives vary the speed the disc
is spinning at so that the data rate of the drive is constant. The drive rotates
the disc faster when reading the inside tracks and slower when reading the outside
tracks as more data is pumped through the head. This is to ensure a constant
data rate regardless of where on the disc it's being accessed. CLV-based drives
generally encounter latency at high-speeds when the rotational speed needs to
be changed.
Contact Image Sensor: A low-cost and lower-profile scan head
based on LED technology.
context switch: An operation that's triggered when a user switches
among multitasking programs. The OS must save the contents of the CPU's registers
before switching to the next program, then restore the registers when the user
switches back to the first program.
continuous level of detail: A new way of representing 3D objects
with a smoothly variable, instead of fixed, polygon count. Allows much more
efficient and scalable use of processing power, as well as a general increase
in framerate and visual realism.
continuous tone: As opposed to line art consisting of solid
blocks of shades or colors, con-tone images (such as photographs or paintings)
have a continual flow of hues.
continuous zoom: Any lens that magnifies the image without
incremental steps.
control: A program module that enhances the functionality of
a program. A control is often a user-interface function. In the Windows environment,
OLE controls and ActiveX controls are examples.
control point: The defining point of a vector line that contains
control handles for setting the algorithm that determines the line's curve.
cooked: Custom-tweaked for uncharacteristically high performance.
A videocard that has been cooked in no way represents the same branded product
that sits on store shelves. Final shipping product often must be sold "underdone"
to ensure stability and compatibility, and to keep mass-production costs down.
coordinate matrix: A set of numbers required to draw a 3D object
on the screen. Each object consists of numerous polygons, often triangles. Each
vertex (corner) of each polygon needs a coordinate matrix to describe its location
in virtual space. The coordinate matrix is usually a set of four numbers describing
the horizontal, vertical, and depth positions of the vertex.
core: The main logic circuits of a microprocessor chip (CPU).
The term usually refers to the microarchitecture (internal design) of a CPU,
exclusive of buses and caches. For example, Intel's Pentium II and Celeron processors
have virtually identical cores, even though they have different configurations
of L2 caches and buses.
core-logic system chipset: Two or more chips on the motherboard
of an IBM PC-compatible computer that connect the CPU to other system devices.
The system chipset defines many of the features of a PC: how much main memory
(RAM) it can hold, how many expansion slots it has, how much memory it can cache,
and so forth.
coverage: The area of a printed page covered with ink.
CPU: Central processing unit. Another term for a microprocessor
chip.
crash stop: Soft plastic material that the heads hit, rather
than hitting metal.
cropping: Deleting peripheral data around a selected portion
of an image.
cross-bar: An architecture within main memory that allows data to be parsed
according to a specific instruction.
crossover point: The point in a sine-wave signal where the
strength begins to drop off due to filtering via capacitors and coils. The official
point is considered when a -3dB drop starts, and continues to roll off until
the signal is fully dampened. Depending on the way the filtering network is
made, you can either allow frequencies past the crossover point to continue
(a.k.a. a hi-pass filter), or dampen frequencies past that crossover point (a.k.a.
a low-pass filter).
CRT: see Cathode Ray Tube
CSMA/CD: Carrier Sense Multiple Access/Collision Detection. The media-sharing scheme used by Ethernet. Basically, it allows computers to communicate with each other only after it detects when the cable is not in use. Machines can be requested to resend their data when CSMA is combined with collision detection and collisions have been detected.
| Author | Charles E. Brown | |
| Company | EWM / PSI | |
| Comments to | ||
| Contact Page | Form | |
| Created | Jan-01-1999 | |
| Updated | Jan-30-2001 | |
|
Copyright ©1999-2001. |
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