Fahrenheit: Either a collaborative effort between Microsoft
and SGI to merge the best elements of DirectX and OpenGL into one API, or
the victory lap that Microsoft makes after it co-ops all the OpenGL technology
into DirectX. Time will tell.
far field: The area of a 3D scene that is far from the
camera. 3D objects in this area will be smaller and details will be harder
to resolve.
Fast Ethernet: see 100BaseT
FAT: A DOS- and Windows-based file system that tracks the location of data
on a disk using File Allocation Tables (FAT), which are simply tables of numbers
that indicate the status of a cluster or the location of the cluster belonging
to a file. A directory table is used to track file names, extensions, date,
and other info, including where the FAT address of where the file starts.
When a file is requested, the table is checked, and the cluster containing
the file is located. The address of the next cluster is also located if the
file is larger than a single cluster, until an END OF FILE designator has
been reached. A FAT entry of 0 indicates that the cluster is free to be written
to. DOS actually writes two FATs to a logical volume where the second is used
to replace the primary in case it becomes damaged.
FAT16: A 16-bit DOS and Windows file system (see FAT) that
varies cluster sizes based on hard drive size. Cluster sizes range from 4K
(for drives up to 127MB), to 4K (255MB drives), 8K (511MB drives), 16K (1GB
drives). and 32K (for drives up to 2GB). The ultimate capacity of a FAT16
partition is 2GB.
FAT32: A 32-bit file system that was introduced with Windows
95 OSR2 that uses 4K cluster sizes for all drive sizes with a maximum capacity
of 8GB.
FAT32X: An extended version of FAT32, the 32-bit file system
introduced with Windows 95 OSR2 that uses 4K cluster sizes. FAT32X allows
partitions larger than 8GB.
ferrite (inductive) heads: Early magnetic hard-disk heads
consisted of thin copper wire wound around a ferrite core with a tiny gap
cut out of it that defined the size of the data bits that could be written
and read. By passing bursts of electrical current in one direction or the
other, electrical induction in the coil created patterns of magnetic fields
of one polarity or the other emanating from the gap that wrote bits onto the
hard disk that spun just below the head. When reading, the magnetic fields
from the passing bits induced a pattern of currents in the opposite direction.
For years, the coils in ferrite heads were meticulously hand-wound.
Fibre Channel: A storage connection technology that resembles
SCSI. Targeted at corporate solutions, fibre channel supports transfer rates
up to 126 devices with a total bus throughput of 100-200MB/sec at distances
ranging from 30 meters (for copper wire) to 10 kilometers (with fibre optic
cabling). Fibre Channel can be configured for point-to-point via a switch
topology or in an arbitrated loop call Fibre Channel Arbitrated Loop (FC-AL).
FA-CL has made it possible for Fibre Channel to be used as a direct disc attachment
interface, opening whole new levels of I/O performance up to designers of
high-throughput, performance-intensive systems.
file format: The specific way data is arranged in a file.
When a word processor saves a text file, for example, it usually doesn't save
only the text--it also saves formatting information. Different programs do
this in different ways, which is why it's often difficult or impossible to
exchange files between programs.
fill-rate: The number of pixels that a videocard pumps
on screen during a fixed span of time; measured in millions of pixels per
second.
fillets: A new surface that is a blend between two other
surfaces.
filtering: The ability to take a pixel point in an image,
perform a comparison between neighboring pixel values, applying a filter that'll
interpolate between the two pixel RGB values, then apply that pixel to that
point. It's a means to smoothing out blocky textures. See also bilinear filtering
and trilinear filtering.
filters: A filter is a circuit that ideally amplifies and
attenuates different frequency components of a sound, thus changing its timbre
and resonant qualities. Digital audio filters are difficult to design because
the standard algorithms are particularly subject to distortion.
firewalls: A software system that isolates a network (such
as an internal corporate intranet) from the rest of the Internet, permitting
only specific data to pass in and out.
FireWire: IEEE 1394, as it's commonly referred to, was
conceived by Apple Computer and then developed within the IEEE 1394 Working
Group. The spec allows for the transport of data up to 200Mbps, the ability
to add and remove devices without powering them down first, and the ability
daisychain up to 63 devices with cable lengths up to 14 feet.
firmware: Instruction code embedded in digital hardware
that enables basic operations.
fixed packet writing: Packets of data written to a disc
are fixed in size. This form of packet writing is necessary for CD-RW media
in order to support random erase.
fixed zoom: Opposite of "continuous zoom."
fixed-length packets: Packets of data are written to a
CD-RW disc with a fixed length of 32K (as required by the UDF standard). CD-RW
drives that support these packets support random erase, which is the ability
to erase a single file at a time, freeing up space that can be used like a
hard drive or floppy disc.
flagella: Whiplike parts of a cell that are organs of locomotion
or that produce a current in the surrounding fluid.
flanging: The result of adding together a sound with a
version of the same sound that has been delayed by a small, but variable,
time. The result is a complex change in timbre caused by the adding together
of certain frequencies of sound, and the cancellation at other frequencies.
So called because it was first done by varying the delay of the sound by putting
fingers on the flange of the reel on a tape recorder.
flash slave: Photovoltaic module that detects burst of
light from on-camera flash and creates a signal to fire external flash unit(s)
in sync with a camera's shutter.
floating-point: A fractional number, such as 9.95 or 98.6.
Computers have a more difficult time working with floating-point numbers than
they do with integers (whole numbers), but the higher precision of floating
point is required for some operations.
FM Synthesis: Frequency Modulation Synthesis. A music simulation
technique that approximates the sounds of real instruments by bending raw
electronic wave forms. Wavetable synthesis, which uses samples of real instruments,
is preferred.
FMV: Full-motion video. Video that plays at full screen
on your PC. It can be used for interactive games such as Tex Murphy Overseer,
or for cut scenes to further a story along such as Heart of Darkness.
focal length: The degree to which a viewing lens displays
the distortion and perspective associated with wide-angle and telephoto lenses.
fogging: The ability for a videocard to correctly simulate
fog in an environment, and to render objects that enter that fog correctly.
This creates a simulation of distance and atmosphere--the farther the object
or terrain is, the higher likelihood it will be enveloped in fog.
force-feedback: Basically vibrating joysticks, wheels,
and devices that help create immersive environments in games. Smash your race
car into a wall and feel the force-feedback wheel shudder. Take off in a helicopter
and a force-feedback stick thrums in unison.
FORTRAN: FORmula TRANslator. FORTRAN is a programming language
invented in the 1950s for scientific and technical computing. It excels at
mathematical operations and is still used today.
Foundation: The original family of DirectX APIs that form
the lowest level of multimedia services. These services typically mirror the
functionality available in hardware.
foundry: A factory that makes computer chips. Also known
as a "fab" (fabrication plant). It's the place where the people in the dust-proof
"bunny suits" work, as seen in Intel's TV commercials. Building and equipping
a modern foundry can cost $1 billion to $2 billion.
400dpi: 400 dots per inch. A measurement of resolution
that defines the output of a display. In terms of pointing devices, dpi tells
the speed and accuracy of its movement. Typical mouse resolution is 100 to
400dpi, but can be up to 1000dpi. The actual accuracy of movement the software
sees is determined by the settings of the mouse driver (many mouse drivers
can adjust mouse sensitivity).
440BX: An Intel core-logic chipset that supports 350MHz
and 400MHz and up CPUs, and a 100MHz system bus.
FP: Floating point. A fractional number, such as 9.95 or
98.6. Computers have a more difficult time working with FP numbers than they
do with integers (whole numbers), but the higher precision of FP is required
for some operations.
fps: Frames per second. The number of times per second
that a scene is redrawn to give the illusion of continuous animation. A movie
is 24fps, a good game should be at least 30fps.
FPU: Floating-point unit. A function unit (collection of
circuits) in a microprocessor that executes floating-point instructions.
frame: An individual still image that is part of larger
series of images, which form a moving picture.
frames: A way of dividing a browser window into two or
more parts. This allows the reader to scroll through one part while leaving
another part--the equivalent of the menubar--available at all times.
frame buffer: A block of memory for temporarily storing
information displayed on the screen. Graphics cards usually have a few megabytes
of fast memory for this purpose. The larger the frame buffer, the more resolution
and colors a computer can display. 3D graphics cards may also store 3D objects
and textures in a frame buffer.
frontside bus: The main system I/O (input/output) interface
that connects a microprocessor to other system devices. Typically, it allows
the processor to communicate with main memory (RAM), the system chipset, PCI
devices, the AGP card, and other peripheral buses. It also connects to the
Level 2 cache unless the processor has a backside bus.
full-duplex: A transmission mode that allows network adapters
and servers to transmit and receive data simultaneously. This requires twice
the bandwidth and a hub or switch that supports this mode.
full-screen, order-independent: Usually used when describing
anti-aliasing, this refers to the fact that a 3D accelerator can apply an
anti-alias filter on a full-screen picture (as opposed to just filtering the
edge of a diagonal line, a.k.a. edge anti-aliasing). Order-independent means
the anti-aliasing filter doesn't care in what order the pixels are being rendered
in 3D space--it'll just anti-alias the whole lot of 'em.
function: A type of subroutine that generally returns a
value when called. For instance, a function named SumAnnualSales might add
up a company's sales for the year and return a dollar value to the calling
program or routine. (See procedure and method.)
function unit: A collection of circuits in a microprocessor
that executes program instructions. There are different types of function
units for different types of instructions: integer, floating point, multimedia,
etc.
fuzz pedals: A simple nonlinear electronic device popular
with musicians that causes interesting and pleasing distortion to the sound,
most typically used with electric guitars.
FX engine: A DSP specifically designed to implement audio-effects processing. Such a DSP would be particularly well-designed for implementing low distortion filters and long delay lines.