Lexicon Of Computer Audio & Video Music Recording
Terminology
| 24P
|
A video term that
is an abbreviation of "24 frames per second,
progressive scan." 24P is a more recent development in digital
video technology that's quite popular due in part to its similarity
with the way in which motion picture film works. Not only does it
take on some of the visual characteristics of film, but it also
makes the transition of film to video (necessary for television
broadcast, VCR tapes, etc.) much easier. It makes the introduction
of digital video (particularly high-definition video and special
effects) in motion pictures smoother and more natural looking.
Here's the history: Most motion pictures (since the advent of sound
film) are shot (or at least shown) at a constant rate of 24
frames per second; each second, 24 separate and distinct
pictures, or "frames," pass by the lens of the camera and the
projector. Each frame is its own unique and complete image; that's
called "progressive." Video tape standards are different: original
black and white video ran at a straight 30 frames per second, while
color video runs at approximately 29.97 frames per second — only
they aren't true "frames" in the film sense. Due to video's nonstop
scanning of magnetic tape, a frame is spread across the tape as
precisely oriented magnetic particles. Furthermore, video tape
"draws" an image on the
cathode ray tube in two alternating sets of scan lines: one
composed of the even-numbered lines and the other making up the
odd-numbered lines. This is why video signals are called "interlaced."
When motion pictures (or any material shot on film) are processed
for video playback they undergo a re-scanning process (often through
a
telecine machine) that converts the
frame rate, in part by doubling some film frames in the video.
The change from progressive to interlaced scanning, in many viewers'
opinions, visibly changes the quality of the original image.
Likewise, visual effects created using existing video frame rates
sometimes do not translate well to film. Digital video created at
24P, however, requires no frame-rate conversion and can freely
translate film into video. Progressive scan combines all the
horizontal lines in the screen into a single field that lights up at
the selected frame rate. It is proving to be particularly effective
in high-definition video projects and has blurred the line between
film and video shoots. "Star Wars Episode II: The Attack of the
Clones" was the first feature-length motion picture shot using 24P
high definition digital video cameras; cameras used for Episode III
are second-generation versions of the equipment. This means that the
live action shots and computer-generated special effects have the
same resolution, same brightness, and same overall quality without
the need for additional conversion. Finally, in one of those
technological puzzles that are so common, there are actually two
versions of 24P: one is more of a "true" 24P as it applies to film
and other specialty equipment, while the other is a slightly slowed
down rate (.1% slower) used by
NTSC video equipment. That rate is about 23.976 frames per
second and is sometimes referred to simply as 23.8. The 23.976 rate
applies to progressive scan
DVD and other NTSC video applications. |
|
|
802.11 |
A family of
specifications developed by the
IEEE for
wireless
LAN use. The standards specify wireless interfacing protocols
between two or more wireless networking systems such as a series of
wireless computers and some type of base station, or even just
between two computers. There are several unique types of 802.11 in
widespread use. These have different transmission methods and/or
data rates. As of this writing the most common of these are: 802.11,
802.11a, 802.11b, and 802.11g. 802.11g systems can work with 802.11b
(also known as Wi-Fi) systems by simply falling back to a slower
data transfer rate. |
|
| ACPI
|
Abbreviation for
Advanced Configuration and Power Interface. A power management
specification for
Windows computers developed by Intel, Microsoft, and Toshiba.
ACPI gives the operating system the ability to control the amount of
power given to each peripheral device, and to turn off devices when
not in use. It also has future implications, such as enabling PC's
to power up simply by touching any key on the keyboard.
|
|
| ADB
|
An abbreviation
for Apple Desktop Bus. The
bus used for connecting peripheral data entry devices to
Macintosh computers. This is how things like the keyboard, mouse,
track ball, joystick, and some tablets connect to a Macintosh. Since
a bus architecture is used they can usually be connected through
each other so that only one actually has to plug into the computer
itself. The connector looks like a very small
MIDI connector with only four pins. In fact, it looks exactly
like an S-Video connector (in a pinch an ADB cable can be used for
S-Video and vice versa). The Apple Desktop Bus has been part of
every Macintosh computer to date but may begin to be phased out in
favor of the faster and more robust
USB (Universal Serial Bus). |
|
| AGP
|
Abbreviation for
Accelerated Graphics
Port, which is a dedicated video card port found on some PC and
Macintosh computers. It conforms to a
bus specification from Intel that greatly speeds up graphics
display and texture rendering, especially virtual reality and 3D
rendering and display. Rather than using the
PCI bus for graphics data, AGP introduces a dedicated
point-to-point channel so that the graphics controller can directly
access main memory. The AGP channel is 32
bits wide and runs at 66 MHz. This translates into a total
bandwidth of 266 MBps, as opposed to the PCI bandwidth of 133 MBps.
AGP provides a coherent memory management design which allows
scattered data in system memory to be read in rapid bursts, thereby
reducing the overall cost of creating high-end graphics subsystems
by using existing system memory. |
|
| AIFF
(Audio Interchange File Format) |
A common digital
audio file specification, AIFF allows a variety of applications
running on different platforms to easily share audio files.
Electronic Arts published the AIFF spec in 1985. Since then, it has
been widely used on Mac, PC, and Atari computers, as well as in a
variety of digitally based music instruments. Most digital audio
editing software will import and export AIFF files, making the
format well suited for situations where more than one program or
platform must access audio data. Kurzweil's K2000 and K2500 will
also recognize AIFF files, making them ideal for exporting samples
to and from computer-based sample editing software. |
|
|
Algorithm |
A step-by-step
problem-solving procedure, especially an established, recursive
computational procedure for solving a problem in a finite number of
steps. Algorithm's can be thought of as similar to computer
programs. They are often run as subroutines to normal operations of
computing devices. Algorithms are used in all sorts of DSP devices
to carry out specific aspects of their functionality.
|
|
| Alias
|
In the world of
computing an alias is an alternative, usually easier to understand,
or more significant name for a particular data object. In the
Macintosh
OS aliases are in the form of icons that look like files or
programs that can be launched, but instead only direct the computer
to the original. These are handy for making convenient references to
certain files or programs without having to move the originals from
their proper and logical location on your hard drive.
Alias is also a false signal that can be
created when working with digital audio data (see WFTD
Aliasing for more info). |
|
| AMS
|
Abbreviation for
Audio MIDI Setup.
Apple Computer's
audio and
MIDI
operating system, which is a component of Mac
OS X. AMS consists of two parts. The first allows you to
configure the
drivers for audio devices connected to the computer, including
defining the
sample rate and
bit depth. The second section provides configuration information
for any MIDI devices (internal or external) used. AMS replaces
Opcode Systems'
OMS (Open Music System) and
MOTU's
FreeMIDI, which were earlier Mac-based MIDI configuration
utilities. |
|
| Apple
Talk |
A network
communication protocol originally developed by Apple for the
Macintosh computer and related peripherals. Apple Talk has been
built in to most Macs sold since the late 1980's, though the
hardware connections have changed a few times along the way. While
Apple Talk is extremely easy to set up and use, it has been known to
occasionally interfere with serial communication or timing with
things like
MIDI interfaces and
synchronizers. On modern Macs (which don't even have
serial ports anymore) this is almost never an issue, but a few
veteran Mac users still like to turn Apple Talk off when doing
critical work. |
|
|
Application (Program) |
A complete,
self-contained program that performs a specific function directly
for the user. This is in contrast to system software such as the
operating system
kernel, server processes and libraries that exists to support
application programs. Many computer gurus believe that the term may
also be used to distinguish programs that communicate via a
graphical user interface from those which are executed from the
command line. |
|
|
Archive |
1. An "archive" is
a collection of historical documents or records that is being
preserved. In the computer-based music and
audio world, "archiving" is the process of collecting,
preparing, and storing
data for long-term or permanent storage. In many cases, this
means gathering all of the
MIDI and audio data that have been recorded or created for a
particular project and storing it on media that will be stable and
readable for long periods of time. But gathering the data is just
one step. The second step for a true archive is ensuring that the
project can be accurately restored or re-created at a later date
even if the
software and hardware tools used to create it are no longer
available. Making this possible may require recording MIDI
tracks as audio
files,
bouncing any audio tracks with the
plug-ins and hardware processing that were used during
mixdown, consolidating tracks that don't contain contiguous
audio
regions into one full-length track, and so on. The Producers &
Engineers Wing of the Recording Academy (NARAS) has created a
document, Recommendation for Delivery of Recorded Music Projects,
that specifies how archived data should be prepared and stored for
maximum protection from damage, obsolescence, and loss. 2. A
compressed version of a file, used to reduce bandwidth or storage
requirements. |
|
| ASCII
|
Acronym
(pronounced "askee") for American Standard Code for Information
Interchange. ASCII was developed by
ANSI (neat: acronyms that rhyme, I feel a song coming on) to
provide a standard way for computer systems to deal with the text
characters we use. When we type ASCII characters from the keyboard
(which looks like words to us), the computer interprets them as
binary so they can be read, manipulated, stored and retrieved.
Each character in the ASCII set is represented by a number from 0 to
127, which can be represented in 7 bits of binary information. For
example, and upper case "A" is ASCII character #65, which in binary
(or to a computer) would look like 1000001. ASCII files are commonly
known as text files and since it is standardized most computers can
read them, which is one big reason why it is so easy to share text
files between different operating systems on radically different
computers. There is also an extended ASCII set where an 8th bit is
added. It supports additional characters (using numbers 128-255),
which is where a lot of the special (non-English) characters and
symbols are represented. Historically one of the ways complex
computer data was (and sometimes still is) sent over the Internet is
by converting it into an ASCII format and sending it as text. That
way the receiving computer could receive it and convert it into code
that could be read locally even though the two computers (or their
operating systems) might "speak" different languages and normally
not be able to communicate with each other. |
|
| ASIO
|
An abbreviation
for Audio Stream Input/Output architecture. Developed at Steinberg,
it is the software engine that is the fundamental access method to
the audio hardware for Cubase VST and is being employed in a growing
number of hardware and software systems for doing audio on
computers.
The computer manufacturers and operating system
vendors target the "Multimedia" market and have implemented audio
playback and recording capabilities specifically for it. This market
however is based on stereo playback and recording, it did not
require synchronization between other Media in the beginning, and
multi channel operation wasn't necessary. So far the only
professional solutions have been proprietary expensive hardware
based systems.
ASIO addresses all areas for pro-audio
recording including flexibility with sample rates and bit depths as
well as synchronization between different media like audio, MIDI and
video. As a result the user gets a low latency, high performance,
easy to set-up and control recording solution. The audio hardware
can be either one or more sound cards with multiple audio input and
output ports that conform to the ASIO specifications. ASIO exists
for PC (Windows) and Macintosh systems currently. |
|
| ATA-2
|
Abbreviation for
Enhanced (some say Expanded)
IDE, or Enhanced Integrated Drive Electronics. Like it sounds,
EIDE is an enhanced version of the old IDE peripheral connection
standard commonly used for hard drives and other storage media with
computers. It provides faster access to the hard drive, support for
DMA, larger capacities, and includes the functionality of
ATAPI. Sometimes EIDE is referred to as
ATA-2. |
|
| ATAPI
|
Abbreviation for
Advanced Technology Attachment Packet Interface. ATAPI is a lot like
IDE, but provides additional commands to enable a computer to
control optical or tape drives. |
|
| Audio
Suite |
The obvious
definition is a room or space for working with audio production.
However Audio Suite is also the name Digidesign coined for
host based
plug-ins in their systems. A
TDM Digidesign system has
proprietary DSP devoted to plug-in processing, but Digidesign
also makes a number of systems where the host computer provides all
of the processing (whether it's in
real time or not). Plug-ins designed to work on that type of
hardware from Digidesign are known as Audio Suite plug-ins. This is
analogous to VST or Direct X plug-ins, just specific to Digidesign
hardware. |
|
|
Audiowire |
The name given for
the special protocol used by Mark of the Unicorn to deliver digital
audio between some of their audio interfaces and their computer
sound cards. The connector is a conventional looking
Firewire connector, but the data is a
proprietary format developed by MOTU. Some MOTU products do use
actual Firewire, which can be plugged directly into any conventional
Firewire equipped computer. The Audiowire products all plug into a
special card that must be installed in the
PCI slot of a computer. |
|
|
Author |
When used as a
verb, the term author means to create or publish a script, program,
or document. In our business this may pertain to a computer program,
operating system (OS),
musical
score, or any of dozens of other types of produced works. For
example, quite often the word gets used in the slightly unusual
context of making some media such as an audio or video CD/DVD.
The process of authoring a DVD is not too dissimilar from writing
computer software. |
|
|
Authorization |
1. The process of
setting up a
copy-protected piece of
software so that it may be legally used. 2. Permission to use a
piece of copy-protected software. An authorization is typically a
single instance of a copy-protection code; a piece of software may
allow for two or even more
authorizations, so that the user can, for example, install and
use it on a desktop computer and a laptop. |
|
|
Automation |
In audio
production automation refers to having things programmed to happen
in
real time during a
mixdown. In the 1970's, when big multitrack tape machines were
becoming common, and overdubbing parts became a standard way of
working, the process of getting a good mix became exponentially more
difficult. No longer was the whole recording of a live performance
where the musicians pretty much balanced their own levels. Many
components were put in later and eventually it became trendy to do
mixes at other studios optimized for that purpose, thereby causing
the mix to have to be created from scratch. Anyone who has ever had
the occasion to be one of the three or four people huddled over the
mixer making adjustments during a manual mixdown can appreciate the
benefits of being able to automate most of the process. Early
automation systems were basic level controls. They were
synchronized to the tape machine by some form of
Time Code (not necessarily
SMPTE) and would remember any moves the engineer made and then
play the data back causing the level change to occur at the proper
time (assuming the automation stayed in sync with the tape - not a
given). They worked by either having motorized
faders, where the motors could be controlled by the automation,
or by using VCA's (Voltage
Controlled Amp), which was a much less expensive and
cantankerous option. VCA's, however, didn't sound as pure as the
passive fader with a motor attached so most successful systems
were "moving fader" based. Later the quality of the VCA based
systems rose (while the cost declined) and they became popular among
smaller studios, but moving fader systems are still considered the
best choice for analog. Not only because they sound better, but
because the tactile feedback of physically moving faders is
something many engineers prefer. During the 1980's many other
aspects of mixing began to be automated. Things like
aux sends,
panning, and eventually even
EQ and
compression could be put under computer control. Nowadays there
are many analog mixing boards that are totally under digital control
and virtually every
parameter can be automated. Further, with the advent of the
DAW, complete recall and automation of every aspect of a mix has
become a standard. |
|
|
Backward Compatible |
Refers to a
hardware or software system that can successfully use interfaces and
data from earlier versions of the system or with other systems. For
example, a new version of sequencing software designed so it can
properly read files from older versions is backward compatible.
Nowadays this type of compatibility is taken for granted with
software, but it wasn't always so easy. The downside of too much
backward compatibility is that software can tend to get bloated and
inefficient by having to deal with too many prior formats. With
hardware it is much more expensive to maintain a high degree of
backward compatibility. Think how much a computer would cost if it
had to have
SCSI, ADB,
serial
ports, parallel ports,
IDE, NuBus,
ISA, PCI, USB,
and
FireWire compatibility. Backward compatibility is more easily
accomplished if the previous versions have been designed to be
forward compatible. |
|
|
Binary |
Literally means
consisting of two parts. A binary numbering system is made up
entirely of only two values, usually zero (0) and one (1). This type
of numbering system has been widely used in digital computers and
other types of digital computing equipment over the years. The
binary numbering system is easy to deploy electronically because the
system only needs to differentiate two values — the 1 or the 0,
which in the
analog world can be represented by a ‘high’
voltage and a ‘low’ voltage. In a binary numbering system it can
take many digits to represent our normal base 10 numbers. There are
generally a fixed number of
bits (8, 16, 24, etc.), which determine the size of the numbers
that can be represented. The way it works is that each binary number
as you move to the left represents a value double the number just to
the right of it. A four bit binary number works as follows:
Bit 4 Bit 3 Bit 2 Bit 1
8x 4x 2x 1x
So, the 4 bit binary number 0001 = 1; 0010 = 2;
0011 = 3; 0100 = 4; 0101 = 5; 0110 = 6; 0111 = 7; 1000 = 8; 1001 =
9, and so on. |
|
| BIOS
|
An acronym for
Basic Input/Output System. Mostly germane to PC compatible
computers, this is usually an
EPROM with computer program instructions in it. A computer
motherboard BIOS controls how the hardware is defined and the basic
functions of the computer (such as controlling the keyboard,
monitor, etc.). With a
SCSI host adapter, its BIOS is used to control SCSI hard disk
drives and perform the boot function. If a host adapter does not
have a BIOS, then hard disk drives controlled by that host adapter
cannot be used to boot from (booting must be done from another
source, such as floppy, IDE, or another SCSI host adapter with a
BIOS). Hard drives can have their own BIOS as well, which defines
their operation. The BIOS can also contain useful software
utilities, and in some cases, can be reprogrammed or updated via
software to accommodate new hardware. Older PC computers often have
to have their BIOS updated in order to properly work with new
hardware. |
|
| Blind
Transfer |
A type of data
transfer mode often used in
SCSI
devices. In Blind Data Transfer mode, the
CPU allows
the SCSI chip to oversee transfers, freeing the CPU for other tasks.
The CPU checks in only once before a
block of
data is transferred, requiring constant timing of the computer,
rather than a polling method where the CPU would have to check for a
Request/Acknowledge handshake with every
byte
transferred. The polling method requires more CPU time, so blind
transfers complete much faster. However they do not work well in
some situations with certain types of hardware. |
|
| Block
|
In audio and
computing the term block merely refers to a segment of data. It is
significant because digitized data is often stored in blocks of a
predetermined size (often 512 or 1024
bytes). For example, a disk might be formatted to hold data in
blocks that are 512 bytes in size. That means if you have a packet
of data to be written that is 1,047 bytes long it will require 3
blocks to store it, even though the third block is technically
almost empty. This empty space can not be used by any other data.
This block method of data storage and retrieval is key to making it
easy for computers to be able to quickly locate specific data on
disks and other storage media. |
|
| Blu-ray
|
An
optical disc format jointly developed by the Blu-ray Disc
Association (BDA), a group of consumer electronics, personal
computer, and media manufacturers (including Apple, Dell, Hitachi,
HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung,
Sharp, Sony, TDK and Thomson). The Blu-ray format was developed to
enable recording, rewriting and playback of high-definition video as
well as store large amounts of data. A single-layer Blu-ray disc can
hold 25GB,
which can be used to record over 2 hours of HDTV or more than 13
hours of standard-definition TV. There are also dual-layer versions
of the discs that can hold 50GB. Optical disc technologies such as
DVD, DVD+/-R, DVD+/-RW, and
DVD-RAM use a red
laser to read and write data. The Blu-ray format uses a
blue-violet laser instead. Despite the different type of lasers
used, Blu-ray hardware is designed be made backwards compatible
through the use of a BD/DVD/CD-compatible optical pickup that allows
playback of standard CDs and DVDs. The benefit of using a
blue-violet laser (405nm) is that it has a shorter
wavelength than a red laser (650nm), which makes it possible to
focus the laser spot with greater precision. This allows data to be
packed more tightly and stored in less space, so it's possible to
fit more data on the disc. Blu-ray was designed with HDTV in mind
and supports direct recording of the
MPEG-2 TS (Transport Stream) used by digital broadcasts, which
makes it compatible with global standards for digital TV. This means
that HDTV broadcasts can be recorded directly to the disc without
any quality loss or extra processing. To handle the increased amount
of data required for HD, Blu-ray employs a 36Mbps
data transfer rate. Blu-ray's backers expect it to replace VCRs and
DVD recorders with the transition to HDTV over the coming years. The
format also has potential to become a standard for PC data storage
and HD movies in the future. |
|
|
Bluetooth |
A short-range
wireless technology that communicates via a frequency-hopping
transceiver over the 2.4-gigahertz radio frequency, a space known as
the Industrial, Scientific and Medical (ISM) band. Bluetooth was
originally conceived as a low cost, low power, short-range
technology that would replace cables on such devices as mobile phone
headsets, handsets and portable computers. However, its promoters
soon envisioned the creation of "personal area networks" in which
computers could be wirelessly connected to printers, audio could be
transmitted over short distances (for example, to the rear speakers
in
surround setups), and
remote control of PDAs or other appliances could be easily
implemented. Some people have referred to it as a sort of wireless
USB, which is a pretty apt description in many respects. First
conceived in 1994 by Ericsson Mobile Communications (now a part of
Sony), by 1998 the Bluetooth Special Interest Group included
industry giants Intel, IBM, Toshiba and Nokia. Today more than 2000
companies produce or are developing Bluetooth enabled products.
Apple Computers incorporate Bluetooth compatibility that allows
keyboards, mice and other peripherals to wirelessly connect to the
main unit. While Bluetooth originally had a transmission range of
only 10 meters, today, three power classes exist for Bluetooth
devices, the most powerful allowing transmissions up to 100 meters.
Bluetooth is a different protocol from
Wi-Fi, but both occupy a section of the 2.4 GHz ISM band that is
83 MHz wide. Bluetooth uses a technology called Frequency Hopping
Spread Spectrum (FHSS) that allows it to hop between 79 different 1
MHz-wide channels in this band whenever it encounters
interference from other transmissions. |
|
| Boot
|
Besides being an
article of footwear, boot refers to the process of starting up a
computer system, or any device with a
CPU. It is spoken as to "boot up," or "booting up." Basically
this is a colloquialism that comes from the idea of pulling itself
up by its own bootstraps. A computer booting up generally goes
through a series of self-tests and loading operational system
instructions. |
|
|
Buffer |
A temporary
storage area for data being transferred from one place in a system
to another, or to another system. Buffers are often used in the
context of computers reading from and writing to various disk
drives, but can come in to play on most any type of data transfer.
Buffers are needed because it often occurs that one or both of the
devices cannot maintain an exact and synchronized data transfer
rate. Buffers provide a place for data to sit while one of the
devices catches up to the other. Cache (see WFTD archive
Cache RAM) is a type of buffer. |
|
|
Buffer Under-Run |
Buffers are often used in
real time data operations to help allow for timing
inconsistencies between the device supplying the data and the device
requesting the data. However, there are limits to how much a buffer
can... well... buffer. Its size and the data rate determine the
limit. If the supply of data stops or slows down the buffer can only
feed the destination device until it is empty. When it runs out of
data a fault in the data will occur, the consequences of which
depend upon the equipment in question. This fault is known as buffer
under-run, which simply means the buffer was not able to supply data
to the destination because it ran out of its supply. In the early
days of CD burning this was a very common problem due to a
combination of small (or no) buffers in the burners and slow disk
access times, not to mention slower computers. Nowadays, CD burning
technology has advanced to the point where buffer under-runs are
fairly easily avoided; though they are not gone completely.
|
|
| Bug
|
Jargon often used
in the computing world to refer to a fault in software (and
sometimes hardware) that causes a malfunction. Bugs may range from
minor annoyances that are easily worked around to crippling
problems. Sometimes a software program can have so many problems it
gets characterized as "buggy." According to folklore, the first
computer bug was an actual bug. Discovered in 1945 at Harvard, a
moth trapped between two electrical relays of the Mark II Aiken
Relay Calculator caused the whole machine to shut down. It turns out
that the person who told the story was already aware of the usage of
the term as it dates all the way back to the early telegraph days.
Some claim the usage is actually older than that. These days you
will see the term applied to any system (computer or otherwise) that
runs with any type of program or set of instructions. This could be
a keyboard, a hard disk recorder, or even a calculator.
|
|
| Cache
RAM |
Most of the RAM
(Random Access Memory) that computers use is inexpensive dynamic
RAM. In modern computers, dynamic RAM is actually too slow to keep
up with the bus speeds. To compensate for this, computers
incorporate a small amount of expensive Cache (or Static) RAM, which
is fast enough to keep up with system speeds (this is also called a
Level 2 or L2 cache). All modern CPUs have a small cache built into
the chip itself (8-16k). External cache memory can also be added to
improve performance. PowerPC's require at least 256k per CPU (or
more). Pentium Pro chips have a built-in L2 (256 or 512k) cache that
runs at a full 200 MHz, greatly speeding performance. How much cache
RAM you should have depends on the amount of total RAM your computer
has. Unless you are running serious graphics systems, 256 or 512k
should be fine. Increasing to 1 Mb will only provide a minor
performance improvement. |
|
|
CardBus |
Cardbus is the
trade name for an advanced PC Card specification, which is used
primarily in notebook and portable computers. It fits into the slot
like a conventional PC Card, but its performance is enhanced over
conventional PC cards with support for
direct memory
access, use of a 32-bit
path for data transfer, and an operating speed, which is several
times greater. Cardbus allows PCMCIA cards to transfer data at rates
exceeding 100MB/sec. &mdash Older 16-bit
PCMCIA
cards transfer data at a rate of 20MB/sec. |
|
|
Carved-top Guitar |
The original
carved-top electric guitar was the 1952 Gibson Les Paul "Goldtop."
Because Gibson had the specialized tooling with which to create a
contoured top that was similar to the arched top of a fine violin,
Maurice Berlin of Chicago Musical Instruments (or CMI, Gibson's
parent company) believed this would set the Gibson
solidbody guitar far ahead of the competition (chiefly Fender at
the time). Initially, the rough carving was done by a machine
copying a 3-dimensional pattern made of steel. The cutter marks were
then smoothed by a
luthier using a stroke belt sander. The operator would hold a
cushioned pad against the running belt pressed to the top of the
instrument in order to create the desired contour. Today, much of
this is accomplished using computer-controlled carvers, after which
hand finishing adds the final touch. |
|
|
Cassette Tape |
Any of several
types of assemblies where audio tape is encased in a self contained
mechanism that provides very simple insertion and/or removal from a
tape recorder or playback machine. These self contained mechanisms
(the cassette) usually provide all of the wheels and rollers
necessary for tape to be able to be moved past a tape head. All that
is required of the tape playing/recording machine is to have motors,
capstan,
pinch roller, gears, and mechanisms designed to provide the
torque to get the tape moving through the cassette and past an
opening where the machine's tape head comes into contact with the
magnetic tape for recording and playback purposes. There have been
many types of cassette tape used over the years in audio and video,
including 8-track, Beta, VHS, 8mm, and DAT (a.ka.
R-DAT, S-DAT, and 4mm), but one type has been so ubiquitous that
it's "real" name has become less known. It is instead simply known
as the generic "cassette tape." The given name for this format years
ago was the compact audio cassette, and was sometimes known as the
musicassette. This format, developed by Phillips in the early
1960's, works similar to an open
reel tape machine, only the tape is much smaller (1/8 inch
wide), speeds much slower (1 & 7/8
i.p.s), and the reels are housed in a cassette, which made it
extremely convenient to use compared to the other options available
at the time, hence its popularity. The compact audio cassette was
largely developed with dictation machines in mind (where the "micro
cassette" later became standard), but quickly became a popular
distribution method for recorded music. The format has also been
instrumental in the explosion of home recording equipment. In the
early 1980's Teac/Tascam developed the "Portastudio," which was a
4-track recorder designed for home studio use. By doubling the tape
speed to 3 & 3/4 i.p.s and employing
dbx noise reduction some pretty decent (by the standard then)
recordings could be made in a true
multitrack fashion. Cassette tapes have also been widely used
over the years as data storage for computer systems. Some of these
have been in the form of standard (more or less) compact audio type
cassettes, while others have been more proprietary formats. Today we
still use several different formats of cassette tape (DAT,
AIT,
DLT, etc.) as a means to archive and backup important computer
data. |
|
| Cat 5
|
Short for Category
5, a common type of
twisted pair cable. Cat 5 cable is used in many networking
environments for high speed data transfer. It is the current
standard (replacing the former standard, Cat 3 cable) for
Ethernet and fast Ethernet networks, where it is generally
terminated with an RJ-45 type connector (similar to the connector
many telephones use). The "category 5" standard states the twisted
pairs must have at least 8 twists per foot. There are other category
standards with different specifications, but Cat 5 is the most
widely known and used at the consumer level right now. Most modern
computers have RJ-45 type connectors built in to them for networking
connections. Since this configuration has become such a common
standard, component parts are widely available and inexpensive,
which has caused even more widespread usage. As such we are
beginning to see these connectors and cables used on more and more
music equipment for certain types of communication. |
|
| CD
Extra |
A CD format that
combines audio and data on the same disc, usually to include extra
content such as interactive multimedia, including video, graphics
and/or other information designed to enhance an audio CD for
consumers with computers. A CD Extra is a
multisession disc, meaning that the audio and data are burned in
separate passes and are contained in different areas of the disc.
|
|
| CD+G
|
An
audio compact disc format that contains graphics data in
addition to the audio data. A CD+G disc can be played on a regular
audio CD player, but when played on a CD+G-compatible player, can
output a graphics signal (typically, the CD+G player is hooked up to
a television set or a computer monitor). After an earlier life
supporting video games, CD+G is being used for CDs for
karaoke systems, with the graphics used to display song lyrics.
A compact disc contains two kinds of data: Content data, which is
used to store audio, computer software, etc., and subchannel data
(or
metadata), which is normally used by the CD player to help
control the disc. In each sector of a CD there are 2,352
bytes of content data and 96 bytes of subchannel data. Each of
the 96 subchannel data bytes can be thought of as being divided into
8
bits. Each of these bits corresponds to a separate stream of
information. These streams are called "channels," and are labeled
starting with the letter P, so: Channel P, Q, R, S, T, U, V, W
carries bit 7, 6, 5, 4, 3, 2, 1, 0 Channels P and Q on a regular
audio CD are used to assist the CD player in tracking the current
location on the disc, and to provide the timing information for the
time display on the CD player. The CD+G format utilizes channels R
through W to store 16-color (4-bit) graphics for a display that is
300x216
pixels in size. The videogame consoles Sega CD, Sega Saturn,
Commodore Amiga CD32, and the Atari Jaguar CD (which was an
attachment to the Atari Jaguar) also played CD+G format CDs.
|
|
|
CD-ROM |
Short for, compact
disc, read-only memory. A CD-ROM is a compact
optical media disc used to store and play back computer data
instead of digital audio. CD-ROMs have become a favorite medium for
installing programs and distributing medium sized chunks of data,
since they cost only slightly more to manufacture than
floppy disks, and most major software applications would require
several floppies to distribute. Today, there is CD-ROM media that
can hold up to 650
megabytes
of data (74 min. is the maximum designed capacity). The
specifications for CD-ROM were first defined in the
Yellow Book standard. |
|
| CD24
|
A CD24 is a
special kind of Compact Disc that can be made and played by the
Alesis MasterLink. It allows you to store audio at higher
sample rates (up to 96kHz)
and
word lengths (up to 24-bits)
than is allowed by the standard consumer \"Red
Book\" CD format (16-bit/44.1kHz). A CD24 can also be played in
a computer\'s CD-ROM drive because it follows the common PC and
Mac-compatible CD-ROM standard
ISO 9660. Also, the audio files on the disc follow
AIFF format, which is readable by almost any audio software
available today. |
|
|
Centronics |
A standard
computer interface for connecting printers, CD-ROM drives and other
devices. Although Centronics Corporation designed the original
standard, the Centronics interface used by modern computers was
designed by Epson Corporation. For PCs, almost all
parallel ports conform to the Centronics standard. Two new
parallel port standards that are backward compatible with Centronics,
but offer faster transmission rates, are
ECP (Extend Capabilities Port) and
EPP (Enhanced Parallel Port). On the Macintosh side of the
fence, Centronic connections are of the
SCSI flavor only (See WFTD:
Centronics 50). |
|
|
Challenge/Response |
A common technique
used for software copy protection. It's comprised of an exchange of
passwords that contain hidden information that permits software to
run and to be stored on a computer's
hard disk. Usually, when an application is first run, the user
is presented with a unique challenge password. This password is
submitted to the manufacturer (or a service company they employ) who
then provides a response password that can be used to "unlock" the
software so it will run on that machine. In some cases the same
response can be used to unlock the software on other machines, but
in many cases the challenge (and consequently the response) are
unique to a given machine, or even to a particular instance of
installation (in other words, if you wipe the software from the
machine and install it again you may be presented with a different
challenge). This system has some advantages over key disk/CD or
dongle copy protection methods: you never need to deal with
anything physical and the entire authorization process can be
performed by e-mail or phone. However, there is one disadvantage,
which is that your authorization is not easily transportable from
one machine to another. Challenge/Response, while still in use,
seems to losing popularity among software developers.
|
|
|
Chipset |
In a personal
computer, the integrated circuit (IC)
chips that define the functions of a
CPU. The chipset is in charge of controlling the flow of
instructions to the CPU as well as defining the available buses.
Chipsets are normally integrated - soldered onto the
motherboard. On early personal computers these functions
required as many as 30 individual chips. Current PCs have
consolidated all these circuits into only two or three chips. Intel
(Pentium)
and AMD-based computers have two distinctive chips. The northbridge
typically handles communications between the CPU,
RAM, and
AGP or
PCI Extended graphics cards. Some northbridge chips also contain
integrated video controllers. The southbridge chip normally defines
and controls the operation of other buses and devices, including the
PCI bus, the
PS/2 interface for keyboard and mouse, the
serial port, the
parallel port, and the
floppy drive controller. The chipset used by a given
manufacturer of motherboards can have a significant impact on the
way in which that board (and the resulting computer that uses it)
will interact with various peripheral devices. Some hardware,
particularly more exotic audio recording hardware, can be pretty
picky about chipsets and their associated data protocols.
|
|
| CISC
|
Acronym for
Complex Instruction Set Computer. This is an instruction set
architecture (ISA) in which each instruction to a
CPU can indicate several low-level operations, such as a load
from memory, an arithmetic operation, and a memory store, all in a
single instruction. The original theory was to have the processor
receive fewer instructions, which would allow it to handle
"high-level" programming languages more easily. This is in contrast
to Reduced Instruction Set Computer (RISC)
design, which executes a rapid sequence of simple instructions.
Before the first RISC processors were designed, many computer
architects were trying to design instruction sets to support
high-level languages by providing "high-level" instructions such as
procedure call and return, loop instructions such as "decrement and
branch if non-zero" and complex addressing modes to allow data
structure and array accesses to be compiled into single
instructions. While these designs achieved their aim of allowing
high-level language constructs to be expressed in fewer
instructions, they did not always result in improved performance.
For example, on one processor it was discovered that it was possible
to improve the performance by NOT using the procedure call
instruction but using a sequence of simpler instructions instead.
Furthermore, the more complex the instruction set, the greater the
overhead needed to decode an instruction, both in execution time and
silicon area. The term, like its antonym RISC, has become less
meaningful with the continued evolution of both CISC and RISC
designs and implementations. Modern "CISC" CPUs, such as the Pentium
4, while they usually support every instruction that their
predecessors did, are designed to work most efficiently with a
subset of instructions more resembling a typical "RISC" instruction
set. Indeed, many CISC CPUs (such as modern x86 processors from both
Intel and AMD) "break" many x86 instructions into a series of
smaller internal "micro-operations" that are then executed
internally by the processor. |
|
|
Classic |
In Macintosh
computers running the
OS X operating system, Classic is the name for a type of
shell program that runs the older
OS 9.2 operating system within OS X. Being able to run the older
OS on top of OS X allows Mac users to continue to use older software
that that doesn\'t work under OS X. |
|
| Click
and Hold |
The action of
clicking your computer's mouse on an object, but not releasing it -
holding the mouse button down. Depending on what you click upon,
this may bring up an additional menu or list of selections you can
make by pulling the mouse down and releasing the button.
|
|
| Click
Track |
A metronomic
"pulse" heard in monitor headsets by the musicians (or conductor in
film scoring) during the performance of music. The purpose of a
click track is the same as any metronome: to guide the musicians
temporally for the sake of timing consistency or some other timing
concern. In film scoring this would be to have
hits and other
cues occur at the proper time in the film. Traditionally click
tracks have been recorded to tape (hence the usage of the word
"track" in the name), but in modern production this is increasingly
rare. Click tracks are quite often generated by computer software
(such as
MIDI sequencers) and played back in real time through some MIDI
sound source. However, in many instances for the sake of
convenience, and as a fail-safe method they may also be recorded to
the multi-track being used. |
|
|
Clipboard |
In Macintosh and
PC computers, and some other systems, the clipboard is a virtual
memory holding area where data can be temporarily stored for certain
tasks. The most common use of the clipboard is for copy (or cut) and
paste operations. When you Copy a line of text, a graphic image,
audio sample, etc. it is stored on the clipboard where it remains
until you replace it with something else. In the Mac the contents of
the clipboard can be viewed under the edit menu when the Finder is
the active application. In Windows systems you can view it by
looking under the Start Menu/Accessories/System Tools/Clipboard
Viewer. Some
Windows programs allow you a choice to append data to the
clipboard or overwrite it each time something new is copied.
|
|
|
Cluster |
On hard drives and
other types of data storage systems, tracks and
sectors are broken into clusters. The cluster is the smallest
unit of storage that is addressable (can be written to or read) on
the device. The size of clusters may vary. Often you'll see sizes of
256 or 512
bytes, but this can vary widely from system to system. Each
piece of data stored on a disk requires at least one cluster. So if
you have a word processing document that's only 50 bytes in size it
will require an entire cluster to store it, even if the clusters are
much greater in size. You can't put two 50 byte files in the same
cluster because the computer (or storing device) would have no way
to address them separately. Larger file's clusters can be scattered
among different locations on the hard disk. The clusters associated
with a file are kept track of in the hard disk's file allocation
table (FAT).
When you save or read a file, the entire file is handled for you and
you aren't aware of the clusters it is stored in. The total number
of clusters available on a disk depends on how it was
formatted and the addressing system used, or more specifically
on the size of the FAT table entry. For example, the
FAT-32 system commonly used is a 32
bit addressing system, which allows enough cluster addresses to
support up to two terabytes (2000 gigabytes) of data, assuming you
have a large enough disk. |
|
| CMOS
|
Acronym for
Complementary Metal Oxide Semiconductor (pronounced 'see-moss'). A
special type of semiconductor with very low power consumption among
other things. They are constructed very differently from a typical
'transistor' or 'integrated circuit,' but perform many of the same
functions. CMOS chips are widely used in computing products. One
specific area concerns the
BIOS or
preferences for some of the basic functionality of a computer. These
are sometimes stored in CMOS-based memory chips, which are kept
under power by a small battery somewhere in the computer.
|
|
| CNC
|
Acronym for
"Computer Numerically Controlled." This is a computer-assisted
routing machine that can shape the wood parts of a production guitar
with astonishing accuracy. As more manufacturers add CNC
capabilities, quality continues to climb higher, as these machines
produce better, more consistent parts, especially solid guitar
bodies. |
|
| Code
|
A set of symbols
that represent assigned meanings (usually used for secrecy). Also
the act of putting a communication into coded form. The word code
has come to be used by computer programmers to describe their work.
Specifically it has been used to distinguish computer instructions
from data, but is now often applied more generically to any and all
instructions used by a computing device, as well as the act of
writing those instructions. |
|
| COM
Port |
Short for
Communications Port. This is a generic term used to identify
I/O ports, usually on PC Computers, that may be used for things
like modems,
MIDI interfaces, and other peripheral devices. PC COM ports are
generally used in conjunction with a number, as in as in COM1, COM2,
COM3, or COM4. These are serial ports and analogous to Macintosh
serial ports. |
|
|
Compile |
To have a computer
translate
source code written in a computer language into an executable
form, which is generally some type of \"machine language\" a
specific computer processor uses. This is usually done by a
translator program called a compiler and represents the most common
way computer programs have been developed for the past few decades.
|
|
|
Component Video |
A video signal
where some or all of the individual components that make the signal
are sent down separate wires (as opposed to
composite video), either in the form of a multi-pin
D-Sub type cable or a five way cable terminating to five
BNC connectors (there are other types, but these two cover the
majority of it). For example, in a computer monitor you may find
that the three primary video colors (Red, Green, and Blue) are each
sent separately, and luminance (brightness) information and video
sync are separate from that, hence the five wires (it can even
be separate further into horizontal and vertical video sync). In
some applications "component" signals are still composite signals of
another kind. Formats such as the 4-pin S-Video, the 2-RCA luma/chroma
standard, or the 3-BNC YUV standard will have some combining of
information, such as the sync signal(s).
Regardless of the kind of cable used, modern
analog computer displays have separate signal and
ground wires for at least the red, green, blue, HSync and VSync
signals. This separation allows the cables to carry much higher
frequencies than would be possible if they were entirely or
partially composited with each other. These higher frequencies allow
for the high
resolutions that computer displays must support. For comparison,
a computer outputting a 640 x 480 resolution image with a 60
Hz interlaced refresh rate (similar to broadcast TV) has a
"dot-clock" frequency of approximately 12 MHz. (Dot-clock represents
the timing between adjacent screen pixels and is the highest
frequency component of any computer's display-generation circuitry.)
At 800 x 600 resolution (also 60 Hz interlaced), that dot-clock
frequency increases to approximately 35 MHz. A modern workstation's
display using 1600 x 1200 resolution at 85 Hz non-interlaced
requires a dot-clock frequency of at least 220MHz.
(Special thanks to inSync reader David Charlap
for some of the computer specific information presented here.) |
|
|
Control Panel |
Basically, this is
just what it sounds like: a panel to control something. The usage of
the term gets confusing to people in how it is applied to computers,
but it's pretty simple. In computing devices, a control panel is a
software program designed to give the user control over some
specific part of the operation of the machine. This could be a basic
function like monitor resolution, or more involved functions
relating to standard and optional hardware or software that may be
installed on a particular system. |
|
|
Control Surface |
In the music and
production world a (hardware) controller is something we use as a
human interface to other elements in a system. For example, a
keyboard controller is used to play keyboard parts, where the
performance data is transmitted to a device that produces the sound,
whether it's a rack mounted module, a software synth, or another
keyboard. A control surface is conceptually a more generic form of
controller. They come in many shapes and sizes with (in some cases)
radically different capabilities, but the thing they have in common
is that they are used to control the functions of some other device,
often a computer software program. In our business the words
"control surface" usually conjure up images of something looking
like a mixing board. These aren't actually mixing boards, but
instead devices used to control other devices, which perform the
functions of a mixing board (mixing,
aux sends,
panning,
EQ, etc.). Now that so much production is done inside of
computer software, it has become increasingly important to provide
tools that enable musicians and engineers easy access to a familiar
set of controls in order for them to most effectively be able to do
their work. As such, control surfaces in many ways mimic the look
and feel of a mixing board, even though in many cases they may
provide more or different capabilities. Some control surfaces are
designed specifically for a specific computer or software system,
while others are more generic and may work with a variety of
different systems. Nowadays many stand alone mixers are really
nothing more than software based mixing boards under the control of
a dedicated control surface, even though the outward appearance is
that of a mixer. In some cases these mixers can also be used to
control other software mixers. |
|
| Copy
|
In computer
applications, Copy is a common convention used by many applications
that allows the end user to copy a defined selection to the
computer's
Clipboard while leaving the defined selection in place and
unchanged. The defined selection is now available for use elsewhere
via the "Paste"
function. |
|
|
Corrupt/Corruption |
Political humor
aside, when we use these terms in the context of making music, we
are generally speaking of data files or media that for one reason or
another have become unusable. The usage comes from the standard
definition, which is (among other things) to spoil, taint, or alter
from the original. Computers and programs running on them expect
data, whether in
RAM or on disk, to be organized in a specific way. If something
happens to the information to alter this organization it is said to
have become corrupt, which usually results in it no longer being
usable, or at least requiring efforts to repair it. Often times when
media fails it is because the
formatting data on it has become corrupt. |
|
| CPU
|
Abbreviation for
Central Processing Unit. The chip on a computer's motherboard which
ultimately controls all the activity of the computer. Standard Macs
have a 680x0 chip (x = 0, 2, 3, or 4) manufactured by Motorola.
PowerPC Macintoshes use a new RISC (Reduced Instruction Set
Computing) chip designed by a conglomerate of computer hardware
manufactures, including Apple, IBM, and Motorola. Most IBM
compatible computes use a chip based on Intel's X86 architecture.
These days most electronic instruments (keyboards, drum machines,
etc.) and digital tape machines have a CPU which controls all of the
functions of the machine. |
|
|
CPUCycle |
In layman's terms
this is a fancy way of talking about events that your computer's
CPU
performs. Each event, which can be triggered by a pulse from the
clock, can
be considered a cycle. Or, as if often the case, the CPU has a
series of little routines it is constantly running. Things like:
check each I/O
port for incoming data (keyboard, mouse, modem, etc.), update the
screen, move data from here to there, etc. Basically a series of
events that are required to keep the computer operating. The
computer keeps repeating them over and over. A cycle can be
considered to be one pass through all of these events.
|
|
| Crash
|
In the computer
world, a crash is generally a condition in which a specific
application or a part of the computer's
operating system stops performing its specific functions and
will not respond to keyboard commands. A crash may manifest itself
in any of several ways, up to and including a complete freeze, where
the
cursor is locked into a specific place on the screen. When an
operating system
kernel is involved, this is often called a system crash.
Depending upon the severity of the crash, a restart may be all that
is required, but large scale crashes usually require restarting
(rebooting) from a system disc or specific software that is designed
to go in and and find the problem. Today crashes are less
destructive than in the early days of personal computers, when a
fresh reinstallation of the entire contents of the internal
hard drive was often required. |
|
| Cross
Platform |
Refers to hardware
or software that is capable of working on, or is compatible with,
multiple platforms. Generally the term is used in the computer world
and means that a device or software package is compatible with two
or more fundamentally different systems, such as PC and Macintosh.
Programs that work on both
Windows NT and
Windows XP, for example, would not be considered \"cross
platform\" as it is understood that those two platforms are very
similar. Sometimes the term is applied to more audio specific
products such as soundware for
synthesizers and
samplers, where it signifies that a given package works on more
than one brand of instrument. For example, a sample library might be
compatible with both Roland and Kurzweil samplers. It is more
common, however, to see the specific brands and type of instruments
listed since there are so many potential distinctions to be aware
of. |
|
|
Crossover Cable |
A type of cable
designed to connect two devices directly together that would
normally have a
hub between. This comes up often with
Ethernet cables. Ethernet RJ-45 connectors are normally wired
for the paradigm where everything runs through a hub. When two
devices are connected directly together the wiring is backwards and
does not match up. So there are crossover cables where the middle
four of the eight wires are reversed from one end to the other. This
is the type of cable required to connect two computers with Ethernet
directly together without the need for a hub or switch. Crossover
cables are also found in other domains, such as
parallel cables for computers. Here they are commonly known as
Null Modem cables. |
|
| CRT
|
Abbreviation for
Cathode-Ray Tube, the technology used in most televisions and
computer display screens. A CRT works by moving an electron beam
back and forth across the inside front of the screen. Each time a
beam makes a pass across the screen, it lights up phosphor dots on
the inside, illuminating the active portions of the screen. The beam
is controlled by electromagnetism, which causes it to scan in an
orderly fashion that is related in time to the data (image) that
causes the energy from the gun to vary, thereby producing (painting)
the images you see. By quickly drawing (scanning) many such lines
from the top to the bottom of the screen, it creates an entire
screen full of images. In order for the beam to return to the top of
the screen after it has reached the bottom a "blanking pulse" is
timed into the data to turn the beam off so it doesn't paint a
diagonal line from the lower right to the upper left hand corner.
This blanking pulse is known as
black burst and is the source of timing used in many
synchronization systems. |
|
| Cut
|
In computer
applications, Cut is a common convention used by many applications
that allows the end user to remove a defined selection (text,
images, sound clips, video clips, etc.) from an active document
while automatically placing it into the computer's
Clipboard for use elsewhere via the "Paste"
function. |
|
| D-Sub
|
D-Sub and DB are
prefixes used to describe a type of multi-pin connectors that happen
to be commonly used in audio equipment. The original manufacturer,
ITT Cannon, adopted the "D" designation as the lead character in
their part numbers signifying the connector type. The shell size, or
capacity, is next in the part number: A=15 pin, B=25 pin, C=37 pin,
D=50 pin and E=9 pin (not originally produced). This type connector
can also be specified with many different styles and quantities (up
to its capacity) of pin: high power, coax and combinations. The most
common connector, early on, was the 25-pin size, which was used on
RS232 ports (a common computer port). Hence DB25M means "D" type,
"B" shell, 25 pins, Male pin. Note that a 15-pin female would be
DA15F. D-Sub is short for the current industrial tag,
D-Subminiature, used by almost all of the manufacturers.
|
|
| DAE
|
Abbreviation for
Digidesign Audio Engine. DAE is the underlying code that Digidesign
has been using to make their audio systems work and communicate with
computer hardware and software. When you launch Pro Tools (or any
application that uses DAE to communicate with Digidesign hardware)
DAE also launches in the background. The main application (such as
Pro Tools) is really just acting as the user interface while DAE is
actually taking care of the underlying mechanics of moving the audio
data in, out, and through the system. DAE is required for software
programs to be able to access Digidesign hardware. |
|
| Daisy
Chain |
A wiring scheme in
which, for example, device A is wired to device B, device B is wired
to device C, etc. All devices may receive identical signals or, in
some instances, each device in the chain may modify one or more
signals before passing them on. Common Daisy Chain examples would be
MIDI devices connected together utilizing their THRU
connections;
SCSI connections with the last device
terminated; certain computer network schemes; reference
clock for digital studio devices; etc. |
|
| DAW
|
Pronounced "Dee -
A - Double-U", the abbreviation (not acronym) for Digital Audio
Workstation. DAW's are common in almost any studio these days. They
are typically defined as having some ability to record, manipulate,
and play back audio recordings or samples. In their early days DAW's
were primarily considered editing stations. Material was taken from
the primary recording media (usually tape) and dumped into one of
these systems for editing, and then returned to the original media
for the remainder of the project. Nowadays DAW's can act as an
entire recording studio with all mixing, processing, and mastering
on one computer. |
|
| DB-25
|
A type of
D-Sub
connector. DB-25's are commonly found on computing equipment where
they are employed to connect peripherals. They are common to
parallel ports or
RS-232
ports on PC computers, but also often used in a variety of ways in
the audio community. For example, TASCAM commonly uses the DB-25
connector for analog and/or digital
I/O on their
products, as do some other brands. |
|
| DDS
|
An abbreviation
for Digital Data Storage. DDS is a data storage format which was
developed from DAT (Digital Audio Tape) by Hewlett-Packard and Sony,
especially for reliably storing computer data. DDS is defined by
international standards and is supported by many manufacturers, but
more importantly, it is subject to thorough collaborative testing
programs which ensure that tapes written by one maker's drives can
be read by those of other manufacturers.
DDS drives are rigorously tested for format
compliance and data interchange according to a scheme that
Hewlett-Packard administers. DDS media is put through a
comprehensive set of tests designed to ensure that only data
cartridges capable of meeting the exacting environmental and
durability requirements of the DDS standards bear the DDS trademark.
This scheme is administered by Sony. |
|
| Delay
Compensation |
A process of
manipulating the timing of digital audio tracks so that any
latency resulting from the application of
plug-in effects or instruments is accounted for, resulting in
the accurate
synchronization of those tracks with other tracks which are not
affected by latency-causing processing. Even with the fastest
possible computer
CPUs and hardware-accelerated
DSP cards, routing an audio track through digital effects
plug-in creates latency in the output of the effected audio. This
latency can be almost imperceptible, such as a few
samples, or it could be greater, up to a few
milliseconds. As a result, that track's audio reaches the output
stage slightly later than tracks that aren't passed through a
plug-in. Multiply the effect of one track's latency by a potential
of several tracks undergoing processing (each with a slightly
different amount of latency) and you eventually end up with a
"smeared" audio output - one in which the tracks aren't in perfect
synchronization with each other, with audible differences in
attacks, phase and releases. Musically speaking, this may not
necessarily be a bad thing (although hardly anyone could argue it's
a good thing), but if you're layering
unison parts, for example, the combined latencies of several
processed tracks can be distracting. It's also very destructive to
building a proper
soundstage in a mix. |
|
|
Desktop |
In computers using
a
GUI the desktop is the whole screen area underneath any open
windows or icons. It is the top level in the hierarchy of the
system: hard drives and other files reside on and can be accessed
from the desktop. |
|
| DFD
|
Direct From Disk (DFD)
is
Native Instruments' term for the technology that allows a
virtual instrument to play
samples directly from
hard drive instead of loading them into
RAM. This allows for playing longer samples than will fit in the
computer's memory, among other things. A small amount of RAM is
still required to "preload" a bit of the sound before it starts
playing, to compensate for the time it takes for the computer to
find the sample on the disk and begin playing it - this is known as
the "preload
buffer." |
|
|
Dial-up |
The earliest (and
exceptionally slow) method of connecting to the
Internet was to use existing telephone lines and a modem that,
together, connected a computer to an internet service provider (ISP).
In its earliest days, the Internet could hardly live up to the hype
as the "information super highway," as the only way to get connected
was via a 2,400bps
modem and a phone line. |
|
|
Differential |
In the computer
world, a "balanced"
signal is known as "differential". The same technique is used - the
signal is sent with the inverse signal running parallel to it.
Sometimes, the two signals' wires are twisted around each other
(known as "twisted pair" wire). Differential signals are used in
10Base-T and 100Base-T Ethernet and some varieties of
SCSI.
(Special thanks to inSync reader, David C. for
this one.) |
|
| Digi
System Init |
Abbreviation for
Digi System Init. Init is a fancy word for
Extension
on the Macintosh - historically the extensions that load upon boot
up were called inits, which is short for
initialize. These days we just call them extensions, but DSI is
an old abbreviation. The DSI is, therefore, an extension that must
be loaded by the computer in order for it to be able to "see" any
Digidesign hardware that may be installed in it. It works in
conjunction with
DAE to enable recording with Digidesign systems.
|
|
|
Digital |
In a general sense
digital refers to information or data that is stored or communicated
as a sequence of discrete values, rather than some scale across a
continual set of values (analog). A digital system may use any (or
several) of many different numbering schemes, including decimal
(base 10), octal (base 8), and
hexadecimal (base 16), but for the most part we associate the
binary (base 2) numbering system with digital as it is the most
commonly used numbering system in digital hardware such as computers
and other logic based systems. For our purposes, digital refers to
the representation of a varying physical property such as sound or
light waves (as in digital audio or video), by means of a series of
numerical values (in binary, ones and zeroes). These digits are
grouped together in "words"
to represent parts (intervals) of the complex character of the audio
or video material. |
|
|
Digital Synthesizer |
A synthesizer that
uses digital signal processing (DSP)
techniques to make sounds. The very earliest digital synthesis
experiments were made with general-purpose computers, as part of
academic research into sound generation. Perhaps the best way to
begin to understand digital synthesis is to compare it to analog
synthesizers. Modular analog synthesis uses voltage to perform its
three primary functions. A voltage-controlled oscillator (VCO)
produces a tone, which is shaped by a voltage-controlled filter (VCF).
The amplitude of the resulting sound is processed by a
voltage-controlled amplifier
(VCA). (These basic building blocks can be rearranged in a
variety of ways, but they still perform similar duties.) Digital
synthesis replaces voltage with numeric representations of values;
so at its most basic, a digital synthesizer uses a digitally
controlled oscillator (DCO),
filter (DCF)
and amplifier (DCA).
However, the broader range of processing power available with DSP
has allowed many variations of synthesis techniques to emerge that
simply weren't possible with analog technologies. Early commercial
digital synthesizers used simple hard-wired digital circuitry to
implement techniques such as
additive synthesis and
FM synthesis. Other techniques, such as
wavetable synthesis,
physicalmodelingsynthesis and
granular, became possible with the advent of high-speed
microprocessor and digital signal processing technology. Some
digital synthesizers now exist in the form of "soft
synth" software that utilizes conventional computer hardware for
processing.
Virtual analog synthesizers, whether in hardware or software
form, are in fact digital synthesizers that emulate the behavior of
analog circuitry. |
|
| DIMM
|
Acronym for Dual
Inline Memory Module. A DIMM is essentially a double
SIMM. Like SIMM\'s they are small circuit boards with several
memory chips installed. The boards can be installed in computers and
other devices to increase their
RAM capacity. A lot of modern day computing hardware uses
SDRAM type memory, which requires a 64-bit data path, as opposed
to the 32-bit
path required by SIMM\'s. Initially this was achieved by installing
SIMM\'s in exact pairs, one for each 32-bit path. Now this is
accomplished with a single DIMM board. |
|
|
Direct I/O |
The trademarked
name for Digidesign's software drivers that allow programs such as
audio sequencers from various companies to directly access
Digidesign audio hardware installed in a computer. Without Direct
I/O drivers most audio programs can only interface with the Apple's
built in audio, which can then often be interfaced with the
hardware-recording card. The disadvantage is that this only allows
for two channel input and output because that is all the computer
supports. Direct I/O gives the software the ability to directly
interface with multi-channel hardware, such as Digidesign's Pro
Tools and Project systems, thereby allowing multiple inputs and/or
outputs to be used simultaneously. Direct I/O drivers have to be
specifically written for each hardware type. Most of the popular
audio sequencer manufacturers (MOTU, Opcode, EMAGIC Steinberg, etc)
have written their own Direct I/O drivers that work with Digidesign
hardware and hardware from other companies. |
|
|
Display |
In the computer
world, a synonym for video
monitor; used for both
LCD and
CRT monitors. In the audio world, "display" is used to refer to
the various types of
LED and LCD visual "readouts" found on
keyboards, processors, and other gear. |
|
| DMA
|
Abbreviation for
Direct Memory Access (or addressing). DMA is a method of
transferring data from one memory area to another without having to
go through the
CPU. In many computer systems DMA is allocated in "channels."
Computers with DMA channels can transfer data to and from devices
much more quickly than those in which the data path goes through the
computer's main processor. DMA channels are limited in number, and
you can't allocate one channel to more than one device. There are
also newer enhanced (faster) versions of DMA known as UDMA, or Ultra
DMA. |
|
| Dolby
Virtual Speaker |
An algorithm
created by
Dolby that attempts to reproduce the dynamics and surround-sound
effects of a precisely placed
5.1-channel speaker system from a consumer electronics device or
personal computer equipped with as few as two speakers. The
algorithm at the heart of Dolby Virtual Speaker technology is based
on psychoacoustic parameters that include an understanding of sound
from both a technical and an experiential perspective. Dolby Virtual
Speaker technology uses biological, psychological, and physical
understanding to create the "impression" of additional speakers
positioned exactly at the recommended locations for a
Dolby Digital sound system with five actual speakers. In other
words, audio channels are processed through filters that simulate
the sonic signature of a speaker located within an acoustic space.
Dolby Virtual Speaker technology was launched in fall 2002 to the PC
industry, and is currently available on select software
DVD players from CyberLink, InterVideo, and Nvidia, as well as
models from leading PC OEMs (including Sharp, NEC, Sony, Fujitsu,
and Hitachi). |
|
|
Dongle |
An electronic
device that attaches to a computer to control access to a particular
application. Dongles provide an effective means of copy protection.
Typically, the dongle attaches to a PC's parallel port or, on a Mac,
to an ADB port. Ideally a dongle passes through all data coming
through the port so it does not prevent the port from being used for
other purposes. In fact, it's possible to attach several dongles to
the same port. Programs that use a dongle query the port at startup
and at programmed intervals thereafter, and terminate if it does not
respond with the dongle's programmed validation code.
|
|
| DOS
|
An acronym for
Disk Operating System. Literally, the term refers that portion of an
operating system that controls writing, storage, and retrieval of
data from storage media, usually spinning disks of various types. In
common usage, the term refers to MS DOS, the complete operating
system developed by Microsoft for IBM-compatible personal computers
in text (non-Windows) modes. |
|
|
Double Precision |
A computer
numbering format in which a number occupies two storage locations in
computer memory (called "address" and "address+1"). A double
precision number, sometimes called a double, may be an integer,
fixed point, or
floating point. The term double precision is not truly accurate
because the "precision" is not really double. The word "double"
simply means that a double-precision number uses twice as many
bits as a regular floating-point number. For example, if a
single-precision number requires 32 bits to define, its
double-precision counterpart will be 64 bits long. Computers with
32-bit data stores (single precision) provide 64-bit double
precision, in a series of 8-byte
words. Most applications conform to an IEEE standard (754) that
defines the encoding of floating-point numbers using 8 bytes.
|
|
| Drive
|
Drive is a
rhythm pattern from the big band era in which the kick drum and
the snare are hit simultaneously on all four
beats of a
measure. Drive may also refer to gain for an
amplifier or
effects unit, and pushing an amp's
preamp to distort can cause
overdrive. Overdrive is generally considered to be another word
for
distortion or
clipping. When you overdrive something with too much level, it
distorts. For guitarists, however, there is a distinction between
overdrive and distortion. In the domain of guitar sounds distortion
generally means extreme distortion and is associated with a buzzing
or "fuzz" type of sound. To guitarists overdrive represents the
guitar equivalent of the general or mechanical definition above. It
is a state of (for lack of a better term) semi-distortion. A
heightened concentration of harmonic energy and presence, but not
the same as all-out distortion. Drive is also a shortened term
referring to
hard drives and CD readers/writers in computers.
|
|
|
Driver |
In the world of
computers, a virtual road map exists that tells data for each piece
of equipment or program which path to take to its chosen
destination. Just like in the real world, you need directions on how
to get from A to B. In the world of computers, we call those devices
"drivers". Drivers are bits of software code used to enable various
pieces of hardware and software so they can be recognized by other
programs in a computer and have the appropriate data routed to them
in a format they can understand. For example, Windows uses drivers
to communicate with a MIDI interface. If you do not have the proper
driver installed your computer may not recognize or work properly
with a given piece of hardware or software. |
|
| DSL
|
Abbreviation for
Digital Subscriber Line. DSL is a high-speed method of sending
computer data over standard copper telephone wires using
sophisticated modulation techniques. There are several types of DSL
connections, but they all require a special DSL modem between your
computer and the phone line. DSL's are sometimes referred to as
"last mile" technologies because they are used only for connections
from a telephone switching station to a home or office, not between
switching stations. This also means you have to be within an
acceptable range of a telephone switching station in order for it to
work well enough to be useful. DSL has become popular the last few
years as a really fast and reasonably affordable way of connecting
home or office computers to the Internet. |
|
| DSP
|
Abbreviation for
Digital Signal Processing. This term gets thrown around all over the
place these days without much regard for what it actually means.
Without getting into a lot of detail it basically just refers to a
specific type of digital processing that is optimized for dealing
with signals. In our case these are often audio signals, but they
don't always have to be. DSP can be thought of as sort of a subset
to the old math coprocessor concept. Math coprocessors were chips
that were included in computers to help the
CPU do massive calculations more efficiently. DSP chips are
designed and optimized to be able to do various (mathematical)
calculations for processing audio or image data. For example, many
of today's effects processors use a special DSP chip made by
Motorola that has been optimized for working with audio data. A
surprising number of different processors use this exact same chip,
but with different software instructions as written by the companies
to have it do what they need for their product. |
|
| DTV
|
Short for Digital
Television. DTV is the transmission of television signals using
digital rather than conventional
analog methods. Analog transmission is in the form of a
constantly variable wave; digital transmission consists of an
electrical pulse that has two possibilities: on and off (or positive
and negative),which are represented by a one and a zero (this is
binary data, the same type of information that a computer
understands), that is then
modulated into an analog transmission. A digital signal can be
more precise than analog due to the fact that the electronics at the
receiving end will either be able to retrieve enough of the digital
information to reconstruct a pretty good signal, or it will be
incapable of reconstructing anything resembling a good signal. It's
pretty much all or nothing, with very little area in between.
Although both signals are transmitted in the same basic way and
supposedly have the same range, they behave differently at the
limits of their ranges. An analog signal gradually degrades over
distance (mostly in amplitude, though there can be other
distortions introduced) and may be barely detectable at the
farther reaches of the broadcast area - this is why the signal from
a distant radio station fades in and out. As the signal reaches the
farther limits of its range, the
signal-to-noise ratio decreases and the quality of the broadcast
suffers, although the range remains the same. In comparison, when
the signal-to-noise decreases in a digital signal, the quality of
the broadcast does not visibly degrade very much (until it drops out
all together) depending upon the error correction capabilities of
the system or generally how effective it is at reconstructing a
usable signal from partial information, but the range shrinks.
|
|
| Dual
Core Processor |
The installation
of two computer
CPU execution cores on a single physical processor. A dual-core
CPU combines two independent processors along with their respective
caches and cache controllers onto a single chip. The advantages
of this approach are many: reduced power consumption (than
equivalent multi-processor systems), less space consumed on the
PCB, reduced heat, and — most importantly — the "threaded
parallelism" — the capability of the CPU to carry out two
independent instructions per
cycle rather than one. In fact, when technology such as Intel's
Hyperthreading is applied, a dual-core CPU can actually load four
instructions into its registers. A side benefit for manufacturers is
the death of the "gigahertz mania" that CPU chips have followed for
several years. The emphasis is on multithreading capacity rather
than clock speed. Dual-core CPUs require support from both the
operating system and the individual application to provide any
visible benefits. At this writing, both AMD and Intel have
commercially available dual-core processors. |
|
|
DualDisc |
A double-sided
optical disc introduced in the United States in 2004. A DualDisc
features an audio layer similar to a
CD (but not following the
Red Book CD specifications) on one side and a standard
DVD layer on the other. This allows artists to distribute
audio-only versions of their work in both 16-bit/44.1kHz
CD and high-resolution (24-bit/96 or 192kHz)
DVD-A stereo file formats, as well as include
surround versions and video content. Technically speaking,
DualDisc is not a "format" in the sense of Red Book CDs or
DVD-Audio. The media is an attempt by several industry giants (EMI
Music, Universal Music Group, Sony/BMG Music Entertainment, Warner
Music Group, and
5.1 Entertainment Group) to deliver albums that can be played on
any optical disc player, whether CD or DVD, in a single package. One
side is the "standard" full-length CD audio album. The other side
offers DVD content. This may include enhanced album audio, 5.1
surround sound, music videos, artist interviews, behind-the-scenes
footage, documentary films, photo galleries, lyrics, computer-ready
digital song files, and Web links - whatever the artist chooses to
include. Although the recording industry is enthusiastic about this
delivery system, the future of DualDisc is far from clear. As of
2005 it's still sitting under a cloud of patent-infringement
lawsuits from the European company DVD Plus, which claims to have
originally developed the technology. In addition, forthcoming
optical technology such as
Blu-Ray and
HD-DVD, with massive file storage capacity, might replace both
CD and current DVD technology. |
|
| DV
|
Abbreviation for
Digital Video. Digital Video is a format for digitizing and storage
of video images. DV is also commonly referred to as DVC, which
stands for Digital Video Cassette. The format uses 4:1:1 sampling,
5:1 compression, and a 25 Mega-bit
(3.1 Mega-byte)
data rate, and records to 1/4\" cassette tapes. What do those
figures mean? The sampling figure (4:1:1) refers to the sampling
rates of various components of the video signal (we\'ll cover more
about this in future inSync issues). The compression ratio is a
generic figure for how much the data is compressed (as in lossy
compression). Other digital video formats - ones that are not
referred to as DV - use different
sample rates (4:2:2, 4:4:4, etc.) and data compression ratios. A
subset of the DV format known as MiniDV, which uses smaller
cassettes, but is basically the same format, has become extremely
popular in the consumer marketplace due to its combination of
reasonably high quality (especially compared to inexpensive
analog systems), low cost, and convenience. Once video is
captured on a DV camera it is very easy to transfer it to a computer
editing system via
Firewire - no \"video capture\" card (and the accompanying
process) is needed. |
|
| DVD
|
Latest info says
"DVD" no longer stands for anything! It used to mean "digital
versatile disc" - and before that it meant "digital video disc." A
new type of 12-centimeter (4.72") compact disc (same size as audio
CDs and CD-ROMs) that holds 10 times the information. Capable of
holding full-length movies and a video game based on the movie, or a
movie and its soundtrack, or two versions of the same movie - all in
sophisticated discrete digital audio surround sound. The DVD
standard specifies a laminated single-sided, single-layer disc
holding 4.7 gigabytes, and 133 minutes of MPEG-2 compressed video
and audio. It is backwards compatible, and expandable to two-layers
holding 8.5 gigabytes. Ultimately two discs could be bounded
together yielding two-sides, each with two-layers, for a total of 17
gigabytes. There are three versions: DVD-Video (movies), DVD-Audio
(music-only) and DVD-ROM (games and computer use). The DVD-Audio
standard is still being defined. Meanwhile a fourth member has
joined the family: DVD-RAM defines specs for a rewritable system,
opening the door for recording. |
|
|
Dynamically Linked Library |
A DLL is a
computer program file consisting of a collection of resources or
routines that are available to other programs, as opposed to a
static library where the contents are copied into one program when
it\'s
compiled. A program that wants to use these routines is linked
with the DLL at the time it is actually started, or later. The term
DLL relates mostly to
Windows products. On the UNIX platform (including Mac
OS X), the term \"Shared Library\" is more commonly used.
|
|
| ECP
|
Abbreviation for
Enhanced Capabilities
Port. The ECP specification was developed by Microsoft and
Hewlett-Packard to increase the
throughput of the
parallel port in PC computers. It is similar to the
EPP, but even more efficient due to the use of
DMA and
buffering. |
|
| EIDE
|
Abbreviation for
Enhanced (some say Expanded)
IDE, or Enhanced Integrated Drive Electronics. Like it sounds,
EIDE is an enhanced version of the old IDE peripheral connection
standard commonly used for hard drives and other storage media with
computers. It provides faster access to the hard drive, support for
DMA, larger capacities, and includes the functionality of
ATAPI. Sometimes EIDE is referred to as
ATA-2. |
|
|
Electroacoustic Music |
Electroacoustic
music is a type of music that originated in the late 1940s, and
early 1950s. Originally, there were two groups of composers who were
at strict odds with each other. In Paris,
Musique Concrete, pioneered by Pierre Schaeffer, was based on
the juxtaposition of natural sounds recorded to tape or disc. In
Cologne, Elektronische Musik, pioneered by Herbert Eimert, was based
around the construction of tones using only
sine waves, which Eimert considered to be an electronic
extension of serialism. The common link between the two schools is
that the music is recorded and performed through
loudspeakers, without a human performer. Currently, the majority
of electroacoustic pieces use techniques from both earlier styles.
Since around the early 1980s, many electroacoustic pieces have
included live performers, either as a performer playing along with a
tape, or, more recently, with live electronic processing of the
performer's sound. The term "acousmatic music" is often used to
refer to pieces that consist solely of prerecorded sound.
Electroacoustic music is a diverse, widely popular field. Important
centers of research and composition can be found around the world,
and there are numerous conferences which present electroacoustic
music, notably the International Computer Music Conference as well
as the Society for Electro-Acoustic Music in the United States
(SEAMUS). |
|
| EMI
|
EMI (Electro
Magnetic Interference) refers to interference in audio equipment
produced by the equipment or cabling picking up stray
electromagnetic fields. This interference usually manifests itself
as some type of hum, static, or buzz. Such electromagnetic fields
are produced by fluorescent lights, power lines, computers,
automobile ignition systems, television monitors, solid state
lighting dimmers, AM and FM radio transmitters, and TV transmitters.
Methods for controlling EMI include shielding of audio wiring and
devices, grounding, elimination of ground loops, balancing of audio
circuits, twisting of wires in balanced transmission lines, and
isolation transformers among others. Completely eliminating EMI in a
system ranges from easy to nearly impossible depending upon the
equipment and the environment in question. |
|
| EPROM
|
Pronounced EE-prom
(almost rhymes with eon), this is an acronym for Erasable
Programmable Read Only Memory. Various types of ROM (Read Only
Memory) chips are used in many computers and synthesizers to hold
instructions or other data (such as sound data) that the machine
uses. ROM chips must be permanently programmed at the time of
manufacture. While being relatively inexpensive, this can be a
problem because all decisions about the data must be permanently
decided at a relatively early stage in the design of the product.
PROM or Programmable Read Only Memory has the ability to be
programmed at any time. The only caveat being that once programmed,
the data is permanent. EPROM chips can be erased by subjecting them
to ultra violet light radiation. This means they can be reprogrammed
and reused as needed, hence the name EPROM. |
|
| ESB
|
Abbreviation for
Emagic System Bridge. The ESB is a software
driver that serves as a link between Emagic's native software
and Digidesign's
TDM hardware. As such it allows users to be able to bring
native processes (plug-ins
and software
synths) running on Logic Audio into the TDM mixer environment.
It consists of two components: Direct TDM and EXS24 TDM.
ESB TDM allows the insertion of up to 32
instances of Emagic's Xtreme
Sampler 24
Bit within the Aux channels of Logic Audio's TDM mixer. The
output signals of inserted EXS24 instances can be further treated,
utilizing all of the possibilities of the TDM
DSP environment. Each EXS24 instance is handled by the
computer's
CPU, and the ESB TDM routes their output signals into the TDM
DSP's. EXS24
MIDI performances are recorded on TDM Auxiliary tracks and are
controlled directly in Logic Audio. This eliminates the need for
OMS, making playback of the EXS24 TDM sample-accurate.
Direct TDM provides an additional audio engine
running in parallel with
DAE/TDM. It works like most native processing engines and offers
up to 64 audio tracks, plug-ins, the use of
VST effects and integration of Emagic or
third party VST 2.0-compatible Audio Instruments. ESB provides
up to eight outputs from this native audio engine, which can be
streamed into Logic Audio's TDM mixer - all within the computer. |
|
|
Ethernet |
A popular type of
networking technology for local area networks developed by Xerox
back in the 1970's. It allows computers, printers, and other devices
to be connected together forming a network where they have access to
one another. It works by breaking data into small "packets" and
sends them through cables as radio frequency signals. Over the years
there have been many developments and advances in Ethernet
technology, the most noticeable of which have provided increased
speeds. Terms like "Fast Ethernet" and "Gigabit Ethernet" among
others are sometimes used to describe speed capabilities with
varying degrees of precision. There is also a commonly used protocol
to describe Ethernet wiring. Ethernet cables are classified in an
XbaseY form, where the X denotes the data rate; "base" means
baseband. (Baseband, as opposed to broadband, means there is only
one data channel, and the entire bandwidth of the cable is devoted
to that single channel. Everything on that cable [transmitted or
received] must use that one channel, which is very fast. All
attached devices [printers, computers, and databases] share by
taking turns using the same cable). The Y denotes the category of
cabling. The letter T means twisted pair, whereas an F means fiber
optic. So, for example, when you see a term like 10base-T, that
means 10 megabits per second, baseband twisted pair cable. 100base-T
means 100 megabits per second, baseband, twisted pair, and
1000base-F means gigabit, baseband, fiber optic cable.
|
|
|
Export |
In the world of
data (computers,
MIDI, digital audio, etc.) exporting means to format data in a
form where it can be read by another application or device.
Sometimes an exported file (or series of files) can be read directly
by the desired application; other times the file must be \"imported,\"
which usually means further translation is required to get it into
the desired environment. |
|
|
ExpressCard |
The ExpressCard,
not to be confused with the card of the "don't leave home without
it" variety, is actually the successor of the PC Card, or
PCMCIA card, as it was known. PCMCIA actually stands for the
organization that developed the standards, which is the "Personal
Computer Memory Card International Association," and not "People
Can't Memorize Computer Industry Acronyms" as it has come to be
known. The ExpressCard standard, which replaces the older
CardBus, was developed to bring the high speed, flexibility, and
lower cost of the
PCI Express (PCIe) and
USB 2.0 interfaces to laptop computers. Theoretically,
ExpressCard will have a maximum throughput of 250MBps (megabytes
per second) for data transfer (500MBps total: 250MBps to the
computer in one direction and 250MBps to the card in the other).
This is in comparison to the 132-MBps PC Card standard.
ExpressCard's throughput is ideal for video transfers and
uncompressed files. To compare it with other throughputs:
Gigabit
Ethernet has a throughput of 125MBps,
FireWire 800 (seen only in new Apple notebooks so far) runs at
100MBps, and USB 2.0 can reach 60MBps. The ExpressCard comes in two
sizes, one 34mm wide and the other 54mm wide in an "L" shape.
Another advantage of the ExpressCard, aside from lower system and
card complexity, is their ability to be
hot plugged. |
|
|
Expression |
One of the
continuous controller commands available in
MIDI. It is one of the original definitions in the MIDI
specification that allows for the
modulation of
synthesizer sounds over time. It is often used to define the
action of things like foot pedals, modulation wheels, and sliders on
keyboards. As defined by the MIDI specification this controller
(number 11) has a range of values from 0 (all the way off) to 127
(all the way on). Most of the time expression is defined as a subset
of Volume (Continuous
Controller 7), especially as it relates to natural
crescendos and
decrescendos by sustained-tone instruments, such as strings,
wind, or synth pads. This allows you to set an overall track level
using
volume and then adjust single
notes or groups of notes by increasing or decreasing the
expression level. This can be achieved live by using a knob or
slider on your synth. In MIDI
sequencing there are many ways to insert expression messages
into a
track. Sophisticated synths and
samplers often incorporate many more elements than volume into
expression parameters, to offer maximum sonic control. These can
include
LFO modulation, increased/decreased sample
crossfades (such as the "breathiness" in flute samples) and
filter values and
resonance. A little-known MIDI fact is that there are TWO
controllers reserved for expression: #11 (coarse) and #43 (fine). In
the standard MIDI environment, controller 11 offers 128 divisions of
volume or any other parameters assigned to expression. Employing the
"fine" adjustment would increase this resolution to 16,384 available
steps! Virtually no instrument employs this, although more powerful
computers and increased sample resolutions and rates might make this
level of control practical. |
|
|
Extension |
In music and
computers an extension can very loosely be thought of as the
Macintosh equivalent to a
driver in the PC world. Extensions are little bits of software
that are loaded into the
RAM of your Mac when it boots. They provide added functionality
to your basic Mac
OS. Many peripherals that connect to a Mac require a special
extension to operate. This would include digital cameras,
MIDI interfaces, modems, fax software, your Palm Pilot, enhanced
track balls, digital audio software and hardware, graphics tablets,
and the list goes on and on. Extensions create a conduit for the
special communication that must take place between the
CPU and these devices. Current versions of the Mac OS include an
Extensions Manager Control Panel that allows the user to manage
which extensions are active and get loaded upon
boot up. There are other third party programs that allow even
more flexibility, and include the ability to change the order in
which they load. These tools exist because extension conflicts -
incompatibilities between different extensions - are a common
problem with Macintosh computers. Extension conflicts can cause
crashes and all kinds of undesirable behavior in your Mac so it's
important to keep an eye on what is installed and loaded into your
machine. The Extensions Manager helps with this, but the Mac will
also display the icon for most of the active extensions and control
panels along the bottom of the screen when it is booting. This is
handy for just keeping an eye on what is happening. Any time you
install new software on your Mac there is the potential to have new
extensions and control panels installed. A good clue that this has
happened is when the installation is complete you get a dialog box
indicating you need to restart the computer in order to use the new
software. |
|
|
Extension Manager |
A
control panel found on Macintosh computers that allows the user
to easily review and enable or disable specific
extensions and control panels. This is important because not all
extensions and control panels are compatible with one another, which
can cause erratic computer operation or crashes. Additionally too
many active extensions can eat up computer resources such as
RAM and
CPU Cycles (which effects the overall speed of the system), not
to mention causing it to take longer for the computer to load them
all on
boot-up. Extension Manager makes it easy to create different
"sets" of extensions for different tasks. One may have a set for
when the computer is used as a
DAW, a different set for playing games, and another set for
office work. |
|
|
Fairlight CMI |
Also known as the
"Computer Musical Instrument," this was the very first
keyboard-based, 8-bit
digital
sampler, with software sequencing and
additive synthesis capabilities. Making its debut in 1980 with
eight
voices (split either
polyphonically or
multitimbrally), the CMI could store a total of 1Mb of
sample data per double-sided, double-density 8-inch
floppy disk, or roughly 40 wavesamples. In all, only about 300
Fairlight CMIs (along with the Series II and Series IIx) were
manufactured from 1980 to 1984 at prices that ranged from $25,000 to
$36,000. Most were sold to the top artists of the day who could
actually afford them, including Peter Gabriel, Stevie Wonder, Jan
Hammer, and Thomas Dolby. |
|
| FAT
|
Abbreviation for
File Allocation Table. The FAT is a special file located on a disk
containing information about the sizes of files stored on the disk
and which clusters contain which files. It can also keep track of
bad spots on a disk so they are not used. Think of it as a sort of
roadmap to the files on a disk. Drives must first read the roadmap
before they can find any of the information stored, or before they
can know where to store any new information. There are a number of
different types (formats) of FATs used that have different
capabilities in terms of how (and how much) data can be stored on a
drive partition. While you don't hear
the term much these days the word "fat" has also been used to
describe Mac programs that are capable of running in the older, non
Power PC environments (68000 series processors) as well as newer PPC
computers (600 and G series processors). They were called "fat"
programs because they were bloated by virtue of having two sets of
code, one for each environment. |
|
|
Fat-32 |
A specific type of
FAT (File
Allocation Table)
format
designed to expand the capacities and capabilities of hard drives
used in a
Windows operating environment. It has all but replaced the old
FAT-16 format used before. FAT-32 was created as a quick-fix to the
problem of computers shipping with hard drives over 2 GB. Prior to
FAT-32, computer manufacturers had to messily split hard drives into
multiple
partitions under 2 GB in size apiece. FAT-32 allows for much
larger partitions and has a number of other advantages.
|
|
| FDDI
|
Abbreviation for
Fiber Distributed Data Interface. FDDI is a networking architecture
and protocol that has been standardized by
ANSI and
ISO and become increasingly popular in high-end installations
the past few years. FDDI uses fiber optic cabling and a closed loop
style of topography to network up to thousands of computers together
at very high speeds over great distances (miles). |
|
| Fibre
Channel |
A serial data
transfer architecture developed by a consortium of computer and mass
storage device manufacturers and now being standardized by
ANSI. Fibre Channel can be used to create a network using
special hardware interfaces to provide very high speed connections
between storage devices (hard drives,
RAIDs, etc.) and computers. The connections are usually done
with optical cables, but
coaxial cable and regular telephone twisted pair can be used
under some circumstances. It can be used along with or instead of
SCSI or other mass storage media and is proving to be a very
effective technology for large audio and/or video production
environments because it allows many users to access the same
physical storage media at speeds high enough to do meaningful work
without having to copy individual files to a local hard drive. Many
operators can literally be working on the same project (and in some
cases the same file) at the same time. |
|
| FIFO
|
An acronym for
First In, First Out. This expression describes the principle of a
queue: what comes in first is handled first, what comes in next
waits until the first is finished, etc. It is analogous to the
behavior of persons "standing in a line" where the persons leave the
line in the order they arrive. The expression FIFO can be used in
different contexts: In computers this term refers to the way data
stored in a queue is processed. Each item in the queue is stored in
a queue data structure. The first data to be added to the queue will
be the first data to be removed, then processing proceeds
sequentially in the same order. This is typical behavior for the
information that is sent to a
CPU. You have encountered FIFO structure if you have ever set or
altered your audio software's
buffer settings. The buffer is a software-defined queue; whether
it's defined in
samples or
milliseconds, you're increasing or decreasing the size of the
queue. In electronics a FIFO is a
semiconductor memory in which the first data to be written is
always the first data to be read. A common application of this is
computer or sampler
RAM. The function includes address counters and control logic. A
FIFO with a clock input is called "synchronous"
as in
SDRAM; otherwise it is
asynchronous. |
|
| File
|
As used by a
computer, a collection of related data or program records stored as
a unit with a single name. Almost all information stored in a
computer must be in a file. There are many different types of files:
data files, text files, program files, directory files, and so on.
Different types of files store different types of information. For
example, program files store programs, or "executable"
code, whereas text files store text, or code that's in the form
of common
ASCII characters recognizable as text. Files are always in a
particular format. For example, if you created a Microsoft Word
document, the file is saved so that Microsoft Word can read it and
open it. Often files cannot be opened to read using conventional
programs, they are simply data files the computer understands. Files
are usually represented by the filename and an extension, which
often specifies what type of file it is. |
|
|
FireWire 800 |
Also known as
1394b,
FireWire 800 is an emerging new standard for high-speed data
transfer. FireWire 800 is essentially the same as FireWire (400),
but twice as fast. Audio and video devices are already cropping up
to take advantage of the bandwidth and ease of use. The good news
for audio and video professionals is that FireWire 800 is not all
that different from FireWire 400 except when it comes to speed.
FireWire 400 compatible devices, such as MOTU\'s 828 or most
Firewire hard drives can still be used in FireWire 800 ports with
the addition of an adapter. FireWire 800 shares the same well-known
features of FireWire 400 such as plug and play connectivity, large
capacity on-bus
power (up to 45W) and large quantity single-bus connection (up to 63
computers and other devices). Due to a highly efficient
architecture, FireWire 800 also allows for longer cable runs than
FireWire 400 (up to 100 meters). Another difference is that FireWire
800 is a 9-pin protocol where FireWire 400 is 4- and/or 6-pin. Apple
has simply improved on an already useful technology. FireWire 800
allows for more through-put at greater distances and is backward
compatible.
USB and FireWire Bandwidth
Comparison:
USB 1.1: 12 Mb per sec
USB 2: 480 Mb per sec
FireWire 400: 400 Mb per sec
FireWire 800: 800 Mb per sec |
|
|
Firmware |
You can think of
it as a combination of hardware and software. Firmware is computer
programming instructions stored on a fixed hardware device such as a
ROM chip. It is basically software that cannot be changed,
except by changing the hardware. Firmware is often responsible for
the behavior of a system when it is first switched on. A typical
example would be a ROM program in a microcomputer that loads the
full
OS from disk or from a network and then passes control to it. In
many electronic instruments we use the entire operating system is in
firmware. This means that any updates require swapping out chips.
|
|
| Fixed
Point |
In computing, a
representation of a number that has a fixed number of digits after
the decimal (or
binary or
hexadecimal) point. For example, a fixed-point number with four
digits after the decimal point could be used to store numbers such
as 1.3467, 281243.3234 and 0.1000, but would round 1.0301789 to
1.0302 and 0.0000654 to 0.0001. Fixed-point differs from
floating point in that it can exactly represent decimal
fractions while still employing the base 2 arithmetic that is
efficient in most computers. When floating-point representations in
computers use base 2 values, they can't exactly represent most
fractions that are easily represented in base 10. For example,
one-tenth (.1) and one-hundredth (.01) can be represented only
approximately by base-2 floating-point representations, while they
can be defined exactly in fixed-point representations by simply
storing the data values multiplied by the appropriate power of 10.
Very few computer languages include support for fixed-point values,
because for most applications floating-point representations are
fast enough and accurate enough. Floating-point representations are
more flexible because they can handle a wider range of numbers.
Floating point is also slightly easier to use, because it doesn't
require programmers to specify a number of digits after the decimal
point. |
|
| Flash
Drive |
These are
ultra-compact
flash memory data storage devices that have an integral USB
interface. They are very small (typically 100mm or about four inches
long), ultra lightweight, removable, and rewritable. They are also
popularly called "thumb
drives" or "jump
drives" because of their size. They are capable of holding a lot
of data, yet are very reliable due to their lack moving parts. The
USB
interface is now universal, so flash drives may be supported
natively by
operating systems as diverse as
Windows,
Mac OS X,
Linux, and
Unix. There is a small
printed circuit board inside these drives, protected by a
plastic or metal casing, making them sturdy enough to be attached
(depending upon the design) to a keychain or lanyard. The protruding
USB connector is protected by a removable cap or by retracting into
the body of the device. Flash drives are active only when plugged
into a host device (typically a laptop computer or USB
hub) which provides the necessary power for the drive to become
active. |
|
|
Floating Point |
A data encoding
technique often used in computers and
DSP chips to more easily deal with the complex math required to
process large chunks of data. Floating Point data consists of three
parts: the sign (makes it a positive or negative value), a mantissa
representing a fractional value with magnitude less than one, and an
exponent providing the position of the decimal point. Floating point
arithmetic allows the representation of very large or very small
numbers with fewer bits. For example, the number 186,000 can be
represented as 1.86 * 10 to the power of 5. It may not look easier
here, but in computer terms the latter expression is much easier to
handle. By shifting the point so that the number of significant
digits in any quantity does not exceed machine capacity, widely
varying quantities can be handled with fewer actual computations.
The scale factor may be fixed for each problem, or indicated along
with the digits and sign for each quantity. Many computers have a
special FPU (Floating Point Unit) or floating point processor in
them designed specifically to carry out complex math most
efficiently. This type of mathematical efficiency doesn't really
help a computer much for word processing or surfing the Internet,
but when complex graphics, or audio, or video manipulation are
required, the addition of an FPU can greatly speed up the
computation time. |
|
|
Floppy Disk |
A data storage
medium that has been widely used in personal computer systems.
\"Floppy\'s\" get their name because the disk itself is not
generally rigid, which at the time of their development was a
distinction from other storage mediums commonly used (even disk
based ones). Often times the disk, which is made of Mylar, is
encased in a plastic envelope or case for protection, but with a way
to allow access to a drive\'s read/write heads when in use. This
case may often be rigid, but so long as the disk inside isn\'t it
qualifies as a floppy disk. While convenient and inexpensive,
floppies have a limited storage capacity and are slow to read and
write data. In recent years they have begun to be phased out in
favor of inexpensive hard drives or other media formats such as
USB-based
flash
RAM, etc. |
|
|
Folder |
In graphical user
interfaces (GUI),
such as
Windows or Mac
OS X, a computer folder is just like a physical folder that sits
on your desk. This one, however, sits on your computer's virtual
desktop and is used to organize information. It may contain
additional folders (which are sometimes called nested folders),
documents, or
files or a combination of all three. Folders are generally at
the top level once you start your computer and access the internal
hard drive. Folders may also contain applications or utilities.
In
DOS and
UNIX, folders are called directories. |
|
|
Format |
The organization
of information according to preset specifications. In digital audio
and computer applications it pertains to the dividing of media into
marked segments and determining how data will be arranged on it. The
process known as formatting prepares a storage medium, usually a
disk, to record data. In this process, the drive writes special
information onto the recording surface(s) in order to divide it into
areas (called blocks) that are ready to accept user data. When you
format a disk, the operating system erases all bookkeeping
information on the disk, tests the disk to make sure all sectors are
reliable, marks any bad sectors, and creates internal address tables
that it later uses to locate information. On many systems it is
possible to perform either a high level or low level format. A
high-level format generally only erases the address tables of a
disk, which makes it appear to be blank even though the data hasn't
been erased. Hard disks also have a low-level format, which sets
certain properties of the disk such as the interleave factor. The
low-level format also determines things like what type of disk
controller can access the disk and, last but not least, does zero
all data. |
|
|
Formatted Capacity |
The capacity of a
drive after it is formatted for a particular type of computer or
computer system. Most hard disks have their capacities rated in
absolute terms. In other words, they are rated at the total raw
amount of storage space available. However, when a drive is
formatted, various types of data are stored on the drive that are
required by the formatting device to be able to read and write data
to it. Not only does this data take up some space, but space is also
lost due to how blocks of available space are allocated, which is
different for each type of system. The amount of available space
that shows up after being formatted on a specific type of system is
the formatted capacity. |
|
| FPU
|
Abbreviation for
Floating Point Unit. Sometimes called the
floating point processor, the FPU is a special chip or a special
part of a larger
CPU chip that is optimized to do intense number crunching
calculations. FPU's are commonly found in computer systems,
especially those optimized for heavy graphic or scientific work that
requires a lot of intense calculations. |
|
|
Fragmentation |
When a computer
write or re-writes a file to a hard disk, it doesn't necessarily
write the file as one contiguous block of information. For a variety
of reasons, it may put different pieces of the file in different
places on the drive. More and more files become fragmented as time
passes. This results in more wear and tear on the drive mechanism as
it jumps around to read the files, and also in a significant
slowdown in access times. The solution to this problem is to
defragment your drive. Defragmenting (also known as "defragging" or
"optimizing") means to re-order the files so that they are each
stored as one contiguous chunk of data. A variety of disk utilities
will perform this function for you, one of the more popular packages
being
Norton Utilities. One of the things that fragments a drive
fastest is hard disk recording. It is wise to be aware of how
fragmented your drive is when recording, as this can seriously
affect system performance. Some manufacturers recommend optimizing
if your drive has as little as 5% fragmentation... |
|
|
Freeware |
This is basically
full-featured computer
software available for download at no cost to the end user.
There are literally thousands of freeware programs and
plug-ins that run the gamut from no-frills basic to
ultra-sophisticated. Freeware falls into a sort of middle of the
road category between commercial software and open source software.
Freeware authors tend to provide what they have programmed for the
benefit of the computer community as a whole, while at the same time
retaining control over the source code and thus preserving what
might at some point become a viable retail product. The only true
criterion for being considered freeware is that software must be
fully functional for an unlimited amount of time at no cost to the
user. However, most freeware authors include some way for users to
make a monetary donation to keep the software current.
|
|
|
Freeze |
A function of some
DAWs that enables a particular track (or group of tracks in some
cases) to be
rendered. In fact, in most ways freeze (which does go by other
names in some software) is just another term for render, but applies
to the unique characteristics of an audio production system. The
idea is to be able to reduce the strain on the
host computer by changing
real-time processes in audio files written to disk. For example,
let's say you have a
soft synth track being processed by a series of
plug-ins. You could freeze the track, which would basically
record the whole setup, including the results of the various
plug-ins to disk. Now each time you play the part back, your
computer is able to easily read a single audio file from disk rather
than having to do all the
synthesis and processing in real-time. If you change some
parameter or make an edit, the track becomes "un-frozen" or
unrendered again so it's back to being a live track - and you must
freeze it again to rewrite an updated audio file. |
|
| Fret
Dress |
A
fret dress is a basic one-piece number with a plunging neckline,
equally at home for fine dining or a casual night out on the town!
Joking aside, a fret dress is a process of leveling frets with some
type of flat, straight abrasive surface in order to eliminate string
buzzing. When frets become worn, they actually tend to splay outward
rather than wear away, which means that they tend to look worse than
they actually are. In most cases a fret dress can solve buzz
problems without re-fretting the guitar. To describe the process,
first, make sure the neck is straight as possible, then a file or
woodworkers' level with sandpaper attached to it may used to sand
down the tops of the frets, taking only the minimum amount needed to
make all fret tops the same height. The frets are re-crowned using a
fret crowning file and then polished to a mirror-smooth surface. New
guitars can benefit from a fret dress, as some may have uneven
frets. Gibson used Plek, a computer-based fret-dressing system
invented by a company of the same name. A fret dress can also be
used to correct minor defects in a guitar neck that might otherwise
be prohibitively expensive to repair. |
|
| FSB
|
FSB is an
abbreviation for Front Side Bus; it is the internal data channel
connecting a computer's processor (CPU),
chipset,
RAM (all flavors),
motherboard
busses and
AGP socket. FSB is described in terms of its width in bits and
it's speed in Mhz. In everyday terms, it is the doorway for the CPU
to talk to the system bus, and how fast the bus can talk to other
computer components. In architectures where the processor interacts
directly with main memory, the definition of a singular front side
bus is less clear. In such a case you would generally specify two
FSB speeds, one for the connection to main memory and one for the
connection to the processor chipset. |
|
| FSF
(Free Software Foundation) |
The Free Software
Foundation (FSF), established in 1985, is dedicated to promoting
computer users' rights to use, study, copy, modify, and redistribute
computer programs. In this case, the concept of free software is a
matter of liberty not price. Think of "free" as in "free speech."
The FSF promotes the development and use of free software,
particularly the
GNU operating system, used widely in its GNU/Linux
variant. The commencement of the GNU project in 1984, with its goal
to give users freedom, required the establishment of new
distribution terms that would prevent the project being turned into
proprietary software. The method used was
Copyleft and the resulting license was called the GNU General
Public License (GNU GPL). Today the GNU GPL is the most widely used
Free Software license, and as its author, the FSF works to help the
wider community use and comprehend it. |
|
| FTP
|
Short for File
Transfer Protocol, FTP is the protocol used on the Internet for
exchanging files. FTP is a client-server protocol that allows a user
on one computer to transfer files to and from another computer over
a
TCP/IP
network. FTP is most commonly used, however, to allow potentially
large numbers of users to download a file or files from a server
using the Internet or to upload a file to a server (e.g., uploading
a Web page file to a server). |
|
| Full
Duplex |
Full Duplex is a
term that comes to us from the telecommunication industry. It is the
ability of a line or channel to simultaneously transmit in both
directions. In the music industry, we most commonly see this term
applied to computer sound cards. A "Full Duplex" audio card is able
to both record and playback at the same time - a handy feature if
you are performing overdubs! |
|
| Gear
Acquisition Syndrome |
Do we really have
to give you the definition of this one? Try using it in a sentence:
"Oh my, it appears that (fill in your name here) has come down with
a bad case of Gear Acquisition Syndrome!" Often referred to by its
acronym, GAS (more properly G.A.S.), it describes what typically
happens to many musicians once they commit to a life of music. It
often starts with the purchase of one item, such as an electric
guitar. That, of course, leads to the purchase of a guitar
amplifier, a
wah pedal, a series of stompboxes, and then down the road
perhaps a
multitrack recorder, a
mixing console,
microphones,
headphones, a computer, and all manner of
software and
plug-ins. Each musician is hit to various degrees by this very
real condition. One may see a fabulous Les Paul BFG in the
Sweetwater
Guitar Gallery and not be able to sleep, eat, or think properly
until he or she calls to make sure that instrument is still
available. Typically, the musician will then purchase the instrument
and begin a long road that truly has no end, as advances in music
technology almost guarantee that eventually, no matter how much gear
a musician has, he or she will eventually discover there is
something more that is required - an acoustic guitar, for example,
for playing a glossy background rhythm part on a recording. At
present, although research continues at a rather slow pace, there is
no known cure for GAS. If there were, NAMM would only take place
every three or four years. It's worth noting that Sweetwater
employees are not immune to this somewhat contagious condition. In
fact, it's often the reason they interview for a job here before
discovering it's the best place on the planet to work, particularly
if you have a bad case of gear acquisition syndrome.
|
|
|
Genlock |
Technically, the
process of
sync generator locking. The term is commonly used in the video
discipline to the synchronization of video signals from one device
with those of another video source. This is required when mixing
signals together, as in overlaying multiple images or computer
graphics on an image from a camera, VCR or videodisc player to
prevent screen flicker or rolling. Genlock is usually performed by
introducing a
composite video signal from a
synchronizer - a
master source (see WFTD
Black Burst) - to the subject, or
slave, sync generator. Then the slave is set to
lock up to, or follow, the master so that both sync generators
are running at the same
frequency and
phase. |
|
| GHz,
Gigahertz |
The gigahertz,
abbreviated GHz, is a unit of alternating current (AC)
or electromagnetic (EM) wave
frequency equal to one thousand million
hertz (1,000,000,000 Hz). The gigahertz is used as an indicator
of the frequency of ultra-high-frequency (UHF)
and microwave EM signals and also, in some computers, to express
microprocessor
clock speed. An EM signal having a frequency of 1 GHz has a
wavelength of 300 millimeters, or a little less than a foot. An
EM signal of 100 GHz has a wavelength of 3 millimeters, which is
roughly 1/8 of an inch. Some radio transmissions are made at
frequencies up to hundreds of gigahertz. Personal computer clock
speeds are increasing month by month as the technology advances, and
reached the 1 GHz point in March of 2000, with a processor from AMD
closely followed by a 1 GHz
Pentium 3 from Intel. Other commonly used units of frequency are
the kHz, equal to 1,000 Hz or 0.000001 GHz, and the MHz, equal to
1,000,000 Hz or 0.001 GHz. |
|
| Gig
|
Short for
gigabyte, which is one billion bytes as determined by the prefix
'gig,' meaning one billion, in front of 'byte.'
To be more thorough, the quantifier 'gig' can specify different
exact values depending upon context. For example, when working with
things that typically come in standard units of 10 like money or
distances it is accepted as meaning 1000 to the power of 3 (one
billion). However, when working in things that tend to come in
multiples of 2 like computer bytes it is thought of as 2 to the
power of 30 (or 1024 to the power of 3), which is precisely
1,073,741,824 - a little over a billion, but who's counting?
Gig also refers to a performance by a musician or
group of musicians, especially in modern or pop music. |
|
|
Gigabit |
Gigabit
Ethernet, primarily used in computer networks, supports a
maximum data rate of 1000 Mbps. At one time, it was believed that
these speeds required fiber optic, but Gigabit Ethernet has now
successfully been implemented on
CAT5 cable (& CAT 6 cable). Currently available on various
computers including the Apple Macintosh, Gigabit is also backward
compatible for use on slower networks as well (such as 100-Base T or
10-Base T). While Gigabit has yet to take a market hold as the front
running network delivery protocol, it works wonders on high
bandwidth information such as digital audio and video.
|
|
|
Gigaflop |
Not a new word,
but one that many people are just now beginning to hear for the
first time due to recent advances in computer technology. The
gigaflop is a measure of speed used in computers. One gigaflop
equals one billion floating-point operations per second. The word
comes from giga (often pronounced jiga), which is a prefix meaning
billion; and flop, which is a clever abbreviation for FLOating
Point. |
|
|
GigaFLOPS |
When dealing with
computers, FLOPS stands for
Floating point Operations Per Second, a standard used to measure
a computer's performance. A gigaFLOPS essentially means that a
computer is capable of performing 10,000,000,000 (ten billion)
operations per second. |
|
|
Graphics Processing Unit (GPU) |
The
microprocessor of a graphics card (or graphics accelerator) for
a computer or game console. Computer graphics involve complex
algorithms that must be translated at very high speeds, and GPUs
are very efficient at manipulating and displaying these graphics.
Their highly
parallel structure makes them more effective than typical
CPUs for this purpose. A modern GPU implements a number of
graphics "primitive" operations — such as simple character
instructions - in a way that makes running them much faster than
drawing directly to the screen with the host CPU. Common operations
for early 2D computer graphics included drawing rectangles,
triangles, circles and arcs. Modern GPUs also have support for 3D
computer graphics, and typically include digital video-related
functions as well. |
|
| GUI
|
Acronym for
Graphic (or Graphical) User Interface. This term loosely applies to
any system in which control, navigation, or commands are issued
through a series of icons, pictures, or other graphic elements that
represent specific parts or functions of that system. The purpose is
to provide a user interface that is simple and intuitive to use. The
most well known example is the Macintosh computer, which was the
first commercially available home computing system with a true GUI
OS built right in. Nowadays many systems have GUI's, including
some synthesizers and effects processors. |
|
|
Hamming Code |
A type of
error-correction scheme named for its inventor, Richard Hamming,
who worked at Bell Labs in the 1940s on the Model V relay-based
computer. He developed his error-correction ideas in 1949 and first
published them in 1950. Hamming codes are commonly used in
telecommunications and in computer
RAM. They are
binary-linear
codes that use seven
bits to represent four bits of
data; the additional three bits are for
parity checking. Hamming codes can detect two errors, but can
only fix a single error. |
|
| Hard
Drive |
As used with a
computer, a hard drive is the mechanism that controls the
positioning, reading, and writing of the hard disk, which provides
the largest amount of data storage for the computer. Although the
hard drive (sometimes referred to as the "hard disk drive") and the
hard disk are not the same thing, they are packaged as a unit, and
so either term is sometimes used to refer to the whole unit. While
there are several interface standards for passing data between a
hard disk and a computer, the most common are
IDE and
SCSI. |
|
|
Harmonic Distortion |
Since no
electronic device is perfectly linear (meaning the output exactly
equals the input) harmonic distortion is a fact of life in all audio
components. Most audio signals have harmonics associated with them
(a perfect sine wave is one notable exception), and that is what
gives them their characteristic sound. An oboe sounds different from
a violin mostly because of the harmonic series produced as part of
their distinct sounds. The corresponding difference in the shape of
their respective waveforms is easily distinguished when viewed on an
oscilloscope or a computer audio editing program. Harmonic
distortion is the result of a device subtly, or not so subtly,
changing the shape of the waveform which alters the relative levels
of various harmonics associated with that sound. The more harmonic
distortion there is the more the sound will begin to take on the
quality we all know and love that we call "distorted".
In spec land you will often see the
specification for THD which stands for Total Harmonic Distortion.
This is a rating given to most gear for the overall percentage of
harmonic distortion added to the signal passing through the device
while operating at (presumably) nominal levels. There are dozens of
ways to measure this spec that can skew the results so keep that in
mind when comparing product literature. |
|
| HD
DVD |
Abbreviation for
High Density Digital Versatile Disc. A digital
optical media format that is being developed as a standard for
high-definition
DVD. HD DVD is similar to the competing
Blu-ray Disc, which also uses the same
CD-sized optical media and 405nm-wavelength
blue
laser. HD DVD is promoted by Toshiba, NEC, Sanyo, Microsoft, and
Intel, and is backed by New Line Cinema, Paramount Pictures,
Universal Studios, and Warner Bros. HD DVD has a single-layer
capacity of 15GB
and a dual-layer capacity of 30GB. Toshiba has announced a
triple-layer disc is in development, which would offer 45GB of
storage. This is smaller than the competing Blu-ray disc, which
supports 25GB for one layer and 50GB for two, but HD DVD proponents
point out that multi-layer Blu-ray discs are still in development.
The surface layer of an HD DVD disc is 0.6 mm thick, the same as DVD
but thicker than the Blu-ray Disc's 0.1 mm layer. HD DVD media
promises to cost less to manufacture than Blu-ray, as HD DVD only
requires modification of existing DVD disc production lines. Both
formats will be backward compatible with DVDs and both employ
MPEG-2 as their primary video
compression techniques. One advantage HD DVD has is its support
by the DVD Forum, a group of hardware and media manufacturers that
sets specifications and standards for DVD-based content. Blu-ray was
developed outside of the DVD Forum, and was never submitted to the
forum for consideration. In April 2005, Apple Computer, a member of
the DVD Forum, updated
DVD Studio Pro to support authoring HD content. DVD Studio Pro
allows for the burning of HD DVD content to DVDs, and HD DVD media
will be supported as burners become available. |
|
|
Header |
In computers and
digital audio a header is a unit of information that precedes a data
object. In file management, for example, a header is a region at the
beginning of each file where bookkeeping information is kept. The
header may contain the date the file was created, the date it was
last updated, the file's size, the
sample rate,
bit depth, whether it's
stereo or
mono, or any other information that may be important to the
system. The header can generally only be accessed by the operating
system or by specialized programs and usually their format and
content conforms to some standard. For example, one of the major
differences between
S/PDIF and
AES/EBU
digital audio signals is the information contained in their headers.
|
|
|
Hexadecimal |
Hexadecimal, or
Hex for short, is a numbering system based on counts of 16 - as
opposed to decimal (the system most of us are most familiar with),
which is based on counts of 10, or
binary, which is based on counts of 2 (ones and zeros). The Hex
characters range from 0 through F in the following order: 0, 1, 2,
3, 4, 5, 6, 7, 8, 8, A, B, C, D, E, F, where A represents our
decimal "10," B "11," and so on. The
hexadecimal numbering system is commonly used as a handy way to
describe computer data because it can represent every
byte as a simple two digit value. For example, the binary
numbers (or byte) 01101001 can be quickly seen in hex as 5D (in
decimal this value would be 105). "Quickly" in the above context is
a relative term; it does take a little practice to be able to "see"
it. In order to be able to recognize when hex numbers are written
they are usually accompanied by the dollar sign ($) or the letter
"H" (or small "h") immediately before or after. So the hex number
above might be written $5D.
MIDI is a data protocol that relies heavily on hex values for
user input. Though these days most of the nuts and bolts of MIDI are
well hidden from users, you will still see some hex values in many
MIDI implementation charts that accompany most MIDI gear, and in
some of the deeper MIDI
sequencing programs. |
|
| HFS
(& HFS+) |
Abbreviation for
Hierarchical File System as is used by the Macintosh computer system
for hard disk data organization. HFS has been used by the Macintosh
since about 1986 and is still in widespread use today. Recently
Apple has introduced an updated architecture they are calling HFS+.
HFS+ addresses a variety of shortcomings in the old HFS, including
the ability to handle files over 2 gig in size, allowing names up to
255 characters long, using more of the available hard disk space and
packing the data more tightly on the drive, thus conserving space.
|
|
| High
Sierra |
An early standard
for CD ROM data based on the
Yellow Book disc format. High Sierra was defined by a group of
12 manufacturers dubbed the High Sierra Group back in 1985. The
group included Apple, Microsoft, Sony, Phillips, etc. The idea was
to provide a single CD ROM format that could be read by Macintosh,
DOS, Unix, and VMS computers. The
ISO 9660 format often used today is based on a modified version
of the High Sierra format. |
|
| Host
|
There are a number
of different meanings for this term. Even when narrowed down to
computers and technology there are still a few different meanings
that are subtly different depending upon the context. Generally it
refers to a device or program that provides services to other
devices or programs. In some computing environments a host is a
(presumably large and powerful) mainframe computer or server that
has clients or terminals attached to it, and provides for their
computing needs accordingly. A computer configured to serve web
pages or other information to users (clients) is known as a host.
Services that provide web serving capabilities are known as hosting
services. A computer connected to a network with full two-way access
to the Internet can be known as a host. Such a computer is given a
"host" number that, together with the network number, forms its
unique
IP address. |
|
| Host
Based |
Refers to
DAW systems that rely mostly upon the host processor (CPU)
of the machine they reside in to provide their processing power. In
the years before computers were able to do much more than provide a
graphics platform for digital audio work a lot of proprietary
hardware was required. Early systems would stand on their own and
just use the computer as the user interface. As computing power rose
over the 1990's, manufacturers began to design systems to take
advantage of the additional capabilities to the point where now it
is common to have an entire virtual studio inside of a typical
desktop PC, complete with mixing,
plug-in processors and synthesizers, and many tracks of
recording just by running software. These systems are known as "host
based," which means they rely on the host CPU (and its related
components) to do all the dirty work as dictated by the software.
The only hardware involved is usually some kind of computer card
and/or external box providing
analog and digital connectivity to the outside world. Host based
systems do still have to compromise in some areas of performance,
but as computer technology continues to advance the differences
between them and their dedicated hardware counterparts continues to
blur. |
|
| Hub
|
In computing a hub
is a device where several devices are connected together, a place of
convergence where data arrives from one or more directions and is
forwarded out in one or more other directions. This may be many
computers on a network, or many devices to one computer. A passive
hub serves simply as a conduit for the data, enabling it to go from
one device (or segment) to another. So-called intelligent hubs
include additional features that enable an administrator to monitor
the traffic passing through the hub and to configure each port in
the hub. Intelligent hubs are also called manageable hubs. A third
type of hub, called a switching hub, actually reads the destination
address of each packet and then forwards the packet to the correct
port. |
|
|
HyperText |
A user interface
system for displaying documents which, according to an early
definition, "branch or perform on request." The most frequently
discussed form of hypertext document contains automated
cross-references to other documents called "hyperlinks." Selecting a
hyperlink causes a computer to display the linked document. This is
one of the foundations of the World Wide Web. The point of hypertext
is to deal with the problem of information overload. In print
reference works (dictionaries, encyclopedias, etc.), cross
references consisting of setting a term in small capital letters,
were employed as an indication that an entry or article existed for
that term within the same reference work. However, that system made
for a slow research process with frequent interruptions to locate
the reference. Computer-based hyperlinks created the opportunity to
display such cross references quickly with minimal interruptions. A
hyperlink can lead to additional text, an image, chart, or graph, or
an entirely different website. Ted Nelson coined the word
"hypertext" in 1965 and helped develop the Hypertext Editing System
in 1968 at Brown University. |
|
| I/O
|
Abbreviation for
Input/Output. Strictly speaking any device that does anything has
input and output. A seesaw, for example, utilizes the energy from
children's legs (the input) to rock back and forth (the output) on a
fulcrum. But the term is mostly used in electronics, especially as
it pertains to computers or any kind of logic functions, but also
with audio and video equipment. Computers have all sorts of I/O,
from serial ports, to
SCSI, to monitor and keyboard ports. Audio and video equipment
is obviously all designed with the ability to get signals in and out
as well. These inputs and outputs, when spoken about collectively,
are sometimes called I/O for short. |
|
| IAC
|
Abbreviation for
Inter Application Communication or Channel, depending upon whom you
talk to. Either way the purpose is the same. IAC is a Mac
driver that was developed years ago and included as part of
OMS to provide a way to link timing and other information
between two different programs running on the same computer. It has
most commonly been used to link a MIDI
sequencing program and an audio recording program together to so
they run in sync on one computer. It does this by providing a
selectable software conduit for
MTC,
MIDI Clock, or other timing and location information to pass
between the two pieces of software. Once enabled timing and location
information can be sent from one program to another causing them to
locate, start, and play in sync. |
|
| Icon
|
In the computer
world, icons are graphic symbols that appear on the virtual desktop.
Each one represents a specific program, disk, file, or document. In
general, the icons representing programs (applications) have the
most sophisticated designs. |
|
| iLok
|
A type of hardware
dongle developed by the
PACE copy protection people and currently used by several
software manufacturers to ensure only authorized (paying) users are
able to run their software. The
iLok plugs into the
USB port of a computer just as many dongles do. The unique
feature of iLok is that the key is purchased separately and can be
programmed to work with many different products. This means the user
doesn't have to end up hanging several different dongles off of a
computer, which often results in conflicts and other erratic
behavior of the system. |
|
| Image
File |
An image file is
used to store an exact replica of a specific set of data on some
type of disk drive or in computer RAM. For example: One might keep
an "image" of a particular floppy disk stored on a hard drive so it
can be retrieved at a later date. The procedure for retrieval
usually involves running some software that recreates the image of
the original floppy disk on a new disk. Image files are also
frequently used with CD writers to prepare data to be written to a
CD. In this case all of the desired files are copied into an "image"
of the CD that is on a hard drive. Once ready, this image can
quickly be written to the recordable CD. Sometimes this procedure is
required in order to be able to write a suitable CD, but this will
vary upon the software and hardware being used. |
|
| iMIDI
|
iMIDI is a
freeware application from Granted Software (currently at beta
version 0.2b) that runs in the background on OS 10.2 or higher, and
allows for
virtual connection between two computers on an Ethernet network.
(iMIDI uses
TCP/IP
to transmit
MIDI information between networked computers.) Using a "local
loopback" feature, iMIDI also supports running a MIDI program such
as Finale or Sibelius connected to a
slave program such as Reason as a source for
sounds and
samples, all on one computer. In that regard, it's like IAC, and
somewhat similar to
ReWire, though it carries MIDI information only, not
audio. |
|
| In
The Box |
A term used to
refer to music or
audio production that takes place entirely - or as entirely as
possible - within a computer-based
DAW. "In the box" generally refers to
mixing the audio in the DAW, using
plug-ins for processing rather than going outside the computer
to external
analog or
digital hardware processors. |
|
| In
The Box |
Term used to
describe a track or project that has been processed and
mixed a project entirely within a computer using a
DAW and
plug-in, without using external hardware processing or
summing/mixing
gear. |
|
|
Installer |
Most
applications and plug-in bundles today come on a disc, often in
a compressed form. Most come with a specialized
software
utility called an installer, which does exactly what the name
suggests: It helps walk the user through the installation process
and often the process of registration and
authorization, as well. All the relevant data is uncompressed
(if required) and then placed exactly where it needs to be in order
for the program or plug-in to operate properly. Often, after
installation and registration, the computer must be restarted in
order for the
operating system to read and recognize the new software.
|
|
|
Instantiate |
Comes from the
word "instance." An instance is a particular realization of some
abstraction or template such as a class of objects or a computer
process. To instantiate is to create such an instance by, for
example, defining one particular variation of object within a class,
giving it a name, and locating it in some physical place. In
DAW parlance, instantiate has become the $3 word for enabling
plug-ins within a session. For example, when you bring up a
reverb in your session it is common to say you have instantiated
your reverb plug-in. |
|
|
Inter-Application MIDI |
Many modern
MIDI based software applications have the ability to communicate
MIDI data with each other inside the computer. Generally this takes
the form of some type of
synchronization information such as
MIDI clock,
MTC, or actual MIDI performance data. The idea is to allow two
programs that may or may not be independent applications to directly
communicate necessary MIDI data with each other without having to
route that data out of the computer's
MIDI interface and then right back in on another
port. Inter-Application MIDI has sort of taken over where the
IAC left off a few years ago, but it is essentially the same
technology. |
|
|
Interface |
This term is used
in a number of different contexts in the world of computers, audio
and video production. In general, an interface is a boundary across
which two systems communicate. It might be a hardware connector used
to link two or more other devices, or it might be a software
convention used to allow communication between two systems. The
MIDI Interface is an example that uses both of these components.
Remember that MIDI is an acronym for "Musical Instrument Digital
Interface." The MIDI specification defines both the hardware
connections - the now-familiar 5-pin
DIN connector, plus the circuitry inside a MIDI device, and the
software code that provides a common language all MIDI devices
understand. With the arrival of computer-based audio recording,
interfaces were developed to transmit audio (after it had undergone
an
A/D conversion) to the computer hardware and software.
Essentially these interfaces serve to encode digital audio data into
a communication
protocol (for example,
SCSI,
USB,
FireWire or proprietary formats) for transmission to a computer
and translate it at that end. A similar approach is involved when
using external storage devices such as FireWire hard drives.
Technically speaking, there is no such thing as a "FireWire drive."
FireWire is simply the data transmission protocol; most drives used
in this context are
ATA or
SATA devices. They require a two-way interface that translates
incoming data from the FireWire cable into a format the ATA drive
can handle when writing to disk, and re-translates data read from
the drive to be transmitted back over the FireWire cable. Last but
not least, the term interface is used to define the connection that
allows interaction between hardware or software and a human user.
The
GUI, or graphic user interface, is a visual representation of
the hardware or software operating system that makes operation
easier (at least in most cases!). Even the small
LCD or
LED displays on synth modules or effects processors are examples
of user interfaces. |
|
|
Internet |
The Internet (most
often written using a capital "i" because it is a proper noun) is a
publicly accessible series of interconnected computer networks that
are capable of transmitting
digital data via packet switching, based on the Internet
Protocal standard or IP. Quite often people make the mistake of
using the terms World Wide Web and Internet interchangeably, but
they are not synonymous. What's the difference? As stated, the
Internet is a series of interconnected computer networks that are
physically linked by either copper wire, fiber-optic cable, or more
recently,
wireless connection. Meanwhile the Web (also capitalized) is
more accurately a series of interconnected documents and other
resources that are linked together by
URLs or hyperlinks. Ergo, the World Wide Web is accessible as a
service of the Internet, as well as e-mail,
file sharing, streaming media, and even online gaming. How the
Internet came into existence is a long, convoluted story, but its
commercialization and the emergence of privately owned Internet
Service Providers (ISPs)
beginning in the late 1980s has had a huge impact on both human
culture and commerce and from all indications the changes it has
brought will only continue. |
|
|
Interrupt/Interrupt Request (IRQ) |
A temporary
suspension of a process. In PC computers interrupts are used to
suspend one activity in order to give priority to another more
important activity. Interrupt signals, also known as Interrupt
Requests (IRQ) are identifiable by a unique number and can have
varying levels of priority, but in general they all cause the
OS to stop what it is doing and decide what to do next. They can
come from software or hardware devices. Many things you do on a
regular basis, such as pressing a key on your keyboard or clicking
your mouse generate an interrupt that causes the computer to take
some action based on how it is programmed to handle that particular
interrupt.
MIDI and other music related hardware connected to PC computers
generally need to have unique IRQ identities in order for
communication between the computer and the hardware to take place
properly. To that end there are methods for choosing the ID on most
hardware that is to be connected to a PC. A similar analogy would be
SCSI devices, where each one has to have a unique ID number. PC
computers have routines known as Interrupt Handlers and Interrupt
Schedulers that enable them to manage the regular flow of
I/O for the system and keep everything running smoothly and on
time. |
|
| ISA
|
Abbreviation for
Industry Standard
Architecture. A PC computer expansion
bus used for modems, video displays, speakers, and other
peripherals. PCs with ISA architecture may have some 8-bit
and some16-bit expansion slots, but the bus itself is capable of
16-bit data. |
|
| ISO
9660 |
A standard file
naming system for
CD-ROM media, published by the
International Organization for Standardization. It provides
cross-platform support for many different computer
operating systems such as Microsoft
Windows,
Mac OS, and systems that follow the Unix specification, so that
data may be exchanged. Almost all computers - and most hardware
synths and samplers - with CD-ROM drives can read files from an ISO
9660-compliant CD-ROM. The ISO 9660 specification has been around
for many years. It was originally issued in 1988, developed by an
industry group named
High Sierra. There are different levels to the standard. Level 1
restricts file names to eight characters with a 3-character
extension (the "XXXXXXXX.XXX" format commonly used since the days of
DOS). Level 1 also specifies the use of upper-case letters,
numbers, and underscore as the only accepted characters. Level 2
allows file names to be up to 31 characters long. Level 3 files can
be fragmented (mainly to allow packet writing, or
track-at-once CD recording). The restrictions on file name
length have been seen by many as a serious limitation of the ISO
9660 system. Many CD authoring applications attempt to work around
this by
truncating filenames automatically, but risk "breaking"
applications that rely on a specific file structure.
|
|
| Java
|
To many audio
engineers Java means coffee, a drink to get you started in the
morning. But to computer savvy people Java is a computer language.
Specifically a platform-neutral language that allows developers to
write programs (often called "applets") that can run on practically
any computer connected to the Internet. In fact, as you've surfed
the Web, you've almost certainly been running Java applets. They're
incorporated into many of the pages you visit on your virtual
journeys, and the software to run those applets is not only part of
the Mac OS but is designed to work seamlessly with browsers that
support it. Right now, there are thousands of Java applets in use
around the world. To see how industries from aerospace to
entertainment to real estate to utilities have been employing Java,
you can visit the
Java Web site. |
|
|
Journaling |
Journaling is a
process designed to protect the file system against power outages or
hardware failures, reducing the need for disk repairs. Journaling is
supposed to protect the integrity of the disk, keeping it from
falling into an inconsistent state by logging actions as they occur.
This allows the computer to replay the information in its log and
complete the action when system power is restored. Journaling is
especially helpful for
servers, maximizing the uptime and speeding up repairs during a
system restart. A journaled disk has a continuous record of changes
made to the files, providing a known safe-spot when the server
reboots. Journaling dramatically speeds up the process of getting a
server and file system back online since the
OS can just replay the most recent actions and have the system
up to date in a matter of seconds, resuming actions that were
interrupted by the hardware or power failure. However, with high-bandwidth
applications like
audio and video production, journaling may slow down access to
the data, resulting in system errors, and it may be advisable to
disable journaling on audio or video
drives. |
|
|
Joystick |
For anyone who
plays video or computer games a joystick is a common household word.
In audio and music production it is a controlling device that can
move along two different axes simultaneously. Similar in concept and
purpose to a
modulation wheel (or other
continuous controller) and a
fader or
pan pot, a joystick divides one input signal among four output
channels. Some keyboards have had joysticks instead of separate
modulation and pitch bend wheels (or sliders) to allow the user
access to both controllers simultaneously via one mechanical
interface. In modern audio production the joystick is starting to
become a replacement for the pan pot. This is because the proper
positioning of sounds in a
5.1 mix (for example) requires more than just left to right pan
positioning. It requires, at minimum, a combination of left/right
and front/rear positioning, which is most easily done with a
joystick. Most software dealing with surround sound will offer some
type of graphical interface based on the two axes provided by a
typical joystick. This usually takes the form of a virtual grid
where each sound can be positioned anywhere along either axis.
|
|
| Jump
Drive/Thumb Drive |
The name given to
small easily transported devices (approximately the size of your
thumb, hence the nickname) that utilize
flash memory for data storage. Jump
drives benefit from being
plug-and-play, as the computer recognizes the drive nearly
instantly and can access the drive without configuring or
installing. Thumb drives are currently available in sizes ranging
from 8MB
to 2GB.
|
|
|
Kernel |
Modern computer
operating systems are typically built in layers, with each layer
adding new capabilities, such as disk access techniques or a
graphical user interface (GUI).
But the essential layer, the foundation on which the rest of the
operating system rests, is typically called a kernel. In general,
the kernel provides low-level services, such as memory management,
basic hardware interaction and security. |
|
| Key
Command |
A key, or
combination of keys, that can be pressed on a computer's QWERTY
keyboard, that takes the place of making a selection or selecting a
menu item with a mouse. An example would be pressing Command-S
on a Mac's keyboard instead of selecting "Save" from a
program's menu. |
|
|
Keyboard |
It's hard to
believe we haven't covered this one before. Essentially, the term
refers to the group of black and white
keys on an acoustic or electric piano, harpsichord or organ, or
synthesizer or other electronic instrument. with the white notes
typically representing "natural" tones, while the black keys
represent
sharps and
flats, although some historical instruments occasionally
reversed this, with black keys for the natural tones. Historically,
keyboards were often referred to as
manuals, from the German word manualiter, which roughly
translates to "playing with the hands." Today a keyboard may also
refer to the part of a computer where data is entered
alphanumerically. (See also "Keybed.")
|
|
| kilo
(lower-case) versus Kilo (upper-case) |
- kilo - A standard prefix (abbreviated "k")
representing 1000. For example, a 4 kiloHertz (kHz) sine wave has
a frequency of 4,000 Hertz.
- Kilo - A standard prefix generally used in
reference to computer equipment. Abbreviated "K", it was developed
to represent the binary value of 2 to the 10th power (1024). Thus,
8 Kilobytes (Kb) of memory is 8 times 1024, or 8,192 bytes.
Tecnically the upper case K represents the prefix Kibi (not Kilo),
which is a more specific term that relates to these computer
oriented values (2 to the 10th power, etc.), though it isn't
commonly used.
|
|
| LAN
|
Abbreviation for
Local Area Network. A LAN is a group of computers and associated
devices that share a common communication line with each other. A
LAN may be as small as one or two computers networked together in a
home, or as large as thousands in a large organization. Typical
LAN\'s, as they are deployed in commercial installations, involve a
server that provides access to resources for various clients or
terminals around the facility. LAN\'s are sometimes connected to a
WAN (Wide Area Network, which is usually, but not necessarily the
Internet) through a switch or some hardware that regulates the flow
of data in and out of a facility. |
|
|
Launch |
To "start" or
"open" a computer
application; to make the application active so you can use it.
|
|
|
Librarian |
In music
production a librarian is software whose function is to organize and
store program information for MIDI instruments and processors.
Librarians can store thousands of different sets of patch data for
each device in a given system. In other words, they store and
organize the actual computer data the device uses to set itself up
to make the various sounds it can make - the parameter data if you
will. They sometimes employ databases so patches may be searched on
key words or attributes of the sound. They can upload or download
the data to and from instruments connected via MIDI by using strings
of
system exclusive commands. This makes it very easy to change the
entire contents of program memory of a given device for each session
or job needing to be done. |
|
| Linux
|
A trademark for an
open-source version of the
UNIX
OS. Originally written from scratch with no
proprietary
code by Finnish programmer Linus Torvalds and a worldwide
assortment of computer geeks, Linux is now probably the most famous
example of free software and of open-source development. The name
Linux strictly refers only to the Linux
kernel, but it is commonly used to describe entire operating
systems that are based on the Linux kernel combined with additional
libraries and development tools. Linux distributions typically
bundle large quantities of software with the core system. The kernel
was originally developed for Intel 386 microprocessors but now
supports a variety of computer architectures. There is a great deal
of commercial support for and use of Linux, both by hardware giants
such as IBM, Hewlett-Packard and Apple and numerous smaller network
and integration specialists. Linux is overtaking many proprietary
versions of UNIX. It is deployed in
applications ranging from personal computers to supercomputers
and embedded systems such as mobile phones and personal video
recorders. Proponents attribute this success to its vendor
independence, low cost of implementation, security, and reliability.
|
|
| Log /
Logging |
In video (and
audio to an extent) applications logging is a process of sifting
through raw footage with the intent to
capture part of it to be edited and used in production. When
logging is done with computer
DAW type systems the user generally selects specified
regions of tape - usually referred to by
time code values - which are accumulated in a capture log. Later
the process is capturing or
sampling the video/audio material is semi-automated. The
computer will operate the tape machine (or whatever type of machine
is being used to play the raw recordings), causing it to locate the
desired locations on tape (disc, etc.), and then have it play while
the material is captured. Often systems will allow various types of
notes and annotations to accompany the log, which is then linked to
the captured material. |
|
|
Lossless Audio Compression |
A data
compression procedure that reduces the size of (encodes) digital
audio
files without sacrificing any audio data, or fidelity, when the
files are expanded (decoded) for playback. The goal of all data
compression is to reduce file size. Originally the value of this was
conservation of hard drive space. If you've used
WinZip or Stuffit you've already compressed and uncompressed
files. But in recent years music distribution over the Internet has
made data compression very important: small files can be transferred
much more quickly and easily than large files. Word processor
documents and spreadsheets are relatively easy to compress; some
codecs use simple substitution of a single character or symbol
to represent a common word or phrase (for example, the word "The"
might encoded as "^" which is a 2/3reduction in size). Typical audio
files such as
AIFF or
WAV, though, are much more difficult to encode and decode. First
of all, each
bit of audio data represents some element of the original
sound's
timbre,
frequency or
amplitude. It can't easily be reduced using a simple replacement
scheme. Second, audio files must be decoded and played in real time
- something that's not required of a compressed document, so the
codec must be able to act quickly on the data as it streams through.
In the late 1990s and early 2000s, Internet users and consumers
satisfied themselves with a number of so-called "lossy" codecs such
as MP3 and
AAC, which use sophisticated
algorithms to discard selected bits contained in the original
audio that have a minimal impact on the overall sound. Some audio
professionals have been confused and frustrated by the widespread
acceptance of these formats because they do deliver lower-quality
frequency response and
dynamic range than the typical
CD. The goal has been to produce algorithms to mathematically
reduce audio data in a way that doesn't lose any of the information.
Now several such ("lossless") audio codecs do exist. They have
achieved compression rates of up to 50% and can perform well on a
number of hardware devices and computer software. Lossless audio
compression uses a combination of mathematical strategies to
accomplish its goal. Many begin by using "prediction," a somewhat
challenging concept: if the values of future audio samples can be
predicted, then it is only necessary to transmit the rules of
prediction along with the difference between the estimated and
actual signals. In other words, the codec analyzes the incoming
data, guesses what the following data might be, then stores only the
portions in which the "real" signal differs from the "predicted"
signal. Lossless codecs also use a combination of finite impulse
response (FIR) and infinite impulse response (IIR)
filters to compensate for the wide dynamic range of musical
material (MP3
and other "lossy" codecs use FIR filters, which, in common
implementations, don't capture dynamic shifts at high frequencies,
which is one element of their "squashed" sound). Finally, lossless
codecs transmit signal at a variable
transfer rate, thus making sure that full-bandwidth
signal passes while low-bandwidth material doesn't clog the stream
with a bunch of zeros. Extensive
buffering (up to 75ms)
helps pass this data to the playback device. In addition, most
codecs employ a means of collecting audio data that is similar on
multiple tracks - room
ambience or cymbal
overtones, for example - and compacting them into one data
stream. This is called "Entropy coding," a term you don't really
need to remember. Among several lossless audio codecs are: Free
Lossless Audio Codec (FLAC), which is a popular
open source code that groups like Phish and Metallica use to
post audio files on their websites; Monkey's Audio, also popular but
Windows-exclusive and dependent upon
CPU speed to deliver fast decoding; Meridian Lossless Packing,
the officially supported codec for
DVD-Audio by the DVD Study Group; WavPack, which uniquely can
generate a "lossy" file (like an MP3) plus a "correction" file that
restores the lost data. In spring 2004, Apple entered the scene with
Apple Lossless Audio Codec (ALAC), which is supported by iTunes
version 4.5 and offers iPod users the ability to listen to tracks
that have the fidelity of uncompressed audio but require a little
more than half the storage space. |
|
| LPT
|
Abbreviation for
Line Print Terminal. On a personal computer this is the usual
designation for a parallel port connection to a printer or other
device such as a scanner or camera. LPT connections are numbered
LPT1, LPT2, LPT3, etc.; most computers have at least one. More
parallel ports can be added by installing parallel port adapter
cards. Parallel computer connections traditionally have used the
Centronics parallel interface for printer communication. A newer
standard called EPP/ECP supports the older interface while providing
faster communication for a range of devices, including scanners and
video cameras. |
|
|
Machine Room |
A room dedicated
for the housing of mechanical devices, normally for the purpose of
isolating them from areas where humans work. This may be due to
noise or heat, or other environmental considerations. As it applies
to audio studios, this is the room where you might place tape
machines, computers, decks and other devices that produce audible
machine noise. By placing these devices in a space other than your
recording and mixing environment, you are freeing your creative
space from the noise that accompanies them — thus allowing focused
recordings and mixing. You can also provide separate, and more
suitable, ventilation for them without disturbing the main
environment. Machine Rooms are found in forms such as expensively
finished rooms in professional studios, bedroom closets in home
studios and everything in between. |
|
| Macro
|
In computer
programming, a new command created by combining a number of existing
ones. For example, a word processing macro might create a letterhead
or fax cover sheet, and insert words, fonts, and logos with a single
keystroke or mouse click. Macros are also useful to automate
computer communications - for example, users can write a macro to
ask their computer to dial an Internet Service Provider (ISP),
retrieve e-mail and USENET articles, and then disconnect. In digital
audio,
MIDI and video applications the options are equally open ended
and far reaching. A macro key on the keyboard combines the effects
of pressing several individual keys. |
|
|
Mapping |
In music terms,
mapping refers to the process of placing individual
samples across a keyboard, matched to their original pitches. In
the early days of sampling, because of memory restrictions, one
sample had to cover two or three notes via
transposition. As an example, a sample of
middle C might have to transpose up and down by a
semitone or two (and sometimes even more). Today, computer-based
samples are almost always limited to a specific
pitch, so that now middle C would have its own dedicated sample,
as would neighboring notes. Sound designers from the 1980s and '90s
will tell you how time-consuming it was to map specific samples in
intervals that would transpose well and thus produce an
acceptable representation of a particular acoustic or electric
instrument. |
|
|
Marker |
Depending on
context, a marker takes on different meanings. When it comes to
editing in
DAW software, having markers can be lifesaving. Quite simple, a
marker is, as the name implies, an icon used to visually identify a
memory location in a
sequence. When creating markers, a dialog box opens allowing
them to be named as well. (e.g., Verse 1, Verse 2 Chorus 3,
and etc.) Along with providing visual reference, markers serve
another very useful function. DAW software such as Pro Tools,
Digital Performer, and Logic Pro use markers to navigate between
locations in a composition. For example, in a song, you would place
markers at the beginning of
verse,
chorus, and
bridge. By clicking on the marker icon (either displayed in a
separate window, or on the sequence's time line), the wiper will
move instantaneously to the marker's location. This is extremely
useful, if for example, you wish to insert an event that occurs in
each of the choruses. You can use the markers to jump to each
location as needed. Since computer monitor screens only have so much
real estate, markers come in particularly handy with longer forms
such as orchestral compositions. They can be used to mark rehearsal
numbers in the
score as well as provide a means of navigating through the
various movements that would otherwise require in inordinate amount
of
scrolling. |
|
| MAS (Motu
Audio System) |
A
plug-in engine developed by MOTU for use with their
DAW software (Digital Performer), offering
real time audio effects use and manipulation in a manner similar
to the use of
auxiliary sends on an outboard mixer. However, instead of using
external processing, the
DSP is done by the host computer and never leaves the digital
domain. Supporting Macs only, MAS isn't interchangeable with any of
the other plug-in engines and will only work with MAS-enabled
software. MOTU also has a third-party developer program for MAS,
which as a plug-in platform has developed a niche for Mac/MOTU
users. |
|
| Max/MSP
|
A visually
oriented programming environment for
audio and multimedia production. Max was conceived in 1986 as a
project for producing interactive music at IRCAM in Paris. The
original author was Miller Puckette. Max was offered commercially
from Opcode Systems in 1991, and in 2000
Cycling ’74 became the publisher. Since that time, Max has
expanded to include audio data (with the introduction of MSP, a
collection of audio objects) and image/matrix data (with the
introduction of Jitter). Max allows you to create your own software
using a visual toolkit of objects, and connect them together with
virtual
patch cords. The basic environment that includes
MIDI, control, user interface, and timing objects is called
“Max.” The audio processing tools comprise the companion software,
MSP. Max is based on the C programming language, but is easy to use
for those familiar with almost any other programming language, or
even for those who have never programmed before. Max was named in
honor of
synthesis pioneer Max Mathews, who first demonstrated music
synthesis on a
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