Equipment & Technical Issues

Computer equipment and digital technology can seem foreign and alienating to those not accustomed to using computers for more than word processing and e-mail. Artists use computer software and hardware as platforms for a range of aesthetic activities. Their equipment can include everything from desktop or laptop computers and personal digital assistants to joysticks, touch screens, and sensors. Because every artwork is unique, determining the necessary system requirements for computer-based art can be tricky. Some projects might call for defunct hardware or software, while others might require sophisticated operating systems and high-speed Internet connections. There are also environmental specifications to consider. Increasingly, computer-based projects are migrating from the static computer screen onto the walls of the gallery. As the lines between single-channel video, media installations, and computer-based works continue to blur, the technological guidelines and specifications overlap as well.

This section does not intend to be a comprehensive list of all the technical elements of computer-based art works, but rather a guide to the basic hardware, software, and network attributes that are used in the installation of many computer-based art exhibitions.


Hardware

Software

Networks



Hardware
Personal Computers

Macintosh: Designed and developed by Apple Inc., the Macintosh was the first commercially successful personal computer to use a graphical user interface (GUI) and mouse instead of a command line interface (such as DOS).

Mac mini

Mac mini is the least expensive Macintosh currently in production and is very useful for media installations.


iMac
iMac. The iMac is a common desktop computer.


PowerMac
PowerMac The PowerMac is the most expensive, and potentially powerful model.


PC: Although the term PC (short for Personal Computer) is broad enough to include Apple computers as well as others, the term is commonly accepted to mean “IBM compatible,” which today means Windows machines. PCs have numerous manufacturers, unlike Apple. These manufacturers include Dell, HP, Compaq, Sony.

Servers

Video Server

Just as DVD replaced VHS and Laserdisc for showing video in art spaces, computers are replacing DVD. When a computer is set up with the sole purpose of playing video, this computer is called a Video server, and it can be assembled from a general-purpose computer like a Mac or Windows PC or it can be manufactured as a stand-alone device, like a DVD player. The advantage of a video server is its ability to play many types of video, including HD (high-definition).

Network Server

See Network section below.

Input Device

Input devices allow a user to interact with the computer. What kind of input device to use (if not specified by the artist) depends on what level of interaction is necessary to animate the work successfully. Some common input devices are:

  Mouse/keyboard. These are the two main input devices for computer installations. The mouse allows for basic “point and click” interaction and the keyboard allows for more traditional input like text entry.

    Touch Screens. Touch screens overlay the display and are typically pressure-sensitive (resistive), electrically-sensitive (capacitive), acoustically-sensitive (SAW or surface acoustic wave) or photo-sensitive (infrared). For simple interactions, these devices replace the keyboard and/or mouse as the primary input device for interacting with a work’s content.

    Image/Video/Audio. Scanners, digital cameras and camcorders, webcams and microphones all can be used as input devices for computer based installations, not only as an input for image and sound, but as a way to track a user’s movement through space.

  Gaming Devices. Common video game inputs are sometimes used in installations, such as joysticks, paddle, and game pads.

Output Device

An output device is any display mechanism that is controlled by a computer. Common display devices include projectors, video and audio monitors. Hard drive playback is an attractive alternative to formats that are unreliable or insist on high compresion levels.

Connections and Cables

Connections and cables are devices for moving analog and digital data in and out of the computer. Some are computer specific and others come from traditional AV connection types.


DVI
  DVI/HDMI is the standard display output of contemporary computers, which transfers video from the computer to the display digitally. Since most of today’s displays (projectors, flat screens) are digital, DVI avoids the digital-to-analog (DA) conversion required if a VGA connection is used (see VGA below). HDMI transfers the video picture the same way as DVI but also includes multiple digital audio channels for surround sound. HDMI is becoming the consumer standard as it is adopted by home theater devices.

  VGA is an analog cable commonly used to connect a computer to a display. VGA accomodates a screen resolution of 640 x 480 pixels. Other resolutions include SVGA = 800 x 600; XGA = 1024 x 768; WXGA = 1280 x 768 (widescreen display); SXGA = 1280 x 1024; UXGA = 1600 x 1200.

  DVI to VGA adaptor. Most older projectors only have VGA inputs, while many new computers are only equipped with a DVI output. A DVI to VGA adaptor is a common connector used (especially for Macintosh users) to remedy this incompatibility.

    Balanced and Unbalanced Audio. Balanced connections are used in pro environments because the twisted-pair structure of a balanced cable reduces potential noise interference. Unbalanced is by far the more common. These connections can use the same RCA cable and connector used in home video and audio equipment, and also commonly seen connecting to a computer with 1/8” mini connector, like those found on headphones for MP3 players.



  USB (Universal Serial Bus) is a common interface for connecting external devices to computers. USB cables can be daisy-chained together from one origin at the computer to connect multiple devices .

  FireWire (IEEE 1394). FireWire is a replacement for SCSI (small computer system interface) that commonly connected older PCs to printers and other external devices. Firewire has become the standard for transferring digital video.


Software
From email to word processing, software is what allows the computer to perform specific functions. In this section, only software that is related to exhibition and playback of artist content will be covered.

Operating Systems

Operating systems are software programs that load and run other programs. In general-purpose operating systems like Windows, Mac OS and Linux, the operating system is required to allow all the applications anyone might install on their computer to communicate with each other and with the hardware.



  Windows. Microsoft’s is the most widely installed OS. The current version is Windows XP.


  Mac OS. The current OS for Macintosh is OS X.
  Linux. Unlike Windows or Mac OS, Linux is an open source operating system, meaning that the underlying code is freely available for anyone to view, copy or modify.


Application Software

Application software describes a loosely defined subclass of software which employs the OS of a computer directly to a task. Typical examples of software applications include word processors, email programs, and media players.


Browsers

The term browser refers to software that allows one to browse the World Wide Web. Depending on the needs of the project, different browsers work better for different playback formats.



  Internet Explorer is a proprietary Web browser made by Microsoft and included as part of Windows operating systems.


  Safari is a Web browser developed by Apple Computer Inc. and available as part of its OS X operating system.
  Mozilla Firefox is a free, open source, cross-platform web browser developed by the Mozilla Corporation and hundreds of volunteers.


Video/Audio Playback

Video and audio exist on a computer as files, and these files use a compression/decompression scheme (Codec) to organize the data. These files could be a movie on a DVD, a clip downloaded from a web site, or an MP3. A file holds the data for that particular piece of media but in order to view or hear it you’ll need a media player, which is analogous to a set-top DVD player (but capable of far greater versatility). Media players play back many kinds of media files. Common media players are QuickTime, Windows Media Player, RealPlayer, iTunes, and numerous other commercial players and shareware players.


Codecs

The amount of data contained in a native video or audio file can be large enough to make playing it, using it, or downloading it impossible or impractical on any but a very fast computer with enormous storage. When a file size is reduced through compression, information is removed, resulting in a file that can’t fully reproduce the original picture/sound information (lossy compression). To use a compressed file it must be decompressed by the hardware or software. This procedure of compressing and decompressing data by using algorithms is called a Codec. The following is a list of common codecs.

Video codecs include:

Quicktime: The default container codec for Apple operating systems.
AVI: The default container codec for Windows operating systems.
Mpeg (Moving Pictures Expert Group): By storing only the changes from one frame to another, instead of each entire frame, MPEG can be a highly compressed format. There are three major MPEG standards: MPEG-1, MPEG-2 and MPEG-4. MPEG-2 is the codec used for DVD videos.
WMV H.264: a version of MPEG-4 being adopted in a wide array of applications including HD-DVD/Blu-ray and iTunes video.

Audio Codecs include:

WAV: Standard Microsoft audio file format for storing audio on Windows machines.
AIFF (Audio Interchange File Format): Standard audio file format for storing and playing sound data on Macintosh computers.
MP3: the audio component of the MPEG-3 codec but used only for audio.
MIDI: Bitstream encoding that can be thought of as instructions which tell a music synthesizer how to play a piece of music. An important attribute of early web style, it is no longer supported by web browsers other than Internet Explorer.


Networks


The following are common components that are found in networks:

Servers: a large computer or series of computers designed for applications serving client computers with data over a LAN or WAN.
Router: a dedicated computer that sends packets of information from one place to another.
IP (Internet Protocol): The address of a computer on a TCP/IP (transmission control protocol/internet protocol) network. IP addresses are written as four groups of up to three digits.
POP (Post Office Protocol). POP is a way of retrieving mail from an email server (POP server).
FIREWALL: A hardware or software system designed to limit access to a computer or a network. Firewalls protect computers from unwanted data coming into the system via the Internet. It can also stop information from getting out, which can be a problem for some artists’ projects.
FTP (File Transfer Protocol): standard protocol for transferring files between computers over the Internet.
Streaming Media: Media that is consumed while it is being delivered. This method transfers data in a steady and continuous stream.
Bluetooth: a wireless standard that allows devices like personal digital assistants (PDA), mobile phones, laptops, phones, and digital cameras to communicate with each other, but only within a 10 meter area. (Bluetooth is named after the Danish king Harold Bluetooth, who united area tribes through diplomacy.)
LAN or WAN: a Local Area Network (LAN) is used for home, office or building sized computer networks. A LAN can be as small as two computers sharing a printer and/or an Internet connection, even if they are using a wireless connection. Wide Area Networks (WAN) consist of many computers across a large area, the Internet being an example. WAN can also connect LANs to one another.
Cable, DSL:Cable and DSL are technologies in use in homes and small offices, which allow a computer or a LAN to connect to the Internet. Cable uses the same connection as cable television; Digital Subscriber Line (DSL) uses the phone line.