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At IU Bloomington, what is the Adaptive Technology Center (ATC)?

The ATC provides a wide range of services to students with disabilities, including reading assistance software, Braille printing, tactile imaging, hardware consultation and training, and more. The ATC office is in the Media Reserve area of the undergraduate section on the first floor of the Main Library.

Visit the ATC Web page at:


To view a video (text included) about ATC services, click ATC video.

The ATC is open Monday-Friday 9am-5pm. For more information, call 812/856-4112 or e-mail  iubdrh@indiana.edu .

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This is document akag in domain all from the Knowledge Base.
Last updated on August 16, 2001

For Mac OS, what was Anarchie?

Anarchie was a powerful FTP application for Mac OS. It was combined with several other network utilities and is now known as Interarchy.

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For Macintosh-compatible computers, what is the Apple Desktop Bus (ADB)?

The Apple Desktop Bus (ADB) first appeared in the Apple IIgs in 1986 and was incorporated into the Macintosh line the following year. Until replaced by the Universal Serial Bus (USB) in late 1998, it was the standard Macintosh interface for low-speed input devices. The connection to the Apple Desktop Bus is through the ADB port, a female 4-pin mini-DIN jack; all ADB-equipped models have one such port and some have two. Next to the jack will probably be an icon that looks like:


Until the migration to USB, nearly all keyboards and pointing devices (e.g., mice, trackpads, trackballs, and tablets) used the ADB port, as did many joysticks. Certain monitors (notably the AppleVision and ColorSync displays) transmit color and resolution information via ADB. The bus can support up to 16 devices in a daisy-chain (i.e., one peripheral connected to another), but Apple recommends a maximum of 3 due to electrical limitations.

Though ADB's throughput of 154 bytes per second is sufficient for most input devices, Apple has phased it out for the more robust USB. USB handles throughputs of up to 12Mbps and supports a much wider variety of peripherals. The iMac was the first Macintosh since the Macintosh Plus to ship without an ADB port.

For more information, refer to Inside Macintosh: Devices. Chapter 5, which is devoted to ADB, is available at the following location:


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In DOS FDISK, what are Primary, Extended, and Active partitions?

Old DOS versions of the FDISK command allow you to create up to four partitions on your hard drive. One of the partitions can be designated a Primary partition, and the others have to be Extended. The Primary partition will be the one used to boot the computer; you should format it so that DOS or some other operating system resides on this partition.

A partition must also be designated Active, otherwise the BIOS (the on-chip program that starts when the computer is turned on) will ignore that partition, even if it is designated Primary.

Using more recent versions of FDISK, you can create, on each physical drive, one Primary DOS partition and one Extended DOS partition. In addition, the Extended DOS partition may be further subdivided into several "logical" or "virtual" drives.

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In DOS, what is an AUTOEXEC.BAT file?

An AUTOEXEC.BAT file contains DOS commands which are executed automatically when a PC boots. The file is usually located in the root directory of the hard drive or floppy from which the computer boots up. The AUTOEXEC.BAT file is used to set defaults and to run programs that should be executed upon startup (comparable to the .login file on Unix accounts). Below is a list of statements that typically go into an AUTOEXEC.BAT file, followed by explanations of each statement's purpose.

The AUTOEXEC.BAT file is an example of a batch file, used to automate functions in DOS. In their simplest form, batch files contain DOS commands. There is, however, a batch file language which includes commands for such things as loops and execution branches.




This optional command will suppress the display of subsequent commands while the AUTOEXEC.BAT file is being executed. You can also use ECHO to display lines of text.




Note: This example PATH command should actually be placed on a single line in the AUTOEXEC.BAT file, with the line wrapping around rather than being interrupted by carriage returns.

Sometimes, you will see the command in the form SET PATH, or PATH = . Both are valid forms of the command.

Use the PATH command to tell DOS which directories to look into when an executable file is not in the current directory. When you enter a line of text at the DOS prompt that is neither a recognized command nor an executable filename in the current directory, DOS will search through the directories in your PATH for a filename that matches the text you entered. This command is highly recommended unless you are using a menuing shell. Many packages (such as WordPerfect) automatically add or modify the PATH line during the installation process. The path cannot exceed 127 characters, and may be further limited by your DOS environment space.

Sometimes you might see more than one PATH command in AUTOEXEC.BAT. The second and subsequent PATH commands might have the form:


%PATH% represents the existing path. This example would add C:\BLASTER to the path.

If you enter PATH at the C:\ prompt, the current path will be displayed. This can be a good troubleshooting tool, as it can tell you if the PATH command in AUTOEXEC.BAT has become too long and thus truncated.



  SET BLASTER=A220 I5 D1 T1 

SET is used to set system variables, which are used to pass information to programs. In these examples, the command is used to tell programs in what directories to store certain files or where configuration files are kept. Some programs (such as Windows) will set up this statement during the installation process, and many programs require SET statement entries in the AUTOEXEC.BAT file to run correctly. In some cases, a backslash following the end of a directory name is required, and spaces at the end of a line may cause trouble. If you enter SET at the C:\ prompt, all the system variables will be displayed.




Use the PROMPT command to alter the default DOS prompt. This particular example makes the DOS prompt display the current path and drive, and is very useful.




CLS clears the screen.

Note: You should only create or edit a DOS text file with a DOS editor such as EDIT, EDLIN, or TED. If you use a word processing program, make absolutely sure that you save the file in text (ASCII) format, rather than any special file format that the word processor normally uses.

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In Java, what is the Abstract Windowing Toolkit?

The Abstract Windowing Toolkit (AWT) is the basic set of Java classes used to build graphical user interfaces (GUIs) for Java applets and applications. Using the AWT, programmers have tools for creating common graphical objects such as windows, dialog boxes, buttons, areas in which to manipulate text, and much more. The AWT also specifies an event handling model which enables a program to respond to the keystrokes and mouse-clicks entered by a user.

For more information, see the following:


Java 1.2 includes a package named Swing that greatly augments the capabilities of the AWT.

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In Microsoft Outlook, what is AutoArchive, and how do I use it?

Note: AutoArchive is not available in versions of Outlook for Mac OS.

AutoArchive is a feature in Outlook that moves old mail and other items to a separate personal folder (.pst) file on your computer's hard drive, or a workgroup or departmental server. By default, it will archive items every 14 days, and will prompt you before doing so. It is also set up to delete expired e-mail messages from your Mailbox.

Several Outlook folders are set up with AutoArchive turned on. These folders and their default aging periods are Calendar (six months), Tasks (six months), Journal (six months), Sent Items (two months), and Deleted Items (two months). Inbox, Notes, Contacts, and Drafts do not have AutoArchive activated automatically.

In addition, you can manually transfer old items to a personal folder. Outlook can archive all types of items, such as Microsoft Excel spreadsheets or Word documents, but only if these files are stored in an e-mail folder. A file that is not stored in an e-mail folder cannot be archived. To manually transfer files, from the File menu, select Archive... .

Setting up AutoArchive

Outlook 98, 2000, and 2002

  1. From the Tools menu, select Options... .
  2. Click the Other tab, and click the AutoArchive... button.
  3. Select or deselect the first checkbox to enable or disable AutoArchive. You can change the settings for individual folders (e.g., Inbox, Calendar, Sent Items, Tasks) by right-clicking the folder and choosing Properties, then clicking the AutoArchive tab.

Outlook 97

  1. From the Tools menu, select Options... .
  2. Select the Autoarchive tab.
  3. Select or de-select the first checkbox to enable or disable AutoArchive. You can change the settings for individual folders (e.g., Inbox, Calendar, Sent Items, Tasks) by right-clicking the folder and choosing Properties, then clicking the AutoArchive tab.

Accessing messages stored by AutoArchive

To use Autoarchiving you will first need to install the Personal Folder service, and set it up to open the appropriate .pst file. For more information on how to do this, see the Knowledge Base article In Microsoft Outlook 97, 98, 2000, 2002, or Exchange, what are personal folder files, and how do I create them? The files are stored in different paths, depending on which version of Outlook and which Windows operating system you are using.

  • Outlook 97 on Windows NT:

To determine the actual .pst file used, from the Tools menu, select Options... , then Autoarchive (as specified above).

Open an AutoArchive file

  1. From the Tools menu, select Services... .
  2. Select Add... , then Personal Folders.
  3. The Create/Open Personal Folders dialog box will open.
  4. Select the folder in which the archive is stored.
  5. Select the file (usually archive.pst) and select Open.
  6. Click OK twice.

You should now see a new set of Personal Folders in the Folder List. If you don't see the Folder List, from the View menu, select Folder List.

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In Windows 2000, what is Active Directory?

Active Directory is a hierarchical collection of network resources that can contain users, computers, printers, and other Active Directories. Active Directory services (ADS) allow administrators to handle and maintain all network resources from a single location. Active Directory is a new feature to Windows 2000 and is not available to Windows 95, Windows 98, Windows NT 4.0, Mac OS, or Unix client software.

Related online NETg tutorials (IU only)

Microsoft Windows 2000 New Features
  Unit: Windows 2000 Essentials
    Lesson: Active Directory

If you haven't used NETg before, see the Knowledge Base document What do I need to know about accessing NETg from the Knowledge Base?

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What are ActiveX controls?

ActiveX controls are small program building blocks that can be used to create distributed applications that work over the Internet through Web browsers. Examples include customized applications for gathering data, viewing certain kinds of files, displaying animation, etc.

The ActiveX programming specification is an extension of Microsoft Windows and the Object Linking and Embedding (OLE) API. ActiveX applications are used mainly with Microsoft's Internet Explorer Web browser.

Like Java applets, programs that use ActiveX controls run on the client computer, not the server.

For more information about ActiveX controls as well as other ActiveX technologies, visit Microsoft's page at:


Related online NETg tutorials (IU only)

Internet and WWW Introduction
  Unit: Basic Internet Services
    Lesson: Multimedia and the Web
      Topic: ActiveX: Components

If you haven't used NETg before, see the Knowledge Base document What do I need to know about accessing NETg from the Knowledge Base?

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What are assembly languages?

An assembly language is a low-level computer language whose instructions correspond directly to the machine language instructions of a specific processor type. In assembly, human-readable mnemonics replace the binary numbers of the machine language. Because each processor type's instruction set is unique, assembly languages are necessarily different among processor types.

In the early days of computing, almost everyone programmed in assembly. It was far easier to work with than any machine language, but still gave the programmer direct access to the CPU. However, as compilers became more efficient, higher-level languages like COBOL and C began to supplant assembly. Though assembly offers a great deal of flexibility and control, programs written in it cannot easily be transported to a different processor architecture. Also, in most high-level languages, each command can correspond to many processor instructions, allowing a programmer to write a program with fewer lines of code. Still, assembly is often the best choice for programs that must interact closely with a computer's hardware.

For more information, consult the following newsgroups:


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What are the Shakespeare systems?

The Shakespeare systems (Ariel, Iago, Kate, and Lear) are intended to provide quick and simple access to electronic mail at IUB. These central Unix computers are dedicated to e-mail, with the addition of a few editing and file transfer programs. Pico, Emacs, and vi are the editing programs available on the Shakespeare systems. Kermit, FTP, and Zmodem are the file transfer programs. The only e-mail program available on the Shakespeare systems is Pine.

The Shakespeare systems are available to all students, faculty, and staff. Each of the four is a pair of Unix computers:

  • Iago, Kate, Lear, and Ariel: The front-end servers are where you use the e-mail program Pine. Normally, you should access them with telnet, but to transfer attachments and other files on your account, use FTP.
  • IMAP1, IMAP2, IMAP3, and IMAP4: The back-end servers, also known as the IMAP servers, are where your electronic mail is actually stored. When you use Pine on Iago, Kate, Lear, or Ariel, it is an IMAP client that accesses your mail here. When you use a workstation-based IMAP client, such as Netscape Messenger, Outlook Express, or Eudora, you access these servers directly. They are not available via FTP or telnet, however.

Iago is paired with IMAP1, Kate with IMAP2, Lear with IMAP3, and Ariel with IMAP4.

If you do not have an account on the Shakespeare systems, you can request one once you have a Network ID. When you do get an account, it will be on only one of the servers. If you use the Shakespeare systems for your e-mail, your address will be:


The current servers are the second generation. In May 2000, all users on the five first-generation computers (Falstaff, Hamlet, Juliet, Ophelia, and Othello) were migrated to their newer counterparts. For information about the differences between the old and new Shakespeare systems computers, see the Knowledge Base document What are the differences between the old and new Shakespeare systems?

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What is Abilene?

Abilene is an advanced backbone network that connects regional network aggregation points, called GigaPoPs. Abilene is a project of the University Corporation for Advanced Internet Development (UCAID); the Abilene network was developed in partnership with Qwest Communications, Nortel (Northern Telecom), and Cisco Systems. UCAID administers the network in support of all its members, including participants in the Internet2 project.

Abilene complements existing research networks already being used by UCAID member researchers and educators. A primary goal of the Abilene project is to support and encourage the development of advanced applications by UCAID university members and, in particular, to support Internet2.

Indiana University is one of a select number of universities that participated in Abilene's Launch Group. IU runs the Abilene Network Operations Center; for more information, see:


For more information about Abilene and IU's involvement, visit:


For more information about UCAID, visit:


For more information about Internet2, visit:


The home page for Internet2 is:


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What is ActiveX?

ActiveX is a term Microsoft uses to describe a number of its COM technologies. However, when most people say "ActiveX", they are really referring to ActiveX controls, Microsoft's answer to Java applets. The two technologies are similar in that they are designed to be downloaded and executed by World Wide Web browsers. The difference is that while ActiveX controls can interface with Microsoft Windows better than Java can, they offer very little cross-platform support.

For more information about ActiveX controls as well as other ActiveX technologies, visit Microsoft's page at:


CNET maintains a library of ActiveX controls, available at the following address:


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What is Ada?

Ada is a high-level programming language with built-in support for concurrent threads of execution. Ada is a fairly close cousin of Pascal and Modula, and was designed to be a general-purpose language for everything from business applications to rocket guidance systems. One of its principal features is that it supports real-time applications. In addition, Ada incorporates modular techniques that make it easier to build and maintain large systems. Ada is often the language of choice for large systems that require real-time processing, such as banking and air traffic control systems.

Ada has been called a bloated language because of its rich syntax and feature set, but that was in the context of the 1980s and before Ada 95. Modern Ada is smaller and less complex than, for example, C++.

Ada is named after Countess Augusta Ada Lovelace (1815-1852) who was a benefactor and collaborator with Charles Babbage. She is credited with having written the first computer program.

For more information on Ada, see:


Another resource is the Ada newsgroup,  comp.lang.ada .

There is a free Ada compiler called GNAT, which is available at:


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What is Adobe Acrobat?

Acrobat is the Adobe Systems family of PDF file (Portable Document Format) editors and viewers.

Acrobat Reader allows you to view and print, but not to edit or create, PDF files. You can download it for free from the Web. A free Web browser plug-in lets you open a PDF file with Acrobat Reader in a Netscape Navigator or Internet Explorer window. You can often download this plug-in, as well as Acrobat Reader, from Web sites offering PDF documents.

The commercial version of Adobe Acrobat includes Acrobat Reader, plus tools for the creation and editing of PDF files and the conversion of other file types to PDF files:

  • PDFWriter creates PDF files from business applications such as Microsoft Word.
  • Distiller converts PostScript output files from programs like Adobe Illustrator into PDF files.
  • SelfSign allows digital signatures.
  • Paper Capture scans paper documents and converts them into PDF files.

Mac OS and Windows users can obtain all Acrobat components. Acrobat Reader is available for a number of Unix implementations. For more information, or to download Acrobat Reader, see Adobe's Acrobat page at:


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What is Adobe Type Manager?

Adobe Type Manager (ATM) is a font management tool available for both Mac OS and Windows, and produced by Adobe Systems. The freeware version, Adobe Type Manager Light, smoothes the on-screen appearance of Type 1 and OpenType fonts, and performs font substitution when documents require fonts that aren't installed. This ensures that fonts look good on screen and in print, even on non-PostScript printers.

You may download ATM Light at the following URL (registration is required):


Note: PostScript font support is built directly into Mac OS X and Windows 2000. ATM Light is required for all other versions of Mac OS, including Mac OS X Classic, as well as for previous versions of Windows. It is also required for Windows 2000 if you use Adobe's multiple master typefaces and want to create custom font instances.

A commercial version of the program, ATM Deluxe, expands upon ATM Light's capabilities. For more information about ATM and Adobe's other font utilities, visit the Adobe Type Library page at:


Note: ATM is also the acronym for Asynchronous Transfer Mode, Automated Teller Machine, and perhaps other technologies. See the Knowledge Base document What is ATM?

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What is AFS?

AFS stands for the Andrew File System, a distributed file system. AFS is conceptually similar to NFS (Network File Server) in that it allows you to share disk space among hosts, but AFS accomplishes this in a different way.

AFS is a global file system that lets all AFS participants on the Internet share one logical file space. The root level directory is /afs, with Internet domains such as indiana.edu descending from there. For example, /afs/umich.edu/... could be a directory. This effectively allows file sharing across the Internet without the use of FTP, and without the localized restrictions of NFS.

UITS now offers the AFS for researchers who require AFS functionality specifically for projects where collaboration with remote AFS sites is critical. AFS is not intended to be used for general data storage at IU. If you use AFS at IU and have an AFS client installed, you can simply change directories on your workstation to a remote collaborator's AFS space located anywhere in the world.

AFS started life as a project at Carnegie Mellon University in Pittsburgh. Some of the main players involved in the development later started a company called Transarc Corporation to market the product. Transarc was acquired by IBM and is now a wholly owned subsidiary.

In addition to the AFS, IU offers a rich suite of distributed storage services such as the Common File Service (CFS) and the Massive Data Storage Service (MDSS).

For more information about AFS, visit:


To see the AFS FAQ, visit:


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What is AGP?

Available on the latest motherboard designs, AGP (Accelerated Graphics Port) is the specification for a new type of video card interface that allows the video card to access system memory (RAM) directly over a very high-speed connection (up to 1.07GB per second at the current 66 MHz system clock speed). This allows four times more bandwidth than with the PCI bus.

The main advantage to AGP is its economic solution to the memory requirements of accelerated 3D video. Video cards traditionally use their own on-board memory for storing images, which allows the video hardware direct, rapid access. With the recent advent of 3D accelerator video cards, the need for video RAM has increased dramatically, since 3D acceleration requires the storage of texture maps, images that are applied to the modeled 3D surfaces. Some of these texture maps can be very large.

While adequate performance can be achieved using the RAM on the video card, it is more economical if the system RAM stores texture maps, since it can accommodate other system needs when not required by the video hardware. Dedicated RAM mounted on the video card cannot be used for purposes other than video.

For more information, see:


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What is AirPort?

Introduced by Apple Computer in 1999, AirPort is a wireless networking technology based on the IEEE 802.11 DSSS standard. There are actually two AirPort products: the AirPort Base Station and the AirPort Card. The Base Station is a wireless hub through which as many as 10 computers may communicate at up to 11Mbps. The Base Station can extend the network to a LAN or the Internet through its built-in Ethernet or modem port.

With the AirPort Card installed, a Macintosh may participate in an AirPort network or any other wireless LAN that conforms to the 802.11 DSSS standard. Models that support AirPort include current iMac models, the iBook, the AGP-based Power Macintosh G4, the G4 Cube, and PowerBook models introduced in 2000 or later. There are third-party AirPort-compatible cards that you can install on older computers. In particular, see the WaveLAN products available from ORiNOCO Wireless:


Both the Card and the Base Station have a range of about 150 feet and are not limited to line-of-sight. The network can even be sustained through closed doors and walls. However, the range and quality of the connection will be affected by the surrounding building material.

For more information about AirPort, visit:


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What is AIX?

AIX is IBM's Unix implementation, which it develops for a number of its products, notably the IBM SP series. Other manufacturers, such as Motorola, also produce hardware that runs AIX. AIX incorporates elements of System V, BSD, and OSF/1, but includes enough unique features to make using, and especially administering, AIX somewhat different from working with other Unix implementations. Nevertheless, recent versions are compliant with most Unix standards.

For more information about AIX, visit the following pages at the IBM Web site:


Also, read the newsgroup comp.unix.aix.

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What is an ACPI BIOS?

ACPI is an acronym that stands for Advanced Configuration and Power Interface, a power management specification developed by Intel, Microsoft, and Toshiba. ACPI support is built into Windows 98 and later operating systems. ACPI is designed to allow the operating system to control the amount of power provided to each device or peripheral attached to the computer system. This provides much more stable and efficient power management and makes it possible for the operating system to turn off selected devices, such as a monitor or CD-ROM drive, when they are not in use.

ACPI should help eliminate computer lockup on entering power saving or sleep mode. This will allow for improved power management, especially in portable computer systems where reducing power consumption is critical for extending battery life. ACPI also allows for the PC to be turned on and off by external devices, so that the touch of a mouse or the press of a key will "wake up" the machine. This new feature of ACPI, called OnNow, allows a PC to enter a sleep mode that uses very little power.

In addition to providing power management, ACPI also evolves the existing plug-and-play BIOS (PnP BIOS) to make adding and configuring new hardware devices easier. This includes support for legacy non-PnP devices and improved support for combining older devices with ACPI hardware, allowing both to work in a more efficient manner in the same computer system. The end result of this is to make the BIOS more plug-and-play compatible.

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What is anonymous FTP?

Many universities, government agencies, companies, and private individuals have set up publicly accessible archives on the Internet. There are thousands of these sites that contain myriad programs, data files, and informational text. Maintainers of such sites establish public directories and files that you may access via FTP, usually in a directory named pub. You can often find specific directions or information about the site in greeting messages or files with names like README.

You can use an FTP client such as Hummingbird FTP for Windows or Transmit for Mac OS to connect to an anonymous FTP site, or you can use FTP from the command line in Unix. For more information, including specific commands and more detailed instructions, see the Knowledge Base document What is FTP, and how do I use it to transfer files? Typically you will need to use the username anonymous and an arbitrary password. Most sites will ask you to enter your e-mail address as the password. If your login is successful, you can then browse the public directories on the other computer.

You can also use anonymous FTP conveniently with your Web browser. For example, to connect to mirrors.aol.com, use the URL:


Remember that anonymous FTP is a privilege granted by the organization that owns the computer to which you are connecting, and you should show good manners in your usage. Don't transfer files you don't need or an excessive amount of material, and try to restrict your transfers to off-peak hours. Many FTP sites are used very heavily, and you may need patience to connect.

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What is ANSI?

ANSI stands for the American National Standards Institute, a general standards organization that facilitates the establishment of standards for many areas, including computing. You may have heard of ANSI C, for instance. The staff at ANSI don't actually make standards themselves, but they coordinate organizations in the United States that do.

Among the standards on which ANSI has worked is a set of cross-platform printer control codes. Pine, for example, sends print commands to your local computer in this form when you configure Pine to use the "attached-to-ansi" printing method. This allows you to print e-mail messages on a printer attached to your local computer even if it is not directly connected to the network. The tricky part is that your communications program must be able to understand the ANSI print codes that Pine sends. Because these ANSI print commands are part of a national standard, many communications programs know what to do with them, but many do not.

For more information, visit the ANSI Web page at:


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What is APAN?

The Asia-Pacific Advanced Network (APAN) is a nonprofit international consortium of numerous Pacific Rim countries. Established in 1997, APAN is intended to be a high performance network for research and development on advanced applications and services. For more information about APAN, see:


What is APL?

A Programming Language (APL) is an array processing language that is used for mathematical modeling and for describing procedures in the processing of information. APL is also increasingly being used for commercial applications. APL interpreters exist for many platforms, including Mac OS, Microsoft Windows, and Unix.

You can find more information about APL at:


What is AppleTalk?

Introduced in 1985, AppleTalk was once the dominant networking protocol for LAN-based Mac OS computers. Primarily used for file sharing and access to network printers, AppleTalk works over several media, including Ethernet, LocalTalk, and modems (with ARA). Though it is receding in importance as TCP/IP becomes the de facto cross-platform networking standard, it is the only protocol all Macintoshes, regardless of age, understand.

For a detailed overview of the AppleTalk protocol, refer to the AppleTalk chapters of Apple's publication, Inside Macintosh: Networking with Open Transport, available online at:


For an even closer look, review Inside AppleTalk, available in PDF format from:


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What is Archie?

Archie is a client program that searches ftp sites. It looks for a specific file you have requested and reports a list of locations where that file is available. You then select one of the hostnames to see instructions about how to retrieve the file. You can access Archie on the World Wide Web at a number of sites, including the following URL:


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What is ARNS?

ARNS (A Remote Network Server) is software that allows your Mac OS computer to use AppleTalk services (such as printing and file sharing) over a modem connection.

ARNS allows you to establish a connection with an AppleTalk network over a PPP or SLIP connection, though ARNS runs at significantly slower speeds. Once an ARNS connection is up and running, you'll be connected to an AppleTalk network where you can access servers and printers. For more information about ARNS, see the University of Melbourne's ARNS page at:


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What is ASCII?

Usually when the term "ASCII" is used, it is describing a text document. If a file is described as ASCII text, this means you can view the contents of the file, change it with an editor, or print it with a printer. It does not contain any special embedded control characters.

"ASCII" is an acronym that stands for American National Standard Code for Information Interchange. It is a widely used standard for encoding text documents on computers.

Every letter, number, and punctuation symbol has a corresponding number, or ASCII code, in this system. For example, the character for the number 1 has the code 49, capital letter A has the code 65, and a blank space has the code 32. This encoding system not only lets a computer store a document as a series of numbers, but also lets it share such documents with other computers that use the ASCII system.

Documentation files or program source code files are usually stored as ASCII text. In contrast, binary files, such as executable programs, graphical images, or word-processed documents, contain other characters that cannot be normally displayed or printed, and are usually illegible to human beings.

The format of a file, whether ASCII or binary, becomes important when you are transferring files between computers. For example, when using FTP, you can transfer ASCII text files without any special consideration. To exchange binary files, however, you must enter the command set binary or otherwise prepare the client to transfer binary files, so that the computer will correctly transmit the special characters in the file. See the documents listed below for more information about how to correctly transfer files.

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What is Asynchronous Transfer Mode (ATM)?

Asynchronous Transfer Mode (ATM) is a transfer protocol with the following characteristics:

  • It is scalable and flexible. It can support megabit to gigabit transfer speeds and is not tied to a specific physical medium.
  • It efficiently transmits video, audio, and data through the implementation of several adaptation layers.
  • Bandwidth can be allocated as it is needed, lessening the impact on and by high-bandwidth users.
  • It transmits data in fixed-length packets, called cells, each of which is 53 bytes long, containing 48 bytes of payload and 5 bytes of header.
  • It is asynchronous in the sense that although cells are relayed synchronously, particular users need not send data at regular intervals.
  • It is connection-oriented, using a virtual circuit to transmit cells that share the same source and destination over the same route.

For more information, visit the Web page of the ATM Forum, a non-profit organization of ATM developers:


Also see the Cell Relay Retreat, which provides many useful links and archives:


Note: ATM is also the acronym for "Adobe Type Manager". For more information, see the Knowledge Base document What is Adobe Type Manager?

Also see:

What is ATM?

Among other things, ATM stands for Asynchronous Transfer Mode and Adobe Type Manager. Asynchronous Transfer Mode is a multipurpose networking technology designed for the efficient transmission of data, voice, and multimedia streams. Adobe Type Manager is a font management tool produced by Adobe Systems.

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What is A/UX?

Primarily based on System V, revision 2, A/UX is a Unix implementation developed by Apple Computer. It runs only on older Macintoshes, specifically certain models with 68030 and 68040 (FPU required) processors. It is not compatible with PowerPC-equipped computers, nor does it run on 68k computers in the LC, Performa, Duo, and Powerbook lines. It is a true Unix, but uses the Mac OS 7 Finder and supports most 68k Mac OS applications. It comes with a standard set of Unix utilities, including an implementation of the X Window System. Some GNU applications have also been ported to A/UX.

Though Apple has discontinued development for A/UX, it is still available from a few resellers. However, because it requires a Unix license, it is not inexpensive, nor is it particularly easy to find. For a forum of discussion about A/UX, visit the comp.unix.aux newsgroup.

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What is awk, and how do I use it?

Although awk is a complete pattern scanning and processing language, it is most commonly used as a Unix command-line filter to reformat the output of other commands. For example, to print only the second and sixth fields of the date command (the month and year) with a space separating them, at the Unix prompt, you would enter:

  date | awk '{print $2 " " $6}'

To read the online manual (the man page) for awk, at the Unix prompt, enter:

  man awk

Also, consult the newsgroup comp.lang.awk.

The GNU Project has also produced a version named gawk. For information about gawk, at the Unix prompt, enter:

  man gawk

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What is the ATX form factor?

Form factor refers to the physical size and shape (according to outside dimensions) of a computer device. It is most often used to describe the size of circuit boards, especially the motherboard and expansion cards.

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ATX form factor

The ATX form factor is a replacement for the older AT and baby AT form factors. Invented by Intel in 1995, it incorporates the first major change in the layout of PC motherboards to occur in years. The ATX motherboard rotates the orientation of the board 90 degrees. This allows for a more efficient design, with disk drive cable connectors closer to the drive bays and the CPU closer to the power supply and cooling fan. All Intel motherboards currently produced are ATX motherboards. Generally speaking, an ATX motherboard is required to use the newest Intel processors. Because of this and the general improvements that ATX brings, the ATX form factor is the form factor of choice for both commercial mass-production systems and for home PC builders.

The ATX form factor involves changes not only to the motherboard design and layout, but also to the case and power supply as well. Improvements and changes are listed below:

  • Integrated I/O port connectors
  • Integrated PS/2 mouse connector
  • Reduced drive bay interference
  • Reduced expansion card interference
  • Better power supply connector
  • "Soft Power" support
  • 3.3V power support
  • Better air flow
  • Improved upgradability

For additional information on the ATX form factor, please see the following sites:


ATX motherboard and case design

The ATX case looks very similar to the baby AT case, except that the holes in back for ports and keyboard and mouse connectors have been altered to allow for the different design of the ATX motherboard. In particular, the ATX motherboard has integrated I/O ports mounted directly on the edge of the board. Most ATX motherboards have, from left to right, stacked keyboard and mouse ports, stacked USB ports, printer and game ports along the top, and two serial ports along the bottom. This design can differ based on the manufacturer of the motherboard. This allows for a much more effective use of interior case space, and decreases the number of cables and connectors that can become disconnected or damaged.

ATX cases often have more drive bays for a given case size. For example, a mid-tower ATX case will often have more available drive bays than a baby AT case of the same size. The ATX case design also generally provides easier interior access to expansion bays.

The ATX power supply is different in a number of important ways. ATX power supplies and motherboards function at 3.3 volts or lower, instead of 5 volts, reducing motherboard cost, energy consumption, and heat production. The fan on the power supply is reversed so that it blows air into rather than out of the case, which helps keep the case clean and reduces heat buildup. This is necessary due to the high heat produced by the new generation of Intel Pentium II/III and AMD processors. The ATX power supply is turned on and off using electronic signaling instead of a physical toggle switch. This allows the computer to be turned on and off using software control, thus improving power management and energy-saving features. Because of this, ATX power supplies must be matched with ATX motherboards.

For additional information on the ATX case design, please see the following:


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What does form factor mean?

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