ACCC Glossary of Computer Terms, T-Z

Contents

T | U | V | W | X | Y | Z

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List of Defined Words

+--+ T +--+

T1

 

A Bell system facility for transmission of data through high-speed leased telephone lines. T1 lines operate at 1.544 Mbps (24 telephone channels), and T3 at 44.736 Mbps (equivalent to 28 T1 lines); see also DS-1 and DS-3.

Tape Drive

An input/output device similar to an audio tape recorder which reads or writes computer data on magnetic tape.

TCP

Transmission Control Protocol: A transport layer protocol in the Internet protocol suite which is concerned with the transmission of commands between hosts, providing reliable communication between the hosts on the network. It keeps track of whatever is sent, breaking it up into smaller packets if necessary, and retransmitting when required. It uses the IP protocol to actually send the information. TCP isdefined in RFC 793. It is connection-oriented and stream-oriented, as opposed to UDP.

TCP/IP

Transmission Control Protocol/Internet Protocol: A set of protocols used to allow computers to share resources across a network. TCP/IP was originally developed for ARPANET, but is now in much wider use. These protocols support file transfer, remote logons, and electronic mail between users on the different host computers on the network. TCP and IP are actually a protocols in the Internet suite, but the designation TCP/IP is commonly used to describe the entire suite, since TCP and IP are the best known of the protocols in the Internet suite, which also includes FTP, TELNET, and SMTP. See also Internet protocols. For a very readable description of TCP/IP and how it's used to carry information through networks, see Introduction to Internet Protocols. 

TELNET

The network terminal protocol: A protocol in the Internet suite for opening interactive sessions from a local host computer to another computer on the network which is physically remote and which may have a different operating system than the local host. See TCP/IP.

Terminal

A computer input/output device which allows a person to interactively communicate with the computer. Most terminals have typewriter style keyboards and a CRT screen for displaying your commands and the computer responses. Real "terminals" are rare these days; most people use personal computers running terminal programs now.

Terminal Emulation Program

Software, which is generally run on personal computers, which performs terminal emulation, allowing the computer to be used as a terminal for interactive use of another computer. See the Network Services Kit. See also emulation.

TeX

A text formatting package: TeX is a typesetting package developed by Donald Knuth which is particularly well suited for scientific, mathematical or other technical writings. See TeX and LaTeX. See also LaTeX.

Text Editor

An interactive program that allows you to input, update, delete and store information on the computer. The information may be programs, data, or actual textual material such as letters or dissertations. See the Inform Text Editors menu.

Text-formatting

The (automatic) layout of a text for the printed page. When used in conjunction with text editors, text formatting programs allow computers to be used for preparing documents: letters, papers, manuscripts, theses, resumes, and the like.

Text wrap

A text formatting term: The ability to wrap text around graphic images on a page layout. Some desktop publishing systems have an automatic text wrap feature that will shorten lines of text when a graphic image is encountered. In other systems, you need to change the length of lines by changing the column margins or by inserting hard carriage returns to shorten the lines.

the

the (The Hessling Editor) is an XEDIT clone for UNIX that is available on all the ACCC UNIX workstations.

TIFF Tagged Image File Format

The most portable file format for color, grayscale, and line-art images.

Tigger

The ACCC's IBM RS/6000 UNIX workstation, tigger.cc.uic.edu; any UIC menber of the UIC faculty or staff may have a personal account on tigger. For more information, see the ACCC Accounts, Machines, Passwords page.

Time-out

A time-out occurs when one network device expects to hear from another but does not receive the reply within a specified period of time. After a time-out, the information is either retransmitted or the link between the two devices is broken.

Token passing or token ring

A transmissions protocol in which a token (a control block) circulates around a ring, passing from one machine on the ring to the next. When a machine on the ring wants to transmit, it takes control of the token and attaches the information to be transmitted to the token. Each machine down the ring examines the token, and receives it if is its destination or sends it to the next machine if it is not. When the transmission is received at its destination on the network, the token is sent on again, empty. Because there is only one token in the ring, there cannot be data collisions in token ring network. Very similar to an IEEE 802.5 LAN.

Track

A unit of measure for space on a disk. On our MVS disk devices (IBM 3350's), a track holds 19,069 bytes.

Tree

A data structure similar to a linked list, except that each element carries with it the address of two or more other elements, rather than just one. Trees are an efficient way of storing items which must be searched for and retrieved quickly.

TSO

Time Sharing Option: An interactive system that the ACCC used to run under MVS on its IBM 3090 mainframe..

TSP

Time Series Processor: A software package designed to develop and use econometric models with time-series data.

Twisted pair

A type of data communications cable that consists of pairs of insulated wires which have been twisted together in a regular spiral pattern. A relatively low-speed transmission medium which is commonly used for telephone and, increasingly, for data networks. See also 10BaseT.

Typeface

A text formatting term: The degree of slant or boldness in a font, examples are Normal (also known as Roman), Italic, Boldface, Boldface Italic and Slant. (Note: Sometimes "style" is used to indicate degree of boldness or slant, and "typeface" used for the overall appearance.) See also Style.

+--+ U +--+

UICMVS

Was the BITNET node name of the UIC ACCC's MVS operating system.

UICVM

UICVM.UIC.EDU was the Internet domain name of the ACCC's VM/CMS system.

 

UNI

User Network Interface; ATM protocol for the interface between ATM users (end-stations) and an ATM network; see also NNI.

UNICOS

Cray Research's original interactive operating system for the Cray X-MP supercomputers. UNICOS provides limited interactive UNIX services for debugging and interactive graphics.

Unit

A measure of computer usage; at the ACCC, each unit is worth approximately $0.0833. See also Service Unit.

UNIX

A multi-tasking operating system frequently used on workstations. Various versions of UNIX run on the ACCC's UNIX workstations: tigger, icarus, and borg. See the Inform Getting Started with UNIX menu.

 

URL

Universal Resource Locator. The particular format for hypertext pointers used by HTML on the WWW.

USENET

Usenet is the set of people who exchange articles tagged with one or more universally-recognized labels, called "newsgroups" (or "groups" for short). Usenet began in 1979, and is one of the largest and oldest cooperative networks. See the ACCC Netnews / Usenet page.

User

Any person who uses a computer or a particular software or hardware system. More specifically, user is sometimes used to refer to the user's computer identification tag, used as an address for electronic mail. Its form depends on individual computer center conventions.

Userid

The login ids on the ACCC's retired VM/CMS system, which were a U followed by a five digit number greater than 08191. See also User. See also Netid.

Upload

To transfer information stored in the user's system to a remote computer system.

UUCP

UNIX-to-UNIX Copy Program: A protocol for communications between UNIX systems, and also a UNIX based network that was closely associated with USENET.

uuencoding

Before MIME, uuencoding was used to transfer binary files or files with longer record lengths by electronic mail. See also xxencoding.

+--+ V +--+

V.22-bis, V.32 or V.32-bis

Modem specifications. For more information, see internet.com's PC Webopaedia entry CCITT. See also CCITT.

VAX

A mainframe computer manufactured by Digital Equipment Corporation (DEC).

 

vBNS

very high-speed Backbone Network Service, the NSF's high-speed ATM research network to replace NSFNet. Connects the five NSF supercomputer centers and four Internet NAPs; UIC was the first additional institution to join.

VDT

Video Display Terminal: an input/output device with a display screen and an input keyboard.

Vector processing

Processing all the elements of a vector simultaneously. In order to do this, the computer has to have one or more vector pipes. The length of the pipe differs between supercomputers.

Verso Page

A text formatting term: The left-hand page of a duplex document with facing pages. See also Recto page.

Vertical justification

A text formatting term: The ability to adjust the spacing between lines of text (leading) in fine increments to make columns and pages end at the same point on the page. The TeX typesetting system can do this.

Video CD-ROM

A CD-ROM standard that uses MPEG to store up to 74 minutes of digital video on one CD-ROM.

Video for Windows

Microsoft's system-level Windows software architecture; similar to QuickTime.

Virtual

Virtual refers to anything that seems real but is actually simulated by the operating system. For example, virtual memory is really disk storage made to look like real memory.

VM, VM/ESA, VM/SP

Virtual Machine, Virtual Machine/Enterprise Systems Architecture, and Virtual Machine/System Product. The ACCC ran the VM is the operating system its IBM 3090 mainframe computer. Under VM, each person is considered to be the operator of his own "virtual" machine, the functional equivalent of a real machine.

VMARCHIVE and VMBACKUP

The archive and backup software that was run on CMS.

VMS

A mainframe operating system generally used on VAX machines.

VSAM

Virtual Storage Access Method: A very fast random access file system for MVS that allows non-sequential retrieval of records based on the value of keys within them.

VT100

A common type of terminal for use with mainframe computers. Most communications programs which allow PC's to communicate with mainframe computers allow the PC to emulate a VT-100 terminal.

VTAM

Virtual Telecommunications Access Method: a set of program that control communication between nodes and applications programs running on a host system.

+--+ W +--+

WAIS:

Wide Area Information System. A query system designed by Thinking Machines. Many Web browsers can query WAIS databases, and thereby do full-text searches on a variety of information.

WAN

Wide Area Network: a network spanning a wide geographic area. See also LAN.

WATBOL

WATerloo COBol: A student version of COBOL written at the University of Waterloo. WATBOL used to be available on CMS.

WATFIV and WATFOR77

Student versions of FORTRAN written at the University of Waterloo. WATFIV has been replaced by a newer version, WATFOR77. WATFIV and then WATFOR77 were available on CMS; neither are available at UIC anymore.

WAV

Popular format for storing audio files in Windows.

WDSF

See ADSM.

WebMail

Eudora is an email reading program, one of three that are supported by ACCC at UIC. (Eudora for Windows and Macs and Pine for UNIX are the other two.)

Widows

A text formatting term: The last line of a paragraph is called a widow when it is forced onto a new page by a page break and is separated from the rest of the paragraph. See also Orphans.

Word Wrap

A text formatting term: Automatic adjustment of the number of words on a line of text, as they are being entered and displayed on the screen, to match the margin settings. The carriage returns that result from automatic word wrap are called "soft" carriage returns to distinguish them from the "hard" carriage returns, which result when <enter is pressed to force a new line. Word wrap is usually available in the "what you see is what you get" word-processing systems which are common on microcomputers.

Workstations

Micro or minicomputers which are nodes on a computer network and which can be used to perform a number of tasks by using their own resources as well as by tapping into the other devices which are shared on the network.

WPG

WordPerfect graphic file format.

WYLBUR

See SUPERWYLBUR

WYSIWYG

A text processing term: What-You-See-Is-What-You-Get (pronounced "Wizzywig") is a term used to describe systems which display full pages of formatted text and graphics on the screen. Some programs are more WYSIWYG than others. The term is also used to describe word processing programs that display different fonts on the screen.

Word Processing

The use of computers to prepare documents. See the Inform Word Processing, Editing, and Printing major topic.

WWW

A network of information servers, principally the ones using HTTP to serve up HTML documents. The servers are linked, not in any tight or formal sense, but because an HTML document from one server might contain pointers to documents on many other servers.

+--+ X +--+

XEDIT

The IBM supplied text editor used for full screen editing under CMS. We no longer have CMS, but we do have the (The Hessling Editor), an XEDIT clone for UNIX, on all the ACCC UNIX workstations, and we have KEDIT on all our public personal computers.

Xerographic printing process

A text formatting term: In the xerographic printing process, printed output is produced using a imaging process. A light source (generally a laser) scans the image onto a photosensitive belt. The list discharges areas on the belt where the image is not to appear. A dry toner of carbon mixed with a plastic binder is then picked up by the remaining charged areas of the belt. The toner is then transferred to a sheet of paper and melted onto its surface.

XON/XOFF

A protocol for controlling the flow of data.

X Windows

A distributed, network and device independent multitasking windowing and graphics system originally developed at MIT for communications between X terminals and UNIX workstations. See the Inform X Windows menu.

xxencoding

Xxencoding is another encoding method that allows you to transfer binary files or files with longer record lengths by electronic mail. See also MIME and uuencoding.

+--+ Y +--+

Yale Ascii Communications Program

Software that ran on IBM Series/1 minicomputer which acted as an interface between the user's terminal and Full Screen VM/CMS.

YTERM

The YTERM terminal emulation and communications program provides error checking file transfer and terminal emulation for IBM compatible DOS machines.

+--+ Z +--+ 

ZIP

Data compression and file packaging programs for personal computers. An example is PKZIP which is available on the Academic Computing and Communications Centers public personal computers.