There are 206 names in this directory beginning with the letter H.
1. A simple hypertext markup language. 2. An indication of a hexadecimal number; 09h is hexadecimal 9.
Hierarchical menu. A pull-down menu that has sub-menus. The sub-menus are indicated by arrows. Putting the pointer on the item that has an arrow opens up the sub-menu. Sometimes a sub-menu will have arrows leading to sub-sub-menus.
Hardware; the physical part of a computer system; the machinery and equipment. Software means the programs that tell the computer what to do.
H1-B Visas may be used to bring a nonimmigrant worker to the United States if the employee is able to fill a position in a specialty occupation for professional position. The employee must prove that he/she is qualified for the position, holding a foreing degree equivalent to that required in the U.S. The visa can be granted from 1-6 years after which time he/she must reside outside the U.S. for at least one year.
1. To use ingenuity and creativity to solve computer programming problems, to overcome the limitations of a system and expand its capabilities. 2. A solution to a programming problem. 3. A clever yet harmless practical joke.
1. One who is knowledgeable about computers and creative in computer programming, usually implying the ability to program in assembly language or low-level languages. A hacker can mean an expert programmer who finds special tricks for getting around obstacles and stretching the limits of a system. 2. To some people it means an unconventional programmer or one who is not formally trained, or one who jerry-rigs programs (making temporary fixes that are not well-done). 3. At MIT, a “hack” means a practical joke, especially one that requires intelligence and technological skill to carry out.
Hardware Abstraction Layer. A translation protocol in Windows NT for porting NT to another platform.
A logic circuit in the arithmetic and logic unit of a computer that adds two one-digit binary numbers, producing a result bit and a carry bit. A half-adder consists of an XOR gate and an AND gate; a full-adder consists of half-adders and other switches.
A communications channel which transmits data in either direction, but only one direction at a time.
A reproduction of a grayscale image which uses dots of varying size or density to give the impression of areas of gray.
Writing a program in a programming language, rather than using high-level programming tools to create the program.
In graphics programs, a pointer shaped like a hand that is used to select and move things onscreen.
A scanner that is held in the hand and passed across the image to be
scanned. Hand-held scanners are less expensive than desktop scanners, but
require a steady hand to get a clear image.
scanned. Hand-held scanners are less expensive than desktop scanners, but
require a steady hand to get a clear image.
In graphics programs, handles are little squares that appear at the edges of selected images or text blocks, which can be used to change the size, shape, or orientation of the selected material.
The transfer of an ongoing wireless call from one transmission site to another without disconnecting the call.
The greeting between two modems, which can be heard as an annoying grating and squealing sound. The handshake introduces the modems to each other so they can establish the transmission speed they will use, whether they will use error correction or compression, and other agreements about how they will exchange information.
The exchange of signals back and forth over a communications network to establish a valid connection between two computers.
A paragraph in which the first line begins at the left margin, and the rest of the lines are indented. Hanging indents are sometimes used when the first line begins with a number and a space before the text, and succeeding lines are indented to where the text begins in the first line.
A paragraph with a hanging indent; every line but the first line is indented from the left margin.
Booting a system from power off. Sometimes a computer which is “locked up,” or “frozen,” must be turned off and on again to clear the memory before it can be operated. A soft boot is restarting the computer without turning the power off.
The main device that a computer uses to store information. Hard disks are rigid aluminum or glass disks about 3.5″ in diameter in a personal computer, and smaller in a laptop. They are coated with ferromagnetic material and rotate around a central axle. Data is transferred magnetically by a read/write head. A hard disk drive for a personal computer may contain as many as eight hard disks, rotating around the same axle. Most hard disks are permanently connected to the drive, but there are removable hard disks. Hard disk access time (the amount of time it takes to retrieve data) is measured in milliseconds.
A hyphen that is always set; for example, the hyphen in “cost-effective.” A soft hyphen, by contrast, will only be set when a word that is not normally hyphenated falls at the end of a line, and must be broken for proper type spacing.
hard page break
A page break inserted by the user with a command in the program. A page will end at a hard page break even if it only has a few lines on it; the bottom of the page will be left blank.
A hard return sends the cursor down to the next line, and is made by pressing the return key; it is equivalent to a carriage return on a typewriter.
A space character that is treated by the machine like a letter, used when the typesetter does not want a line break in the middle of a phrase, multiple-word proper name, or series of ellipses. Also called a fixed space.
Referring to instructions that are written directly into a program and therefore cannot be easily modified, rather than instructions that can be modified by a user.
The hardware is the physical part of a computer system; the machinery and equipment. Compare with software
Handshaking signals between two computers which are carried by voltage levels or pulses on wires. A software handshake communicates the same information by way of characters inserted into the data stream. Computers use handshaking signals to indicate to each other when to start or stop sending data.
Sending signals between two computers that indicate to each other when to start or stop sending data. The handshaking signals are carried by voltage levels or pulses on wires. A software handshake can communicate the same information using characters inserted into the data stream.
A device that monitors the hardware circuits of a computer for the purpose of checking the performance of the system.
The CPU family which is the basis for a particular machine. Each hardware platform has its own machine language, and all software used by it must use that language. Some examples of hardware platforms are: x86 (Intel CPU: used by PCs); 680×0 (Motorola CPU: used by Macs); PowerPC (Apple, IBM, Motorola CPU: used in PowerMacs); VAX (Digital minicomputers); S/370 (IBM mainframes); Unisys (Unisys mainframes); SPARC (Sun); CDC (CDC mainframes and midrange computers); PA-RISC (HP workstations and minicomputers).
1. Having a direct physical connection, such as by wire or cable. 2. Controlled by wiring of the hardware, rather than by software.
Undesired harmonic frequencies that result from irregularities in a transmission line.
A powerful, fast and flexible data retrieval program that allows searchers to use keywords to quickly locate files. Search results display lines from the files containing the search string and full paths to the files. The Harvest site (http://harvest.cs.colorado.edu/) provides detailed instructions and online help.
ASCII character 35: # . Also called number sign, because it is used to stand for “number;” or pound sign, because it is used to stand for “pound.”
The standard set of commands used by the Hayes modem, which are widely used by other modems (called Hayes-compatible).
Hayes Microcomputer Products, Inc.
A modem manufacturer in Atlanta, GA. Many modems are designed to be compatible with Hayes modems, which have set a standard.
Intelligent modems for personal computers from Hayes Microcomputer Products, Inc., Atlanta, GA. The commands used by the Hayes modems have become an industry standard and are now used by many other modems.
Hayes Standard AT Command Set
The set of commands used by Hayes modems, which became an industry standard and are widely used by other modems as well.
Human-Computer Interaction. The study of how humans interact with computers, used to design computers which are easy for humans to use.
Head Disk Assembly. The mechanical parts of a disk drive, including the read/write heads, platters, and other non-electronic components.
High-Speed Digital Subscriber Line. A transmission method that makes it possible to transmit data at high speeds over ordinary copper telephone wires. See ADSL.
Hexadecimal. The base 16 numbering system, sometimes used as a short way of representing binary numbers. The digits 0-9 are used, plus the letters A-F which stand for numbers 10 to 15. The farthest-right digit is the ones place; the digit next to the left is the 16s place; the next place to the left is 16^2 = 256, etc. Each place is 16 times the place immediately to the right of it.
The base 16 numbering system, sometimes used as a short way of representing binary numbers. The digits 0-9 are used, plus the letters A-F which stand for numbers 10 to 15. The farthest-right digit is the ones place; the digit next to the left is the 16s place; the next place to the left is 16^2 = 256, etc. Each place is 16 times the place immediately to the right of it.
Hexadecimal digit. Hexadecimal numbers use the digits 0-9, then A=10, B=11, C=12, D=13, E=14, F=15.
1. High Frequency. Electromagnetic frequencies in the range of 3 to 30 megaherz. 2. Human Factors. The physical and psychological requirements of human beings that must be considered when designing computer systems and programs, in order to make products that are practical, efficient, and easy to use.
Hierarchical File System. A system in which data is stored hierarchically in directories and subdirectories (as in DOS), or folders within folders (as in Macintosh). Most operating systems have hierarchical file systems.
Hypertext General Markup Language. A formatting code for marking up text files, which makes up part of SGML.
A file that ordinarily is not visible in the file directory and cannot be accessed by unauthorized users. Some operating system files are hidden, to prevent inexperienced users from inadvertently deleting or changing these essential files. Some file utility programs also allow users to hide files. In DOS and DOS-related operating systems, the dir command lists all files except hidden files. In versions of DOS since 5.0, the command dir /ah will list hidden files. In UNIX, the ls command lists all files except hidden files (files whose names begin with a dot); the command ls -al lists the hidden files.
In a graphical user interface, a menu selection that instructs the computer not to show certain things on screen; for example, hard returns, the toolbox, guide lines, etc. The opposite command is “show . . . “.
hierarchical file system
(HFS). A system in which data is stored hierarchically in directories and subdirectories (as in DOS), or folders within folders (as in Macintosh). Most operating systems have hierarchical file systems.
(Also called h-menu). A pull-down menu that has sub-menus. The sub-menus are indicated by arrows. Putting the pointer on the item that has an arrow opens up the sub-menu. Sometimes a sub-menu will have arrows leading to sub-sub-menus.
Dividing a network into a hierarchy of smaller networks, and making each level responsible for its own routing. The Internet has three levels in its hierarchy: backbones, mid-level networks, and stub networks. Backbones are responsible for routing between mid-level networks, mid-levels route between sites, and each site does its own internal routing.
Hierarchical Storage Management
(HSM). An automatic system that moves files from hard disk to other storage media after a certain length of time, or according to other specifications of the user.
High Density Floppy Disk. Currently high-density floppy disks are 1.4 MB. Density refers to the amount of data stored per square inch.
ASCII defines code numbers for 128 characters, which are the alphabetic and numeric characters on a keyboard and some additional characters such as punctuation marks. High ASCII includes additional ASCII characters up to 256, which may include foreign language accents, math symbols, trademark and copyright symbols, etc. These characters are not the same on all computers.
high definition television
(HDTV). The next standard in television and video, which will have higher resolution, better color, and better audio. There are both analog and digital versions of HDTV.
high performance addressing
(HPA). A kind of display used on some multimedia notebook computers, that delivers high-quality graphics comparable to Active Matrix (TFT) Displays.
High Performance Computing and Communica
(HPCC). A U.S.government plan to increase people's computer knowledge by creating scientific workstations, experimental systems, and a high-speed network linking government agencies, private companies, and schools with supercomputer systems.
HIgh Performance Parallel Interface
(HIPPI). A high-speed communications bus used over short distances with supercomputers or high-speed LANs. It may be used within a computer room to connect a supercomputer with other computers, routers, and peripherals.
High Performance Serial Bus
A Macintosh and IBM PC serial bus interface standard (IEEE 1394), which provides high-speed communications and can support up to 63 peripherals. It allows devices hooked to it, for example a scanner and a printer, to communicate with each other without having to use the system memory or the CPU.
The high number of dots per square inch required to produce a high-quality image in printing or on a computer display screen. The higher the resolution, the finer the image quality. Good laser or inkjet printers and scanners provide a resolution of 600 dots per inch; high-quality typesetting machines can print at 2,540 dpi.
The first format for recording files and directories on CD-ROMs, which has been replaced by ISO 9660.
High Sierra Format
(HSF). A logical format and file structure for CD-ROMs that paved the way for ISO 9660. As the industry began to evolve many different proprietary CD-ROM formats, the need for a common standard became obvious. A meeting was held at Del Webb's High Sierra Hotel and Casino, in Lake Tahoe, Nevada, at which representatives from various companies worked together to arrive at a standard. The result of this meeting was “Working Paper for Information Processing: Volume and File Structure for CD-ROM Information Exchange (1986),” which became known as the High Sierra Format. Later, HSF was modified and evolved into ISO 9660, the key standard for worldwide acceptance of CD-ROMs.
High-bit-rate Digital Subscriber Line
(HDSL). Or High-speed Digital Subscriber Line. A transmission technology that can send data at high speeds over regular copper telephone lines. Unlike ADSL, HDSL transmits data at the same speed in both directions, typically 784Kbps.
(HD). Having high storage capacity per unit of area. High-density disks store more information than double-density disks, but less than extra-high-density disks. Currently, high-density 3.5″ floppies are 1.4 MB. The 3.5″ high-density floppy disk has an HD logo on it and has two holes at the top. High-density 5.25″ disks are1.2MB.
(HLL). A language for programming computers which does not require detailed knowledge of a specific computer, as a low-level language does. High-level languages do not have to be written for a particular computer, but must be compiled for the computer they will work with. High-level languages are closer to human language than low-level languages, and include statements like GOTO or FOR which are regular words.
high-speed digital subscriber line
(HDSL).A form of DSL, HDSL is a transmission method that makes it possible to transmit data at high speeds (1.544 Mbps in both directions) over ordinary copper telephone wires. See ADSL.
To select text or graphics for moving, editing, or deletion. Text can be selected by dragging the cursor over it; an image by clicking on it. A highlighted area of text appears in a different color from the other text; for example, white with a black background. Highlighted graphics show in other ways.
HIgh Performance Parallel Interface. A high-speed communications bus used with supercomputers or high-speed LANs.
A character set of symbols used in one of the two main Japanese phonetic alphabets, in which each character takes up 1 byte.
1. One visit to a World Wide Web page by a user. Many servers have counters on their home pages to tell how much traffic they are getting. 2. A cache hit is a successful retrieval of data from a cache.
Human Interface Technology Laboratory. The Human Interface Technology Laboratory at the University of Washington, a center of research and development in new interface technology.
Head Mounted Display. A helmet with stereoscopic goggles for the wearer's eyes, and stereo headphones over the ears; used as an interface through which the wearer can experience a virtual reality environment.
A kind of punch card which can be punched with hole patterns in 80 columns and 12 rows.
The earliest automatic data processing system, developed by Herman Hollerith. The Hollerith machine was used to count the United States 1890 census. The data was recorded on hand-punched cards and counted by means of a tabulating machine.
An American inventor (1860-1929). He invented the punched card and the Hollerith machine for tabulation. His machine was used for the U.S. Census of 1890. He formed the Tabulating Machine Company in 1896. In 1911, it merged with several other companies and became the Computing-Tabulating-Recording Company, precursor to IBM.
A method of data storage. The data is stored as a holographic (3-dimensional) image by passing light through light-sensitive crystals that retain the light patterns.
The key in some programs that moves the cursor to the beginning of the current line, or in combination with the control key, moves the cursor to the beginning of the document.
A computing environment in which hardware and system software come from the same vendor.
Originally, a manufacturer of temperature control devices. Honeywell’s Information Systems division became one of the first major computer companies in the United States, producing advanced, high-performance computers. Honeywell took over General Electric computers, then later was taken over by Bull to become part of Bull HN.
A feature of software or hardware that is included in order to provide for future expansion. In programming, for example, a hook may be instructed to call an outside routine, or may allow for entry of a variable. The more hooks, the more the product allows for additions or changes.
Free software that gives a limited sample of how a program works, intended to hook the user into buying the full version.
In communications routing, a transmission from one network node to another. A message sent over a long distance may need to make a series of hops to get from its source to its destination.
Rear Admiral Grace Hopper, U.S. Navy (1906-1992); originator of the concept of the compiler, and developer of the first commercial high-level language, which evolved into COBOL.
Electricity travels one foot in a nanosecond (a billionth of a second). The speed that electricity can travel limits the speed at which signals can travel in an electric circuit, and therefore limits the possible speed of a computer.
An application used by many different kinds of organizations, such as word processing or bookkeeping software. Contrast vertical application.
The number of pixels per horizontal line, or the number of columns in a matrix.
Adding more computer systems to a multiprocessing environment, in contrast to vertical scaling, in which more processors are added to the same computer system.
horizontal scan frequency
The number of scan lines per second displayed on a monitor screen, expressed in kilohertz.
horizontal scan rate
(HSR). The number of scan lines displayed per second on a computer monitor, expressed in kilohertz (kHz).
Software used by many different kinds of organizations, such as word processing or bookkeeping software. Contrast vertical software.
1. A computer connected to a network, that provides data and services to other computers. Services may include data storage, file transfer, data processing, e-mail, bulletin board services, World Wide Web, etc. 2. A multiuser computer that has terminals attached to it.
1. A computer connected to a network, that provides data and services to other computers. Services may include data storage, file transfer, data processing, email, bulletin board services, World Wide Web, etc. 2. A multiuser computer that has terminals attached to it.
The unique name that identifies a computer on a network. On the Internet, the host name is in the form “comp.xyz.net”; if there is only one Internet site the host name is the same as the domain name. One computer can have more than one host name if it hosts more than one Internet site, however (for example, “home.xyz.net” and “comp.xyz.net”); in that case “comp” and “home” are host names and “xyz.net” is the domain name.
A key or combination of keys that can either switch a user to a different program, or causes another function to occur in the computer. Usually, it is used to activate a terminate-and-stay-resident (TSR) program.
hot potato routing
A way of routing messages in a network in which each message is immediately sent on its way as soon as it arrives.
To remove and replace a component of a system while the power is on and the system is still operating.
A fast, flexible, and user-friendly Web page editor from Sausage Software, http://www.sausage.com/ .
High Performance Addressing. A kind of display used on some multimedia notebook computers, that delivers high-quality graphics comparable to Active Matrix (TFT) Displays.
High Performance Computing & Communications. A U.S.government plan to increase people's computer knowledge by creating scientific workstations, experimental systems, and a high-speed network linking government agencies, private companies, and schools with supercomputer systems.
High Speed. A modem status signal indicated by a light on the modem, which means the modem is currently operating at its highest transmission rate.
Hue, Saturation, Brightness. A method of describing color. Hue is the color itself; saturation is how pure the color is; and brightness is how light or dark the hue is.
High Sierra Format. A logical format and file structure for CD-ROMs that paved the way for ISO 9660. As the industry began to evolve many different proprietary CD-ROM formats, the need for a common standard became obvious. A meeting was held at Del Webb's High Sierra Hotel and Casino, in Lake Tahoe, Nevada, at which representatives from various companies worked together to arrive at a standard. The result of this meeting was “Working Paper for Information Processing: Volume and File Structure for CD-ROM Information Exchange (1986),” which became known as the High Sierra Format. Later, HSF was modified and evolved into ISO 9660, the key standard for worldwide acceptance of CD-ROMs.
Hierarchical Storage Management. An automatic system that moves files from hard disk to other storage media after a certain length of time, or according to other specifications of the user.
Horizontal Scan Rate. The number of scan lines displayed per second on a computer monitor, expressed in kilohertz (kHz).
HyperText Markup Language. The language used to create World Wide Web pages, with hyperlinks and markup for text formatting (different heading styles, bold, italic, numbered lists, insertion of images, etc.).
Codes in HTML that give instructions for formatting or other actions. World Wide Web documents are set up using HTML tags which serve various functions such as controlling the styling of text and placement of graphic elements and providing links to interactive programs and scripts. Examples of tags are
baseline return, which creates a line break;
. . . a pair of tags that horizontally center the enclosed text; image source, used to insert a graphic image into an HTML document.
baseline return, which creates a line break;
Bringing an HTML-coded page into compliance with established HTML standards. There are a number of validation sites on the Internet that provide the service of checking an HTML page and identifying any problems. The reason for validating an HTML page is to make sure it can be read by the different browsers that are in use.
An extended version of the original HTML, which expanded HTML's ability to handle documents containing multimedia objects.
Time Extensions for HTML. A proposal by Compaq, Microsoft, and Macromedia to extend time capability into a Web browser. HTML+TIME includes a set of elements and attributes to include time in a document, and a mechanism to turn it into a time-based presentation. HTML+TIME reuses concepts and techniques of SMIL (Synchronized Multimedia Integration Language, which makes possible the broadcast of television-like content on the Web), but with some simplification and improvement. Using HTML+TIME, authors do not have to learn a programming language for writing timed HTML presentations.
HyperText Transfer Protocol. The protocol most often used to transfer information from World Wide Web servers to browsers, which is why Web addresses begin with http://. Also called Hypertext Transport Protocol.
A packet of information which an HTTP server sends to a World Wide Web browser, to be sent back by the browser every time it reconnects with that server. HTTP cookies can be used to identify registered users.
Hypertext Transfer Protocol daemon. A World Wide Web server from NCSA, which is compatible with HTTP/1.0.
Like the hub of a wheel, a central device that connects several computers together or several networks together. A passive hub may simply forward messages; an active hub, or repeater, amplifies or refreshes the stream of data, which otherwise would deteriorate over a long distance.
A character coding technique for data compression; the complete set of codes can be represented as a binary tree called a Huffman tree.
(HF). The physical and psychological requirements of human beings that must be considered when designing computer systems and programs, in order to make products that are practical, efficient, and easy to use.
Human Interface Technology Laboratory
(HITL). The Human Interface Technology Laboratory at the University of Washington, a center of research and development in new interface technology.
(HCI). The study of how humans interact with computers, used to design computers which are easy for humans to use.
The interface between a human and a computer; for example, a command line interface, a graphical user interface, virtual reality interfaces.
Referring to a state in which a system is up and running but for some reason cannot complete a process; the system can do some things but is not fully functional.
A group of programmers who create free software; their home page is at http://www.hungry.com/.
hunt and peck
A way of typing using only one or two fingers and visually finding each key, slower than touch typing with all ten fingers.
Describing a method of typing by using only one or two fingers and visually finding each key, slower than touch typing with all ten fingers.
A computer which is a combination of analog and digital computer systems. A hybrid computer uses analog-to-digital conversion and digital-to-analog conversion, and may input or output either analog or digital data. One use for these computers is in robotics. See analog computer, digital computer.
A data management program developed for Apple and Macintosh computers. It organizes information into stacks of cards (as seen on the computer screen, not usually printed and made into hard copy). Each card can contain text, graphics, sound, animation, and video. A user can read the cards one at a time like the pages of a book, or follow a thread that jumps from card to card by means of hypertext links. A HyperCard stack can be used for something simple like a collection of recipes; more complex links would be needed for an organizational flow chart; even more sophisticated would be an interactive multimedia presentation with many possible paths to take through the information. With HyperCard and the HyperTalk programming language, users can develop their own applications. Similar programs for PC are HyperPad and ToolBook.
A link connected with a graphic image; the graphic equivalent of hypertext. Clicking on the image activates the link.
A link in an HTML document that leads to another World Wide Web site, or another place within the same document. Hyperlinks are usually underlined or shown in a differentcolor from the surrounding text. Sometimes hyperlinks are pictures.
An interactive map with hyperlinks that lead to more detailed information about each particular area.
The linking of multimedia to Web documents; the integration of text, images, sound, graphics, animation, and video through hyperlinks.
A program for PCs that is similar to HyperCard for Macintosh. HyperPAD is from Brightbill-Roberts & Company.
Text that has hyperlinks. When hypertext is viewed with an interactive browser, certain words appear as highlighted by underlining or color; clicking on a highlighted link leads to another location with more information about the subject. The term was invented by Ted Nelson.
Hypertext Markup Language
(HTML). The language used to create World Wide Web pages, with hyperlinks and markup for text formatting (different heading styles, bold, italic, numbered lists, insertion of images, etc.).
Hypertext Transfer Protocol
(HTTP). The protocol most often used to transfer information from World Wide Web servers to browsers, which is why Web addresses begin with http://.
HyperText Transmission Protocol, Secure
(HTTPS). Netscape's version of HTTP for secure transactions.
The automatic dropping of a hyphen when it is not necessary to divide a word; for example, when the text block is made wider or narrower, and the end of the line comes in a different place.
Hyphens at the end of three or more consecutive lines; considered by style by editors.
Breaking a word with a hyphen to keep a line from being too long. Word processing programs usually hyphenate words automatically using a hyphenation dictionary.
A file, usually in a word processing or desktop publishing program, which defines where hyphens will be placed for common words.
A distance from the right margin within which a word will be hyphenated if needed to make the line space properly.
(HYpertext browser for TELNET Network accessible sites). Hytelnet is also Peter Scott's hypertext database of over 1800 publicly accessible Internet sites, including libraries, Campus-Wide Information Systems, gopher, WAIS, WWW systems, Freenets, and more. HYTELNET software for PC, Macintosh, Unix and VMS systems is available via anonymous ftp from ftp.usask.ca (188.8.131.52) in the /pub/hytelnet directory. The Macintosh, Unix and VMS versions make automatic telnet connections to remote sites. There is also a Hytelnet mailing list, HYTEL-L.