Sample Materials for CSAT Paper -1 (G.S.) Pre 2013: "Science & Technology: Internet/Computer Glossary"

Subject: Science & Technology:
Topic: Internet/Computer Glossary

What is the Internet?

The Internet, sometimes called the “information superhighway” is a vast computer network of computer networks.

Some Other Facts about the Internet:
— The Internet is accessible in more than 100 countries, and there are more than 1 million Web servers worldwide.
— An average World Wide Web page contains about 500 words, and experts put the number of Web pages at somewhere between 30 million and 50 million.
— The average web user is 35.2 years old and accesses the web primarily from home. The Internet is not owned or funded by any one institution, organization, or government. It does not have a CEO and is not a commercial service. The internet is, however, directed by the Internet Society (ISOC) composed of volunteers. The ISOC appoints a sub-council, the Internet Architecture Board (IAB), which works out issue of standards, network resources, network addresses, and so on. Another volunteer group, the Internet Engin-eering Task Force (IETF), handles day-to-day issues of Internet operation. Practically speaking, the Internet is composed of people, hardware and software. With the proper equipment on both ends, you can also use the Internet to access vast amounts of information, including text, graphics, sound and video. From your computer, you can send e-mail, ‘Chat” with other others on another continent, work with other on an electronic whiteboard and with the appropriate equipment, video-conference.

How Can You Get There?

First, you need the equipment. You can get basic Internet access with any computer that has a modem connected to phone line. However, to take full advantage of all the Internet has to offer, you need either a Macintosh that has a 68040 or higher CPU or a PC that has an 80486 or higher CPU. With either system, you need the following:
— At least 4 megabytes of RAM (8 is recommended)
— A 250-megabyte hard drive
— A 14:4-bps modem (28.8 or faster in even better)

An Internet services provider (ISP) is a company that provides access to the Internet; some provide content and e-mail. The best-know ISPs are the commercial online services such as America Online.
CompuService, Prodigy and MSN (The Microsoft Network), but many national companies (for example, MCI and AT&T) and local and regional companies also provide Internet access. ISPs generally charge a monthly subscription rate. Some may charge additionally for connect time beyond that included in the monthly rate, but In 1997 It became increasingly common to charge a set monthly fee for unlimited access, Including e-mail and access to a news server

Internet Resources

What you can do on the Internet depends on which resource you access. Electronic mail is probably the most popular and widely used resource on the Internet to use it you must know and. accurately Input, the recipient’s address. An e-mail address consists of user nameaservice, and a domain, For example, in Walmanac@aol.com The World Almanac’s e-mail address, Walmanac is the user name, aol the service (In this case, America Online), and .com the domain (in. this case, a commercial organization). Domains are identified in the Domain Name Service, also known as the Domain Name System. A consortium between AT&T and Network Solutions, called InterNIC (Internet Network Information Center), manages the task of registering addresses, or domain names. In mid-1997 com, org, and net domain names cost $100 for 2 years (and $50 per year, thereafter). Domain, names can be applied for online through http://rs.internic.net or by contacting Network Solutions, InterNIC Registration Services, 505 Huntmar Park Dr., Herndon. VA 20170.
Here are the most, familiar domains

Domain	What it is
Com	A commercial organization business, or company
Edu	An education
Gov	A nonmilitary government entity
In	An international organization
Mil	A military organization
Net	A network administration
Org	Some other organization

Outside the U.S., the final part of a domain name represents the name of the coutry where the site is located, for example, jp for Japan, uk for Great Britain, and ru for Russia.

FAQs. Frequently Asked Questions documents contain the answers to common Internet questions. Reading some of these documents should help Internet newcomers.

FTP. File Transfer Protocol is a method of transferring files on the Internet and a type of Internet site. Using FTP, you log on to a remote site, usually a server, view the available files, and copy them to your computer. The address for an FPT site begins with ftp. Gopher. Developed at the University of Minnesota, home of the Golden Gophers, Gopher is a hierarchy if menus you can use to browse the Internet or search for a specific file. These menus are available on numerous Gopher servers on the Internet. Any Internet address that begins with gopher points to a location on a Gopher server.

Newsgroups; Newsgroup, a classic institution of the Internet, are found on the part of the Internet called Usenet In a newsgroup, messages concerning a particular topic are posted in a pubic forum. You can simply read the postings, or you can post an article yourself.

The World Wide Web: The Web may be the most complete realization of the Internet to date. It was developed in the early 1990s at the European Center for Nuclear Research as an environment in which scientists in Geneva, Switzerland could share information. It has evolved into a medium that consists of text graphics audio Animation and video. The address of a Web site usually begins with http://www. The World Wide Web is a graphical environment that can be navigated through hyperlinks. From one site you click on hyperlinks to go to any number of related sites.

How the World Wide Web Works

The Internet involves 3 fundamental elements: server, client, and network. A server is a computer program that makes data available to other programs on the same or other computers-It “serves” them. A client is a computer that requests data from a server. A network is an interconnected system in which multiple computers can communicate. The communication may be via copper wire, coaxial cable, fiber optic cable, satellite transmission, etc. The software by which you access Internet resources is the, browser. When you go to a site on the World Wide Web, you access the site’s files.

Here are the steps in opening and accessing a file:
— In the browser, specify the address, or URL, of the Web site.
— The browser sends your request to the Internet service provider’s server.
— That server sends the request to the server at the specified URL.
— The file is sent to the Internet service provider’s server, which sends the file back to the browser, which displays the file.

Safety and Security on the Internet

The Internet has no governing body through which laws and policies are enforced, and its original Inhabitants were known for their opposition to censorship. The use of Internet is seen as a part of free speech.
The Supreme Court adopted the view of Internet advocates that there is no way to screen material from children without censoring the source of the material. Thus, the responsibility for safety and security on the Internet rests with those who use it. Common sense dictates some basic rules of conduct:
— If you encounter an area that you find offensive-for example, a newsgroup or a chat room-remove that area from your list of places to visit.
— If you feel someone is being threatening or dangerous, inform your Internet service provider, which can issue a warning or can even withdraw entirely the person’s online privileges.
— Be conscious of your privacy needs, as you would in any other situation where you interact with strangers. Children, especially, should not give out their phone number, address, or other personal information.
— Be extremely careful about giving out credit card numbers. They will not be 100% secured.
— The two major browsers, Netscape Navigator and Internet Explorer, both contain features that let you filter the content that can be viewed on your computer. Among other blocking devices are the following: - Cyber Patrol (Microsystems Software, 800-828-2608); which lets parents select categories to block (pornography, etc.) and blocks transmission of personal data.
— CYBERsitter (Solid Oak Software, 800-388-2761), which lets you customize a list of sites and categories to block.
— Microsoft Plus! for Kids (Microsoft), which includes password-protected controls and other security features.
— Net Nanny (Net Nanny Ltd., 800-340-7177), which can log visited sites and shut down the computer if inappropriate sites are accessed.
— Rated-PG (PC Data Power, 800-404-9913), which allows parents to block Web sites and unapproved CD-ROMs and diskettes.
— SurfWatch (Spyglass, 800-458-6600), which screens Web sites, newsgroups, and other areas. Netparents.org is an association devoted to providing information about such resources. Check out its Web site at http ://www. netparents.org

Searching the Internet

A search engine is a special Web site you can use to locate Web sites based on specific keywords. Many of the newer search engines actively search the Web, checking that existing URLs in their giant databases still work and adding information about new sites. The programs that do this are called Web crawlers, spiders, or bots (short for robots). Some search engines store only the title and URL of sites; others index every word of a bite’s content. Some of the most popular are described below.
AltaVista, sponsored by Digital Equipment Corp., processes more than 2.5 million search requests every day. It has catalogued more than 15 billion words on some 30 million Web pages, as well as all 13.000 Usenet newsgroups. It collects Web pages at the rate of 2.5 million a day. Find AltaVista at http://www.altavista.digital.com. Excite lets you search more than 50 million Web pages, 140,000 Web site listings, and thousands of Usenet postings. You can search either by keyword or by concept. Find Excite at http://www.excite.com. HotBot features a menu-driven search engine. You can search by file type, date, geographic location and domain, and Web site, as well as by categories such as Dictionaries, Atlases, Web tools, etc. You can access HotBot at http://www.hotbot.com.
InfoSeek is a full-text search system that calls itself the ‘Web’s largest directory.” You can use it to find email addresses, street maps and investing opportunities. Enter a word or a question, or chose from a category to search. Access InfoSeek at http://www2.infoseek.com.
Lycos is a search service and more. Use it to find personal home pages, to locate the best Web sites in a particular country, and to track UPS packages. Find Lycos at http://www.lycos.com.
Open Text Index is a very powerful, multilingual search engine with which you can do a weighted search and receive information ranked by relevancy. You can find Open Text at http:I/www.opentext.com. WebCrawler is also much more than a search service. In addition to searching the Web, you can get free e-mail, and browse or submit free classified ads. Access WebCrawler at http:Iiwebcrawler.com.
Google and Yahoo are perhaps the best known and most, often used of all the search services. In addition to the standard search options, they now includes Yellow Pages, maps, classified ads, and stock quotes, as well as sports scores.

Internet Lingo

The following abbreviations are commonly used in Internet documents and in email
BTW: by the way
F2F: Face to face, a personal meeting
FCOL: For crying out loud
FTIW: For that it’s worth
FYI: For your information
GOK: God only knows
HHOK: Ha, ha-only kidding
HHOS: Ha, ha-only serious
IMHO: In my humble opinion
IMO: In my opinion
LOL: Laughing out loud
OTOH: On the other hand -
Rofl or ROTFL: Rolling on the floor laughing
TAFN: That’s all for now
Emotions, or smileys, are a series of typed characters that, when turned sideway, resemble a face and express an emotion. Here are some smileys that often encountered on the Internet.
:-) Smile
;-) Wink
:-* Kiss :- ( Unhappy
:-o Shouting
:-.b .. Drooling
=: o Argh!
{*} A hug and a kiss

Ques. 1 : Define Intranet and point out it differences with Internet?

Ans. Intranet : An intranet is the use of internet technologies within an organization (or company) to achieve better results than conventional means of data access and transfer. Intranet helps in outting cost, easy and fast accessibility of day to day information. Loosely defined, it is simply a type of client server system.

Differences with Internet:
(a) Intranet is a network within the organization whereas Internet is a world wide network.
(b) Intranet has access to Internet but not vice versa.

Hardware and software components of an intranet:-
(a) IP n/w
(b) HTTP Server
(c) SMTP/POP3/IMAP4 server
(d) LDAP server
(e) S509 certificate server
(f) Java ORB
(g) Document server
Advantages of Intranet:
(a) cheaper
(b) versatile
(c) flexible
(d) speedy
(e) lower cost.

Ques. 2 : Comment on the following in not more than 50 words each:-

— Bluetooth
— Broadband
— Bandwidth

Ans. Bluetooth An industry-standard, for a low power short-range radio link for connecting electronic devices. Devices such as mobile phones, laptop computers and digital cameras that are equipped with Bluetooth can share data information such as phone numbers, calendar events and digital images within a range of about 10 meters. Neither cables nor line-of-sight infrared are needed.
Broadband A Local Area Network (LAN) residing on coaxial cable capable of transporting multiple data, voice and video channels. Broadband channels have enough bandwidth to carry full motion video, stills graphics, audio and text (e.g.., fiber optics, cable television, ITFS).
Bandwidth Loosely, a reference to how much information can be sent through a connection. Bandwidth is usefully measured in bits per second (bps): A full page of text is about 30,009 bits. A fast modem (28.8 Kbps) can move 28,000 bits in one second. (That is approximately the limit of data transfer speed over standard phone circuits.) Full-screen, full-motion video requires approximately 10 million bps. The need for more bandwidth to support the growing number of Internet users and the rapidly-increasing amount of information with which they are dealing is prompting a wide-spread move from standard phone circuits and lines to high-speed technologies.

Ques. 3 : What is Hybrid Satellite?

Ans. Hybrid Satellite Satellite that carries two or more different communication payloads (i.e. supports both C-band & Ku-band transponders).

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Accumulator A register that is the source of on operand and the destination of the result for most arithmetic and logic operations.

Active-Highs The active state is the one state.

Active-low The active - state is the zero state

Address The identification code that distinguishes one memory location or input/output port from another and that can be used to select a specific one.

Addressing Methods (Modes) The methods for specifying the addresses to be used in an instruction. Common addressing methods include direct, indirect indexed, relative and stack.

ALGOL Algorithmic Language, a widely used high-level language designed for system and scientific applications.

Analog Continuous signal or representation of a quantity that can take, any value.

Anode Positive terminal.

Architecture Structure of a system. Computer architecture often refers specifically to the CPU.

Arithmetic-Logic Unit (ALU) A device that can perform any of a variety of arithmetic or logical functions under the control of function inputs.

Arithmetic Shift A shift operation that preserves the value of the sign bit (most significant bit).

Arm See Enable, but particularly applied to enabling interrupts.

Assembler A computer program that converts assembly language programs into a form (machine language) that the computer can understand. The assembler translate memonic instruction codes into binary numbers, replaces names with their binary equivalents, and assigns locations in memory to data and instructions.

Asynchronous Operating without reference to an overall timing source, that is, operation at irregular intervals.

Attached Input/Output An addressing method for input/output ports that identifies the ports either directly (if the port is attached to the CPU) or from the address in memory to which the port is attached. The port is usually selected with special instruction that are decoded either in the CPU or in the memory section. Systems using attached I/O are frequently based. On LSI devices that combine memory, input/output, and processor functions.

Autoindex An index register that is automatically incremented (auto increment) italics or decremented (auto decrement) with each use.

Auxiliary Carry Bit See Half-Carry Bit.

Add-On A program, which provides extra facilities for a WWW browser. Add-ons are also sometimes known as helper applications, especially when dealing with Macintosh computers. Netscape has popularized the alternate term “plug-ins” for helper applications, which actually work within a browser rather than alongside it.

Auto-Reply A message sent automatically in response to incoming e-mail. Auto replies are useful for those who want to immediately acknowledge e-mail inquiries, but who can’t respond quickly in person.

Autoresponder An auto responder is program that will automatically respond to an e-mail message sent to a predefined address in your domain. This is useful for automatically sending out information via email bases on a user’s emailed request.

Application A program designed to assist in the performances of a specific test, such as word processing accounting, or inventory management.

Archie An Internet utility for finding files in public archives obtainable by anonymous FTP. Archie is a shortened form of archive. See FTP.

Asynchronous communications a method of data communication in which the transmission of bits of data isn’t synchronized by a clock signal, but is accomplished by sending the bits one after another, with a start it and a stop-bit to mark the beginning and end, respectively, of each data unit.

Asynchronous digital subscriber loop (ADSL) a data communication method that can deliver through existing telephone lines a single, compressed, high quality,, video signal at a rate .of 1.5 Mb per second in addition to an ordinary telephone conversation;

Bank A directly addressable set of registers or memory locations. The register or other storage device that selects banks is called a bank Switch.

Baud Rate Generator A device that generates the proper timing interval between bits for serial data transmission.

Baudot Code A 5-bit character code used in telegraphy and some communications terminals.

BCD (Binary-Coded Decimal) A method for representing decimal numbers whereby each decimal digits separately coded into a binary Number.

Benchmark Program A sample program used to evaluate and compare computers.

Bidirectional Capable of transporting signals in either direction,

Binary Number system with base 2; having two distinct levels.

Bit A binary digit, possible values zero or one.

Bit Manipulation (or Bit Banging) The examination and changing of single bits or small groups of bits within a word.

Bit Slice A section of a CPU that may be combined in parallel with other such sections to form complete CPUs with various word lengths.

Bootstrap Loader (or Bootstrap) Technique for loading first instructions of a program into memory and then using these instructions to bring in the rest of the program. The first instructions (called the bootstrap) may reside in a special read-only memory.

Borrow A status bit that is one if the result of an unsigned subtraction was negative.

Bottom-Up Design A design method in which parts (or modules) of a system are designed and tested separately before being combined.

Bounce Moving back and forth between states before reaching a final state.

Branch Instruction See Jump Instruction.

Breakpoint A location specified by the user at which program execution, is to end temporarily. Used as an aid in program debugging.

Bus A group of parallel lines that connect two or more devices

Bus Contention A situation in which two or more devices are trying to place data on a bus at the same time:

Bus Driver A device that amplifies outputs sufficiently so that they can, be recognized by the devices on a bus.

Bus Isolation Buffering parts of the bus away from other parts with, buffers and drivers.

Bus Transceiver A device that acts as both a bus driver and bus receiver; that is, it interfaces a bidirectional bus to two unidirectional buses.

Byte The basic grouping of bits that the computer handles as a unit, most often, eight bits in length.

Backup (noun); back up (verb) As a noun, a duplicate copy of a program, a disk, or data As a verb, to make a duplicate copy of a program, a disk or data.

Broadband network A local area network on which transmissions travel as ratio- frequency signals over separate inbound and outbound channels. Stations on that network are connected by coaxial or fiber-optic cable which can carry data, voice and video simultaneously.

Bezier curve a mathematically generated line that can take the form of non uniform curves.

BinHex a method of encoding binary files so that the coded file contains nothing but the standard American Standard code for Information interchange (ASCII) characters and can therefore be transferred to other computers via the internet.

Bot the multi-user dungeons (MUDs) and Internet Relay Chat (IRC), a character whose on-screen actions stem from a program rather than a real person. The term is a contraction of robot.

Call See Subroutine.

Carry Bit A Status bit that is one if the last operation generated a carry from the most significant bit.

Cartridge (or 3M Mag-Tape Cartridge) A compact, endorsed packing of magnetic tape that uses ¼-inch tape and records 1600 bits per inch at 30 in./s on four tracks.

Cassette An enclosed package of magnetic tape usually housed in a plastic container. Both audio and digital versions exist, the digital ones are more reliable and more expensive. The standard unit is the Philips-type cartridge, which consists of 282 feet of 0.015-in. Magnetic tape, phase encoded at 800 bits per inch.

Cathode Negative terminal.

Central Processing Unit (CPU) The control section of a computer. It contains, the arithmetic unit, registers, instruction-decoding mechanism, and timing and control circuitry.

Chip A substrate containing a single integrated circuit.

Clear Set state to zero, an input to a device that sets the state to zero.

CMOS Complementary metal-oxide semiconductor, a logic family that uses complementary N-channel and-P-channel MOS field-effect transistors to provide high noise immunity and low power consumption.

Coding The writing of programs in a language that is comprehensible to a computer system.

Common-Anode Display A multiple display in which signals are applied-to the cathodes of the individual displays and the anodes are tied together to the power supply, it uses negative logic (i.e., a logic zero turns a display on).

Common-Cathode Display A multiple display in which signals are applied to the anodes of the individual-displays and the cathodes are tied together to ground. Uses positive logic (i.e., a logic one turns a display on). .

Common I/O Uses the same lines for input and output.

Comparator A device that produces outputs that show whether one input is greater than, equal to, or less than the other input. Both analog and digital comparators exist.

Compiler A program that converts a program in a high-level or procedure-oriented language into an assembly or machine language program.

Condition Code (or Flag) A single bit that indicates a condition within the computer, often used to choose, between alternate instruction sequences.

Condition Code Register A register that Contains one or more condition codes.

Control Memory A memory that holds micro programs-that is, a memory used to-decode

Computer instructions

Control Memory A magnetic memory that can be magnetized in one of two directions so as to represent a bit of data.

Counter A clocked device that enters a different state after each clock -pulse (up to its capacity), and produces an output that reflects the total number of clock pulses it has received. Counters are also referred to as dividers, since they divide the input frequency by in where is the capacity of the counter.

Cross-Assembler An assembler that runs on a computer other than the one for which it assembles programs.

CRT Cathode-ray tube.

Current Page The page of memory on which the present instruction is located.

Current-Loop Interface (or Teletype Interface) An interface that allows connections between digital logic and a device that uses current-loop signals-that is, typically the presence of 20 milli Ampere in the loop is a logic one and the absence of that current is a logic zero.

Cycle Stealing Using a cycle during which the CPU is not accessing the memory for a DMA operation.

Cycle Time Time interval at which a set of operations is repeated regularly in the same sequence.

Cyclic Redundancy Check (CRC) An error-detecting code generated from a polynomial that can be added to a data record or sector.

Call Centre An umbrella term that generally refers to reservations centers, help desks, information lines of customer service centers, regardless or how they are organized or what types of transactions they handle.

CDMA Code Division Multiple Access is one of serval digital wireless transmission methods in which signals are encoded using a pseudo-random sequences-which corresponds to a different communication channel that the receiver also knows and can use to decode the received signal. CDMA is one of serial “spread spectrum” techniques. CDMA offers improvements over analogue transmission in the area of reduced call dropping, battery power conservation, more secure transmission and increased service options.

Clarke Orbit That circular orbit in space, 22, 237 miles from the surface of the earth, at which geosynchronous satellites are placed. This orbit was first postulated by the science fiction writer Arthur C Clarke in Wireless World magazine in 1945. Satellites placed in these orbits, although traveling around the earth at thousands of miles an hour, appear to be stationary when viewed from a point on the earth, since the earth is rotating upon its axis at the same angular rate that the satellite is traveling around the earth.

Coax, Coaxial Cable Also called coaxial line. A transmission line in which the inner conductor is completely surrounded by an outer conductor (the shield-either a solid metal or braided metal grounded shield), so that the inner and outer conductor are coaxially separated. The line has no external fields. It has a wide bandwidth capacity that can carry several television channels and hundreds of voice channels.

Crackers Users who try to gain illegal access to computers. They are usually malicious in their intentions. See also hackers.

Cyberspace A term originated by “cyberpunk” author William Gibson in his novel.

Chat Real-time conversation via computer. Also an Internet utility program that supports chat.

Cursor A special on-screen indicator, such as a blanking underline or rectangle, that place at which keystrokes will appear when typed.

Checksum an acronym for summation check. In data communications, an error checking. technique in which the number of bits in a unit of data is summed, transmitted along with the data is summed, along with the data and checked by the receiving computer.

Circuit Switching Network a type of wide area network (WAN), epitomized by the world telephone system in which the originating and receiving stations are linked by a single, physical circuit, created by complex switching mechanisms.

Daisy-Chain An input or output method whereby signals pass from one device to another until accepted or blocked. Activity near the control unit for the chain will block activity farther from the Control unit.

Data Acquisition System A system that will accept several analog inputs and produce corresponding digital data. The system usually includes sample and hold circuitry, multiplexers, and converters.

Data Fetch Cycle A computer operation cycle during which data is brought from memory to the CPU.

Data Pointer (Or Pointer) A register or memory location that holds an address rather than the data itself.

Debounce Convert the output from a Contact with bounce into a single, clean transition between states.

Debounce Time The amount of time required to debounce a closure.

Debug To eliminate programming errors, sometimes referred to as verifying the program.

Debugger (or Debug Program) A program that helps in finding and correcting errors in a user program.

Decade Counter A counter with ten different states.

Decimal Adjust An operation that converts a binary arithmetic result to a decimal (BCD) result.

Decoder A device, that produces unencoded outputs from coded inputs.

Delay Time The amount of time between the clocking signal and the actual appearance of output data, Of the time between input and output.

Demultiplexer A device that directs a time-shared input to one of several possible outputs according to the state of the select inputs.

Destructive Readout (DRO) The contents cannot be determined without changing them.

Development System A special computer system that includes hardware and software specifically designed for developing programs and interfaces.

Diagnostic (Program) A program that checks part of a system for proper operation.

Digital Haying discrete levels, quantified into a series of distinct levels.

Direct Addressing An addressing method whereby the address of the operand is part of the instruction.

Directly Addressable Can be addressed without changing the contents of any registers or bank switches.

Direct Execution A method whereby the computer directly executes statements in a high-level language rather than translating those statements into machine or assembly language.

Disable Prohibit an activity from proceeding or a device from producing data outputs.

(Output) Disable Time The amount of time required for an active to-state output to enter the third or open-circuit state.

Disarm See Disable, but particularly applied to disabling interrupts.

Disk Operating System (DOS) An operating system that transfers programs and data to and from a disk, which may be either flexible or fixed-head; the operating system may itself be largely resident on the disk.

Diskette See Floppy Disk.

Divider See Counter.

Dual Inline Package (DIP or Bug) A semiconductor chip package having two rows of pins perpendicular to the edges of, the package, sometimes called a bug, since it appears to have legs.

Dynamic Memory A memory that loses its contents gradually without any external causes.

Dedicated Line A communications line used solely for computer connections.

Dial-up Connection A connection to the internet using a modem and telephone line.

DNS (Domain Name Server) A server, which converts between domain names and IP numbers. All computers on the Internet have an IP address; most also have one or more easy—to-remember domain names, as well.

Domain The most general portion of a domain name, upon with the naming hierarchy of computer on the Internet is based. Common domains for sites within the U.S. include corn (commercial), .edu (educational), gov (government), mil (military), net (networking) and org (non-profit organization). Other countries each have at least one unique domain for their own sites. See also domain name, IP number.

Domain Name The unique name- that identifies .an Internet site (for example www.gonix.com or awsd.com). Domain names always have two or more parts separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one domain name, but a given domain name points to only one machine. It is possible for a domain name to exist but not be connected to an actual machine. This is often done so that a group or business can have an Internet e-mail address and/or offer other services without having to establish a real Internet site. In these cases, some real Internet machine must handle those services on behalf of the “virtual domain”. See also domain, IP number.

Delimiter a code, such as a space, tab, or comma, that marks the end of one section of a command and the beginning of another section.

EBCDIC Expanded Binary-Coded Decimal Interchange Code, an 8-bit character code often used in large computers.

ECL Emitter-coupled logic, a high-speed bipolar - technology often used in computer mainframes.

Editor A program that manipulates text material and allows the user to make corrections, additions, deletions, and other changes.

Effective Address The actual address used by a particular instruction to fetch or store data.

Emulator A micro programmed copy of an existing system.

Enable Allow an activity to proceed or a device to produce data outputs. Encoder A device that produces coded outputs from unencoded inputs.

EPROM (or EROM) Erasable PROM, a PROM that can be completely erased by exposure to ultraviolet light.

Error-Correcting Code A code that can be used by the receiver to correct errors in the messages to which the code is attached; the code itself does not contain any additional message.

Ergonomics the science of designing machines, tools, computers and physical work areas so that people find then easy and healthful to use.

Electronic Frontier Foundation (EFF) a nonprofit publish advocacy organization dedicated to ensuring the survival of privacy and civil liberties in the computer age.

False Start Bit A start bit that does not last the minimum required amount of time, usually caused by noise on the transmission line.

Fan-In The number of inputs connected to a gate.

Fan-Out The maximum number of outputs of the-same family that can be connected to a gate without causing current overload.

Field-Programmable Logic Array (FPLA) A programmable logic array that can be programmed by the user.

Firmware Micro programs, usually implemented in read-only memories.

Fixed instruction Computer A computer for which the manufacturer determines the instruction set. As opposed to micro programmable computer.

Fixed Memory See ROM. Flag See Condition Code.

Flatpack A semiconductor chip package in which the pins are in the same plane as the package rather than perpendicular to it as in a DIP.

Flip-Flop A digital electronic device with two stable states that can be made to switch from one state to the other in a reproducible manner.

Floating Not tied to any logic level, often applied to tri-state outputs that are in the high— impedance state. TTL devices usually interpret a floating input as a logic one.

Floppy Disk (or Flexible Disk). A flexible magnetic surface that can be used as a data storage device; the surface is divided into sectors. An IBM-compatible floppy disk is one that uses formattinsg and sectoring techniques originally introduced by IBM. The individual floppy disk is sometimes called a diskette.

Flowchart A graphical representation of a procedure or computer program.

FORTRAN A high-level (procedure-oriented) programming language devised for expressing scientific problems in algebraic notation. Short for Formula Translation Language.

Firewall A security system intended to protect an organization’s network against external threats such as hackers, from another network. See also proxy server.

Flame An abusive or personally insulting e-mail message or newsgroup posting.

Free Slots Free slots are the slots left in the dynamic sub-frame after all stream, guaranteed (CIR) and preemptive (EIR) bandwidth requests are satisfied. Free slots are allocated to all VASTs (up or down), except the master, in a round-robin fashion.

FTP File Transfer Protocol is an application that runs over ICP (transport layer) and IP (network layer). It allows for bulk data (a large file) to be transferred from one computer to another with error detection and retransmission. It uses the sliding window mechanism for acknowledgment. This is a very common customer application.

FAQ (Frequently Asked Questions) List Documents that list and answer the most common questions on a particular subject. Almost every Usenet group, regularly posts a FAQ list. They are usually written by people who are tired of respectably answering the same question.

FOMA Freedom of Mobile Multimedia Access, the world’s, first 3G mobile services.
Gate A digital logic element where binary value of the output depends on the values of the inputs according to some logic rule.

General-Purpose Interlace Bus (GPIB or Hewlett-Packard Bus) A standard interface for the transmission of parallel data in a network of instruments. The GPIB has 8 data lines, 8 control lines, and 8 ground lines.

General-Purpose Register A register that can be used for temporary data storage.

Gray Code A binary code sequence in which only one bit changes in a transition to the next higher or lower value.

Gateway Technically hardware or software setup that translates between two dissimilar protocols. (For example AOL and Prodigy have gateways that translate between their internal, proprietary e-mail formats and the Internet e-mail format.) More generally, the term is used to describe any mechanism for proving access from one system to another.

Gopher An Internet utility for finding textual information and presenting it to the user in the form of hierarchical menus, from which the user selects submenus or files that can be downloaded and display. Gopher is being superseded by the World Wide Web.

Glitch a momentary power interruption or some other unexpected fluctuation in electronics circuits, such as those caused by power surges or dirty connections, that causes computer system to generate garbage output or; in the extreme, to crash.

Gigabit a unit of measurement approximately equal to one billion bits, usually used when indicating the amount of data that can be transferred or transmitted per second.

Half-Carry (or Auxiliary Carry) Bit A status bit that is one if the last operation produced a carry from bit 3 of an 8-bit word. Used on 8-bit microprocessors to make the correction between binary and decimal (BCD) arithmetic.

Hardware Physical equipment forming a computer system

Hex (1) Containing six distinct logic elements, as in hex buffers; (2) abbreviation for exadecimal or base 16.

Hexadecimal Number system with base 16. The digits are the decimal numbers 0 through 9, followed, by the letters A through F.

High-Impedance State See Tri-State.

High-Level Language (or Procedure-Oriented Language) A programming language in which the statements represent producers rather than single machine instructions FORTRAN, COBOL, and BASIC are three common high-level languages. A high-level language requires a compiler that translates each statement into a series of machine language instructions.

Hold Time The amount of time after the end of an activity signal, during which some of the signal must be stable to ensure the achievement of the correct final state.

Hackers Computer users Who understand the “ins and outs” of computers, networks, an the Internet in general. Hackers are generally benign. See also crackers.

Hotline Services A private, point-to-point telephone connection. With such a connection there is no need to dial: one telephone rings as soon as the other is picked up.

Hits As regards the Internet, the number of document requests being answered by server. The number of a hits on a website does not equal the number of visitors single visitor can request several different pages during a visit, thus register in multiple hits. As well, even a single request for a single page can register multiple hit as - graphic elements are requested from the server separately from the page’s text.

Home Page The basic “introductory” page of a website. It is usually intended that the home page be the primary point of entry into a site. See also Site.

Host Any computer on a network that is a repository for services available to other computers on the network. It is quite common to have one host machine provide several different services, such as Gopher, Usenet and WWW.

HTML (Hyper Text Markup Language) The coding language used to create hypertext documents for use on the World Wide Web. HTML looks very much like old-fashion typesetting code, in which a block of text is surrounded with codes (or “tags”) that indicate how it should appear. The primary difference between HTML and typesetting code is that instead of defining appearance, proper HTML markup defines purpose (Thus it is referred to as “structural markup.”) See also HTTP, URL and WWW.

HTTP (HyperText Transfer Protocol) The protocol for moving hypertext files across the internet. It requires an HTTP client program (browser) on one end of the transfer and an HTTP server program on the other. HTTP is the most important protocol used on the WWW. See also HTML, URL and WWW.

Hard copy Printed output on paper, film, or other permanent medium. See soft copy.

Hypermedia The integration, of any combination of text, graphics, sound, and video into a primarily associative system of information storage and retrieval in which users jump from subject to related subject.

Hot Key a key board short cut that accesses a menu command.

Image Map A graphic image on a Web page in which different “hot” areas serve as clickable links to other pages. Image maps are sometimes called “active maps.

IEEE Standard 488 Bus See General-Purpose Interface Bus.

Immediate Addressing An addressing method in which the operand is part of the instruction itself.

Immediate Data Data that is part of the instruction that uses it.

Implied (or Inherent) Addressing The operation code itself specifies all the required addresses.

In-Circuit Emulator A device that allows a prototype to be attached to a development system for testing and debugging purposes.

Index Register A register that can be used to modify memory address.

Indexed Addressing An Addressing method in which the address included in the instruction is modified by the contents of an index, register in. order to find the actual address of the data.

Indirect Addressing An addressing method in which the address of the data, rather than the data itself, is in the memory location specified-by-the-instruction.

Input/Output (Section) The section of the computer that handles communications with external devices.

Instruction A group of bits that defines a computer operation and is part of the instruction set.

Instruction Cycle The process of fetching, decoding, and executing an instruction. Instruction Execution the process of performing the operations indicated by an instruction.

Instruction (Execution) Time-The time required to fetch, decode, and execute an instruction

Instruction Fetch The process of addressing memory and reading an instruction word into the CPU for decoding.

Instruction-Length The number of words of memory needed to store a complete instruction.

Instruction Repertoire See Instruction Set.

Instruction Set The set, of general-purpose instructions available with Ii given computer- that is, the set of inputs to which the CPO will produce a known response during the instruction fetch cycle.

Integrated Circuit (IC) A complete circuit on a single substrate or chip.

I2L (Integrated Injection Logic) a bipolar technology that uses only transistors (both vertical and lateral) to provide moderate speed, low power consumption, and high density.

Intelligent Terminal (or Smart Terminal) A terminal that has some data processing capability or local computing capability.

Interpreter A program that fetches and executes instructions written in a high-level language. An interpreter executes each instruction as soon as it reads the instruction; it does not produce an Object program, as a compiler does.

Interrupt A computer input that temporarily suspends the normal sequence of operations and, transfers control to a special routine.

Intelterrupt-Driven System A system that depends On interrupts to handle input and output or that ideal until its receives an interrupt.

Interrupt Mask (Interrupt Enable) A mechanism that allows the program to specify whether interrupts will be accepted.

Interrupt Service Routine A program that performs the actions required to respond to an interrupt.

Inverter A logic device that complements the input.

Isolated Input/Output. An addressing method for I/O -ports that Uses an addressing system distinct from that used by the memory section.

IDC Internet Data Centers Telecom service providers, large/multinational corporation and government institutions need mit digital information. Strands, although about the thickness of a human hair, nearly unlimited capacity :-Bundled in protective sheathing about the diameter of a human thumb, fiber can carry more information than copper cable the diameter of a utility pole. It is a method for transmission of information (voice, video, data). Bandwidth capacity of fiber optic cable is much greater than conventional cable or copier wire.

IP Number A unique number (Sometimes called a “dotted quad”) consisting of 4 parts separated by dots (for example, 199.171.33.46). Every machine on the Internet has a unique IP number. If a machine does not have an IP number, it s not really on the Internet. Most machines also have one or more domain names that are easier for people to remember. See also domain, domain name.

IPP (Internet Presence Provider) A company or organization which provides It “storage space” on the Internet for their customers’ information, usually for a fee. See also ISP.

IRC (Internet Relay Chat) A huge- multi-user —live chat facility IRC is the worldwide “party line” of the computer world. There are a number of major IRC servers around the world, which are linked to each other. Anyone can create a “channel” which others can join. Anything that anyone types in a given channel is immediately seen by everyone else in the channel.

Icon A small image displayed on the screen to represent an object that can be manipulated by the user.

Infobahn a term preferred by some for the so called information super high way, a high speed information system that would link homes, schools and offices with high bandwidth local) delivery systems and backbone systems capable of gigabit-per second speed. Interlacing a monitor technology that uses the monitor’s electron gun to paint every other line of the screen with the first pass and the remaining lines on he second pass.

IDC Internet Data Centers. Telecom service providers, large/multinational corporations and government institutions need certain infra-structure facilities to deliver new and competitive solutions to meet their customer’s demands. These infrastructure facilities are called IDCs.

INMARSAT International Maritime satellite organization. Agency that operates a network of satellites for international transmissions for all type of international mobile services, including maritime, aeronautical and land mobile.

Interoperability the ability of one computer system to control another, even though the two systems are made by different manufactures.

Java A new programming language developed by sun Microsystems. It is specifically designed for writing programs that can be downloaded from the Internet and immediately run on a client computer. (This differs from standard CCI programs, which run on the server.) Using small Java Programs, or “applets,” Web pages car include a wide variety of fancy elements such as high quality animations. Java promises to substantially alter the way people interact on the WWW.

Jump Instruction An instruction that places a new value in the program counter, thus departing from the normal one-step incrementing. Jump instructions may be conditional; that is, the new value may only be placed in the program counter if certain conditions are met.

Jump Table A table that contains the addresses of routines to which the computer car transfer control.
K 2IO or 1024 words, a unit of memory.

Keyboard A collection of key switches.

Keyboard Encoder A device that produces a unique output code for each possible closure on a keyboard.

Keyboard Scan The process of examining the rows and columns of a matrix keyboard to- determine which keys have been pressed.

Kilobit 1000 bits.

Kludge Pronounced .“klooj”. A short-term or makeshift hardware construction. Also, program characterized by a lack of design or forethought as if written in a hurry fo satisfy an immediate need. A kludge basically operates properly, but lacks elegance or logical efficiency.

Kiosk a publicly accessible computer system that has been set up to allow interactive information browsing.

Kernel in an operating system the core portion of the program that reside in memory and perform the most essential operating system tasks, such as handling disk input and output operations and managing the internal memory.

Label A name attached to a particular instruction or statement in a program that identifies the location in memory of the object code or assignment produced from that instruction or statement.

Large-Scale Integration (LSI) An integrated circuit with complexity equivalent to over 100 ordinary gates.

Latch A temporary storage device controlled by a timing signal. The contents of the latch re fixed at their current values by a transition of the timing signal (clock) and remain fixed until the next transition.

Light-Emitting Diode (LED) A semiconductor device that emits light when biased in the forward direction.

Linear Select Using coded bus lines individually for selection purposes rather than decoding the lines, linear select requires no decoders but allows only on separate devices to be connected rather than 2, where n is the number of lines.
Linking Loader A loader that will enter a series of programs and subroutines into memory and provide the required interconnections.
Loader A program that reads a user or system programs from an input device into memory.
Logic Analyzer A test instrument, that detects and displays the state of parallel digital signals.
Logic Design Design using digital logic circuits.
Logical Shift A shift operation that places zeros in the empty bits.
Logical Sum A bit-by-bit EXCLUSIVE-O Ring of two binary, numbers.
Look ahead Carry A device that forms the carry bit from a binary addition without using the Carries from each bit position.
Loop A self-contained sequence of instructions that the processor repeats until a terminal condition is reached. A conditional jump instruction can determine if the loop should be continued or terminated.
Low-Level Language A language in which each statement is directly translated into a single machine language instruction. See Assembly Language and Machine Language.
Low-Power Schottky TTL A low-power variant of standard TIL.
Leased Line A phone line that is, rented for exclusive 24-hours-a-day, 7-days-a week use. The highest speed data connections require leased lines.
Link A hypertext link (either a designated section of text, a specific graphic or a portion of an Image, map) on a Web page which when, selected, will cause another document to be loaded.
Listserv (or List Server) The most common kind of maillist Listservs originated on BITNET, but are now common on the Internet.
Login Either the account name used to gain access to a computer system or the act of accessing a computer system.
Lynx The standard text-based tM1JW browser See also browser, Mosaic, Netscape
Laptop A small, portable computer that runs on either batteries or AC power, designed for use during travel. Laptops have flat LCD or plasma screens and small keyboards, Some weigh as little as 5 pounds.
Latency in a computer network, the amount of time required for a message to travel from the sending to the receiving computer.
Machine Code See Machine Language.
Machine Cycle The basic CPU cycle. One machine cycle is the time required to fetch data from memory or execute a single-word operation.
Machine Language The programming language that the computer can directly understand with no translation other than numeric conversions. A machine language program can be loaded into memory arid executed, the value of very bit in every instruction in the program must be specified.
Macro A name that represents a sequence of instructions. The assembler replaces a reference to the macro with a copy of the sequence.
Macro assembler An assembler that has facilities for macros.
Macroinstruction An overall computer instruction fetched from the main memory in a micro programmed computer.
Majority Logic A combinational logic function that is true when more -than half the inputs are true.
Mark The one state on a serial data communications line.
Mask (1) A glass photographic plate that defines the diffusion patterns in integrated circuit production. (2) A bit pattern that isolates one or more bits from a group of bits.
Maskable interrupt An interrupt that the system can disable.
Matrix Keyboard A keyboard in which the keys are connected in rows and columns.
Medium-scale Integration (MSI) An integrated circuit with a complexity of between 10 and100 gates.
Megabit One million bits.
Memory (Section) The section of a computer that serves as storage for data and instructions. Each item the memory bas a unique address that the CPU can use to fetch it.
Memory address Register (or Storage Address Register) A register that holds the address of the memory location being accessed.
Memory-Mapped Input / Output An addressing method for I/O ports that uses the same addressing -system as that Used by the memory section.
Meta-Assembler An assembler for which the input instruction patterns can be defined and that can, therefore assemble programs for different computers.
Microassembler An Assembler specifically designed for writing micro programs.
Microcomputer A computer whose CPU is a microprocessor. A microprocessor plus memory and input/output circuitry.
Microcontroller A micro programmed control system without arithmetic capabilities.
Microinstruction One of the words in control memory-that is, one of the organized sequence of control signals that form the instructions at the control level.
Microprocessor The central processing unit of a small computer, implemented on one or a few LSI chips.
Microprocessor Analyzer A piece of test equipment that can be used to trace and debug the operations of a microprocessor.
Microprogram A program written at the control level and stored in a control memory
Microprogrammable Having a micropro-grammed control function that the user can change. That is, the user can add, enter or replace microprograms.
Microprogrammed Having the control function implemented through microprogramming.
Microprogramming The implementation of the control function of, a processing system as a, sequence of control signals that is organized into words arid stored in a control memory.
Mnemonics Symbolic names or abbreviations for instructions, registers, memory locations, etc. which suggest their actual functions or purposes.
Modular Programming A programming method whereby the entire task is divided into logically separate sections or modules.
Monitor A simple operating system that allows the user to enter or change programs and data, to run programs, and to observe the status of the various sections on the computer.
Monostable Muitivibrator (or One-Shot) A device that produces-a single pulse of known length in response to a pulse input.
MOS Metal-oxide semiconductor a semiconductor process that uses field-effect transistors in which the current is controlled by the electric field around a gate.
Multiplexer (or Selector) A device that select one of several possible inputs to be placed on a times-shared output bus according to the state of the select input. Also called
MUX.
Multiprocessing Utilizing two or more processors in a single system, operating out of common memory.
Mosaic The first WWW browser that was available with the same interface for Macintosh, Windows and UNIX systems. It was developed at the National center for Supercomputing Applications (NCSA). The introduction of the Mosaic browser in 1994 was largely responsible for the initial explosion in, popularity of the Web. See also browser, Lynx, Netscape
Multimedia A document or program which incorporates a combination of text, graphics, audio and video.
Motherboard The main circuit board containing the primary components of a computer system.
Mouse A common pointing device. It has a flat-bottomed casing designed to be gripped by one hand; one or more buttons on the top; a multidirectional detection device (usually a ball) on the bottom; and a cable connecting the mouse to the computer. To select items or choose commands on the screen, the user presses on of the mouse’s buttons, producing a “mouse click.”
Metal-oxide varistor (MOV) a device used to protect the computer from abnormally highline voltages.
Multiplexing in LANs the simultaneous transmission of multiple messages in one channel.
Nanosecond 10-9 second abbreviated ns.
Negative Logic Circuitry in which a logic zero is the active or ON state.
Nesting Constructing subroutines or interrupt service routine so that one transfers control to another arid so on. The nesting level is the number of transfer required to reach a particular routine without returning.
Nibble A sequence of four bits operated on as a unit.
N-Key Rollover (NKRO) Resolving any number of simultaneous key closures into consecutive output codes.
NMOS N-channel metal-oxide semiconductor a logic family that uses N-channel MOS field-effect transistors to provide high density arid medium speed:
Noise Margin The noise voltage required to make logic circuits malfunction
Nondestructive Readout (NDRO) The contents of the device can be determined without changing those contents.
Nonmaskable Interrupt An interrupt that the system cannot disable.
Nonvolatile Memory A memory that does not lose its contents when power is removed.
No-Op (or No Operation) An instruction that does nothing other than increment the program counter.
Netizen A “citizen of the Internet,” or someone who uses networked resources. The term connotes civic responsibility and participation.
Netmail The FidoNet equivalent of e-mail.
Netscape A WWW browser and the company which produces it. Netscape Navigator is a Web browser originally based on the Mosaic program. It is currently the most widely-used of all Web browsers, though its extensive incorporation of non-standard HTML markup is a cause of constant argument in the Web community. Its primary author, Mark Andreessen, was hired away from the NCSA by Jim Clark, with whom he founded the company now known as Netscape Communications Corporation. See also browser,. Lynx, Mosaic.
Netiquette Short for network etiquette.
Newbie An Inexperienced user on the Internet.
N-AMPS (Narrowband AMPS) Narrowband Advanced Mobile Phone service. Combines the AMPS transmission standard with digital signaling information to effectively triple the capacity of AMPS while adding basic messaging functionality.
Neuromancer. The word is currently used to describe the whole range of information resources available through Computer networks.
Object Program (or. Object Code) The program that is the output of a translator program, such as an assembler or compiler. Usually a machine language program ready for execution.
Octal Number system with base 8. The digits are the decimal numbers 0 through 7.
Offset A number that is to be added to another number to calculate an effective address.
One-Address Instruction An instruction in which only one data address must be specified. The other data, if necessary, is presumed to be in the accumulator.
One’s Complement A bit-by-bit logical complement of a binary number. One-Shot See Monostable Multivibrator.
On Shot See Monostable Multivibrator.
On-Line System A computer system in which information reflecting current activity is introduced as soon as it occurs.
Open-Collector Output A special output that is active-low but not high. Such outputs can be wire-ORed to form a bus employing negative logic.
Operating System System software that controls the overall operation of a computer system and performs such tasks as memory allocation, input and output distribution, interrupt processing, and job scheduling.
Operation code (Op Code) The part of an instruction that specifies the operation to be performed during the next cycle.
Optoisolator Semiconductor device consisting of an LED and a photodiode or phototransistor in close proximity, current through, the LED causes internal light emission that forces current to flow in the phototransistor. Voltage differences have no effect because the devices are electrically separated.
Overflow Bit A status bit that is one if the last operation produced a two’s complement overflow.
Overly The section of a program that is actually resident in memory at a particular time. A large program can be divided into overlays and run on a computer having limited memory, but backup storage for of the rest of program.
Online Connected or relating to the Internet.
OSI (Open System Interconnection) A new technical specification of communication protocols which is currently working alongside, but which may eventually replace, IP.
POP (Post Office Protocol) The protocol that defines how e-mail software such as Eudora gets mail from a mail server. Also-referred to as POP3. See also MW.
Page A subdivision of the memory section.
Page Zero The first page of memory; the most significant address bits (or page number) are-zero.
Parallel More than one bit at a time.
Parity A1 bit code that makes the total number of one bits in the word, including the parity bit, odd (odd parity) or even-(even parity).
Parity Bit A status bit that is one if the last operation produced a result with even (if even parity) or odd (if odd parity) panty.
Passing Parameters See Subroutine.
Pipelining Overlapping cycles so that different parts of consecutive cycles are performed at the same time.
PL/I Programming Language 1, a high-level language developed by IBM that combines many of the features of earlier languages, such as ALGOL, COBOL and FORTRAN. Many versions exist for microprocessors, such as PLIM, MPL, SM/PL, and PLuS.
PMOs P-channel metal-oxide - semiconductor, & logic family that Uses P-channel MOS field effect transistors to provide high density and low speed.
Pointer Register or memory location that contains an address rather than data.
Polling Determining the state of peripherals, or other devices by examining each one in succession.
Pop (or Pull) Remove an operand from a stack.
Power-On Reset A circuit that automatically causes, a RESET signal when the power is turned on, thus starting the system in a known state.
Printed Circuit Board (PC Board) A circuit board in which the connections are made by etching with a mask.
Priority Interrupt System An interrupt system in which some interrupts have precedence over others-that is, will be serviced first or can interrupt the others service routines.
Procedure-Oriented Language See High Level Language.
Program A sequence of instructions properly ordered to perform a particular task.
Program Counter A register that specifies the address of the next instruction to be fetched from program memory.
Program Library A collection of debugged and documented programs.
Programmable Interface An interlace device that can have its active logic structure varied under program control.
Progrmmable Logic Array (PLA) An array of logic elements that can be programmed to perform a specific logic function; like a ROM except that only certain addresses are decoded.
Programmable Timer A device that can provide various timing modes and intervals under program control.
Programmed Input/Output (I/O) Input/Output performed under program control without using interrupts or direct memory access.
PROM Programmable read-only memory, a memory that cannot be changed during normal operation but that can be programmed by the user under special conditions. The programming is generally not reversible.
PROM Programmer. A piece of equipment that is used to change the contents of a PROM.
Prototyping System (or Development System) A hardware system used to breadboard a computer-base product. Contains the computer plus, the software and hard\Yare required for efficient development.
Pseudo-Operation (or Pseudo-Instruction) An assembly language operation code that directs the assembler to perform come action but does riot result in a machine language instruction.
Pull See Pop.
Pullup Resistor A resistor connected to the power supply that ensures that an otherwise open circuit will be at the voltage level of the power supply.
Pulse Generator A device that produces a single pulse or a series of pulses of predetermined length in response to an input signal.
Push Enter an operand into a stack.
PoP (Point of Presence) A city or location from which it is possible to connect to a network often with dial-up lines If an ISP has a PoP in Omaha, for example, it means either that there is a local phone number in Omaha from which callers can connect or that there is a location in Omaha where leased lines can connect to their network.
Part Most generally, a physical connection through which information goes into and/or out of a computer. On the Internet, “port” can also refer to a number that is, part of a URL. Every service on an internet server “listens” on a particular port number on that server. Most Web servers, for example, listen on port 80. Services can also listen on non-standard ports, in which case the port number must be specified in the URL address. Finally, to “port” a piece of software is to translate it from one type of computer system to another.
ProComm A standard telecommunications program for IBM systems.
Protocol A means by which different types of computer communicate with each other.
Pixel Short for picture element; also called pel. One spot in a rectilinear grid of thousands of such spots that are individually “painted” to form an image produced on the screen by a computer or an paper by a printer.
Proxy server A firewall component that manages Internet traffic to and from a local area network and can provide other features, such as document caching and access control.
PROLOG a high level programming language used in artificial intelligence research and applications, particularly expert systems. It is short for Programming in Logic.
Queue (or FIFO) A set of registers or memory locations that are accessed in a first-in, first-out manner. That is, the first data entered into the queue will be the first data read.
Random Access All internal storage locations- can be accessed in the same amount of time. Real time in synchronization with the actual occurrence of events.
Real Time Clock A device, that interrupts a CPU at regular time intervals.
Recursive subroutine A subroutine that calls itself as part of its, execution.
Reentrant Subroutine A Subroutine that be executed correctly even while the same routine is being interrupted or otherwise held in abeyance.
Refresh The processor or restoring the contents of a dynamic memory before they are lost.
Register Direct Addressing An addressing method that is the same as direct addressing except that the address is a register rather than a memory location.
Register Indirect Addressing An addressing method that is the same as indirect addressing except that the address is in register rather in a memory location.
Relative Addressing An addressing method in which the address specified in the instruction is the offset from a base address. The base address may be the content of the program counter or a base, register. Relative addressing allows programs to be easily relocated in memory.
Relocatable Can be placed in any part of memory without changes-that is, a program that can occupy any set of consecutive memory addresses.
Reset A signal that starts a system in a known state.
Resident Software Software that can run on the computer itself, unlike cross-assembler or cross-compilers, which must run on another computer.
Ripple Carry Forming the carry bit from a binary addition by using the carries from each bit position.
ROM Simulator A device that allows read/write memory to act like ROM during system development; the simulator usually has special display arid debugging features.
Routine A program or subprogram.
RS Flip-Flop A flip-flop that can be placed in the I state by a signal on the SET input or i the 0 state by a signal on the RESET input.
RS-232 A standard interlace for the transmission of serial digital data.
Router A special-purpose computer of software package that handles the connection between two or more networks. Routers spend all of their time looking at the destination addresses of the packets passing through them and deciding on which route to send them See also packet switching.
Recto the right hand page in facing page; In a book or magazine, the recto page in the right-hand, odd-numbered page.
RAID a group of hard disks under the control of array management software that work together to improve performance and decrease the odds of losing data due t mechanical or electronic failure by using such techniques as data striping.
Schmitt Trigger A circuit used to produce a single, sharp transition (i.e., a pulse) from slowly changing input.
Scratch TTL. A high-speed valiant of standard TTL.
Scratch-Pad Memory Memory locations or registers that are used to store temporary intermediate results.
Second Source A manufacturer who supplies a device or product originated by another manufacturer.
Self-Assembler An assembler that runs on the computer for which it assemble programs.
Self Checking Number A number in which some of the digits serve to check for possible errors in the other digits and do not contain any additional information.
Self-Test A procedure whereby a system checks the correctness of its own operation. Separate 110 Uses different lines for input and output.
Sequencer A device- that controls the ordering in time of the state of a system or the order in which instructions are executed.
Serial One bit at a time.
Serial-Access A storage device (such as a magnetic type) from which data can only be reached or retrieved by passing through all intermediate locations between the desired one and the currently available one.
Set Make state a logic one.
Setup Time The time, prior to a clock transition, during which data must be stable for proper operation.

Seven-Segment Code The code required to represent decimal digits or other characters on a seven-segment display.

Seven-Segment Display A display made up of seven separately controlled elements that can represent decimal digits or other characters.

Shift Register A clocked device that moves its contents one bit to the left or right during each clock cycle.

Sign Bit The most significant bit of a register or memory location; a status bit that is one if the most significant bit of the result of the previous operation was one.

Sign Extension The result of a right arithmetic that Copies the sign bit-into the succeeding less significant bits.

Sign-Magnitude Number A number in which the most significant bit represents the sign or polarity and the remaining bits represent the magnitude.

Signal Conditioning Making a signal compatible with the input requirements of a particular device through buffering, level translation, amplification, etc.

Signature Analysis A method whereby faults can be found in bus-oriented digital systems by examining the time histories of signals at particular nodes.

(Software) Simulator A computer program that follows the actions of a system in detail and that can be used for debugging or testing.

Sink Current The ability of a device to accept current from external loads.

Small-Scale Integration (SSI) An integrated circuit with a complexity of ten gates or less. Snapshot Record of the entire state of a system at a particular point in time.

(Computer) Software Computer programs.

Software Interrupt See Trap.

SOS Silicon-on-sapphire, a faster MOS technology that uses an insulating sapphire substrate.

Source Program Computer program written in an assembly, or high-level language.

Space The Zero state on a serial data communications line.

SPDT Switch Single-pole, double-throw switch with one, common line and two output

SPST Switch Single-pole single-throw switch with one common line and one output line.

Stack A sequence of registers or memory locations that are used in a last-in, first-out manner-that is the last data entered is the first to be removed and vice versa..

Stack Addressing An addressing method whereby the data to be used is in a stack.

Stack Pointer A register or memory location that is used the address a stack. Stand-Alone System A Computer system that does not require a connection to another computer.

Standard Teletypewriter A teletypewriter that operates asynchronously at a rate of ten characters per second.

Standby (or Quiescent) Power The amount of power required to maintain the contents of a memory when it is not being accessed.

Start Bit A one-bit signal that indicates the start of data transmission, by an asynchronous device.

State Counter A counter that contains the number of states that have occurred in the current operation.

Static Memory A memory that does not change its contents without external causes, opposite of dynamic memory.

Status Bit See Condition Code.

Status Register (or Status Word) A register whose contents reflect the current status of the computer; may be the same as condition code register.

Stop Bit A one-bit signal that indicates the end of data transmission by an asynchronous device.

Strobe A one-bit signal that identifies or describes another set of signals and that can be used to clock or enable a register.

Structured Programming A programming method whereby all programs consist of structures from a limited but complete set; each structure should have a single entry and a single exit.

Subroutine A subprogram that can be reached from more than one place in a main program. The process of passing control from the main program to a subroutine is a Subroutine Call and the mechanism is a Subroutine

Linkage. The data and addresses that the main program makes available to the subroutine are Parameters, and the process of making them available is called Passing Parameters.

Subroutine Call See Subroutine.

Synchronization Making two signals Operate according to the same clocking signal.

Snail mail A phrase popular on the Internet for referring to mail services provided by the United State Postal Service and similar agencies in other countries.

Answer of Question 1: A

Answer of Question 2: C