Hardware
The term hardware covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.
History of computing hardware First Generation (Mechanical/Electromechanical) Calculators Antikythera mechanism, Difference Engine, Norden bombsight
Programmable Devices Jacquard loom, Analytical Engine, Harvard Mark I, Z3
Second Generation (Vacuum Tubes) Calculators Atanasoff-Berry Computer
Programmable Devices ENIAC, EDSAC, EDVAC, UNIVAC I
Third Generation (Discrete transistors and SSI, MSI, LSI Integrated circuits) Mainframes System/360, BUNCH
Minicomputer PDP-8, PDP-11, System/32, System/36
Fourth Generation (VLSI integrated circuits) Minicomputer VAX, AS/400
4-bit microcomputer Intel 4004, Intel 4040
8-bit microcomputer Intel 8008, Intel 8080, Motorola 6800, Motorola 6809, MOS Technology 6502, Zilog Z80
16-bit microcomputer 8088, Zilog Z8000, WDC 65816/65802
32-bit microcomputer 80386, Pentium, 68000, ARM architecture
64-bit microcomputer [14] x86-64, PowerPC, MIPS, SPARC
Embedded computer 8048, 8051
Personal computer Desktop computer, Home computer, Laptop computer, Personal digital assistant (PDA), Portable computer, Tablet computer, Wearable computer
Server class computer
Theoretical/experimental Quantum computer
Chemical computer
DNA computing
Optical computer
Other Hardware Topics Peripheral device (Input/output) Input Mouse, Keyboard, Joystick, Image scanner
Output Monitor, Printer
Both Floppy disk drive, Hard disk, Optical disc drive, Teleprinter
Computer busses Short range RS-232, SCSI, PCI, USB
Long range (Computer networking) Ethernet, ATM, FDDI
Software
Software refers to parts of the computer that have no material form; programs, data, protocols, etc are all software. When software is stored in hardware that cannot easily be modified (such as BIOS ROM in an IBM PC compatible), it is sometimes termed firmware to indicate that it falls into an area of uncertainty between hardware and software.
Computer software Operating system Unix/BSD UNIX System V, AIX, HP-UX, Solaris (SunOS), FreeBSD, NetBSD, IRIX
GNU/Linux List of Linux distributions, Comparison of Linux distributions
Microsoft Windows Windows 9x, Windows NT, Windows CE
DOS QDOS, PC-DOS, MS-DOS, FreeDOS
Mac OS Mac OS classic, Mac OS X
Embedded and real-time List of embedded operating systems
Experimental Amoeba, Oberon/Bluebottle, Plan 9 from Bell Labs
Library Multimedia DirectX, OpenGL, OpenAL
Programming library C standard library, Standard template library
Data Protocol TCP/IP, Kermit, FTP, HTTP, SMTP
File format HTML, XML, JPEG, MPEG, PNG
User interface Graphical user interface (WIMP) Microsoft Windows, GNOME, QNX Photon, CDE, GEM
Text user interface Command line interface, shells
Other
Application Office suite Word processing, Desktop publishing, Presentation program, Database management system, Scheduling & Time management, Spreadsheet, Accounting software
Internet Access Browser, E-mail client, Web server, Mail transfer agent, Instant messaging
Design and manufacturing Computer-aided design, Computer-aided manufacturing, Plant management, Robotic manufacturing, Supply chain management
Graphics Raster graphics editor, Vector graphics editor, 3D modeler, Animation editor, 3D computer graphics, Video editing, Image processing
Audio Digital audio editor, Audio playback, Mixing, Audio synthesis, Computer music
Software Engineering Compiler, Assembler, Interpreter, Debugger, Text Editor, Integrated development environment, Performance analysis, Revision control, Software configuration management
Educational Edutainment, Educational game, Serious game, Flight simulator
Games Strategy, Arcade, Puzzle, Simulation, First-person shooter, Platform, Massively multiplayer, Interactive fiction
Misc Artificial intelligence, Antivirus software, Malware scanner, Installer/Package management systems, File manager
Wednesday, February 20, 2008
Tuesday, February 19, 2008
Computer Glossary P - Z
P - S
palm A hand-held computer.
PC Personal computer. Generally refers to computers running Windows with a Pentium processor.
PC board Printed Circuit board. A board printed or etched with a circuit and processors. Power supplies, information storage devices, or changers are attached.
PDA Personal Digital Assistant. A hand-held computer that can store daily appointments, phone numbers, addresses, and other important information. Most PDAs link to a desktop or laptop computer to download or upload information.
PDF Portable Document Format. A format presented by Adobe Acrobat that allows documents to be shared over a variety of operating systems. Documents can contain words and pictures and be formatted to have electronic links to other parts of the document or to places on the web.
Pentium chip Intel's fifth generation of sophisticated high-speed microprocessors. Pentium means “the fifth element.”
peripheral Any external device attached to a computer to enhance operation. Examples include external hard drive, scanner, printer, speakers, keyboard, mouse, trackball, stylus and tablet, and joystick.
personal computer (PC) A single-user computer containing a central processing unit (CPU) and one or more memory circuits.
petabyte A measure of memory or storage capacity and is approximately a thousand terabytes.
petaflop A theoretical measure of a computer's speed and can be expressed as a thousand-trillion floating-point operations per second.
platform The operating system, such as UNIX®, Macintosh®, Windows®, on which a computer is based.
plug and play Computer hardware or peripherals that come set up with necessary software so that when attached to a computer, they are “recognized” by the computer and are ready to use.
pop-up menu A menu window that opens vertically or horizontally on-screen to display context-related options. Also called drop-down menu or pull-down menu.
Power PC A competitor of the Pentium chip. It is a new generation of powerful sophisticated microprocessors produced from an Apple-IBM-Motorola alliance.
printer A mechanical device for printing a computer's output on paper. There are three major types of printers: Dot matrix: creates individual letters, made up of a series of tiny ink dots, by punching a ribbon with the ends of tiny wires. (This type of printer is most often used in industrial settings, such as direct mail for labeling.) Ink jet: sprays tiny droplets of ink particles onto paper. Laser: uses a beam of light to reproduce the image of each page using a magnetic charge that attracts dry toner that is transferred to paper and sealed with heat.
program A precise series of instructions written in a computer language that tells the computer what to do and how to do it. Programs are also called “software” or “applications.”
programming language A series of instructions written by a programmer according to a given set of rules or conventions (“syntax”). High-level programming languages are independent of the device on which the application (or program) will eventually run; low-level languages are specific to each program or platform. Programming language instructions are converted into programs in language specific to a particular machine or operating system (“machine language”) so that the computer can interpret and carry out the instructions. Some common programming languages are BASIC, C, C++, dBASE, FORTRAN, and Perl.
puck An input device, like a mouse. It has a magnifying glass with crosshairs on the front of it that allows the operator to position it precisely when tracing a drawing for use with CAD-CAM software.
pull-down menu A menu window that opens vertically on-screen to display context-related options. Also called drop-down menu or pop-up menu.
push technology Internet tool that delivers specific information directly to a user's desktop, eliminating the need to surf for it. PointCast, which delivers news in user-defined categories, is a popular example of this technology.
QuickTime® Audio-visual software that allows movie-delivery via the Internet and e-mail. QuickTime mages are viewed on a monitor.
RAID Redundant Array of Inexpensive Disks. A method of spreading information across several disks set up to act as a unit, using two different techniques: Disk striping: storing a bit of information across several discs (instead of storing it all on one disc and hoping that the disc doesn't crash). Disk mirroring: simultaneously storing a copy of information on another disc so that the information can be recovered if the main disc crashes.
RAM Random Access Memory. One of two basic types of memory. Portions of programs are stored in RAM when the program is launched so that the program will run faster. Though a PC has a fixed amount of RAM, only portions of it will be accessed by the computer at any given time. Also called memory.
right-click Using the right mouse button to open context-sensitive drop-down menus.
ROM Read-Only Memory. One of two basic types of memory. ROM contains only permanent information put there by the manufacturer. Information in ROM cannot be altered, nor can the memory be dynamically allocated by the computer or its operator.
scanner An electronic device that uses light-sensing equipment to scan paper images such as text, photos, and illustrations and translate the images into signals that the computer can then store, modify, or distribute.
search engine Software that makes it possible to look for and retrieve material on the Internet, particularly the Web. Some popular search engines are Alta Vista, Google, HotBot, Yahoo!, Web Crawler, and Lycos.
server A computer that shares its resources and information with other computers, called clients, on a network.
shareware Software created by people who are willing to sell it at low cost or no cost for the gratification of sharing. It may be freestanding software, or it may add functionality to existing software.
software Computer programs; also called “applications.”
spider A process search engines use to investigate new pages on a web site and collect the information that needs to be put in their indices.
spreadsheet Software that allows one to calculate numbers in a format that is similar to pages in a conventional ledger.
storage Devices used to store massive amounts of information so that it can be readily retrieved. Devices include RAIDs, CD-ROMs, DVDs
streaming Taking packets of information (sound or visual) from the Internet and storing it in temporary files to allow it to play in continuous flow.
stylus and tablet A input device similar to a mouse. The stylus is pen shaped. It is used to “draw” on a tablet (like drawing on paper) and the tablet transfers the information to the computer. The tablet responds to pressure—the firmer the pressure used to draw, the thicker the line appears.
surfing Exploring the Internet.
surge protector A controller to protect the computer and make up for variances in voltage.
T – Z
telnet A way to communicate with a remote computer over a network.
trackball Input device that controls the position of the cursor on the screen; the unit is mounted near the keyboard, and movement is controlled by moving a ball.
terabytes (TB) A thousand gigabytes.
teraflop A measure of a computer's speed. It can be expressed as a trillion floating-point operations per second.
Trojan Horse See virus.
UNIX® A very powerful operating system used as the basis of many high-end computer applications.
upload The process of transferring information from a computer to a web site (or other remote location on a network). v. To transfer information from a computer to a web site (or other remote location on a network).
URL Uniform Resource Locator. 1. The protocol for identifying a document on the Web. 2. A Web address (e.g., www.census.gov). A URL is unique to each user. See also domain.
UPS Universal Power Supply or Uninterruptible Power Supply. An electrical power supply that includes a battery to provide enough power to a computer during an outage to back-up data and properly shut down.
USB Universal Serial Bus. An industry standard for connecting different compatible peripheral devices across multiple platforms. Devices include printers, digital cameras, scanners, game pads, joysticks, keyboards and mice, and storage devices. USB peripherals offer the use of plug-and-play convenience by eliminating the need to turn off or restart the computer when attaching a new peripheral. Users can connect USB peripherals whenever they need them. For example, a user producing a newsletter could easily swap a digital camera for a scanner-without any downtime. Small, simple, inexpensive, and easy to attach, USB supports simultaneous connection of up to 127 devices by attaching peripherals through interconnected external hubs.
USB hub A multiple-socket USB connecter that allows several USB-compatible devices to be connected to a computer.
USENET A large unmoderated and unedited bulletin board on the Internet that offers thousands of forums, called newsgroups. These range from newsgroups exchanging information on scientific advances to celebrity fan clubs.
user friendly A program or device whose use is intuitive to people with a nontechnical background.
video teleconferencing A remote “face-to-face chat,” when two or more people using a webcam and an Internet telephone connection chat online. The webcam enables both live voice and video.
virtual reality (VR) A technology that allows one to experience and interact with images in a simulated three-dimensional environment. For example, you could design a room in a house on your computer and actually feel that you are walking around in it even though it was never built. (The Holodeck in the science-fiction TV series Star Trek: Voyager would be the ultimate virtual reality.) Current technology requires the user to wear a special helmet, viewing goggles, gloves, and other equipment that transmits and receives information from the computer.
virus An unauthorized piece of computer code attached to a computer program or portions of a computer system that secretly copies itself from one computer to another by shared discs and over telephone and cable lines. It can destroy information stored on the computer, and in extreme cases, can destroy operability. Computers can be protected from viruses if the operator utilizes good virus prevention software and keeps the virus definitions up to date. Most viruses are not programmed to spread themselves. They have to be sent to another computer by e-mail, sharing, or applications. The worm is an exception, because it is programmed to replicate itself by sending copies to other computers listed in the e-mail address book in the computer. There are many kinds of viruses, for example: Boot viruses place some of their code in the start-up disk sector to automatically execute when booting. Therefore, when an infected machine boots, the virus loads and runs. File viruses attached to program files (files with the extension “.exe”). When you run the infected program, the virus code executes. Macro viruses copy their macros to templates and/or other application document files. Trojan Horse is a malicious, security-breaking program that is disguised as something benign such as a screen saver or game. Worm launches an application that destroys information on your hard drive. It also sends a copy of the virus to everyone in the computer's e-mail address book.
WAV A sound format (pronounced “wave”) used to reproduce sounds on a computer.
webcam A video camera/computer setup that takes live images and sends them to a Web browser.
Window A portion of a computer display used in a graphical interface that enables users to select commands by pointing to illustrations or symbols with a mouse. “Windows” is also the name Microsoft adopted for its popular operating system.
World Wide Web (“WWW” or “the Web”) A network of servers on the Internet that use hypertext-linked databases and files. It was developed in 1989 by Tim Berners-Lee, a British computer scientist, and is now the primary platform of the Internet. The feature that distinguishes the Web from other Internet applications is its ability to display graphics in addition to text.
word processor A computer system or program for setting, editing, revising, correcting, storing, and printing text.
Worm See virus.
WYSIWYG What You See Is What You Get. When using most word processors, page layout programs (See desktop publishing), and web page design programs, words and images will be displayed on the monitor as they will look on the printed page or web page.
palm A hand-held computer.
PC Personal computer. Generally refers to computers running Windows with a Pentium processor.
PC board Printed Circuit board. A board printed or etched with a circuit and processors. Power supplies, information storage devices, or changers are attached.
PDA Personal Digital Assistant. A hand-held computer that can store daily appointments, phone numbers, addresses, and other important information. Most PDAs link to a desktop or laptop computer to download or upload information.
PDF Portable Document Format. A format presented by Adobe Acrobat that allows documents to be shared over a variety of operating systems. Documents can contain words and pictures and be formatted to have electronic links to other parts of the document or to places on the web.
Pentium chip Intel's fifth generation of sophisticated high-speed microprocessors. Pentium means “the fifth element.”
peripheral Any external device attached to a computer to enhance operation. Examples include external hard drive, scanner, printer, speakers, keyboard, mouse, trackball, stylus and tablet, and joystick.
personal computer (PC) A single-user computer containing a central processing unit (CPU) and one or more memory circuits.
petabyte A measure of memory or storage capacity and is approximately a thousand terabytes.
petaflop A theoretical measure of a computer's speed and can be expressed as a thousand-trillion floating-point operations per second.
platform The operating system, such as UNIX®, Macintosh®, Windows®, on which a computer is based.
plug and play Computer hardware or peripherals that come set up with necessary software so that when attached to a computer, they are “recognized” by the computer and are ready to use.
pop-up menu A menu window that opens vertically or horizontally on-screen to display context-related options. Also called drop-down menu or pull-down menu.
Power PC A competitor of the Pentium chip. It is a new generation of powerful sophisticated microprocessors produced from an Apple-IBM-Motorola alliance.
printer A mechanical device for printing a computer's output on paper. There are three major types of printers: Dot matrix: creates individual letters, made up of a series of tiny ink dots, by punching a ribbon with the ends of tiny wires. (This type of printer is most often used in industrial settings, such as direct mail for labeling.) Ink jet: sprays tiny droplets of ink particles onto paper. Laser: uses a beam of light to reproduce the image of each page using a magnetic charge that attracts dry toner that is transferred to paper and sealed with heat.
program A precise series of instructions written in a computer language that tells the computer what to do and how to do it. Programs are also called “software” or “applications.”
programming language A series of instructions written by a programmer according to a given set of rules or conventions (“syntax”). High-level programming languages are independent of the device on which the application (or program) will eventually run; low-level languages are specific to each program or platform. Programming language instructions are converted into programs in language specific to a particular machine or operating system (“machine language”) so that the computer can interpret and carry out the instructions. Some common programming languages are BASIC, C, C++, dBASE, FORTRAN, and Perl.
puck An input device, like a mouse. It has a magnifying glass with crosshairs on the front of it that allows the operator to position it precisely when tracing a drawing for use with CAD-CAM software.
pull-down menu A menu window that opens vertically on-screen to display context-related options. Also called drop-down menu or pop-up menu.
push technology Internet tool that delivers specific information directly to a user's desktop, eliminating the need to surf for it. PointCast, which delivers news in user-defined categories, is a popular example of this technology.
QuickTime® Audio-visual software that allows movie-delivery via the Internet and e-mail. QuickTime mages are viewed on a monitor.
RAID Redundant Array of Inexpensive Disks. A method of spreading information across several disks set up to act as a unit, using two different techniques: Disk striping: storing a bit of information across several discs (instead of storing it all on one disc and hoping that the disc doesn't crash). Disk mirroring: simultaneously storing a copy of information on another disc so that the information can be recovered if the main disc crashes.
RAM Random Access Memory. One of two basic types of memory. Portions of programs are stored in RAM when the program is launched so that the program will run faster. Though a PC has a fixed amount of RAM, only portions of it will be accessed by the computer at any given time. Also called memory.
right-click Using the right mouse button to open context-sensitive drop-down menus.
ROM Read-Only Memory. One of two basic types of memory. ROM contains only permanent information put there by the manufacturer. Information in ROM cannot be altered, nor can the memory be dynamically allocated by the computer or its operator.
scanner An electronic device that uses light-sensing equipment to scan paper images such as text, photos, and illustrations and translate the images into signals that the computer can then store, modify, or distribute.
search engine Software that makes it possible to look for and retrieve material on the Internet, particularly the Web. Some popular search engines are Alta Vista, Google, HotBot, Yahoo!, Web Crawler, and Lycos.
server A computer that shares its resources and information with other computers, called clients, on a network.
shareware Software created by people who are willing to sell it at low cost or no cost for the gratification of sharing. It may be freestanding software, or it may add functionality to existing software.
software Computer programs; also called “applications.”
spider A process search engines use to investigate new pages on a web site and collect the information that needs to be put in their indices.
spreadsheet Software that allows one to calculate numbers in a format that is similar to pages in a conventional ledger.
storage Devices used to store massive amounts of information so that it can be readily retrieved. Devices include RAIDs, CD-ROMs, DVDs
streaming Taking packets of information (sound or visual) from the Internet and storing it in temporary files to allow it to play in continuous flow.
stylus and tablet A input device similar to a mouse. The stylus is pen shaped. It is used to “draw” on a tablet (like drawing on paper) and the tablet transfers the information to the computer. The tablet responds to pressure—the firmer the pressure used to draw, the thicker the line appears.
surfing Exploring the Internet.
surge protector A controller to protect the computer and make up for variances in voltage.
T – Z
telnet A way to communicate with a remote computer over a network.
trackball Input device that controls the position of the cursor on the screen; the unit is mounted near the keyboard, and movement is controlled by moving a ball.
terabytes (TB) A thousand gigabytes.
teraflop A measure of a computer's speed. It can be expressed as a trillion floating-point operations per second.
Trojan Horse See virus.
UNIX® A very powerful operating system used as the basis of many high-end computer applications.
upload The process of transferring information from a computer to a web site (or other remote location on a network). v. To transfer information from a computer to a web site (or other remote location on a network).
URL Uniform Resource Locator. 1. The protocol for identifying a document on the Web. 2. A Web address (e.g., www.census.gov). A URL is unique to each user. See also domain.
UPS Universal Power Supply or Uninterruptible Power Supply. An electrical power supply that includes a battery to provide enough power to a computer during an outage to back-up data and properly shut down.
USB Universal Serial Bus. An industry standard for connecting different compatible peripheral devices across multiple platforms. Devices include printers, digital cameras, scanners, game pads, joysticks, keyboards and mice, and storage devices. USB peripherals offer the use of plug-and-play convenience by eliminating the need to turn off or restart the computer when attaching a new peripheral. Users can connect USB peripherals whenever they need them. For example, a user producing a newsletter could easily swap a digital camera for a scanner-without any downtime. Small, simple, inexpensive, and easy to attach, USB supports simultaneous connection of up to 127 devices by attaching peripherals through interconnected external hubs.
USB hub A multiple-socket USB connecter that allows several USB-compatible devices to be connected to a computer.
USENET A large unmoderated and unedited bulletin board on the Internet that offers thousands of forums, called newsgroups. These range from newsgroups exchanging information on scientific advances to celebrity fan clubs.
user friendly A program or device whose use is intuitive to people with a nontechnical background.
video teleconferencing A remote “face-to-face chat,” when two or more people using a webcam and an Internet telephone connection chat online. The webcam enables both live voice and video.
virtual reality (VR) A technology that allows one to experience and interact with images in a simulated three-dimensional environment. For example, you could design a room in a house on your computer and actually feel that you are walking around in it even though it was never built. (The Holodeck in the science-fiction TV series Star Trek: Voyager would be the ultimate virtual reality.) Current technology requires the user to wear a special helmet, viewing goggles, gloves, and other equipment that transmits and receives information from the computer.
virus An unauthorized piece of computer code attached to a computer program or portions of a computer system that secretly copies itself from one computer to another by shared discs and over telephone and cable lines. It can destroy information stored on the computer, and in extreme cases, can destroy operability. Computers can be protected from viruses if the operator utilizes good virus prevention software and keeps the virus definitions up to date. Most viruses are not programmed to spread themselves. They have to be sent to another computer by e-mail, sharing, or applications. The worm is an exception, because it is programmed to replicate itself by sending copies to other computers listed in the e-mail address book in the computer. There are many kinds of viruses, for example: Boot viruses place some of their code in the start-up disk sector to automatically execute when booting. Therefore, when an infected machine boots, the virus loads and runs. File viruses attached to program files (files with the extension “.exe”). When you run the infected program, the virus code executes. Macro viruses copy their macros to templates and/or other application document files. Trojan Horse is a malicious, security-breaking program that is disguised as something benign such as a screen saver or game. Worm launches an application that destroys information on your hard drive. It also sends a copy of the virus to everyone in the computer's e-mail address book.
WAV A sound format (pronounced “wave”) used to reproduce sounds on a computer.
webcam A video camera/computer setup that takes live images and sends them to a Web browser.
Window A portion of a computer display used in a graphical interface that enables users to select commands by pointing to illustrations or symbols with a mouse. “Windows” is also the name Microsoft adopted for its popular operating system.
World Wide Web (“WWW” or “the Web”) A network of servers on the Internet that use hypertext-linked databases and files. It was developed in 1989 by Tim Berners-Lee, a British computer scientist, and is now the primary platform of the Internet. The feature that distinguishes the Web from other Internet applications is its ability to display graphics in addition to text.
word processor A computer system or program for setting, editing, revising, correcting, storing, and printing text.
Worm See virus.
WYSIWYG What You See Is What You Get. When using most word processors, page layout programs (See desktop publishing), and web page design programs, words and images will be displayed on the monitor as they will look on the printed page or web page.
Computer Glossary A - F
A - C
applet A small Java application that is downloaded by an ActiveX or Java-enabled web browser. Once it has been downloaded, the applet will run on the user's computer. Common applets include financial calculators and web drawing programs.
application Computer software that performs a task or set of tasks, such as word processing or drawing. Applications are also referred to as programs.
ASCII American Standard Code for Information Interchange, an encoding system for converting keyboard characters and instructions into the binary number code that the computer understands.
bandwidth The capacity of a networked connection. Bandwidth determines how much data can be sent along the networked wires. Bandwidth is particularly important for Internet connections, since greater bandwidth also means faster downloads.
binary code The most basic language a computer understands, it is composed of a series of 0s and 1s. The computer interprets the code to form numbers, letters, punctuation marks, and symbols.
bit (short for “binary digit”). The smallest piece of computer information, either the number 0 or 1.
boot
To start up a computer. Cold boot—restarting computer after having turned off the power. Warm boot—restarting computer without having turned off the power.
browser
Software used to navigate the Internet. Netscape Navigator and Microsoft Internet Explorer are today's most popular browsers for accessing the World Wide Web.
bug
A malfunction due to an error in the program or a defect in the equipment.
byte
Most computers use combinations of eight bits, called bytes, to represent one character of data or instructions. For example, the word “cat” has three characters, and it would be represented by three bytes.
cache
A small data-memory storage area that a computer can use to instantly re-access data instead of re-reading the data from the original source, such as a hard drive. Browsers use a cache to store web pages so that the user may view them again without reconnecting to the Web.
CAD-CAM
Computer Aided Drawing-Computer Aided Manufacturing. The instructions stored in a computer that will be translated to very precise operating instructions to a robot, such as for assembling cars or laser-cutting signage.
CD-ROM
Compact Disc Read-Only Memory. An optically read disc designed to hold information such as music, reference materials, or computer software. A single CD-ROM can hold around 640 megabytes of data, enough for several encyclopedias. Most software programs are now delivered on CD-ROMs.
CGI Common Gateway Interface. A programming standard that allows visitors to fill out form fields on a Web page and have that information interact with a database, possibly coming back to the user as another Web page.
CGI may also refer to Computer-Generated Imaging, the process in which sophisticated computer programs create still and animated graphics, such as special effects for movies.
chat
Typing text into a message box on a screen to engage in dialog with one or more people via the Internet or other network.
chip
A tiny wafer of silicon containing miniature electric circuits that can store millions of bits of information.
client
A single user of a network application that is operated from a server. A client/server architecture allows many people to use the same data simultaneously. The program's main component (the data) resides on a centralized server, with smaller components (user interface) on each client.
Cookie
A text file sent by a Web server that is stored on the hard drive of a computer and relays back to the Web server things about the user, his or her computer, and/or his or her computer activities.
CPU
Central Processing Unit. The brain of the computer.
cracker
A person who “breaks in” to a computer through a network, without authorization and with mischievous or destructive intent (a crime in some states).
crash
A hardware or software problem that causes information to be lost or the computer to malfunction. Sometimes a crash can cause permanent damage to a computer.
cursor
A moving position-indicator displayed on a computer monitor that shows a computer operator where the next action or operation will take place.
cyberspace Slang for the Internet.
D - F
database
A collection of similar information stored in a file, such as a database of addresses. This information may be created and stored in a database management system (DBMS).
debug
Slang. To find and correct equipment defects or program malfunctions.
default
The pre-defined configuration of a system or an application. In most programs, the defaults can be changed to reflect personal preferences.
desktop
The main directory of the user interface. Desktops usually contain icons that represent links to the hard drive, a network (if there is one), and a trash or recycling can for files to be deleted. It can also display icons of frequently used applications, as requested by the user.
desktop publishing
The production of publication-quality documents using a personal computer in combination with text, graphics, and page layout programs.
directory
A list of files stored in the computer.
disk Two distinct types. The names refer to the media inside the container: A hard disc stores vast amounts of data. It is usually inside the computer but can be a separate peripheral on the outside. Hard discs are made up of several rigid coated metal discs. Currently, hard discs can store 15 to 30 Gb (gigabytes) A floppy disc, 3.5" square, usually inserted into the computer and can store about 1.4 megabytes of data. The 3.5" square “floppies” have a very thin, flexible disc inside. There is also an intermediate-sized floppy disc, trademarked Zip discs, which can store 250 megabytes of data.
disk drive
The equipment that operates a hard or floppy disc.
documentation
The instruction manual for a piece of hardware or software.
domain
Represents an IP (Internet Protocol) address or set of IP addresses that comprise a domain. The domain name appears in URLs to identify web pages or in email addresses. For example, the email address for the First Lady is first.lady@whitehouse.gov, “whitehouse.gov” being the domain name. Each domain name ends with a suffix that indicates what “top level domain” it belongs to. These are: “.com” for commercial, “.gov” for government, “.org” for organization, “.edu” for educational institution, “.biz” for business, “.info” for information, “.tv” for television, “.ws” for website. Domain suffixes may also indicate the country in which the domain is registered. No two parties can ever hold the same domain name.
domain name
The name of a network or computer linked to the Internet. Domains are defined by a common IP address or set of similar IP (Internet Protocol) addresses.
download The process of transferring information from a web site (or other remote location on a network) to the computer. It is possible to “download a file” or “view a download.”
v. To transfer information from a web site (or other remote location on a network) to the computer.
DOS
Disk Operating System. An operating system designed for early IBM-compatible PCs.
Drop-down menu
A menu window that opens vertically on-screen to display context-related options. Also called pop-up menu or pull-down menu.
DSL
Digital Subscriber Line. A method of connecting to the Internet via a phone line. A DSL connection uses copper telephone lines but is able to relay data at much higher speeds than modems and does not interfere with telephone use.
DVD
Digital Video Disc—Similar to a CD-ROM, it stores and plays both audio and video.
ebook
An electronic (usually hand-held) reading device that allows a person to view digitally stored reading materials.
email
Electronic mail; messages, including memos or letters, sent electronically between networked computers that may be across the office or around the world.
emoticon
A text-based expression of emotion created from ASCII characters that mimics a facial expression when viewed with your head tilted to the left. Here are some examples:
:-) Smiling
:-( Frowning
;-) Winking
:_( Crying
encryption
The process of transmitting scrambled data so that only authorized recipients can unscramble it. For instance, encryption is used to scramble credit card information when purchases are made over the Internet.
ethernet
A type of network.
ethernet card
A board inside a computer to which a network cable can be attached.
file
A set of data that is stored in the computer.
firewall
A set of security programs that protect a computer from outside interference or access via the Internet.
Firewire
Apple® Computer's high-speed data transfer. Frequently used to import video to a computer.
folder
A structure for containing electronic files. In some operating systems, it is called a “directory.”
fonts
Sets of typefaces (or characters) that come in different styles and sizes.
freeware
Software created by people who are willing to give it away for the satisfaction of sharing or knowing they helped to simplify other people's lives. It may be freestanding software, or it may add functionality to existing software.
FTP File Transfer Protocol. A format and set of rules for transferring files from a host to a remote computer.
applet A small Java application that is downloaded by an ActiveX or Java-enabled web browser. Once it has been downloaded, the applet will run on the user's computer. Common applets include financial calculators and web drawing programs.
application Computer software that performs a task or set of tasks, such as word processing or drawing. Applications are also referred to as programs.
ASCII American Standard Code for Information Interchange, an encoding system for converting keyboard characters and instructions into the binary number code that the computer understands.
bandwidth The capacity of a networked connection. Bandwidth determines how much data can be sent along the networked wires. Bandwidth is particularly important for Internet connections, since greater bandwidth also means faster downloads.
binary code The most basic language a computer understands, it is composed of a series of 0s and 1s. The computer interprets the code to form numbers, letters, punctuation marks, and symbols.
bit (short for “binary digit”). The smallest piece of computer information, either the number 0 or 1.
boot
To start up a computer. Cold boot—restarting computer after having turned off the power. Warm boot—restarting computer without having turned off the power.
browser
Software used to navigate the Internet. Netscape Navigator and Microsoft Internet Explorer are today's most popular browsers for accessing the World Wide Web.
bug
A malfunction due to an error in the program or a defect in the equipment.
byte
Most computers use combinations of eight bits, called bytes, to represent one character of data or instructions. For example, the word “cat” has three characters, and it would be represented by three bytes.
cache
A small data-memory storage area that a computer can use to instantly re-access data instead of re-reading the data from the original source, such as a hard drive. Browsers use a cache to store web pages so that the user may view them again without reconnecting to the Web.
CAD-CAM
Computer Aided Drawing-Computer Aided Manufacturing. The instructions stored in a computer that will be translated to very precise operating instructions to a robot, such as for assembling cars or laser-cutting signage.
CD-ROM
Compact Disc Read-Only Memory. An optically read disc designed to hold information such as music, reference materials, or computer software. A single CD-ROM can hold around 640 megabytes of data, enough for several encyclopedias. Most software programs are now delivered on CD-ROMs.
CGI Common Gateway Interface. A programming standard that allows visitors to fill out form fields on a Web page and have that information interact with a database, possibly coming back to the user as another Web page.
CGI may also refer to Computer-Generated Imaging, the process in which sophisticated computer programs create still and animated graphics, such as special effects for movies.
chat
Typing text into a message box on a screen to engage in dialog with one or more people via the Internet or other network.
chip
A tiny wafer of silicon containing miniature electric circuits that can store millions of bits of information.
client
A single user of a network application that is operated from a server. A client/server architecture allows many people to use the same data simultaneously. The program's main component (the data) resides on a centralized server, with smaller components (user interface) on each client.
Cookie
A text file sent by a Web server that is stored on the hard drive of a computer and relays back to the Web server things about the user, his or her computer, and/or his or her computer activities.
CPU
Central Processing Unit. The brain of the computer.
cracker
A person who “breaks in” to a computer through a network, without authorization and with mischievous or destructive intent (a crime in some states).
crash
A hardware or software problem that causes information to be lost or the computer to malfunction. Sometimes a crash can cause permanent damage to a computer.
cursor
A moving position-indicator displayed on a computer monitor that shows a computer operator where the next action or operation will take place.
cyberspace Slang for the Internet.
D - F
database
A collection of similar information stored in a file, such as a database of addresses. This information may be created and stored in a database management system (DBMS).
debug
Slang. To find and correct equipment defects or program malfunctions.
default
The pre-defined configuration of a system or an application. In most programs, the defaults can be changed to reflect personal preferences.
desktop
The main directory of the user interface. Desktops usually contain icons that represent links to the hard drive, a network (if there is one), and a trash or recycling can for files to be deleted. It can also display icons of frequently used applications, as requested by the user.
desktop publishing
The production of publication-quality documents using a personal computer in combination with text, graphics, and page layout programs.
directory
A list of files stored in the computer.
disk Two distinct types. The names refer to the media inside the container: A hard disc stores vast amounts of data. It is usually inside the computer but can be a separate peripheral on the outside. Hard discs are made up of several rigid coated metal discs. Currently, hard discs can store 15 to 30 Gb (gigabytes) A floppy disc, 3.5" square, usually inserted into the computer and can store about 1.4 megabytes of data. The 3.5" square “floppies” have a very thin, flexible disc inside. There is also an intermediate-sized floppy disc, trademarked Zip discs, which can store 250 megabytes of data.
disk drive
The equipment that operates a hard or floppy disc.
documentation
The instruction manual for a piece of hardware or software.
domain
Represents an IP (Internet Protocol) address or set of IP addresses that comprise a domain. The domain name appears in URLs to identify web pages or in email addresses. For example, the email address for the First Lady is first.lady@whitehouse.gov, “whitehouse.gov” being the domain name. Each domain name ends with a suffix that indicates what “top level domain” it belongs to. These are: “.com” for commercial, “.gov” for government, “.org” for organization, “.edu” for educational institution, “.biz” for business, “.info” for information, “.tv” for television, “.ws” for website. Domain suffixes may also indicate the country in which the domain is registered. No two parties can ever hold the same domain name.
domain name
The name of a network or computer linked to the Internet. Domains are defined by a common IP address or set of similar IP (Internet Protocol) addresses.
download The process of transferring information from a web site (or other remote location on a network) to the computer. It is possible to “download a file” or “view a download.”
v. To transfer information from a web site (or other remote location on a network) to the computer.
DOS
Disk Operating System. An operating system designed for early IBM-compatible PCs.
Drop-down menu
A menu window that opens vertically on-screen to display context-related options. Also called pop-up menu or pull-down menu.
DSL
Digital Subscriber Line. A method of connecting to the Internet via a phone line. A DSL connection uses copper telephone lines but is able to relay data at much higher speeds than modems and does not interfere with telephone use.
DVD
Digital Video Disc—Similar to a CD-ROM, it stores and plays both audio and video.
ebook
An electronic (usually hand-held) reading device that allows a person to view digitally stored reading materials.
Electronic mail; messages, including memos or letters, sent electronically between networked computers that may be across the office or around the world.
emoticon
A text-based expression of emotion created from ASCII characters that mimics a facial expression when viewed with your head tilted to the left. Here are some examples:
:-) Smiling
:-( Frowning
;-) Winking
:_( Crying
encryption
The process of transmitting scrambled data so that only authorized recipients can unscramble it. For instance, encryption is used to scramble credit card information when purchases are made over the Internet.
ethernet
A type of network.
ethernet card
A board inside a computer to which a network cable can be attached.
file
A set of data that is stored in the computer.
firewall
A set of security programs that protect a computer from outside interference or access via the Internet.
Firewire
Apple® Computer's high-speed data transfer. Frequently used to import video to a computer.
folder
A structure for containing electronic files. In some operating systems, it is called a “directory.”
fonts
Sets of typefaces (or characters) that come in different styles and sizes.
freeware
Software created by people who are willing to give it away for the satisfaction of sharing or knowing they helped to simplify other people's lives. It may be freestanding software, or it may add functionality to existing software.
FTP File Transfer Protocol. A format and set of rules for transferring files from a host to a remote computer.
Monday, February 18, 2008
Computer Production Market
The market for computer products is a multi-billion dollar business where one can find a perfect balance of technology and efficiency. The huge industrial market is lead by such names as IBM, Hewlett Packard, and Compaq. In the world today, computers are used for a variety of tasks and play a crucial role in the areas of academics and business. The steps that are taken to bring the computer from several small components to a desktop product are organization of the manufacturing facility, assembly of hardware, installation of software, and a test process. The production of a high quality product is important to computer buyers. The following discussion demonstrates steps large corporations take to make an efficient computer. Companies such as IBM and Apple computers are well known in the computer industry. These companies have several manufacturing facilities around the world where thousands of computers are built. Manufacturing factories, which typically range between “75,000 to 200,000 square feet”() in size, produce approximately 14,000 systems weekly. Companies generally use 2 methods of computer assembly. One method involves complete unit assembly by one person, the other being group assembly where several people construct a single computer (the latter method is known as assembly line production). A factory employing the single unit assembly method produces about 40 to 60 computers a day (this number varies base on the complexity of the system being assembled). The assembly line method yields approximately 70 computers a day in the average factory. The assembly line method is the most efficient way to produce computes as individual workers become highly specialized in a specific task. In addition, the next person down the ‘line’ can check the pervious person’s work to check for errors. “Additional inspection [, as used on assembly lines] tends to increase the computer’s quality”(). The first step in manufacturing a computer is for the designer to consider a balance between economic need (customers price level) with computer power and practicality. Manufacturers try to make the best computer (in a given price range) for the lowest cost. Once a specific model is designed the company orders the high quality parts from their own component manufacturing divisions or outside suppliers. Inventory control is an important part of acquiring components as, to remain efficient, the company tries to avoid overstocking. Manufacturers take note of the consumer demand, on a daily basis to efficiently establish quantities for the production line. Top manufactures such as IBM and Apple buy computer components for their products based on “availability, quality and priority of the configuration” (). When assembling a computer, there are 8 to 10 major components installed including the processor speed chip, the motherboard, RAM (Random Access Memory), diskette drive, modem or network card, video card, hard drive, sound card, and CD-ROM. Before the components are placed into the computer, each part undergoes an extensive testing process called “quality control” (). Quality control ensures that faulty systems are not shipped. As an initial step, prior to the assembly process, an inspection of the outer case to ensure that there are no scratches or defects. The brand name and indicator labels are put onto the computer case at this time. Next the motherboard is installed and prepared for the processor chip. The chip (which is often a Pentium chip) is attached to the motherboard along with the RAM component. Once the chip and RAM are installed, the internal speakers and sound card are placed into the case. The hard drive, disk drive and CD-ROM drive are in snuggly attached to the computer chassis. All these components are then attached to the motherboard with cables so that they may communicate with each other. Power supply is then applied to the computer and other additional components such as the video card, and modem are added near a final stage of assembly. After all these components are installed to create the finished ‘PC’, the unit is thoroughly inspected to ensures that all the cables connections are in place and all other defects are fixed. Inspectors also ensure that cables are in appropriate places so that they do not touch components. This is important as heat given off components, while operating can cause minor explosions. The CMOS (complementary metal-oxide semiconductor- circuitry for the memory and processor) is set up at this time. The top cover is placed onto the computer and it is shipped off for further testing. All companies differ in their testing of finished products. A common in most companies includes the 48-hour burn in period. This period is very similar to the burn in period that a car undergoes following production. After the 48-hour burn in, final diagnostic tests are completed to ensure all components are working well. If a computer is ordered with sound cards, speakers are attached to the unit and they also are tested. Mouse and keyboard components are tested manually by connecting a testing mouse and keyboard to the ports. The computer is then shipped from the manufacturing site to the distribution center. At the center, additional tests are possible as computers are randomly checked and inspected. The computer is then further shipped to department or retail stores for sale to the consumer. In conclusion, the production of a computer from a number of components to a finished product is a complex procedure. It is crucial to have a well-organized computer manufacturing facility, and it is important that assembly and insulation of all components is carried out accurately. Final testing is the concluding step in computer manufacturing process. The testing phase is most important, as consumers demand high quality and efficient products. In society today, computers are essential for the flow of information and important technical tasks. The usefulness of the computer and subsequent consumer demand for improved models will keep pressure on manufactures to build more efficient, high quality machines in future years.
Computer Production Market
The market for computer products is a multi-billion dollar business where one can find a perfect balance of technology and efficiency. The huge industrial market is lead by such names as IBM, Hewlett Packard, and Compaq. In the world today, computers are used for a variety of tasks and play a crucial role in the areas of academics and business. The steps that are taken to bring the computer from several small components to a desktop product are organization of the manufacturing facility, assembly of hardware, installation of software, and a test process. The production of a high quality product is important to computer buyers. The following discussion demonstrates steps large corporations take to make an efficient computer. Companies such as IBM and Apple computers are well known in the computer industry. These companies have several manufacturing facilities around the world where thousands of computers are built. Manufacturing factories, which typically range between “75,000 to 200,000 square feet”() in size, produce approximately 14,000 systems weekly. Companies generally use 2 methods of computer assembly. One method involves complete unit assembly by one person, the other being group assembly where several people construct a single computer (the latter method is known as assembly line production). A factory employing the single unit assembly method produces about 40 to 60 computers a day (this number varies base on the complexity of the system being assembled). The assembly line method yields approximately 70 computers a day in the average factory. The assembly line method is the most efficient way to produce computes as individual workers become highly specialized in a specific task. In addition, the next person down the ‘line’ can check the pervious person’s work to check for errors. “Additional inspection [, as used on assembly lines] tends to increase the computer’s quality”(). The first step in manufacturing a computer is for the designer to consider a balance between economic need (customers price level) with computer power and practicality. Manufacturers try to make the best computer (in a given price range) for the lowest cost. Once a specific model is designed the company orders the high quality parts from their own component manufacturing divisions or outside suppliers. Inventory control is an important part of acquiring components as, to remain efficient, the company tries to avoid overstocking. Manufacturers take note of the consumer demand, on a daily basis to efficiently establish quantities for the production line. Top manufactures such as IBM and Apple buy computer components for their products based on “availability, quality and priority of the configuration” (). When assembling a computer, there are 8 to 10 major components installed including the processor speed chip, the motherboard, RAM (Random Access Memory), diskette drive, modem or network card, video card, hard drive, sound card, and CD-ROM. Before the components are placed into the computer, each part undergoes an extensive testing process called “quality control” (). Quality control ensures that faulty systems are not shipped. As an initial step, prior to the assembly process, an inspection of the outer case to ensure that there are no scratches or defects. The brand name and indicator labels are put onto the computer case at this time. Next the motherboard is installed and prepared for the processor chip. The chip (which is often a Pentium chip) is attached to the motherboard along with the RAM component. Once the chip and RAM are installed, the internal speakers and sound card are placed into the case. The hard drive, disk drive and CD-ROM drive are in snuggly attached to the computer chassis. All these components are then attached to the motherboard with cables so that they may communicate with each other. Power supply is then applied to the computer and other additional components such as the video card, and modem are added near a final stage of assembly. After all these components are installed to create the finished ‘PC’, the unit is thoroughly inspected to ensures that all the cables connections are in place and all other defects are fixed. Inspectors also ensure that cables are in appropriate places so that they do not touch components. This is important as heat given off components, while operating can cause minor explosions. The CMOS (complementary metal-oxide semiconductor- circuitry for the memory and processor) is set up at this time. The top cover is placed onto the computer and it is shipped off for further testing. All companies differ in their testing of finished products. A common in most companies includes the 48-hour burn in period. This period is very similar to the burn in period that a car undergoes following production. After the 48-hour burn in, final diagnostic tests are completed to ensure all components are working well. If a computer is ordered with sound cards, speakers are attached to the unit and they also are tested. Mouse and keyboard components are tested manually by connecting a testing mouse and keyboard to the ports. The computer is then shipped from the manufacturing site to the distribution center. At the center, additional tests are possible as computers are randomly checked and inspected. The computer is then further shipped to department or retail stores for sale to the consumer. In conclusion, the production of a computer from a number of components to a finished product is a complex procedure. It is crucial to have a well-organized computer manufacturing facility, and it is important that assembly and insulation of all components is carried out accurately. Final testing is the concluding step in computer manufacturing process. The testing phase is most important, as consumers demand high quality and efficient products. In society today, computers are essential for the flow of information and important technical tasks. The usefulness of the computer and subsequent consumer demand for improved models will keep pressure on manufactures to build more efficient, high quality machines in future years.
Saturday, February 16, 2008
All About Computer Viruses
Your computer is as slow as molasses. Your mouse freezes every 15 minutes, and that Microsoft Word program just won’t seem to open.
You might have a virus.
Just what exactly is a virus? What kind is in your computer? How did it get there? How is it spreading and wreaking such havoc? And why is it bothering with your computer anyway?
Viruses are pieces of programming code that make copies of themselves, or replicate, inside your computer without asking your explicit written permission to do so. Forget getting your permission down on paper. Viruses don’t bother to seek your permission at all! Very invasive.
In comparison, there are pieces of code that might replicate inside your computer, say something your IT guy thinks you need. But the code spreads, perhaps throughout your office network, with your consent (or at least your IT guy’s consent). These types of replicating code are called agents, said Jimmy Kuo, a research fellow with McAfee AVERT, a research arm of anti-virus software-maker McAfee Inc.
In this article, though, we’re not talking about the good guys, or the agents. We’ll be talking about the bad guys, the viruses.
A long, long time ago in computer years, like five, most viruses were comprised of a similar breed. They entered your computer perhaps through an email attachment or a floppy disk (remember those?). Then they attached themselves to one of your files, say your Microsoft Word program.
When you opened your Microsoft Word program, the virus replicated and attached itself to other files. These could be other random files on your hard drive, the files furthest away from your Microsoft Word program, or other files, depending on how the virus writer wanted the virus to behave.
This virus code could contain hundreds or thousands of instructions. When it replicates it inserts those instructions, into the files it infects, said Carey Nachenberg, Chief Architect at Symantec Research Labs, an arm of anti-virus software-maker Symantec. Corp.
Because so many other types of viruses exist now, the kind just described is called a classic virus. Classic viruses still exist but they’re not quite as prevalent as they used to be. (Perhaps we could put classic viruses on the shelf with Hemingway and Dickens.)
These days, in the modern era, viruses are known to spread through vulnerabilities in web browsers, files shared over the internet, emails themselves, and computer networks.
As far as web browsers are concerned, Microsoft’s Internet Explorer takes most of the heat for spreading viruses because it’s used by more people for web surfing than any other browser.
Nevertheless, “Any web browser potentially has vulnerabilities,” Nachenberg said.
For instance, let’s say you go to a website in IE you have every reason to think is safe, Nachenberg said.
But unfortunately it isn’t. It has virus code hidden in its background that IE isn’t protecting you from. While you’re looking at the site, the virus is downloaded onto your computer, he said. That’s one way of catching a nasty virus.
During the past two years, another prevalent way to catch a virus has been through downloads computer users share with one another, mostly on music sharing sites, Kuo said. On Limewire or Kazaa, for instance, teenagers or other music enthusiasts might think they’re downloading that latest Justin Timberlake song, when in reality they’re downloading a virus straight into their computer. It’s easy for a virus writer to put a download with a virus on one of these sites because everyone’s sharing with everyone else anyway.
Here’s one you might not have thought of. If you use Outlook or Outlook Express to send and receive email, do you have a preview pane below your list of emails that shows the contents of the email you have highlighted? If so, you may be putting yourself at risk.
Some viruses, though a small percentage according to Nachenberg, are inserted straight into emails themselves.
Forget opening the attachment. All you have to do is view the email to potentially get a virus, Kuo added. For instance, have you ever opened or viewed an email that states it’s “loading”? Well, once everything is “loaded,” a virus in the email might just load onto your computer.
So if I were you, I’d click on View on the toolbar in your Outlook or Outlook Express and close the preview pane. (You have to click on View and then Layout in Outlook Express.)
On a network at work? You could get a virus that way. Worms are viruses that come into your computer via networks, Kuo said. They travel from machine to machine and, unlike, the classic viruses, they attack the machine itself rather than individual files.
Worms sit in your working memory, or RAM, Nachenberg said.
OK, so we’ve talked about how the viruses get into a computer. How do they cause so much damage once they’re there?
Let’s say you’ve caught a classic virus, one that replicates and attacks various files on your computer. Let’s go back to the example of the virus that initially infects your Microsoft Word program.
Well, it might eventually cause that program to crash, Nachenberg said. It also might cause damage to your computer as it looks for new targets to infect.
This process of infecting targets and looking for new ones could eventually use up your computer’s ability to function, he said.
Often the destruction a virus causes is pegged to a certain event or date and time, called a trigger. For instance, a virus could be programmed to lay dormant until January 28. When that date rolls around, though, it may be programmed to do something as innocuous but annoying as splash popups on your screen, or something as severe as reformat your computer’s hard drive, Nachenberg said.
There are other potential reasons, though, for a virus to cause your computer to be acting slow or in weird ways. And that leads us to a new segment – the reason virus writers would want to waste their time creating viruses in the first place.
The majority of viruses are still written by teenagers looking for some notoriety, Nachenberg said. But a growing segment of the virus-writing population has other intentions in mind.
For these other intentions, we first need to explain the “backdoor” concept.
The sole purpose of some viruses is to create a vulnerability in your computer. Once it creates this hole of sorts, or backdoor, it signals home to mama or dada virus writer (kind of like in E.T.). Once the virus writer receives the signal, they can use and abuse your computer to their own likings.
Trojans are sometimes used to open backdoors. In fact that is usually their sole purpose, Kuo said.
Trojans are pieces of code you might download onto your computer, say, from a newsgroup. As in the Trojan War they are named after, they are usually disguised as innocuous pieces of code. But Trojans aren’t considered viruses because they don’t replicate.
Now back to the real viruses. Let’s say we have Joe Shmo virus writer. He sends out a virus that ends up infecting a thousand machines. But he doesn’t want the feds on his case. So he instructs the viruses on the various machines to send their signals, not of course to his computer, but to a place that can’t be traced. Hotmail email happens to be an example of one such place, Kuo said.
OK, so the virus writers now control these computers. What will they use them for?
One use is to send spam. Once that backdoor is open, they bounce spam off of those computers and send it to other machines, Nachenberg said.
That’s right. Some spam you have in your email right now may have been originally sent to other innocent computers before it came to yours so that it could remain in disguise. If the authorities could track down the original senders of spam, they could crack down on spam itself. Spam senders don’t want that.
Ever heard of phishing emails? Those are the ones that purport to be from your internet service provider or bank. They typically request some information from you, like your credit card number. The problem is, they’re NOT from your internet service provider or your bank. They’re from evil people after your credit card number! Well, these emails are often sent the same way spam is sent, by sending them via innocent computers.
Of course makers of anti-virus software use a variety of methods to combat the onslaught of viruses. Norton, for instance, uses signature scanning, Nachenberg said.
Signature scanning is similar to the process of looking for DNA fingerprints, he said. Norton examines programming code to find what viruses are made of. It adds those bad instructions it finds to its large database of other bad code. Then it uses this vast database to seek out and match the code in it with similar code in your computer. When it finds such virus code, it lets you know!
You might have a virus.
Just what exactly is a virus? What kind is in your computer? How did it get there? How is it spreading and wreaking such havoc? And why is it bothering with your computer anyway?
Viruses are pieces of programming code that make copies of themselves, or replicate, inside your computer without asking your explicit written permission to do so. Forget getting your permission down on paper. Viruses don’t bother to seek your permission at all! Very invasive.
In comparison, there are pieces of code that might replicate inside your computer, say something your IT guy thinks you need. But the code spreads, perhaps throughout your office network, with your consent (or at least your IT guy’s consent). These types of replicating code are called agents, said Jimmy Kuo, a research fellow with McAfee AVERT, a research arm of anti-virus software-maker McAfee Inc.
In this article, though, we’re not talking about the good guys, or the agents. We’ll be talking about the bad guys, the viruses.
A long, long time ago in computer years, like five, most viruses were comprised of a similar breed. They entered your computer perhaps through an email attachment or a floppy disk (remember those?). Then they attached themselves to one of your files, say your Microsoft Word program.
When you opened your Microsoft Word program, the virus replicated and attached itself to other files. These could be other random files on your hard drive, the files furthest away from your Microsoft Word program, or other files, depending on how the virus writer wanted the virus to behave.
This virus code could contain hundreds or thousands of instructions. When it replicates it inserts those instructions, into the files it infects, said Carey Nachenberg, Chief Architect at Symantec Research Labs, an arm of anti-virus software-maker Symantec. Corp.
Because so many other types of viruses exist now, the kind just described is called a classic virus. Classic viruses still exist but they’re not quite as prevalent as they used to be. (Perhaps we could put classic viruses on the shelf with Hemingway and Dickens.)
These days, in the modern era, viruses are known to spread through vulnerabilities in web browsers, files shared over the internet, emails themselves, and computer networks.
As far as web browsers are concerned, Microsoft’s Internet Explorer takes most of the heat for spreading viruses because it’s used by more people for web surfing than any other browser.
Nevertheless, “Any web browser potentially has vulnerabilities,” Nachenberg said.
For instance, let’s say you go to a website in IE you have every reason to think is safe, Nachenberg said.
But unfortunately it isn’t. It has virus code hidden in its background that IE isn’t protecting you from. While you’re looking at the site, the virus is downloaded onto your computer, he said. That’s one way of catching a nasty virus.
During the past two years, another prevalent way to catch a virus has been through downloads computer users share with one another, mostly on music sharing sites, Kuo said. On Limewire or Kazaa, for instance, teenagers or other music enthusiasts might think they’re downloading that latest Justin Timberlake song, when in reality they’re downloading a virus straight into their computer. It’s easy for a virus writer to put a download with a virus on one of these sites because everyone’s sharing with everyone else anyway.
Here’s one you might not have thought of. If you use Outlook or Outlook Express to send and receive email, do you have a preview pane below your list of emails that shows the contents of the email you have highlighted? If so, you may be putting yourself at risk.
Some viruses, though a small percentage according to Nachenberg, are inserted straight into emails themselves.
Forget opening the attachment. All you have to do is view the email to potentially get a virus, Kuo added. For instance, have you ever opened or viewed an email that states it’s “loading”? Well, once everything is “loaded,” a virus in the email might just load onto your computer.
So if I were you, I’d click on View on the toolbar in your Outlook or Outlook Express and close the preview pane. (You have to click on View and then Layout in Outlook Express.)
On a network at work? You could get a virus that way. Worms are viruses that come into your computer via networks, Kuo said. They travel from machine to machine and, unlike, the classic viruses, they attack the machine itself rather than individual files.
Worms sit in your working memory, or RAM, Nachenberg said.
OK, so we’ve talked about how the viruses get into a computer. How do they cause so much damage once they’re there?
Let’s say you’ve caught a classic virus, one that replicates and attacks various files on your computer. Let’s go back to the example of the virus that initially infects your Microsoft Word program.
Well, it might eventually cause that program to crash, Nachenberg said. It also might cause damage to your computer as it looks for new targets to infect.
This process of infecting targets and looking for new ones could eventually use up your computer’s ability to function, he said.
Often the destruction a virus causes is pegged to a certain event or date and time, called a trigger. For instance, a virus could be programmed to lay dormant until January 28. When that date rolls around, though, it may be programmed to do something as innocuous but annoying as splash popups on your screen, or something as severe as reformat your computer’s hard drive, Nachenberg said.
There are other potential reasons, though, for a virus to cause your computer to be acting slow or in weird ways. And that leads us to a new segment – the reason virus writers would want to waste their time creating viruses in the first place.
The majority of viruses are still written by teenagers looking for some notoriety, Nachenberg said. But a growing segment of the virus-writing population has other intentions in mind.
For these other intentions, we first need to explain the “backdoor” concept.
The sole purpose of some viruses is to create a vulnerability in your computer. Once it creates this hole of sorts, or backdoor, it signals home to mama or dada virus writer (kind of like in E.T.). Once the virus writer receives the signal, they can use and abuse your computer to their own likings.
Trojans are sometimes used to open backdoors. In fact that is usually their sole purpose, Kuo said.
Trojans are pieces of code you might download onto your computer, say, from a newsgroup. As in the Trojan War they are named after, they are usually disguised as innocuous pieces of code. But Trojans aren’t considered viruses because they don’t replicate.
Now back to the real viruses. Let’s say we have Joe Shmo virus writer. He sends out a virus that ends up infecting a thousand machines. But he doesn’t want the feds on his case. So he instructs the viruses on the various machines to send their signals, not of course to his computer, but to a place that can’t be traced. Hotmail email happens to be an example of one such place, Kuo said.
OK, so the virus writers now control these computers. What will they use them for?
One use is to send spam. Once that backdoor is open, they bounce spam off of those computers and send it to other machines, Nachenberg said.
That’s right. Some spam you have in your email right now may have been originally sent to other innocent computers before it came to yours so that it could remain in disguise. If the authorities could track down the original senders of spam, they could crack down on spam itself. Spam senders don’t want that.
Ever heard of phishing emails? Those are the ones that purport to be from your internet service provider or bank. They typically request some information from you, like your credit card number. The problem is, they’re NOT from your internet service provider or your bank. They’re from evil people after your credit card number! Well, these emails are often sent the same way spam is sent, by sending them via innocent computers.
Of course makers of anti-virus software use a variety of methods to combat the onslaught of viruses. Norton, for instance, uses signature scanning, Nachenberg said.
Signature scanning is similar to the process of looking for DNA fingerprints, he said. Norton examines programming code to find what viruses are made of. It adds those bad instructions it finds to its large database of other bad code. Then it uses this vast database to seek out and match the code in it with similar code in your computer. When it finds such virus code, it lets you know!
Thursday, February 14, 2008
Early Computers: A History of Computing
Computers are a part of our everyday lives, but about two decades ago, computers were just beginning to enter homes. Many people don’t realize what the computer evolved from, and the speed at which computer technology has taken to arrive to what it is today.
The earliest know computer is the abacus, invented by the Chinese in 2600 B.C. Not many people consider this to be a computer, but by definition, it is. One of the more recent early computers was built by Herman Hollerith, who invented a machine that used a system of cards with holes in them. By using these cards he was able to calculate the United State Census. Hollerith’s Computer Tabulating-Recording Company changed its name in 1924 to International Business Machines, IBM for short. This is the same IBM that is known today to many computer users. During the 1980s and 1990s, IBM was a large player in the personal computer market. It was as important as Microsoft is the to the world of computing today. The main term that was used was, “IBM-Compatible.”
A large movement in computer technology was the use of vacuum tubes. In 1904 John Ambrose Fleming invented the first commercial diode vacuum tube. Thomas Edison already discovered this, but discarded the discovery as useless. Before the vacuum tube was discovered, computers were made of gears and switches. Now with the vacuum tube, it acted as a switch turning on and off much faster than standard switches. This also caused less wear and tear on the machine, prolonging the life of the computer, lessening the frequency of repairs.
In 1943 ENIAC (Electronic Numerical Integrator Analyzer and Computer) was built. It was the first all electronic computer, and required so much electricity that when the power was turned on, the lights around Philadelphia dimmed. The ENIAC was used by the United States Military to produce trajectory tables. The ENIAC was able to compute 5,000 additions a second, but it took 2 days to set up these equations. The cost of the ENIAC was $500,000, weighed 30 tons, 100 feet long, and 8 feet high. Inside the ENIAC were 1,500 relays, and 17,468 vacuum tubes. These vacuum tubes consumed 200 kilowatts of electricity, thus causing it’s own circuits to fry. The ENIAC broke down frequently. The problem was that the tubes within the ENIAC produced heat, and turned the ENIAC into an over, causing frequent self-destruction.
In July of 1980, IBM met with Bill Gates to discuss creating an operating system for IBM’s new secret project, a personal computer. IBM almost scrapped the personal computer project in hopes of purchasing Atari, and take over production. But they stuck with their personal computer, and their operating system. On August 12, 1981, IBM released their personal computer, named the IBM PC (this is where the term PC originated from).
The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. As for memory, the computer came with 16 kilobytes, which could be expanded to 256k. The computer came with one or two 160k floppy disk drives (5.25 inch). An optional feature was a color monitor. The price tag for this luxurious item was (starting at) $1,565. Today though, it would be the equivalent of $4,000.
For months after the introduction of the IBM PC, Time Magazine named the computer “Man of the Year.” However, IBM wasn’t the only computer on the market. In December of 1983, Apple Computers ran its’ famous “1984” MacIntosh TV commercial. The purpose was to make the commercial eligible for awards during 1984. The commercial itself cost 1.5 million, and ran only once in 1983. It was replayed by new and talk shows, and it made TV history. The next month, Apple Computer ran the same ad, but this time during the NFL Super Bowl, and millions saw their first view of the MacIntosh computer. The commercial showed the IBM world being destroyed by a new machine, the MacIntosh.
And the last big piece of computer history is something that everyone knows, Microsoft Windows operating system. On November 10, 1983, at the Plaza Hotel in New York City, Microsoft announced the release of Microsoft Windows, a new operating system that would provide a graphical user interface (GUI) and multitasking environment for IBM computers. Windows was (summed up) a visual version of DOS. Microsoft promised that the new program would be on the shelf by April 1984. Windows was almost named Interface Manager, but Rowland Hanson (marketing), convinced Microsoft founder Bill Gates that Windows was a better name. Microsoft finally shipped Windows on November 20, 1985, two years after they had initially promised release.
Now you know where computers originated from, and where such companies as Apple, IBM, and Microsoft got their start. As you can see, it wasn’t easy, but they got through it. What would the world be like if Windows was called Interface Manager instead?
The earliest know computer is the abacus, invented by the Chinese in 2600 B.C. Not many people consider this to be a computer, but by definition, it is. One of the more recent early computers was built by Herman Hollerith, who invented a machine that used a system of cards with holes in them. By using these cards he was able to calculate the United State Census. Hollerith’s Computer Tabulating-Recording Company changed its name in 1924 to International Business Machines, IBM for short. This is the same IBM that is known today to many computer users. During the 1980s and 1990s, IBM was a large player in the personal computer market. It was as important as Microsoft is the to the world of computing today. The main term that was used was, “IBM-Compatible.”
A large movement in computer technology was the use of vacuum tubes. In 1904 John Ambrose Fleming invented the first commercial diode vacuum tube. Thomas Edison already discovered this, but discarded the discovery as useless. Before the vacuum tube was discovered, computers were made of gears and switches. Now with the vacuum tube, it acted as a switch turning on and off much faster than standard switches. This also caused less wear and tear on the machine, prolonging the life of the computer, lessening the frequency of repairs.
In 1943 ENIAC (Electronic Numerical Integrator Analyzer and Computer) was built. It was the first all electronic computer, and required so much electricity that when the power was turned on, the lights around Philadelphia dimmed. The ENIAC was used by the United States Military to produce trajectory tables. The ENIAC was able to compute 5,000 additions a second, but it took 2 days to set up these equations. The cost of the ENIAC was $500,000, weighed 30 tons, 100 feet long, and 8 feet high. Inside the ENIAC were 1,500 relays, and 17,468 vacuum tubes. These vacuum tubes consumed 200 kilowatts of electricity, thus causing it’s own circuits to fry. The ENIAC broke down frequently. The problem was that the tubes within the ENIAC produced heat, and turned the ENIAC into an over, causing frequent self-destruction.
In July of 1980, IBM met with Bill Gates to discuss creating an operating system for IBM’s new secret project, a personal computer. IBM almost scrapped the personal computer project in hopes of purchasing Atari, and take over production. But they stuck with their personal computer, and their operating system. On August 12, 1981, IBM released their personal computer, named the IBM PC (this is where the term PC originated from).
The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. As for memory, the computer came with 16 kilobytes, which could be expanded to 256k. The computer came with one or two 160k floppy disk drives (5.25 inch). An optional feature was a color monitor. The price tag for this luxurious item was (starting at) $1,565. Today though, it would be the equivalent of $4,000.
For months after the introduction of the IBM PC, Time Magazine named the computer “Man of the Year.” However, IBM wasn’t the only computer on the market. In December of 1983, Apple Computers ran its’ famous “1984” MacIntosh TV commercial. The purpose was to make the commercial eligible for awards during 1984. The commercial itself cost 1.5 million, and ran only once in 1983. It was replayed by new and talk shows, and it made TV history. The next month, Apple Computer ran the same ad, but this time during the NFL Super Bowl, and millions saw their first view of the MacIntosh computer. The commercial showed the IBM world being destroyed by a new machine, the MacIntosh.
And the last big piece of computer history is something that everyone knows, Microsoft Windows operating system. On November 10, 1983, at the Plaza Hotel in New York City, Microsoft announced the release of Microsoft Windows, a new operating system that would provide a graphical user interface (GUI) and multitasking environment for IBM computers. Windows was (summed up) a visual version of DOS. Microsoft promised that the new program would be on the shelf by April 1984. Windows was almost named Interface Manager, but Rowland Hanson (marketing), convinced Microsoft founder Bill Gates that Windows was a better name. Microsoft finally shipped Windows on November 20, 1985, two years after they had initially promised release.
Now you know where computers originated from, and where such companies as Apple, IBM, and Microsoft got their start. As you can see, it wasn’t easy, but they got through it. What would the world be like if Windows was called Interface Manager instead?
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