Acronym for the American National Standards Institute. Founded in 1918, ANSI is a voluntary organization composed of over 1,300 members (including all the large computer companies) that creates standards for the computer industry.
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The Auto Insert Notification enables the autorun.inf file on a CD to automatically be run when a CD is inserted into a CDROM drive.
Going in two directions. This is usually in reference to printers and cables. Being bi-directional allows the system to talk to the printer and the printer to talk back to the system.
(Basic Input Output System) An essential set of routines in a PC, which is stored on a chip and provides an interface between the operating system and the hardware. The BIOS supports all peripheral technologies and internal services such as the real-time clock (time and date).
On startup, the BIOS tests the system and prepares the computer for operation by querying its own small CMOS memory bank for drive and other configuration settings. It searches for other BIOS's on the plug-in boards and sets up pointers (interrupt vectors) in memory to access those routines. It then loads the operating system and passes control to it. The BIOS accepts requests from the drivers as well as the application programs.
A bit is the smallest unit of information handled by a computer. One bit expresses a 1 or a 0 in a binary numeral, or a true or false logical condition. A group of 8 bits makes up a byte, which can represent many types of information, such as a letter of the alphabet, a decimal digit, or other character. Bit is also called binary digit.
The volume on a hard drive where the operating system in stored. The Boot Volume is the volume loaded when the machine is turned on.
A common pathway, or channel, between multiple devices. The computer's internal bus is known as the local bus, or processor bus. It provides a parallel data transfer path between the CPU and main memory and to the peripheral buses. A 16-bit bus transfers two bytes at a time over 16 wires; a 32-bit bus uses 32 wires, etc. The bus is comprised of two parts: the address bus and the data bus. Addresses are sent over the address bus to signal a memory location, and the data is transferred over the data bus to that location.
Various buses have been used in the PC, including the ISA, EISA, Micro Channel, VL-bus and PCI bus. Examples of other peripheral buses are NuBus, TURBOchannel, VMEbus, MULTIBUS and STD bus.
A temporary storage area for frequently-accessed or recently-accessed data. Cache is used by the computer to quickly move data between the RAM and the CPU. The two kinds of cache are: internal (memory cache) and external (disk cache). Internal cache is built into the CPU, and external cache is on the motherboard. When an item is called for, the computer first checks the internal cache, then the external cache, and finally the slower main storage (hard drive). A cache hit (accessing data from a cache) takes much less time than retrieving information from the main memory; the cache has high-speed memory chips. The cache may also be used as a temporary storage area for data that will be written to disk when the computer is idle.
An area of memory internal to some microprocessors that holds recently used instructions. Instruction Cache holds predefined Instructions that can be called when needed. This cache cannot be written to, only read from.
Instruction Cache is combined with Data Cache to create what is called L1 or L2 Cache. The advantages of separating the data and instruction caches are that it makes it simpler for instructions and data to be simultaneously fetched from memory. In systems in which the CPU is pipelined and can fetch instructions and operand simultaneously, it is a great advantage to have separate buses to memory to fetch these items, rather than forcing a stall and fetching them one at a time.
An electronic circuit board or system. In a personal computer, controllers contain the circuitry to run a peripheral device and are either contained on a plug-in expansion board or on the motherboard. Increasingly, plug-in boards for disk control, networking, sound, etc., are being replaced by built-in circuits (chips) on the motherboard.
In larger computers, a controller may be contained on one or more boards or in a stand-alone cabinet.
Cookies are bits of information stored in a small text file on your hard disk. Cookies contain information about your preferences and other items that can be used by a website to may your web visit quicker, easier, and customized to your liking.
Allowing a website to create a cookie on your machine poses no risk to the security of your system. Web Sites cannot retrieve any data from your machine but the information stored in the cookies.
Central Processing Unit (CPU).The CPU controls the operation of a computer. Units within the CPU perform arithmetic and logical operations and decode and execute instructions.
Each type of processor has several slightly different variations, called a "stepping". Stepping 0 (zero) cores are the original production run. When minor imperfections (bugs) are found in the instruction programming (micro-code) of the core or in other parameters of the chip, they are fixed and the next batch of cores will incorporate the changes. This batch will be identified as stepping 1. If another change is required later, the stepping number will be incremented again. As each successive refinement to the chip is made, the next higher stepping number will be assigned. Usually the higher stepping cores make the best, most stable CPU's.
Concentrical tracks on one or more disk sides the hard drive's read/write head can be positioned over. The heads are mounted on a "fork" which positions all heads in a certain cylinder position.
An area of memory internal to some microprocessors that holds recently used instructions. Data cache is used specifically for storing and retrieving data.
Data Cache is combined with Instruction Cache to create what is called L1 or L2 Cache. The advantages of separating the data and instruction caches are that it makes it simpler for instructions and data to be simultaneously fetched from memory. In systems in which the CPU is pipelined and can fetch instructions and operand simultaneously, it is a great advantage to have separate buses to memory to fetch these items, rather than forcing a stall and fetching them one at a time.
A group of computers that are part of a network and share a common directory database. A domain is organized in levels and is administered as a unit with common rules and procedures. Each domain has a unique name.
On the Internet, domains are defined by an IP address. All devices sharing part of the IP address are in the same domain. In an Internet address, the domain is generally the word or number that indicates the type of entity that owns the address, for example, .com or .org.
Duplex is the ability of a system to transmit data either one way or both ways over a communications channel. Full Duplex allows the information to travel both directions and Half Duplex only allows the information to travel one-way.
Acronym for Electro-Magnetic Field. A field of force, produced by electric charges and currents, which has both an electric and a magnetic component and contains electromagnetic energy. The properties of electromagnetic fields were outlined by Scottish physicist James Clerk Maxwell in 1865.
A table or list maintained by some operating systems to keep track of the status of various segments of disk space used for file storage. File allocation table is also called FAT. FAT only supports partitions of less than 2GB.
See also FAT32; NTFS; File System
A derivative of the File Allocation Table file system. FAT32 is a File System that supports smaller cluster sizes than FAT, which results in more efficient space allocation on FAT32 drives. FAT32 supports larger partitions than FAT.
See also FAT, NTFS, File System
A file system is the overall structure in which files are named, stored, and organized. There are basically three types of file systems currently used on standard PC's, FAT, FAT32, and NTFS
Software stored in ROM or PROM; essential programs that remain even when the system is turned off. Firmware is easier to change than hardware but more permanent than software stored on disk.
A method for storing and calculating numbers in which the decimal points do not line up as in fixed point numbers. The significant digits are stored as a unit called the "mantissa," and the location of the radix point (decimal point in base 10) is stored in a separate unit called the "exponent." Floating point methods are used for calculating a large range of numbers quickly.
Floating point operations can be implemented in hardware (math coprocessor), or they can be done in software. In large systems, they can also be performed in a separate floating point processor that is connected to the main processor via a channel.
Font smoothing is a system enhancement that makes text easier to read and more pleasant to look at.
Font smoothing works by adding intermediate colored pixels to the corners, curves and diagonals of characters in order to make them appear smoother and less jagged than they would otherwise.
Full Window Drag is the ability to move open windows around on the desktop using the mouse.
A set of special keys on a computer keyboard that are numbered F1, F2, etc. that perform special functions depending on the application program in use. Also called F keys.
A Head refers to the hard drives read/write head currently active. Since most hard drives have at least 2 heads also the term Side is used for referring which disk and side has an "active" head over it.
Specified in Active Directory Users and Computers or Local Users and Groups, the home directory is a folder that is accessible to the user and can contain files and programs for that user. A home directory can be assigned to an individual user or can be shared by many users. Some programs use the home directory as the default folder for the Open and Save As dialog boxes. Other programs use My Documents.
In Intel-based PC's, usually Operating System functions are called via software-interrupts. Somewhere at a low memory address there is a pointer table. The pointers in it point to Operating System functions. One of them is used for Int13, which happens to be the entry point for a number of low-level disk access routines in the BIOS, like functions to read and write "absolute" (specified in Cylinder/Head/Sector values) sectors. At entry of the basic Int13 routine, the contents of one of the CPU registers defines which sub-function to call. Most Int13 sub-functions use other CPU registers to pass the values for the cylinder, head, sector, number of sectors to transfer and a memory address.
Level 1 (L1) cache is a memory cache that is built into the CPU chip. The L1 cache is a small, fast memory area that works together with the L2 cache to provide the CPU much quicker access to important and frequently-used data than searching the main memory.
Level 2 (L2) cache is a collection of memory chips on the motherboard. The L2 cache is a static RAM secondary memory area which is slower than the L1 cache but faster than main memory. An L2 cache is typically 256KB or 512KB. Increasing a level 2 cache may speed up some applications and have no effect on others. The L1 cache and L2 cache are used together.
A group of computers and other devices dispersed over a relatively limited area and connected by a communications link that allows one device to interact with any other on the network. Local area network is also called LAN.
A Logical Serial Number is a unique number assigned to each I/O device.
Files that can be assigned to user accounts. Typically a batch file, a logon script runs automatically every time the user logs on. It can be used to configure a user's working environment at every logon, and it allows an administrator to influence a user's environment without managing all aspects of it. A logon script can be assigned to one or more user accounts.
Short for Media Access Control address, a hardware address that uniquely identifies each node of a network. In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sub layers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network media. Consequently, each different type of network media requires a different MAC layer.
On networks that do not conform to the IEEE 802 standards but do conform to the OSI Reference Model, the node address is called the Data Link Control (DLC) address.
(MultiMedia EXtensions) A set of 57 additional instructions built into Intel CPU chips that are used for faster audio, video, graphics and modem operations. MMX is found in Pentium MMX and Pentium II chips, but not in Pentiums and Pentium Pros. MMX instructions allow operations to be performed simultaneously on multiple units of data; for example, eight 8-bit units or four 16-bit units can be added or multiplied at the same time. In addition, MMX includes a multiply-add instruction that allows most of the capabilities of a DSP chip to be provided at very high speed. MMX provides these capabilities on integer data only.
Intel's competitors (AMD, Cyrix and Centaur) have extended their MMX-compliant chips with proprietary Floating Point instructions for performing the geometry calculations required to move 3-D objects on screen. In order to allow 3-D applications to run on computers with different instruction sets, the chip vendors have helped Microsoft modify its Direct3D graphics system to support their variations. Similar to the way 3-D accelerator cards work that have specialized functions built in, if Direct3D finds special instructions in the CPU, it uses them. If not, it uses regular instructions.
An advanced file system designed for use specifically within the Windows 2000 and Windows NT operating system. It supports file system recovery, extremely large storage media, long file names, and various features for the POSIX subsystem. It also supports object-oriented applications by treating all files as objects with user-defined and system-defined attributes.
See also FAT; FAT32; File System
A portion of a physical disk that functions as though it were a physically separate disk. Partitions can be created only on basic disks.
Generally, a connection point on your computer where you can connect devices that pass data into and out of a computer. For example, a printer is typically connected to a parallel port (also called an LPT port), and a modem is typically connected to a serial port (also called a COM port).
A print processor works in conjunction with a printer driver to de-spool the spooled print jobs during print spool file playback.
Print processors are the components that make necessary alterations to print jobs, based on the data type of the print job. A print processor might recognize only one data type, or it might recognize several data types.
A mechanism allowing one system to "front" for another system when responding to protocol requests. Security applications in firewalls use proxy services to screen the secured network from users on the Internet.
A list of programs or tasks waiting for execution. In 'Windows' printing terminology, a queue refers to a group of documents waiting to be printed.
In NetWare and OS/2 environments, queues are the primary software interface between the application and print device; users submit documents to a queue.
In Windows, however, the printer is that interface and the documents are sent to a printer, not a queue.
Random Access Memory. The working memory of the computer. RAM is the memory used for storing data temporarily while working on it, running application programs, etc. "Random access" refers to the fact that any area of RAM can be accessed directly and immediately, in contrast to other media such as a magnetic tape where the tape must be wound to the point where the data is. RAM is called volatile memory; information in RAM will disappear if the power is switched off before it is saved to disk. There is also a form of non-volatile RAM, which must be continually energized by a battery to maintain its content. The most common form of RAM is built from semiconductor integrated circuits.
Acronym for Remote Access Service. RAS is a support for dialup connections. Remote access is the ability to get access to a computer or a network from a remote distance. A remote access server is the computer and associated software that is set up to handle users seeking access to network remotely. Sometimes called a communication server, a remote access server usually includes or is associated with a firewall server to ensure security and a router that can forward the remote access request to another part of the corporate network.
Simply defined as unprocessed data.
The maximum number of frames per second that a computer monitor can display (expressed in hertz). Each frame begins with the electron gun at the upper left corner of the screen. An electron beam is scanned horizontally across the screen, making one line; it moves down slightly to make the next line, and continues until it reaches the bottom. The electron gun returns to the upper left corner to begin the next frame. Too low a refresh rate causes a flickering screen, which is hard on the eyes.
A Drive that is not physically located on the system but rather is accessed through a LAN.
A standard high-speed parallel interface defined by the American National Standards Institute (ANSI). A SCSI interface is used for connecting microcomputers to peripheral devices such as hard disks and printers, and to other computers and local area networks (
LAN). Small computer system interface is also called SCSI.
A sector is the smallest unit that can be read from/written to a disk. Without special drivers, DOS and Windows can only cope with 512-byte sectors.
The computer's shell is the software interface between the user and the computer's operating system. A shell extension is a small system utility that increases the functionality of the shell, making the computer easier to use.
A System Directory is a folder that is used by the system for a default purpose. For example, the Fonts folder, which generally is located at c:\windows\fonts, is used by all applications to store any fonts that are installed.
Target ID is the address given to a SCSI device to uniquely identify it on a SCSI bus. Each SCSI device is generally capable of changing its Target ID by adjusting the jumpers on the device itself. The standard addresses are numbered 0 through 7 for a total of eight.
A track is the combination of the cylinder all heads are over, and the selected head.
Simulating more memory than actually exists, allowing the computer to run larger programs or more programs concurrently. It breaks up the program into small segments, called "pages," and brings as many pages into memory that fit into a reserved area for that program. When additional pages are required, it makes room for them by swapping them to disk. It keeps track of pages that have been modified, so that they can be retrieved when needed again.
If a program's logic points back and forth to opposite ends of the program, excessive disk accesses, or "thrashing," can slow down execution.
Virtual memory can be implemented in software only, but efficient operation requires virtual memory hardware. Virtual memory claims are sometimes made for specific applications that bring additional parts of the program in as needed; however, true virtual memory is a hardware and operating system implementation that works with all applications.
A portion of a physical disk that functions as though it were a physically separate disk.. Volumes in Windows as local disks such as C: or D:.
A group of users who work on common projects and share information on computers that are interconnected, often over a local area network (LAN).