To transfer information from the computer's memory to a more permanent storage medium such as a hard disk.
In IBM-compatible computers, a code number generated when a key on the keyboard is pressed or released. Each key and shifted key is assigned a unique code that the computer's BIOS translates into its ASCII equivalent.
An optical device used to digitize images such as line art or photographs, so that they can be merged with text by a page-layout or desktop publishing program or incorporated into a CAD drawing.
Standard Generalized Markup Language. A standard (ISO 8879) for defining the structure and managing the contents of any digital document.
In PCs based on the 80386 (or later) processor, the technique of copying the contents of the BIOS ROM into faster RAM when the computer first boots up; also known as shadow RAM or shadow ROM
An interprocess communications technique in which the same memory is accessed by more than one program running in a multitasking OS. Semaphores or other management elements prevent the applications from "colliding," or trying to update the same information at the same time.
A simple, low-cost modem that can only transmit information over short distances, such as from one side of a building to the other.
A semiconductor material used in many electronic devices. Silicon is a very common element found in almost all rocks and in beach sand, and when "doped" with chemical impurities, becomes a semiconductor. Large cylinders of silicon are cut into wafers, and then etched with a pattern of minute electrical circuits to form a silicon chip.
A floppy disk that is certified for recording with frequency modulation encoding. Single-density disks have been superseded by double-density disks and high-density disks.
SIMM. Individual RAM chips are soldered or surface mounted onto small narrow circuit boards called carrier modules, which can be plugged into sockets on the motherboard. These carrier modules are simple to install and occupy less space than conventional memory modules.
Serial Line Internet Protocol. A communications protocol used over serial lines or dial-up connections. Along with PPP, SLIP is one of the most popular protocols used when connecting a PC to the Internet.
The DOS device driver that provides compatibility for hard-disk controllers that cannot work with EMM386 and Windows running in enhanced mode. Use the DEVICE command to load this device driver in CONFIG.SYS. This command does not load the DOS disk cache; use the SMARTDRV command for that.
Part of the software support needed for PCMCIA hardware devices in a portable computer, controlling the interface to the hardware.
Socket services is the lowest layer in the software that manages PCMCIA cards. It provides a BIOS-level software interface to the hardware, effectively hiding the specific details from higher levels of software. Socket services also detect when you insert or remove a PCMCIA card and identify the type of card it is.
An application program or an operating system that a computer can execute. Software is a broad term that can imply one or many programs, and it can also refer to applications that may actually consist of more than one program.
A Unix-based operating system from SunSoft that runs on Intel processors and supports a GUI,e-mail, the Network File System, and Network Information Service. Solaris brings a common look-and-feel to both SPARC and Intel platforms.
An add-in expansion board for the PC that allows you to produce audio output of high-quality recorded voice, music,and sounds through headphones or external speakers. Almost all multimedia applications take advantage of a sound boar if one is present.
The original human-readable version of a program, written in a particular programming language, before the program is compiled or interpreted into a machine-readable form.
A slang expression used to describe any badly designed or poorly structured program that is hard to unravel ( and understand) as a bowl of spaghetti.
Scalar Processor ARChitecture. A 32-bit RISC processor from Sun Microsystems.
A family of Unix workstations from Sun Microsystems,based on the SPARC processor. SPARCstations range from small, diskless desktop systems to high-performance,tower SPARC servers in multi-processor configurations.
A group that meets to share information about a specific topic.
A reserved area of memory used to keep track of a program's internal operations, including functions, return addresses, passed parameters,etc. A stack is usually maintained as a "last in, first out" (LIFO) data structure, so that the last item added to the structure is the first item used.
A system designed to meet specific individual needs that does not rely on or assume the presence of any other components to complete the assigned task.
A network topology in the form of a star. At the center of the star is a wiring hub or concentrator, and the nodes or workstations are arranged around the central point representing the points of the star.
In asynchronous transmissions, a start bit is transmitted to indicate the beginning of a new data word.
A type of computer memory that retains its contents as long as power is supplied; it does not need constant refreshment like dynamic RAM chips. A static RAM chip can only store about 1/4th of the information that a dynamic RAM chip can. However, SRAM is faster than DRAM , it has an access time of 15-30 nanoseconds. It is often used in caches.
A family of fixed-function graphics accelerator chips from S3 Corporation. These chips (86C801,86C805,86C924, and the 86C928) are used in many of the accelerated graphics adapters that speed up Window's video response.
In asynchronous transmissions, stop bits are transmitted to indicate the end of the current data word. Depending on the convention in use, one or two stop bits are used.
A high-speed tape backup system, often used to make a complete backup of an entire hard disk.
A streaming tape is designed to optimize throughput so that time is never wasted by stopping the tape during a backup; this also means that the computer and backup software also have to be fast enough to keep up with the tape drive.
A pen-like pointing device used in pen-based systems and personal digital assistants.
The inactive base material used in the construction of a disk, tape, printed circuit boad, or integrated circuit.
The most powerful class of computer. The term was first applied to the Cray-1 computer. Supercomputers can cost in the billions, and have extremely vast capabilities.
A microprocessor architecture that contains more than one execution unit, or pipeline, allowing the processor to execute more than one instruction per clock cycle.
An enhancement to the Video Graphics Display video standard defined by VESA. SuperVGA video adapters can display at least 800 pixels horizontally and 600 vertically, and up to 1600 horizontally and 1200 vertically, with 16;256;32,767;or 16,777,216 colors displayed simultaneously. Most SVGA boards contain several megabytes of video RAM for increased performance.
A manufacturing technology in which integrated circuits are attached directly to the printed circuit board, rather than being soldered into pre-drilled holes in the board. This process also allows electronic components to be mounted on both sides of a board.
A sudden and often destructive increase in line voltage. A regulating device known as a surge suppressor or surge protector can protect computer equipment against surges.
Also known as surge protector. A regulating device placed between the computer and the AC line connection that protects the computer system from power surges.
On a hard disk, a file used to store parts of running programs that have been swapped out of memory temporarily to make room for other running programs. It may be permanent, always occupying the same amount of hard disk space even though the application that created it may not be running, or is temporary, and only created as and when needed.
The process of exchanging one item for another. In a virtual memory system, swapping occurs when a program requests a virtural memory location that is not currently in memory; the information is then read from disk, and displaces old information held in memory.
The timing of separate elements or events to occur simultaneously.
In a multimedia presentation, synchronization ensures that the audio and video components are timed correctly.
In a computer-to-computer communications, the hardware and software must be synchronized so that the file transfers can take place.
The process of updating files on both a portable comp and a desktop system so that they both have the latest versions.
In communications, a transmission method that uses a clock signal to regulate data flow. Synchronous transmissions do not use start and stop bits.
The part of a DOS disk which contains the partition table, the file allocation table, and the root directory.
In DOS and OS/2, the file attribute that indicates that the file is part of the OS, and should not appear in normal directory listings. There are also furthr restrictions on a system file; you cannot delete, copy, or display the contents of such a file.
The date and time as maintained by the computer's internal clock.
A disk that contains all the files necessary to boot and start the OS. In most computers, the hard disk is the system disk.
In DOS and OS/2, a file whose system attribute is set. In IBM's PC-DOS, the two system files are called IBMBIOS.COM and IBMDOS.COM; in MS-DOS, they are called IO.SYS and MSDOS.SYS. These files contain the essential routines needed to manage devices, memory, and I/O operations.
In Windows OSes, an initialization file that contains information on your hardware and the internal Windows operating environment.
A set of IBM standards, first introduced in 1987, that define a consistent set of interfaces for future IBM software. Three standards are defined:
1.Common User Access (CUA): A GUI definition for products designed for use in an object-oriented operating environment.
2.Common Programming Interface(CPI): A set of APIs designed to encourage independence from the underlying OS. The standard database query language is SQL.
3.Common Communications Support (CCS): A common set of communications protocols that interconnect SAA systems and devices.
The programs that make up the operating system(OS), along with the associated utility programs, as distinct from an application program.
The time and date maintained by the internal clock inside the computer. This internal clock circuitry is usually backed up by a small battery so that the clock continues to keep time even though the computer may be switched off. The system time is used to date-stamp files with time of their creation or revision.
The case that houses the processor, motherboard, internal hard- and floppy disks, power supply, and the expansion bus.