<<< Back

 

ECC (Error Correction Code) An electronic method of checking the integrity of data stored in DRAM. ECC is a more elaborate error-detection method than parity; it can detect multiple-bit errors and can locate and fix single-bit errors. ECC usually uses three additional bits per byte of data (compared to one additional bit for parity).

EDO (Extended Data Out) A form of DRAM technology that shortens the read cycle between memory and CPU. On computer systems designed to support it, EDO memory allows a CPU to access memory 10 to 20 percent faster than comparable fast-page mode chips.

EEPROM (Electrically Erasable Programmable ROM) A type of chip in which higher voltage may be applied to one of the pins to erase its previous memory before a new instruction set is electronically written.

EIA (Electronic Industries Association) A trade association representing the U.S. high technology community which began life in 1924 as the Radio Manufacturers Association. It has been responsible for developing some important standards, such as the RS-232, RS-422 and RS-423 standards for connecting serial devices. In 1988, it spun off its Information & Telecommunications Technology Group into a separate organization known as the TIA.

EISA (Extended Industry Standard Architecture) Primarily a desktop specification for high-performance computers(32-bit bus that can transfer 4 bytes at a time at a speed of about 20 MHz). Competes with IBM's Micro Channel architecture (MCA). EISA computers can use existing PC, XT, and AT add-in cards; MCA computers can't. See also Micro Channel architecture.

ELF (Extremely Low Frequency) Very low frequency monitor emission of magnetic fields.

ELF guidelines are established to ensure that computers are safe and energy efficient.

Embedded SCSI devices Devices that contain their own host adapter, whereby the SCSI interface is built into the device.

EMM386.EXE A DOS utility that creates upper memory blocks (commonly used in pre-Windows 95 systems).

EMS (Expanded memory) Memory outside of the conventional linearly addressed memory that is accessed in 16K segments, or pages, by way of a window to upper memory.

Encoding A method whereby a group of data bits is translated into a group of recording bits.

Encrypting virus A type of virus that transforms itself into a nonreplicating program in order to avoid detection. It transforms itself back into a replicating program in order to spread.

Enhanced BIOS A newer BIOS that has been written to accommodate the larger-capacity gigabyte drives.

Enhanced IDE technology A newer drive standard that allows systems to recognize drives larger than 528 MB and to handle up to four devices on the same adapter.

Environment subsystems A Windows NT user mode process in which a subsystem runs an application in its own private memory address space as a virtual machine. (Compare to integral subsystems.)

 E-mail (electronic mail) The exchange of messages via a bulletin board or on-line service. One user leaves the message on the service "addressed" to another user. The other user later connects to the same service and can read the message and reply to it.

EPP (Enhanced Parallel Port) A parallel port that conforms to the EPP standard developed by the IEEE (Institute of Electrical and Electronics Engineers) 1284 standards committee. The EPP specification transforms a parallel port into an expansion bus that can handle up to 64 disk drives, tape drives, CD-ROM drives, and other mass-storage devices. EPPs are rapidly gaining acceptance as inexpensive means to connect portable drives to notebook computers.

EPROM chip (Erasable Programmable ROM) A type of chip with a special window that allows the current memory contents to be erased with special ultraviolet light so that thae chip can be reprogrammed. Many BIOS chips are EPROMs.

ERASE command A DOS command that deletes or erase files (for example, ERASE FILE.EXT deletes the file named FILE.EXT FROM THE CURRENT DISK).

ESD (Electrostatic discharge) Another name for static electricity, which can damage chips and destroy systemboards, even through it may not be felt or seen with the naked eye.

Escalating The process of a technician passing a customer's problem to higher organizational levels, if he or she cannot address the problem.

Ethernet The most popular network technology used today. It uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD) and can be physically configured as a bus or star network.

Event Viewer A Windows NT utility that tracks and logs events as they are performed by the applications, processes, or user actions. Accessed by:

Click Start, Programs, Administrative Tools, and then selecting Event Viewer.

Expanded memory Memory that can be used by some DOS software to access more than the normal 640K (technically, more than 1Mb). 80386, 80386SX, and 80486 computers can create expanded memory readily by using an EMS (expanded memory specification) driver provided with DOS, through Microsoft Windows, or through a memory manager such as Quarterdeck QEMM or Qualitas 386 To The Max. To use expanded memory, a program must be EMS-aware or run under an environment such as Microsoft Windows. 8088- and 80286-based computers often need special hardware to run expanded memory. See also memory.

Executive Services In Windows NT, a subsystem running in kernel mode that interfaces between the user mode and HAL.

Expansion Card A circuit board that fits into a computer expansion slot to add a certain function (like a modem, sound card, or SCSI interface).

Expert systems Computerized software that uses a database of known facts and decision-making processes.

Extended memory Memory above 1Mb in 80286 and higher computers. Can be used for RAM disks, disk caches, or Microsoft Windows, but requires the processor to operate in a special mode (protected mode or virtual real mode). With a special driver, you can use extended memory to create expanded memory. See also memory, RAM, ROM.

External cache Static cache memory, stored on the systemboard, that is not part of the CPU (also called Level 2 or L2 cache).