PC Hardware

Technical Terms Beginning With E

ECC (error-correction coding)

The use of a code to verify or disprove that a data string received is the same as the data sent.

ECP (Extended Capabilities Port)

Developed by Hewlett-Packard and Microsoft. It features 2 MB per second data transfer and bidirectional 8-bit operation. ECP specifies whether transmitted information consists of data or commands for the peripheral.

EGA (Enhanced Graphics Adapter)

An improvement on the older CGA standard. Supports a resolution of up to 640 pixels by 350 pixels at 16 colors in text-only mode or 640 x 200 at 2 colors in graphics mode. The EGA standard was not fully backward-compatible with CGA and MDA.

e-mail (electronic mail)

The transmission of messages by computer from one person to another, often via the Internet.


The act of encoding data so that it can be read only by the intended party. A secure Web site or Internet-based transaction uses some form of encryption.

Enhanced IDE (EIDE)

A standard developed in order to increase the size of available disk drives and the speed of data transfer between the host and the disk drive. See also Integrated Drive Electronics (IDE)

EPP (Enhanced Parallel Port)

Features 2 MB per second data transfer rates, bidirectional 8-bit operation, and addressing to support multiple (daisy-chained) peripherals on a single computer.

error messages

Brief technical messages that are displayed when an error occurs.


A type of local area network in which communication takes place by means of radio frequency signals carried by a coaxial cable.

Expanded Memory (EMS)

A technique, developed by Lotus/Intel/Microsoft (LIM), that adds addressable memory to a computer system, overcoming the original MS-DOS upper memory limit. The LIM expanded memory specification uses a 64-KB section of memory (usually in upper memory) to provide a "window" into which data can be written. Once in this area, the data can be transferred to the expanded memory. The memory chips are located on an expansion card installed inside the computer.

expansion buses

Provide the connection between expansion cards (drive controllers, video cards, modems and so forth) and the system bus.

expansion slots

Specialized sockets that allow additional devices (circuit boards/adapter cards) to be attached to the motherboard (by means of the expansion bus). These are used to expand or customize a computer. They are an extension of the computer's bus system.

extended memory (XMS)

RAM above the 1-MB address. Extended memory is accessed through an extended memory manager (HIMEM.SYS for DOS).