DMA channel

Direct Memory Access channel. The pathway through which data is transferred between main storage and I/O devices. This transfer method requires no processor intervention.

DOS

Disk Operating System. A commonly used operating system that controls the computer’s input and output functions. See also Operating system.

Double-density

A type of diskette format that allows you to store twice as much data as the standard-density format. A 5¼-inch double-density diskette can store 360KB of data. A 3½-inch double-density diskette can store 720KB of data.

Drive designator

The letter name of a disk drive, followed by a colon-for example, C : .

EGA

Enhanced Graphics Adapter. A type of display adapter card that allows you to display high-resolution graphics on a compatible monitor. It can display up to 43 lines of text with 80 characters on each line, or it can display monochrome or 16-color graphics at resolutions up to 640 x 350.

EISA

Extended Industry Standard Architecture. A bus standard for IBM compatible computers that extends the ISA bus architecture to 32 bits and allows more than one computer to share the bus easily.

6 Glossary