DOS
The Disk Operating System that controls the computer’s input and output functions. See Operating system.
Double-density
A type of diskette format that allows you to store twice as much data as the standard-density format. A 3 l/z-inch double-density diskette can store 720KB of data. A 5 ‘/+inch double-density diskette can store 360KB 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 color 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 up to 640 x 350 resolution.
Executable file
A file containing program instructions, as opposed to data created with an application program. An executable file has the extension .BAT, .COM, or .EXE.
Expanded memory
Memory that specially-written MS-DOS application programs can use with an Expanded Memory Specification (EMS) device driver such as EMM386.SYS. Expanded memory does not fill a certain range of memory like conventional and extended memory; expanded memory can be mapped from the memory area between 640KB and 1MB.