A small device that connects two pins on an option card, a disk drive, or the main system board to activate a particular function.

Key disk

A diskette containing a copy-protected program that must remain in the diskette drive while you are using the program.

Kilobyte (KB)

A unit used to measure storage space in a computer’s memory or on a disk. One kilobyte equals 1024 bytes.

LIM 4.0 EMS

Version 4.0 of the Lotus/Intel/Microsoft Expanded Memory Specification-a protocol that allows certain application programs to use memory that MS-DOS cannot use.

Main system board

The board built into your computer containing the circuitry the computer requires to operate.

Math coprocessor

A microprocessor that enables the computer to process certain mathematical calculations and display graphic images faster. In this computer, the 50 MHz model includes a built-in math coprocessor and the 25 MHz model can be upgraded with an 80487SX chip with built-in math coprocessor.

MCGA

Monochrome/Color Graphics Adapter. A type of display adapter that controls either a monochrome or color graphics monitor.

10Glossary