Numeric keypad

The number and cursor control keys grouped together on the right side of the keyboard. The operation of the dual-use keys

on the numeric keypad is controlled by the key.

Operating speed

The speed at which the computer’s processor can execute commands, usually expressed in megahertz (MHz). See also Megahertz.

Operating system

A collection of programs that manage a computer’s operations, such as interpreting input, managing files, and reading and writing data to disk. The operating system (such as MS-DOS, OS/2, or UNIX) provides the foundation for the other programs and controls hardware resources.

Option curd

A circuit board you can install inside the computer to provide additional capabilities, such as a modem or an additional I/O port. Option cards plug directly into option slots so you do not have to alter a computer’s circuitry to enhance your system.

O S / 2

Operating System/2. The operating system developed jointly by Microsoft and IBM that provides protected mode processing and multitasking capabilities. See also DOS, MS-DOS,and Operating system.

OverDrive processor

An optional microprocessor chip that doubles the internal processing speed of the microprocessor and includes a built-in math coprocessor.

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