Serial

The type of interface that transmits data one bit at a time. See Interface and Parallel.

SIMM

See Memory module.

Software

The programs that enable your computer to perform the tasks and functions you indicate.

Subdirectory

A directory or group of files that branches down from another subdirectory or from the root directory.

Switch

An option added to an MS-DOS command that modifies the way the command works. Switches are usually preceded by a / (forward slash). For example, if you add the /S switch to a FORMAT command, MS-DOS installs the operating system on the diskette as it formats it. See Parameter.

System diagnostics

,A series of checks you can perform on the computer to make sure the hardware is functioning correctly.

System diskette

A diskette that contains the operating system.

18 Glossary