Roof directory

The highest or main directory in a hierarchical disk directory structure. All other directories are subdirectories of the root directory. MS-DOS designates the root directory with a \ (backslash).

RS-232C

A widely used, standard type of serial communication. You can connect an RS-232C device to the computer’s built-in RS-232C serial port.

Sector

A small section of a disk track (typically 512 bytes long) that provides an address at which the computer can store and retrieve data. See also Track.

Self testsee Power-on diagnostics.

Serial

The type of communication that transmits data from a serial interface to a serial device, one bit at a time, over a single wire. See also Interface and Parallel.

Shadow RAM

The feature in your computer that automatically copies the contents of the system, video, and any external BIOS ROMs into the RAM area of memory to speed up processing.

SIMM

20 Glossary