RS-232C

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

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 Truck.

Self test

See 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

See Memory module.

Software

The collection of instructions (or programs) that tell your computer hardware to perform the tasks and functions you specify. See also Hardware and Program.

20Glossary