Operating system

A collection of programs that allows a computer to control its operations. The operating system determines how programs run on the computer and supervises all input and output. Your computer comes with MS-DOS, an operating system by Microsoft.

Option card

A circuit board that you install in a slot in your main unit or expansion chassis. Option cards provide additional capabilities, such as more memory or an internal modem.

Parallel

A type of interface that transmits data in groups of bits. Distinguished from serial, a type of interface in which bits are transmitted one at a time.

Parameter

A term added to a command that tells the computer how to perform the command (for example, what data file to use or what particular conditions to look for).

Parity

Data signals sent during communications to detect transmission errors.

Partition

To divide a hard disk into logical sections for use by one or more operating systems. A hard disk must be partitioned before it can be formatted, even if only one operating system is going to be used on the disk.

Pathname

The list of directories the operating system must search through to locate a file. For example, the pathname for a file named CONTRACT.TXT that is located in the BUSINESS subdirectory is \ BUSINESS \ CONTRACT.TXT.

12 Glossary