Epson EISA Desktop - Manual (Page 160)

Control code
A command (generated when you hold down and press
another key on the keyboard) that instructs the computer to
perform a specific function.
Coprocessor
An optional device that enables the computer to process certain
mathematical calculations faster.
Copy-protected program
A type of program that cannot be copied. Some copy-protected
programs require you to leave the program diskette in the
drive while you are using it. Some also require the computer to
be running at low speed instead of high speed. See also
Automatic speed.
CPU
Central Processing Unit. The primary unit of the computer that
interprets instructions, performs the tasks you indicate, keeps
track of stored data, and controls all input and output
operations.
Cylinders
The vertical alignment of tracks in a hard disk that can be lined
up under one read/write head. The number of tracks on a disk
is equal to the number of cylinders times the number of heads.
Data
Information such as text or graphics stored or processed by a
computer.
4 Glossary