Epson 500 Series - Manual (Page 106)

COM1
The name that MS-DOS uses to identify the primary serial port.
CONFlG.SYS file
A special system file that MS-DOS executes each time you turn on or
reset the computer. You use this file to customize your system by
installing device drivers, setting limits for files and buffers, and
Specifying Ms-DOS commands to be run during startup.
Controller
A hardware component of your computer that manages the operation
of the display, hard disk, or diskette drive.
Coprocessor
An optional integrated circuit (chip) that assists the CPU in
performing certain numeric 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 diskette
drive while you are using it Some also require the cormputer to be
running at low speed instead of high speed.
CPU
Central Processing Unit. The integrated circuit (chip) responsible for
integrating program instructions, performing calculations, and
controlling all input and output operations
CPU speed
The speed which the CPU can execute commands. The Action Note
can run at high or low speed. Also called clock speed, execution
speed, or operating speed.