Epson 10020 - Manual (Page 227)

MS-DOS
Microsoft Disk Operating System. The operating system that
comes with your computer. See Operating system.
Numeric
keypad
The number keys grouped to the right of the keyboard.
Operating speed
The speed at which the central processing unit can execute
commands. Also called execution speed. The Apex can run at
4.77
MHz or 10 MHz.
operating system
A collection of programs (such as MS-DOS) that manages a
computer’s operations. The operating system determines how
programs run on the computer and supervises all input and
output.
Option card
A circuit board you install inside the computer to provide
additional capabilities, such as a modem, a hard disk controller,
or a mouse.
Parallel
The type of interface that transmits data in groups of bits. See
Interface and Serial.
Parameter
A qualifier added to a command that tells the computer what
particular conditions to look for.
Parent directory
The directory immediately
above
a given directory in the
directory tree. In pathnames, the parent directory is represented
by the symbol .. (two periods).
Glossary 11