Epson 20 - Manual (Page 199)

Hard disk
The enclosed unit used to store data permanently. Unlike a
diskette, it is fixed in place. It can process data more rapidly and
store many more files than a diskette.
Hardware
Any physical component of a computer system, such as a
monitor, printer, keyboard, or CPU.
Hexadecimal
A base 16 numbering system frequently used by programmers.
Any decimal number between 0 and 255 can be represented by a
two-digit hexadecimal number.
High-density
A type of diskette format that allows you to store more data than
normal. A 5¼-inch high-density diskette can store 1.2MB of data.
A 3½-inch high-density diskette can store 1.44MB of data.
Input/output (I/O) port
See Port.
Interface
A physical or software connection used to transmit data between
equipment or programs.
Internal command
An MS-DOS command that is stored in the command processor
of the operating system; it is not a separate program file. This
means that you can execute an internal command without
specifying a pathname. Examples include COPY, DEL,
RENAME, and DIR, among others. Unlike external commands,
internal commands can be executed from any drive or directory.
Jumper
A small device that fits over two small pins on a circuit board to
activate a particular function.
Keyboard
A device resembling a typewriter keyboard to enter letters and
numbers to the computer.
8 Glossary