Epson 4500 - Manual (Page 304)

binary is base 2 and uses only the digits 0 and 1. All information in
computer systems is handled in binary form represented by electrical
signals that are on or off. A binary digit is often called a bit: any
decimal number between 0 and 255 can be expressed by an eight-bit
binary number.
on line
When the printer is on line, it is able to communicate with the
computer connected to it.
paper-out sensor
A small switch behind the platen that sends a signal when it is not in
contact with paper, informing the printer and remote computer that
there is no paper loaded, and causing the
PAPER OUT
light to go on.
paper tension unit
The part of the printer that fits above the platen to assure proper paper
tension in the printing area.
parallel interface
An interface that connects the computer and the printer. A parallel
interface transmits data one character or code at a time. See also serial
interface.
platen
The black roller that provides the backing for the paper during
printing.
print quality
Your printer has two types of print quality; draft and Letter Quality.
Draft is for high-speed, draft quality jobs; Letter Quality is used to
produce more polished documents.
proportional printing
Printing in which the character width varies from character to
character. For example, a capital W receives much more space than a
lowercase i. The result looks more like a typeset book than a
typewritten draft.
6 Glossary