number systems
Three number systems are commonly used with printers:
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
decimal is base 10 and uses the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. (This is the most familiar system.)
hexadecimal (hex) is base 16 and uses the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F. This is frequently used by programmers. Any decimal number between 0 and 255 can be expressed by a
on line
When the printer is on line, it is able to communicate with the computer connected to it.
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.
6Glossary