Epson LQ-2550 User Manual - Page 263

number systems Three number systems are commonly used with printers: 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 two-digit hex number. binary is base 2 and uses only the digits 0 and 1. All information in computer systems is handled in binary form to represent 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 can communicate with the computer connected to it. parallel interface See inferface. parity Parity is a method for a computer and printer to check the reliability of data transmission. platen The black roller that provides a backing for the printing. print quality Your printer has two types of print quality: draft and Letter Quality (LQ). Draft is for high-speed, draft-quality jobs; LQ is for final, polished documents. proportional printing Printing in which the width of the character varies from character to character. For example, an uppercase W receives much more space than a lowercase i. The result looks more like a typeset book than a typewritten draft. Glossary GL-5