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Chapter 12- Printers | Up
Fire Controlman Volume 03-Digital Data Systems | Next
CONTROL CODES |
TOPIC 1—FUNDAMENTALS OF
PRINTING
The purpose of any printer is to transform
information from computers into characters or pictures
on paper so that humans can read the information. In
other words, printers provide a hard-copy output that
we can understand. This topic will introduce you to the
fundamentals of printing: character sets, line
characteristics, and orientation.
CHARACTER SETS
A character set is a predefine table of characters
that a printer will print. Early printer and computer
manufacturers often defined their own codes to
represent each character to be printed. Since the
computers and printers from different manufacturers
didn’t talk the same language, users trying to build
customized systems often ran into major
communications problems. These problems led to the
development of the American National Standard Code
for Information Interchange (ASCII, pronounced
as-key).
The ASCII Character Set
ASCII codes are 8-bits long, and standardize the
codes for alphanumeric characters, some special
characters, and some control codes. Codes 0 through
31 and 127 are control codes. Codes 32 through 126
are printable character codes. Table 12-1 lists the
printable ASCII codes with their decimal codes.
Table 12-1.—Printable ASCII Codes
12-2
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