Epson LQ-1500 User Manual page 53

and some of the LQ-1500's functions. Because of these standard codes,
you can use your LQ-1500 printer with virtually any kind of com-
puter without having to worry about their ability to talk to each other.
Your LQ-1500 printer can communicate with any computer that uses
ASCII.
How Many Names Can One Code Have?
Although these codes are standard from computer to computer, the
way they are referred to is not standard. The same ASCII code can be
called by many different names. For example, the letter A is repre-
sented by the decimal number 65 in ASCII. This code may either be
called A or 65. In the BASIC programming language, this code may
be referred to as CHR$(65).
At other times, ASCII codes are referred to by their hex value. Hex
is short for hexadecimal, which is a base-16 numbering system (our
usual numbering
required for a base-16 number system, hex uses the digits 0 through 9
and the letters A through F. In hex, A is 41H, where the H stands for
hex.
Most of the time we don't have to give this code system a thought. If
you press A on the keyboard, the computer sends the code to print an
A to printer.
the
Some ASCII codes don't
important of these are the codes that have values of less than 32. These
codes are used to control many of the LQ-1500's functions. Most key-
boards can produce these codes, by holding down the control key
(often marked
CTRL)
produces ASCII 1,
CRTL/A
Because of the way
as control A, control B, etc.
Most of these control codes also have names
functions. For example ASCII 13, which is the code to start a new line,
is called carriage return. The following chart shows many different
ways of referring to the code for the carriage return function.
46
is a base-10 system). Since 16 digits are
system
keys on the keyboard. The
have
while pressing a letter key. The combination of
CTRL/B
codes are created, they are often referred to
these
produces ASCII 2, and so on.
that
most
describe their