Epson LQ-1500 User Manual - Page 53

How Many Names Can One Code Have?, often marked

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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 computer 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 represented 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 system is a base-10 system). Since 16 digits are 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 the printer. Some ASCII codes don't have keys on the keyboard. The most 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 keyboards can produce these codes, by holding down the control key (often marked CTRL) while pressing a letter key. The combination of CRTL/A produces ASCII 1, CTRL/B produces ASCII 2, and so on. Because of the way these codes are created, they are often referred to as control A, control B, etc. Most of these control codes also have names that describe their 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

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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
system
is a base-10 system). Since 16 digits are
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
the
printer.
Some ASCII codes don’t
have
keys on the keyboard. The
most
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)
while pressing a letter key. The combination of
CRTL/A
produces ASCII 1,
CTRL/B
produces ASCII 2, and so on.
Because of the way
these
codes are created, they are often referred to
as control
A, control B,
etc.
Most of these control codes also have names
that
describe their
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