Epson MX-80 F/T Type II, Operation Manual

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If you are already familiar with the above terms, skip these paragraphs.
(1) ASCII code
Characters in computer systems are represented by groups of bits. The various
groups of bits that represent the set of characters that are the “alphabet” of
any given system are called a “coding system,” or simply “code.”
Codes for representing the information vary in relation to both the number of
bits used to define a single character in the assignment of bit patterns to each
particular character.
In US ASCII (The United States of America Standard Code for Information
I n t e r c h a n g e ) c o d e t h e b i t g r o u p ( 0 1 0 0 0 0 0 1 )
2
= < 4 1 >
H
r e p r e s e n t s t h e
character “A”.
The sending and receiving equipment must be programmed to acknowledge
the code used in computer systems.
The MX-80 Type II has 96 character set and control codes. In addition, it has
an international character set as shown in a previous chapter. Those characters
are put in some addresses of the ASCII code table instead of the standard
characters. And those can be accessed by a particular control code or the DIP
switch.
Alphabets, numbers and special symbols are addressed from <2O>
H
to <7E>
H
a n d f r o m < A 0 >
H
t o < F E >
H
. So same characters are put in two different
addresses. The selection of which one to use is up to you if your machine has
an 8-bit data bus line.
(2) Escape codes
In a lot of control codes that the MX-80 Type II has, you might be confused
by the word “ESCAPE“.
Some alphabetical letters and some numbers follow it. Each of them causes a
special function to the printer, i.e.
(a) To format a sentence.
(b) To do emphasized printing.
(c) To select paper end detector programmably.
(d) To set column length.
(e) To select an international character set.
(f) Others.
Generally, printer control codes, especially like “ESCAPE,” are not standardiz-
ed. Every computer and printer manufacturer applies its own meaning to such
codes.
The “ESCAPE” codes used in the MX-80 Type I I should not be confused with
the escape key which some computers have. So be familiar with EPSON’s
control codes.
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