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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