Before looking at the printer in detail, some terms should be defined first so that you can understand them more easily and in less time.
They are;
*ASCII code
*Escape codes
*“+” symbol
*2, D and H
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 Inter- change) code the bit group (01000001)z = ~41 >H represents the character “A”. The sending and receiving equipment must be programmed to acknowledge the code used in computer systems.
The
Alphabets, numbers and special symbols are addressed from <~O>H to
<7 E > H and from < A0 > H to < FE > H. So same characters are put in two differ- ent addresses. The selection of which one to use is up to you if your machine has an
(2)Escape codes
In a lot of control codes that the
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 standardized. Every computer and printer manufacturer applies its own meaning to such codes.
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