ASCII code

ACSII is stand for American Standard Code for Information Interchange. A coding standard for characters, numbers, and symbols that is same as the first 128 characters of ASCII character set but differ from remaining character.
The ASCII is divided into four group of 32 characters which is excluding the extended characters that define by IBM.

The first 32 characters is codes 0 through 1Fh, form a special set of characters. It is also called control characters.Control characters is capable to perform varios display control operation rather than displaying symbols.Unfortunately, different control characters perform different operation on different output devices.

The second group of 32 ASCII characters codes comprise varios punctuation symbols, special characters, and the numerics digits. The most common characters in this group include the:

• space characters (code 20h)
• numeric digits 0 -9 ( codes 30h - 39h)
  

The third group of 32 ASCII characters is use for alphabetic characters.The ASCII codes for the characters "A" through "Z" in the range 41h through 5Ah. Since there are only 26 different characters, the remaining six codes holds various special symbols.

The fourth, and the final group of 32 ASCII characters codes are used for the lower case alphabetic symbols, five additional special symbols. and anothercontrol character.

ASCII data is the standard for interchange across computer systems and programs. If you will program in the assembly language you will be dealing with ASCII characters.