ASCII is the coding system that is used
primarily on personal computers that we will be using in this class.
Remember, computer can only
process numbers, and cannot use text (character information) directly.
Its necessary to fool
the computer by coding characters as numbers, which it can process.
ASCII and EBCDIC codes both provide a way to accurately
encode and
then decode data from one form to the other.
Some examples of ASCII Code :
The letter A is
actually stored as the number 65
The letter B is
actually stored as the number 66
The letter C is
actually stored as the number 67
The letter D is
actually stored as the number 68
The letter a is
actually stored as the number 97
The letter b is actually stored as the number
98
The letter c is
actually stored as the number 99
The letter d is
actually stored as the number 100
The spacebar
is actually stored as the number 32
The character ! is actually stored as the number 33
The symbol 1 is
actually stored as the number 49
The letter 9 is
actually stored as the number 57
The number 65 might be stored as
text,
as the character 6 followed by the
character 5 (65),
or as a numeric value in
a single byte with the value 65.
Note that the value 65
could be the letter A or the number 65.
When a programmer designs a program, he or she instructs
the computer whether it should use the numeric value
or
the character represented by that value.