ASCII Demonstration Program (DOS)
Use this program
to type in anything you like and see how the computer stores it.
Remember that the computer
stores everything as numeric data,
and that the ASCII code provides a way for all computers to decode it
(at least all those that use this code, which includes nearly all PCs.)
Click here for ASCII definition
Click here for chart of some ASCII characters and their
ASCII codes
Download the program to your computer or run it from the
Internet
Type any text into the
program and press <Enter>
To view the ASCII code for
whatever you type.
Press
<Esc>ape to close the program.
When you run the program,
you will see this screen first :
Type anything and press the <Enter> key
display what you typed in ASCII.
The program will display each character in decimal (‘normal’ numbers)
and in binary code, which is the the <zeroes and ones you’ve heard
so much about.
The next screen looks like
this :
Note
that the numbers in the column that says “ASCII” are decimal values,
and that the “Binary” column is the “zeroes and ones” equivalent of the decimal
value on the same line..
In
other words, the letter ‘e’ is ASCII value 101,
which the computer stores as the eight binary digits ‘0, 1, 1, 0, 0, 1, 0 and
1’
that together are referred to as a ‘byte.’
Each
byte (8 bits) can store a single character,
upper case and lower case letters, digits, punctuation marks,
and some other special characters, such as parentheses, brackets, etc.
Try
typing some from the keyboard using this program
and notice that no two characters have the same ‘pattern.’
Press <Esc>ape key to return to the screen to enter different characters.
Try some of these
:
These examples show the differences between codes for
different characters,
and also the logical similarities of the patterns using the “ASCII” code.
These examples use the characters “ABCD”
and “abcd” and “1234”
which are the first four letters of the alphabet and the first four
numeric digits,
and I hope to show how this coding system makes sense and why it is useful.
The “EBCDIC”
system is very similar, but this illustrate the idea behind both systems.
Try typing letters in
alphabetical order and notice the pattern :
Results in these ASCII
values :
Notice that the ASCII
values for these four characters are also consecutive (65, 66, 67, and 68)
Looking at the bits in the last 4 positions, we see that they remain the
same in the next examples, too.
Now do the same thing
with lower case letters :
Notice that “ABCD” and
“abcd” are nearly identical,
except that the lower case versions have an “1”
instead of a “0” as in the upper case version of the same letter.
Notice that the ASCII
values for these four characters are also consecutive (97, 98, 99, and 100)
and that they are the same as the upper case ASCII + 32,
(because the extra bit has a value of 32).
Looking at the bits in the last 4 positions, we see that they remain the
same in the other examples, too.
Now, try consecutive
digits :
Notice that the only differences between “ABCD” and “1234” are that the bit
in position 2 is a “0”
but the bits in positions 3 and 4 are now “1” :
Notice that the ASCII values for these four characters are also consecutive
(49, 50, 51, and 52)
Looking at the bits in the last 4 positions, we see
that they remain the same as in the first two examples.