ASCII Table
Computers were new and exciting machines for the adventurous to program and operate
in the early part of this century. As the technology of computers developed compatibility
issues arose. The mathematical value for each letter on the keyboard is a good example.
Every time a key is pressed on the keyboard an electrical contact is made inside of
the keyboard. Eventually the key pressed corresponds to a unique number that is
then translated into the binary equivalent and processed by the computer. Well what
happens if everyone is programming in different values for the keys on their keyboards?
As an example, let's give uppercase "A" the value of 65. If you gave a different
letter on your keyboard, say "D" for example, the value of 65 we have a compatibility
problem. If I was to use your computer the value 65 would actually be "D" instead
of "A." As a result it wasn't long before the ASCII table was created to help universalize
values for characters on the keyboard. It's a lot like the System International
(SI), the metric system, that is used internationally by scientists and most major
countries around the world.
Now that the ASCII table is used by programmers and computer producers around the
world all the computers can communicate via the ASCII table values. As an example,
computers on the Internet can transfer ASCII (Plain Text) files back and forth between
different platforms (Mac & IBM) without any errors in translating or interpreting the
file! A partial list of ASCII table values is given below. See if you can complete
the ASCII table for characters A-Z and a-z, and then compare it with a friend to
see if your guesses are correct.
ASCII Character Decimal Value & Binary Value
space 32 0010 0000
! 33 0010 0001
" 34 0010 0010
# 35 0010 0011
$ 36 0010 0100
A 65 0100 0001
B 66 0100 0010
' 96 0110 0000
a 97 0110 0001
b 98 0110 0010
Now that you've completed the table can you identify a pattern in the binary values?
Look at how the position of 0's and 1's change. Do you know why?