e. Deciphering American Standard Code For Information Interchange I
Representation. The ASCII is constructed so that certain bits signal one piece of
information, that is, capital letter or numeral. The remaining bits identify the letter or
numeral itself. The ASCII code for the capital letter "A," for example, is decimal 65, or
binary 01000001. Lowercase "a" is 97, or binary 01100001. The difference is in the
three left most bits, which are bracketed (see above). The last three bits, then,
distinguish between upper- and lowercase letter. All uppercase letters will start with the
binary digits 010, all lowercase letters with the digits 011.
Figure 1-28. The three left most bits in ASCII, signal upper- or lowercase.