VSI  Pascal  uses  the  extended  American  Standard  Code   for
  Information  Interchange (ASCII) character set.  The is extended
  ASCII character set contains 256 characters, which  include  the
  following:

   o  Uppercase letters  A  through  Z  and  lowercase  letters  a
      through z

   o  Integers 0 through 9

   o  Special characters, such as the ampersand (&), question mark
      (?), and equal sign (=)

   o  Nonprinting characters, such as the space, tab,  line  feed,
      carriage  return, and form feed (use of these characters may
      improve the legibility of your programs)

   o  Extended, unspecified characters with numeric codes from 128
      to 255

  The VSI Pascal compiler does not distinguish  between  uppercase
  and   lowercase   letters   except   when   they  appear  inside
  apostrophes.

  For a complete listing of the ASCII character set, see  the  "HP
  Pascal Language Reference Manual."