code: public static boolean validChar(char toTest) {
          if (toTest >= 'A' && toTest <= 'Z') return true;
          if (toTest >= '0' && toTest <= '9') return true;
          
          return (toTest == '_' || toTest == '^' || toTest == '$' ||
                  toTest == '~' || toTest == '!' || toTest == '#' ||
                  toTest == '%' || toTest == '&' || toTest == '-' ||
                  toTest == '{' || toTest == '}' || toTest == '(' ||
                  toTest == ')' || toTest == '@' || toTest == '\''||
                  toTest == '`');
      }
docs: /*
  Its in the DOS manual!(DOS 5: page 72)
  
  Valid: A..Z 0..9 _ ^ $ ~ ! # % & - {} () @ ' `