docs: def select_font(self, font):
          '''Select font type
          
          Choices are: 
          <Bit map fonts>
          'brougham'
          'lettergothicbold'
          'brusselsbit'
          'helsinkibit'
          'sandiego'
          <Outline fonts>
          'lettergothic'
          'brusselsoutline'
          'helsinkioutline'
          
          Args:
              font: font type
          Returns:
              None
          Raises:
              RuntimeError: Invalid font.
          '''
          fonts = {'brougham': 0, 
                   'lettergothicbold': 1, 
                   'brusselsbit' : 2, 
                   'helsinkibit': 3, 
                   'sandiego': 4, 
                   'lettergothic': 9,
                   'brusselsoutline': 10, 
                   'helsinkioutline': 11}
          
          if font in fonts:
              if font in ['broughham', 'lettergothicbold', 'brusselsbit', 'helsinkibit', 'sandiego']:
                  self.fonttype = self.font_types['bitmap']
              else:
                  self.fonttype = self.font_types['outline']
                  
              self.send(chr(27)+'k'+chr(fonts[font]))
          else:
              raise RuntimeError('Invalid font in function selectFont')