code: def standard_block(self, bytes_):
          
          self.out(self.LH(len(bytes_) + 1))  # + 1 for CHECKSUM byte
  
          checksum = 0
          for i in bytes_:
              checksum ^= (int(i) & 0xFF)
              self.out(i)
  
          self.out(checksum)
docs: Adds a standard block of bytes. For TAP files, it's just the
          Low + Hi byte plus the content (here, the bytes plus the checksum)