'Read one page from the file. Return True if successful,
False if there were no more pages.'

def _read(self):

    while True:
        byte = ord(self.file.read(1)[0])
        self._dtable[byte](self, byte)
        if (byte == 140):
            return True
        if (self.state == _dvistate.post_post):
            self.close()
            return False
