More on quipus
With no writing system, the Incas used “quipu” to record information—a system of knotted braids. Quipus were apparently a kind of accounting system, used, for instance, to keep inventories of the Emperor’s llama herds, and the population of the empire. Some people think that they were also used as a kind of mnemonic device to help people recall epic stories. The quipus were knotted and deciphered by a class of scribes called “quipu-camayo”.
Unfortunately, made of yarn, quipus have all decayed. And many were burnt by the Spaniards. There are only a handful remaining.
Now Gary Urton, professor of anthropology at Harvard University, has developed a new theory which is that quipus used a kind of 7-bit binary system. I can’t wait for his new book to come out!