Quipu

Quipus (or khipus), sometimes called talking knots, were recording devices historically used in the region of Andean South America. A quipu usually consisted of colored, spun, and plied thread or strings from llama or alpaca hair. It could also be made of cotton cords. The cords contained numeric and other values encoded by knots in a base ten positional system. Quipus might have just a few or up to 2,000 cords.
Archaeological evidence has shown that systems similar to the quipu were in use in the Andean region from c. 3000 BC. They subsequently played a key part in the administration of Tahuantinsuyu, the empire controlled by the Incan ethnic group, which flourished across the Andes from c. 1450 to 1532 AD. As the region was subsumed under the invading Spanish Empire, the use of the quipu faded from use, to be replaced by European writing systems. However, in several villages, quipu continued to be important items for the local community, albeit for ritual rather than recording use.
Quipu is the Spanish spelling and the most common spelling in English. Khipu (pronounced [ˈkʰipu]) is the word for "knot" in Cusco Quechua (the native Inca language); the kh is an aspirated k. In most Quechua varieties, the term is kipu.
Considerably more information on the Wikipedia page : the Wikimedia commons page is .
The Quipu/Khipu Database Project website is - it ran from 2002-2005, and the website was last updated in 2009. The Ancient History Encyclopedia page is . The Ancient Scripts page is , and the Mathematical Association of America page is .
Category:Undeciphered writing systems