What is the writing system of the Inca's?

The writing system used by the Incas is called Quipus, also referred to as "talking knots." A quipu was colored threads made of llama or alpaca hair, or cotton. A quipu could have up to 2,000cords, and can be compared to a string mop. The quipus may have been attached to wood bases. This system helped the Incas collect and record data, tax records, census records, military organization and calendars.