Khipu

Pronounced “key-poo”.

A device consisting of cords or threads of different colours arranged and knotted in various ways, used originally by the Incas of Peru and the surrounding areas for recording events, keeping accounts, sending messages, etc.

So basically this is the old Inca system of recording using intricately connected, coloured and knotted cords. This included numerical recording using a decimal number system, and it is now being thought was also textual as well as numeral. There’s an interesting article on this in the current issue of New Scientist [paywall].

The word has multiple origins being partly a borrowing from Spanish and partly Quechua. It arrived in English, via the Spanish, around 1580.