Sending data through a paper cup

Whilst developing ideas for SPACE’s Schools out for Summer program I was thinking of a way of rhythmically sending information without using clapping or the voice but something else that was physical, lo-fi and cheap to do. Tony reminded me of an old cup and string toy that makes clicks when you pull your fingers along a knotted string.

So we sat around in the Owl Project studio wondering if it could be used to transmit information. I went away and figured out the code for it to work. I ended up writing some software that looks for a start and stop bit and then checks between for 1s or 0s. Have a look at the video below and it should make sense.

So for each letter you needed to tie or not tie ten knots like below. The only way I could make it work was to include a start and stop bit as 1. So an ASCII character is made up of 8 bits plus a start and stop bit. A total of 10 bits.


I found it pretty exciting to print a letter on a screen with such a system. In the workshop situation it kind of worked but it was pretty fiddly for people to tie knots and get it right and then it is actually pretty hard to pull your fingers along the string at the right speed to make it work. So overall I would say it was a little too problematic for a workshop setting.

I was chatting to Alex McLean about the experiment and he told me about the Pre-Columbian information storage system of Quipi.


Quipu with string cords wrapped in different colored threads. Cotton and camelid fibers. Wari Empire (AD 500 – 1000), probably, pre-Inka quipu. American Museum of Natural History, N° 41.2/7679. Photo, courtesy of the AMNH

Alex told me about a show he had worked on at the Open Data Institute

In this show Dave Griffiths and Julian Rohrhuber worked on a piece called ‘Inca Telefax. Listening to Precolumbian Administration without understanding a word’, which is a computer-generated sound installation creating an aural insight into quipu, identifying rhythmic structures.

David Griffiths has written a long blog post about the project here.


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