[hangsi]

This is excellent. I wonder how deep the roots of pre-20th century computing systems go. Babbage, Lovelace and the Difference engine are well catalogued, and I have seen a Jaccard loom in a museum with my own eyes.

What comes before this that isn't a history of mathematics, aside from the abacus? If this search is broad enough to include the topic of this article and Luca Pacioli's briefly mentioned double-entry ledgers from Italy, then I can imagine systems from all over the world where commerce flowed or administration ruled: similar systems must have existed in China and India, and I have heard of the Quipu system in the Andes that functioned as a digital storage medium for thousands of years.

How many modern components of information systems are reinventions of past ideas, rather than upgrades?