So from the hour I wasted yesterday poking around the web after reading this article - http://webhome.idirect.com/~totton/abacus/PDF.htm http://webhome.idirect

So from the hour I wasted yesterday poking around the web after reading this article - http://webhome.idirect.com/~totton/abacus/PDF.htm http://webhome.idirect.com/~totton/abacus/PDF.htm Seems like the best free resource. This book seems like the standard english text on soroban - https://smile.amazon.com/Japanese-Abacus-Its-Use-Theory/dp/0804802785/ https://smile.amazon.com/Japanese-Abacus-Its-Use-Theory/dp/0... The first few chapters are great. This book from the sixties mentions that abacus are actually a middle-eastern invention and came east with trade. Abacus in fixed frames are a later invention for speed but earlier versions would have more resembled a backgammon table using pebbles. https://en.wikipedia.org/wiki/Abacus https://en.wikipedia.org/wiki/Abacus https://en.wikipedia.org/wiki/Salamis_Tablet https://en.wikipedia.org/wiki/Salamis_Tablet This led to this pretty interesting paper - https://arxiv.org/pdf/1206.4349.pdf https://arxiv.org/pdf/1206.4349.pdf It seems like there is a pretty large gap in our understanding of how people actually did calculation? Cheers