We watched Tim Hunkin's fun video (original from c.1987) on fax machines, and when he got to the bit where he and the late Rex Garrod demonstrated how they send messages over long distances, I knew, without a shadow of a doubt, Terry Pratchett had watched this too, and that it was at least partly the inspiration for the clacks.

And I was both happy and sad at the same time.

https://www.youtube.com/watch?v=yuUyt9RG7pk

#TheSecretLifeOfMachines #TerryPratchett #TimHunkin #FaxMachines