If you like Nixie tubes and/or DIY calculators, checkout this interesting talk from the HP Handheld Conference in Orlando last month by [Eric Smith] from Brouhaha and [John Doran] from Time Fracture.

We’ve all got calculators on our phones, in our web browsers, and even in the home “assistant” that’s listening in on your conversations all day on the off chance you blurt out a math question is can ...