Thanks for the reply! It was a very interesting read for sure. The polar->rectangular conversions can be done with an $15 Casio FX-115ES from Walmart pretty eas

Thanks for the reply! It was a very interesting read for sure. The polar->rectangular conversions can be done with an $15 Casio FX-115ES from Walmart pretty easily although RPN is much nicer than scrolling around a bunch when the equations get long. He might already know that, or find it interesting. I've never heard of an Oliveti vacuum tube machine, but will look it up. The IBM 360 machine he mentioned is probably not that different to what we do today (I bet the software has only changed in minor placed). The biggest difference is it's moved to Nix or Windows and off the mainframe and we can simulate massive scale problems in seconds. Of course that means we steadily increase the scope of the problem until you get a process that takes 24 hours ;). I'm impressed with anyone who can use a slide-rule for anything more complex than multiplication. Props to your dad btw. I love my job and it's fascinating to see how past engineers managed to essentially do the same things with tools that seem archaic today. I guess this is similar to modern day software engineers on HN getting really excited bout the Xerox Alto Smalltalk machine & the Symbolics Lisp Machines. The past is neat.