I used a TI-59 with the printer in my business until I retired about 10 years ago. I still have a software TI-59 on my desktop computer and on my cell phone. Best calculator ever. I have a few slide rules, I loved them but the TI-59, boy that did some great work and they were programmable, you could store 1000 commands and store them on a magnetic strip so that you could run different programs for different calculations you were doing. It is true I could have done the same thing, even better in just about any programming language and there were some calculations I would program to do but for the most part every day calculations for heating a variety of materials in a particular amount of time, the old TI was fantastic.
Yes I still have a few slide rules but mostly they are gathering dust. Every once in a while when I bump into one I will do a few calculations and then put it back. They were great when that was all we had but now we have better.
I too had a T59 with programs, etc. even learned to program it and write my own. I had and still have several printers. My printers kept crapping out, so I bought several over the years.