“TI doesn’t use RPN - that was HP.”
I cannot use a regular calculator, and Nat Semi used to make some RPN calculators also.
I saw a hp at a pawn shop that they wanted way too much for.
I told them it was a worthless calculator that did not work, but that I collected stuff like that anyway.
They got offended and told me it totally worked so I asked them to multiply 3 x 5. when they failed I offered them $5
My old HP42S LCD screen went weird, picked up two for posterity off ebay. Have a couple 300+ line programs I wrote that I cannot part with firing up to remind myself I was not always stupid.