Casio fx 31. Dad bought this during his college days in 1978. Running flawlessly since 41 years now. I use it sometimes when I'm bored of using my phone. : r/BuyItForLife
Vintage casio fx-31 rare scientific calculator - Sold through Direct Sale - 227848270
www.casio-calculator.com Casio 001
calculators\Casio fx-31 - calculator.org
VINTAGE CASIO FX-31 VFD Scientific Calculator Good Condition WORKING £20.00 - PicClick UK
Two NOS Casio F-31's if you have ons share it, I've never seen anyone else display one!! I had 3 but sometimes you've got to let one go to friends! : r/casio