Cool stuff for sale mega-thread.

In a stationary shop before most were wiped out by the likes of Staples.

In the early 1980s, when we were do integration in maths at college, I spotted a newspaper advert for a Casio calculator saying "Integrals Integrated". That lunchtime I rode my Motorbike to such a shop in town and bought one. Back then you needed a newspaper advert to show you what was now possible. I couldn't find that advert but found dozens of Youtube videos explaining how to do it on more modern Casios.

I think the one I bought, with something like 38 programmable steps, was the very first integral capable calculator from Casio.

While on the subject of calculators, in the 1980s there was a huge rivalry between and investments by Sharp and Casio to make a "Credit Card size calculator". Not just in length and height, but in thickness too. I think Casio won that, but the calculators were very fragile so few have survived.