CASIO fx-4000P scientific calculator from 1986

[cdmackay]

I just got a new-in-box 4000P from TAS, for £40, which I thought not too bad.

Turned out to be new-in-sealed-box, which I didn't expect.

So, everything pristine, but still had the original 1985 CR2032 lithium batteries fitted (not working). I was a little nervous on opening it up, but it's OK: one battery had leaked just a tiny bit. I scraped off the terminals, and fitted new batteries, and it's working well.