Scientific calc in creditcardsize?

From: Wilhelm Loidl
Email: wltec@gmx(dot)net


(dot) = . hello! i look for a replacement for my beloved casio cfx-400 watch - unique, because it handles binary, log, ... in a very small size. it is very hard to find such a watch on ebay, so my question is: are there small (credit-card-size and smaller) calculater with scientific functions (also from the past) available on earth? thank you and please forgive my poor english!!!