Oldest computer you've used for "real work"?

[ggauny@live.fr]

My first Hp is 25 not c, after hp 67 the best for me, 41c, 41cx, hp 16, hp18, hp 19bII, hp 28s, hp95 lotus123, hp 42s, hp48sx, hp48gx, hp50g and of course THE PRIME. I am better programer in pure RPN. Prime is difficult to master (where are you Mister Wickes ,). But thanks at all of you, i progress ! Cheers.