2 HP 16C Calculators Up for Discussion

[burkhard]

Thanks for the explanation J.E. Davenport!

If somebody is desirous of a museum-quality beauty of an 16C, I have one in storage at home.

It is a really "SUPER-rare" model in that it looks nearly perfect (including the emblem) and passes all the self-tests but somehow does integer multiplication and division incorrectly. (I have two others which act fine and this one doesn't). But it is pretty!

I fiddled with it for a while trying to figure out exactly what is happening and if I remember right, some of the upper bits are getting dropped on those operations. I seem to recall integer addition and subtraction are OK and I think everything in floating point was as well. My assumption is a bad µP chip (since problems seem confined to certain integer operations), but maybe it is a RAM chip somehow. Just guessing, though. I should probably put it up on here with some pictures. I bet somebody with an ugly 16C donor could bring it up to snuff. I occasionally look for ugly-dead donors, but no luck yet.